Table of Content

30 June 2020, Volume 38 Issue 3

Previous Issue    Next Issue

SPECIAL REPORT

Research progress on miRNA-mediated schistosome-host interactions

HE Xing, PAN Wei-qing

2020, 38(3):  259-262.  doi:10.12140/j.issn.1000-7423.2020.03.001

Asbtract ( )   HTML ( )   PDF (31257KB) ( )  

References | Related Articles | Metrics

Schistosomiasis is a serious but neglected tropical infectious disease, with more than 200 million infected people worldwide. A better understanding of the schistosome-host interactions is the key to effectively controlling and ultimately eliminating this disease. miRNA is an endogenous non-coding small RNA, which acts post-transcriptional regulation of gene functions. Recently, growing evidence indicates that miRNA is a crucial regulator of schistosome-host interactions. In this review, we summarize research advances on miRNA-mediated schistosome-host interactions.

ORIGINAL ARTICLES

Praziquantel inhibits splenic macrophage proliferation and inflammatory reaction in mice infected with Schistosoma japonicum

WANG Wei, ZHAO Cheng-si, MIAO Ting-ting, ZHOU Chun-lei, ZHANG Cheng-cheng, QIN Min, SHAO Tian-ye, WANG Yong

2020, 38(3):  263-270.  doi:10.12140/j.issn.1000-7423.2020.03.002

Asbtract ( )   HTML ( )   PDF (30699KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To explore the effect of praziquantel treatment on the number and function of splenic macrophages in mice infected with Schistosoma japonicum. Methods Thirty-five female C57BL/6J mice were randomly divided into healthy control group, uninfected plus praziquantel-treatment group, infected group, infected plus praziquantel-treatment group, solvent control group, adoptive transfer group and adoptive transfer treatment group (5 mice each). Mice in the latter five groups were each infected with 14 ± 2 cercariae of S. japonicum through abdominal skin. Ten weeks after infection, the mice in the solvent control group were injected with sterile saline through tail vein, and the mice in the adoptive transfer group and the adoptive transfer treatment group were injected with (1-2) × 10⁶ green fluorescent protein (GFP)⁺Ly-6C⁺ monocytes through tail vein. The mice in the uninfected plus praziquantel-treatment group, the infected plus praziquantel-treatment group and the adoptive transfer treatment group were given praziquantel treatment (300 mg/kg every 12 h) for consecutive 28 days. The mice in healthy control group, infected group, solvent control group and adoptive transfer group were gavaged with 1% carboxymethyl cellulose solution every 12 hours for consecutive 28 days. Then spleen tissues from each group of mice were taken to evaluate the effect of praziquantel treatment on the spleen tissue damage by HE staining. To evaluate the effect of praziquantel on the proliferation of macrophages, the number of Ly-6C⁺ macrophages and the expression of Ki-67 within Ly-6C⁺ macrophages in the spleen were assessed by flow cytometry. Real-time fluorescence quantitative PCR (qRT-PCR) was performed to detect the expression of inflammatory factors TNF-α and IL-1β in mouse splenic macrophages. Flow cytometry was used to calculate the proportions of GFP⁺Ly-6C⁺ macrophages in the spleen in order to evaluate the effect of praziquantel on their recruitment. Adherent macrophages from spleens of mice 10 weeks post-infection were used for in vitro experiment. The macrophage culture was treated with 20 μg/ml praziquantel or dimethyl sulfoxide for 24 h, consequently, flow cytometry was used to examine the proportion of Ly-6C⁺ macrophages in the collected wall-adherent cells of the two groups. Results Visual inspection and HE staining showed clear internal structures of spleen parenchyma of mice in the healthy control group and uninfected plus praziquantel-treatment group, with white and red pulps in clear structure, splenocytes arranged regularly, no sign of pathological damage to the spleen. Splenomegaly was seen in mice of the infected group, with disordered histological structure, unclear distribution of red and white pulps, partial congestion of the spleen sinus, and irregular arrangement of cells. In the mice of the infected plus praziquantel-treatment group, the splenomegaly was relieved, the parenchymal structure repaired, the red and white pulps reformed, and the spleen cells distributed regularly. The flow cytometry showed that no GFP-positive macrophages were found in the spleens of mice in the solvent control group, adoptive transfer group and adoptive transfer treatment group. The total proportions of splenic macrophages in the healthy control group, uninfected plus praziquantel-treatment group, infected group, and infected plus praziquantel-treatment group were (6.1 ± 1.4)%, (6.0 ± 0.6)%, (21.3 ± 2.3)%, and (7.8 ± 1.6)%, respectively; the relative proportions of Ly-6C⁺ macrophages were (27.3 ± 2.4)%, (26.6 ± 1.5)%, (57.3 ± 5.2)%, and (25.7 ± 2.8)%, respectively; the absolute numbers of Ly-6C⁺ macrophages were (0.3 ± 0.1) × 10⁶, (0.3 ± 0.1) × 10⁶, (23.7 ± 4.8) × 10⁶, and (0.4 ± 0.1) × 10⁶, respectively; and the proportions of Ly-6C⁺ macrophages positive for intracellular Ki-67 were (39.8 ± 7.6)%, (51.3 ± 2.3)%, (64.3 ± 11.5)%, and (40.4 ± 2.9)%, respectively. These indicators were all significantly higher in the infected group than in the healthy control group (P < 0.05 or 0.01), and lower in the infected plus praziquantel-treatment group than in the infected group (P < 0.01). The results of qRT-PCR showed that the relative transcription levels of TNF-α mRNA in splenic macrophages of the healthy control group, uninfected plus praziquantel-treatment group, infected group, and infected plus praziquantel-treatment group were 0.9 ± 0.1, 1.2 ± 0.01, 6.3 ± 0.7, and 0.9 ± 0.1, respectively; the relative transcription levels of IL-1β mRNA were 1.0 ± 0, 1.7 ± 0.7, 9.4 ± 0.9, and 1.4 ± 0.1, respectively; both were significantly higher in the infected group than in the healthy control group (P < 0.05 or 0.01), and significantly lower in the infected plus praziquantel-treatment group than in the infected group (P < 0.01). The flow cytometry assay of in vitro experiment showed that the percentages of Ly-6C⁺ macrophages in the control group and praziquantel treatment group were (85.4 ± 0.6)% and (82.1 ± 0.6)%, respectively with significant difference between the two(P < 0.05). Conclusion Praziquantel could inhibit the proliferation of Ly-6C⁺ macrophages in the spleen of mouse infected with S. japonicum and reduce the expression of inflammatory factors, thereby alleviating splenomegaly and splenic inflammation in mice.

Effects of Schistosoma japonicum infection on OVA-induced allergic airway inflammation in mice

LI Zhi-dan, ZHANG Wei, WANG Xiao-ling, XU Bin, HU Wei

2020, 38(3):  271-278.  doi:10.12140/j.issn.1000-7423.2020.03.003

Asbtract ( )   HTML ( )   PDF (27916KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To investigate the effects of Schistosoma japonicum infection (21 days after infection) on ovalbumin (OVA)-induced allergic airway inflammation in mice. Methods Twenty female BALB/c mice were randomly divided into the healthy control group, infection group (INF), OVA group and infection+OVA group (INF+OVA), 5 mice each. Mice of the INF and INF+OVA groups were infected with 15 ± 2 S. japonicum cercariae by abdomen patches. Mice in the INF+OVA group and OVA group were intraperitoneally injected with 10 μg of OVA plus 2 mg of aluminum adjuvant to sensitize on day 21 and 35 after infection, and were given with aerosolized 1% OVA in PBS/mouse to challenge on day 42-46 after infection, whereas the mice of healthy control and infection group were challenged with PBS aerosol. Mice tail vein blood was collected on day 35 and 42 (sensitizing phase), and day 49 (challenging phase) for determination of serum IgE and OVA-specific IgE by ELISA. All mice were sacrificed on day 49 after infection, and lung and spleen tissues were collected. A part of the lung tissue was used to prepare pathological paraffin sections stained by hematoxylin eosin (HE) and periodic acid Schiff (PAS), to observe morphological changes in lung tissue vessel, inflammation peri-bronchi (inflammation score), and in hyperplasia of epithelial cells (hyperplasia score); the other part of lung and spleen tissues was used to prepare single cell suspensions for assaying proportions of CD4⁺CD25 ⁺Foxp3⁺ Tregs by flow cytometry. Results ELISA showed that the A₄₅₀ readings of serum IgE in the INF group on day 35, 42 and 49 were 0.291 ± 0.037, 0.388 ± 0.038 and 0.472 ± 0.053, respectively, which were significantly higher than those in healthy control (0.032 ± 0.018, 0.050 ± 0.016 and 0.043 ± 0.026) (all P < 0.01); the A₄₅₀ readings of IgE in the OVA group on day 35, 42 and 49 were 0.097 ± 0.065, 0.164 ± 0.083 and 0.274 ± 0.07, respectively, of which the readings on day 42 and 49 were significantly higher than those in healthy control (P < 0.01); the A₄₅₀ readings of IgE in the INF+OVA group on those days were 0.305 ± 0.054, 0.359 ± 0.037 and 0.454 ± 0.017, respectively, all significantly increased compared to the OVA group (P < 0.01). On day 35, 42 and 49 after infection, the A₄₅₀ values of OVA-specific IgE in the OVA group were 0.115 ± 0.021, 0.078 ± 0.014 and 0.245 ± 0.040, respectively, all significantly increased compared to the control group (0.081 ± 0.007, 0.054 ± 0.008, and 0.079 ± 0.008) (P < 0.01, 0.05, 0.05). However, those in the OVA+INF group (0.034 ± 0.009, 0.038 ± 0.016 and 0.203 ± 0.017) were all significantly lower than those in the OVA group (P < 0.01, 0.01, 0.05). Pathological examinations on day 49 after infection showed that the lung tissue inflammation scores on inflammatory cell infiltration peri-bronchi and blood vessels in the healthy control group, INF group, OVA group and INF+OVA group were 1.33 ± 0.47, 2.33 ± 0.27, 3.5 ± 0.19 and 2.87 ± 0.45, respectively, of them the inflammation score in the INF and OVA groups were both significantly increased, compared to the healthy control group (P < 0.01), while the score in the INF+OVA group was significantly reduced (P < 0.05). The hyperplasia scores in the healthy control group, INF group, OVA group and INF+OVA group were 0, 0, 2.12 ± 0.80 and 1.72 ± 0.55, respectively. The hyperplasia score in the OVA group was significantly increased compared to the healthy control group (P < 0.05), whereas the difference between the INF+OVA group and the OVA group was insignificant (P > 0.05). The assay results of flow cytometry on day 49 after infection showed that the proportions of Tregs in spleen and lung tissues were (16.24 ± 3.06)% and (10.19 ± 0.01)% in the healthy control group, (27.23 ± 5.62)% and (13.05 ± 1.10)% in the INF group, (17.22 ± 1.43)% and (12.34 ± 2.25)% in the OVA group, and (27.96 ± 1.80)% and (15.04 ± 1.41)% in the INF+OVA group, respectively. The lung and spleen Treg proportions in the INF group were significantly up-regulated compared to the healthy control group (both P < 0.05), while there was no significant difference between the OVA and control groups (P > 0.05). The spleen tissue Treg proportion showed a significant increase in the INF+OVA group compared to the OVA group (P < 0.01), while the lung Treg proportion showed no significant change (P > 0.05). Conclusion S. japonicum infection (21 days after infection) showed rsignificant regulatory effect on the OVA-induced allergic airway inflammation, reducing the serum OVA-specific IgE level at the sensitization and challenge phases of allergic inflammation, suppressing peri-bronchi and peri-vascular inflammatory cell infiltration induced by OVA, and leading to elevate Treg proportion in the spleen tissue.

IL-18 enhances the immunoprotective effect of pcDNA3.1/SjOST48 against Schistosoma japonicum infection

TAN Xiao, XIAO Chu-li, XIAO Fei, WANG Shuo, QING Rui, HUANG Ze-zhi

2020, 38(3):  279-285.  doi:10.12140/j.issn.1000-7423.2020.03.004

Asbtract ( )   HTML ( )   PDF (25390KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To investigate if IL-18 can enhance the immunoprotective effect of pcDNA3.1/SjOST48 against Schistosoma japonicum infection. Methods pcDNA3.1/SjOST48 and pcDNA3.1/IL-18 eukaryotic vectors were constructed to express recombinant proteins. Western blotting was performed to detect the expression of pcDNA3.1/SjOST48 and pcDNA3.1/IL-18 in HeLa cells, and ELISA was performed to examine IL-18 levels in culture medium. One hundred BALB/c female mice were randomly divided into 5 groups: PBS group (blank control), pcDNA3.1 group (empty vector), pcDNA3.1/IL-18 group, pcDNA3.1/SjOST48 group, and pcDNA3.1/SjOST48+pcDNA3.1/IL-18 group, and were immunized with corresponding recombinant plasmid (30 μg) for three times at intervals of 14 days by intramuscular injection (100 μg/ml) at the quadriceps of the left hind leg femur. Two weeks after the last immunization, five mice in each group were selected for blood collection, and serum levels of IgG and its subclasses (IgG1 and IgG2a) were detected by ELISA. Three weeks after the last immunization, 5 mice of each group were selected for collection of spleen, to isolate spleen lymphocytes under sterile conditions; and the contents of TNF-α, INF-γ, IL-4, IL-6 and IL-8 in the lymphocytes culture supernatant and the proliferation of spleen lymphocytes were assessed by ELISA. Two weeks after the last immunization, 15 mice of each group were infected with 20 ± 1 cercariae of Schistosoma japonicum and sacrificed 6 weeks later. The liver tissue was obtained aseptically to calculate egg reduction rate; adult worms were collected by portal vein perfusion to calculate worm reduction rate. Another portion of liver tissue was used for hematoxylin & eosin (HE) staining to observe the amount of S. japonicum egg granuloma and inflammatory infiltration. Results ELISA results showed that at two weeks after the last immunization, the IgG antibody levels in mice of the pcDNA3.1/SjOST48+pcDNA3.1/IL-18 group, the pcDNA3.1/SjOST48 group, and the pcDNA3.1/IL-18 group were 0.82 ± 0.07, 0.41 ± 0.06, and 0.16 ± 0.05, respectively, all significantly higher than that in the pcDNA3.1 group (0.12 ± 0.03, P < 0.05). The IgG antibody level of the pcDNA3.1/SjOST48+pcDNA3.1/IL-18 group was significantly higher than those of the pcDNA3.1/SjOST48 group and the pcDNA3.1/IL-18 group (P < 0.05). The IgG2a/IgG1 ratio in the pcDNA3.1/SjOST48+pcDNA3.1/SjOST48 and pcDNA3.1/SjOST48 groups were 4.02 ± 0.01 and 2.51 ± 0.01 (P < 0.05), respectively, both >1, while those of the other 3 groups were all <1. At 3 weeks after the last immunization, the contents of IL-2, TNF-α, INF-γ, IL-6 and IL-17 in the supernatant of spleen lymphocytes in the pcDNA3.1/SjOST48+pcDNA3.1/IL-18 group were (101.82 ± 8.90) pg/ml, (738.02 ± 146.22) pg/ml, (593.41 ± 51.07) pg/ml, (685.64 ± 171.2) pg/ml and (261.32 ± 48.19) pg/ml, respectively, all significantly higher than those in the pcDNA3.1/SjOST48 group [(55.82 ± 9.69) pg/ml, (538.21 ± 85.26) pg/ml, (393.41 ± 51.07) pg/ml, (335.64 ± 62.63) pg/ml, (118.32 ± 8.91) pg/ml] (P < 0.05) and the pcDNA3.1/IL-18 group [(35.16 ± 6.43) pg/ml, (284.40 ± 69.96) pg/ml, (141.91 ± 24.48) pg/ml, (198.44 ± 38.15) pg/ml, and (47.66 ± 14.33) pg/ml] (P < 0.05). All the three groups had significantly higher contents of IL-2, TNF-α, INF-γ, IL-6 and IL-17 than the pcDNA3.1 group [(12.91 ± 8.01) pg/ml, (74.86 ± 6.64) pg/ml (23.75 ± 6.06) pg/ml, (82.75 ± 10.96) pg/ml, and (22.91 ± 13.80) pg/ml, respectively] (P < 0.05). The content of IL-4 in the supernatant of spleen lymphocytes in the pcDNA3.1/SjOST48+pcDNA3.1/IL-18 group was (12.28 ± 7.08) pg/ml, which showed no significant difference from those of the pcDNA3.1/SjOST48 [(15.03 ± 10.12) pg/ml], pcDNA3.1/IL-18 [(13.59 ± 4.42) pg/ml] and pcDNA3.1 groups [(16.13 ± 10.08) pg/ml] (P > 0.05). The proliferation level of spleen lymphocytes in the pcDNA3.1/SjOST48+pcDNA3.1/IL-18 group was 11.84 ± 0.16, higher than that in the pcDNA3.1/SjOST48 group (5.93 ± 0.25) (P < 0.05) and the pcDNA3.1/IL-18 group (3.19 ± 0.36) (P < 0.05), and all three were higher than that in the pcDNA3.1 group (2.08 ± 0.16) (P < 0.05). Six weeks after S. japonicum infection, the average number of adult worms detected from mice in the pcDNA3.1/SjOST48+pcDNA3.1/IL-18 group was (14.33 ± 1.08), and the worm reduction rate and egg reduction rate were 46.19% and 44.68%, respectively, significantly higher than those of the pcDNA3.1/SjOST48 immunized group (32.18% and 35.78%) and the pcDNA3.1 /IL-18 group (13.22% and 16.68%) (P < 0.05). HE staining of liver tissue showed that, in comparison to other groups, mice in the pcDNA3.1/SjOST48+pcDNA3.1/IL-18 group had fewer nodules of worm eggs on the liver surface and significantly decreased S. japonicum egg granulomas, and the inflammatory infiltration was unapparent. Conclusion IL-18 can induce a higher level of Th1 and Th17 immune response in mice immunized with pcDNA3.1/SjOST48, and enhance the immuno-protective effects of pcDNA3.1/SjOST48 against S. japonicum infection.

Development and preliminary evaluation of a rapid visualization detection method for circulating nucleic acids of Schistosoma japonicum based on RPA-LFD

DENG Wang-ping, HONG Qing-hua, XU Bin, WANG Sheng-lin, WANG Li-ping, XU Jing, HU Wei, ZHOU Xiao-nong

2020, 38(3):  286-292.  doi:10.12140/j.issn.1000-7423.2020.03.005

Asbtract ( )   HTML ( )   PDF (23654KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To develop a rapid visualization method for specific nucleic acid fragments of Schistosoma japonicum by combining recombinase polymerase amplification (RPA) and lateral flow dipstick (LFD) methods, and evaluate its application value in detecting circulating nucleic acid of Schistosoma spp. in infected mouse serum. Methods RPA primers and probe were designed to target the S. japonicum non-long terminal repeat retrotransposons SjCHGCS19. RPA was performed using S. japonicum genomic DNA as the template, and the amplification product was examined by the LFD method. After optimizing the RPA reaction temperature and time, the RPA-LFD assay was established. The sensitivity of RPA-LFD assay was evaluated by detecting 10^-1, 10^-2, 10^-3, 10^-4, 10^-5, 10^-6 and 10^-7 ng of S. japonicum genomic DNA; and the assay specificity was evaluated by detecting genomic DNA from S. japonicum, S. haematobium, S. mansoni, Paragonimus westermani and Clonorchis sinensis. Mouse dummy positive sera containing 0.01, 0.1, 1, 10 or 100 ng of S. japonicum adult worm genomic DNA were prepared, and mouse experiment was conducted by infection with 40 S. japonicum cerariae, from which tail vein serum was obtained before infection and on days 7, 21 and 35 after infection. Then, circulating DNA was extracted from mice dummy positive sera and infected mice sera, and examined by the RPA-LFD method, to evaluate the method’s feasibility and value of early detection in assaying specific schistosome nucleic acids in serum samples. Results The RPA-LFD assay was established to rapidly detect SjCHGCS19 repeat sequence with visualized results. The target fragments could be detected in 10 min, at 30-45 ℃. The optimal reaction condition was 39 ℃ for 20 min. The lowest detectable limit for S. japonicum adult worm genomic DNA was 10^-6 ng (1 fg). Evaluation of the specificity indicated that the RPA-LFD method showed cross-reaction with the genomic DNA of S. mansoni and S. haematobium, but not with that of P. westermani and C. sinensis. The RPA-LFD assay was able to detect 0.01-100 ng of schistosome DNA fragment in mice dummy positive sera, and the free SjCHGCS19 DNA fragment in the infected mice sera on days 7, 21 and 35 after infection. Conclusion A RPA-LFD method was established for rapid visualizing detection of circulating nucleic acids of S. japonicum. This method is highly sensitive and has potential applicability for early detection of schistosome infection.

Establishment of recombinase polymerase amplification technique for rapid detection of Schistosoma japonicum nucleic acid

WANG Sheng-lin, DENG Wang-ping, LI Yin-long, WANG Li-ping, ZHANG Li-juan, LV Shan, XU Jing

2020, 38(3):  293-298.  doi:10.12140/j.issn.1000-7423.2020.03.006

Asbtract ( )   HTML ( )   PDF (20832KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To establish a sensitive, specific, simple and rapid method for detecting Schistosoma japonicum nucleic acid by using the recombinase polymerase amplification (RPA) technique. Methods Specific primers were designed to target the 28S ribosomal S. japonicum (Sj28S) gene using Primer Premier 5 software. The RPA method was established and the reaction conditions were optimized. The specificity and sensitivity of the method were tested using genomic DNA extracted from S. japonicum at different stages, S. mansoni, S. haematobium, Oncomelania hupensis infected with single-tail cercariae, Clonorchis sinensis, Fasciola gigantica, Paragonimus westermani, and Taenia saginata. The detection performance and reproducibility of the RPA method were assessed using the mixed genomic DNA from infected and non-infected O. hupensis at various ratios (1 : 10, 1 : 50, 1 : 100, 1 : 250, 1 : 500, 1 : 1 000, 1 : 2 000). Results The RPA method specifically amplified the 216-bp target gene fragment of S. japonicum. The optimal reaction conditions of RPA were at 39 ℃ for 20 min. No cross reactions occurred with the genomic DNA of S. mansoni, S. haematobium, O. hupensis infected with single-tail cercariae, C. sinensis, F. gigantica, P. westermani, T. saginata and O. hupensis with negative infection. The lowest detectable limit of the RPA method for genomic DNA of S. japonicum adults was 100 fg/μl, and for the recombinant plasmid was 100 copies/μl. In addition, the RPA method could exactly detected the target DNA of S. japonicum at different stages. Tested with mixed genomic DNA of infected and all snails at various ratios, the lowest detectable limit of the RPA method for the target DNA fragment was 1 : 1 000. The test was repeated for 5 times, and all produced consistent results, with no false negative or false positive results. Conclusion The RPA method established for detecting S. japonicum nucleic acid displays high sensitivity and specificity, and is simple and rapid to use. Thus, the method could be used for rapid detection and risk monitoring.

γδ T cells-secreted IL-17A aggravates liver fibrosis in mice infected with Schistosoma japonicum via activating hepatic stellate cells

SUN Lei, HU Yuan, SHEN Yu-juan, CAO Jian-ping

2020, 38(3):  299-303.  doi:10.12140/j.issn.1000-7423.2020.03.007

Asbtract ( )   HTML ( )   PDF (19684KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To investigate the effect of IL-17A-producing γδ T cells on the development of early liver fibrosis induced by Schistosoma japonicum infection. Methods Ten wild-type (WT) female C57BL/6 mice were randomly divided into the healthy control group and the WT infection group, five mice each. Another group of five C57BL/6-background T cell antigen receptor δ chain gene knockout (TCR δ KO) mice served as the TCR δ KO infection group. Mice in the two infection groups were infected with S. japonicum cercariae (20 ± 2 each) by using abdominal patches, while the healthy control group was not infected. Six weeks after infection, the mice were anaesthesized and sacrificed, and liver tissues were collected, homogenized, and lysed. The pellets after lysis underwent density gradient centrifugation to obtain liver nonparenchymal cells. The content of IL-17A expressed by γδ T cells among the liver nonparenchymal cells was determined by flow cytometry. The IL-17A concentration in the lysate supernatant was examined by ELISA. Another part of the liver tissue was fixed in 4% paraformaldehyde, followed by hematoxylin-eosin (HE) and Masson staining to observe the deposition of collagen fibers. Meanwhile, peripheral blood was collected the mice of all groups to determine the serum concentration of IL-17A. A human hepatic stellate cell line (LX-2 cells) was used to examine the relative transcription level of mRNA of α-smooth muscle actin (α-SMA) and collagen type I (Col 1) in the LX-2 cells by fluorescent quantitative PCR. The assay was carried out by assigning the cell culture into 3 groups, of which the test group was assayed by adding IL-17A to a final concentration of 10 ng/ml, while the positive group and negative control group was assayed by adding IL-13 to a final concentration of 10 ng/ml and equal volume of PBS. Results The results of flow cytometry showed that the percentage of IL-17A-secreting Vγ2 subtype γδ T cells in the WT infection group was (48.0 ± 1.0)%, which was significantly higher than that in the control group [(17.0 ± 1.6)%, P < 0.01]. Masson staining revealed that the collagen deposition area in the mice of the TCR δ KO group was (3.5 ± 0.2) × 10⁴ μm², which was smaller than that in the WT infection group [(6.4 ± 0.5) × 10⁴ μm², P < 0.01]. ELISA assay showed that the IL-17A concentration in the sera and liver lysate supernatant of the infected TCR δ KO mice was (34.0 ± 22.3) pg/ml and (101.6 ± 18.6) pg/ml, respectively, both lower than those in the WT infection group [(143.9 ± 33.8) pg/ml, P < 0.05; (217.2 ± 19.2) pg/ml, P < 0.01, respectively]. Fluorescent quantitative PCR showed that the mRNA expression of α-SMA and Col 1 in LX2 cells after IL-17A stimulation was up-regulated by (4.0 ± 0.7) and (8.7 ± 1.2) folds, respectively, compared to the control group (P < 0.05, P < 0.01). Conclusion The IL-17A secreted from γδ T cells may involve in the development of hepatic fibrosis induced by S. japonicum infection in mice probably via activating hepatic stellate cells.

Expression and function of arginase in livers of mice infected with Echinococcus granulosus

CAO Sheng-kui, ZHANG Xiao-fan, WEI Yu-huan, PAN Jia-ming, CAO Jian-ping, SHEN Yu-juan, CHEN Jia-xu

2020, 38(3):  304-309.  doi:10.12140/j.issn.1000-7423.2020.03.008

Asbtract ( )   HTML ( )   PDF (18255KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To investigate the expression and function of arginase (ARG) in livers of mice infected with Echinococcus granulosus. Methods Eighteen female BALB/c mice were randomly divided into the infection and control group, 9 mice each. Mice in the infection group were each given 2 000 live protoscoleces of E. granulosus by intraperitoneal injection, while the control group was injected with the same volume of saline. Liver leukocytes were isolated 270 days after infection. The expression levels of ARG and nitric oxide synthase (NOS) were examined by Western blotting, and the protein abundance was analyzed with the Image J software. The ARG activity in liver leukocytes, and urea and nitric oxide contents in liver tissues were assessed with the ARG activity detection kit, urea detection kit and nitric oxide (NO) detection kit, respectively. The expression of ARG-1 in various myeloid cells and CD3ζ in T cells in the liver were analyzed by flow cytometry. Data were analyzed using the SPSS 20.0 software. Results Western blotting showed that the gray value of ARG-1 expression in liver leukocytes in the infection group was 1.03 ± 0.01, which was significantly higher than that in the control group (0.12 ± 0.01, P < 0.01); the expression gray value of ARG-2 and inducible nitric oxide synthase(iNOS) in the infection group was 0.54 ± 0.01 and 0.64 ± 0.02, while that of control group was 0.55 ± 0.02 and 0.59 ± 0.02, respectively; no significant differences were found between the groups (P > 0.05). In the infection group, the ARG activity in liver leukocytes, and urea and NO contents in liver tissues was (0.03 ± 0.00) U/ml, (0.66 ± 0.02) mmol/L and (14.63 ± 1.55) μmol/L, respectively, being significantly different from those in the control group [(0.02 ± 0.00) U/L, (0.04 ± 0.01) mmol/L, and (29.22 ± 0.36) μmol/L, respectively] (P < 0.05). Flow cytometry showed that the relative fluorescence density of ARG-1 expression in CD11b⁺CD11c⁺, CD11b⁺F4/80⁺, CD11b⁺Gr-1⁺, CD11b⁺Gr-1⁺Ly-6C-Ly-6G⁺, CD11b⁺Gr-1⁺Ly-6C⁺-Ly-6G^- and CD11b⁺Ly-6G⁺ liver cells in the infection group were 1.41 ± 0.12, 1.21 ± 0.06, 1.52 ± 0.16, 1.30 ± 0.03, 1.58 ± 0.12 and 1.21 ± 0.04, respectively, all items being significantly higher than those in the control group (1.00 ± 0.14, 1.00 ± 0.05, 1.00 ± 0.01, 1.00 ± 0.07, 1.00 ± 0.03 and 1.00 ± 0.02; P < 0.05). The relative mean fluorescence density of CD3ζ in liver CD4⁺ and CD8⁺ T cells in the infection group were 0.82 ± 0.04 and 0.78 ± 0.05, respectively, both significantly lower than those in the control group (1.00 ± 0.05, 1.00 ± 0.07; P < 0.05). Conclusion Higher expression of ARG-1 in liver leukocytes was found in mice infected with E. granulosus, which may antagonize the NOS to some extent; meanwhile, the expression of CD3ζ in the CD4⁺ and the CD8⁺ T cells was down-regulated.

Establishment and application of a multiplex recombinase-aided isothermal amplification technique for identifying Echinococcus granulosus and Echinococcus multilocularis

ZHOU Hong-rang, MAO Guang-yao, WANG Xiao-ling, CHEN Mu-xin, YU Qing, WANG Ying, Ai Lin, XIAO Ning

2020, 38(3):  310-316.  doi:10.12140/j.issn.1000-7423.2020.03.09

Asbtract ( )   HTML ( )   PDF (17253KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To establish a multiplex recombinase-aided isothermal amplification (mRAA) method for rapid detection of Echinococcus granulosus G1 (EgG1) and E. multilocularis (Em) DNA. Methods The mRAA rapid detection method for Echinococcus was established by designing primers based on the mitochondrial genes of EgG1 and Em as target sequences. The sensitivity of the mRAA method was assessed by amplifications of EgG1 and Em genomic DNA at concentrations of 10.00, 5.00, 1.00, 0.50, 0.10, 0.05, and 0.01 ng/μl and of pMD19-T (Simple) recombiant plasmids at 10⁵, 10⁴, 10³, 10² and 10 copies/μl. The specificity of the mRAA method was evaluated by using genomic DNA of Taenia saginata, T. asiatica, T. multiceps, Dipylidium caninum, Toxocara canis, Trichuris trichiura Linnaeus, Giardia lamblia, Fasciola hepatica, Paragonimus westermani, Fasciola gigantica and Clonorchis sinensis as templates for amplification. To verify the reliability and feasibility, optimized mRAA method was used to examine three fecal samples of dogs with simulated infection of mixed EgG1 and Em. 19 liver tissue samples of infected animals(10 with EgG1 infection and 9 with Em infection) collected from field, 7 fecal samples of infected dogs (5 EgG1 infected and 2 Em infected) collected from field. Results The established mRAA method could specifically amplify the EgG1 and Em mitochondrial gene fragments with the sequence lengths of 250 and 500 bp, respectively. The detactable limit of EgG1 and Em genomic DNA by mRAA was 2 pg/μl, and that of the EgG1 and Em recombinant plasmids was 200 copies/μl. The mRAA method showed negative results of amplification on genomic DNA of T. saginata, T. asiatica, T. multiceps, D. caninum, T. canis, T. trichiura Linnaeus, G. lamblia, F. hepatica, P. westermani, F. gigantica and C. sinensis. It was demonstrated that the mRAA method successfully detected EgG1 and Em DNA from the fecal samples of dogs with simulated infection of mixed EgG1 and Em, the liver tissue of infected field animals, and fecal samples of infected field dogs. Conclusion The mRAA method displays evident sensitivity, specificity and reliability, and could be used for rapid detection of EgG1 and Em DNA.

Effects of supernatant of different hepatoma cells on the vitality of Echinococcus granulosus protoscoleces in vitro

CHEN He-jie, JIANG Hui-jiao, LIANG Qian, Wu Jie, GUI Xian-wei, ZOU Hai-liang, XING Zhi-kun, WANG Er-qiang, CHEN Xue-ling, WU Xiang-wei

2020, 38(3):  317-323.  doi:10.12140/j.issn.1000-7423.2020.03.010

Asbtract ( )   HTML ( )   PDF (16019KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To explore a new model for long-time retainment of the vitality of Echinococcus granulosus protoscoleces in vitro by comparing the effects of supernatant of three hepatocarcinoma cell lines on the vitality of E. granulosus protoscoleces in vitro. Methods Serum-free supernatants of three liver carcinoma cell lines, Huh7, Hepa1-6, and HepG-2, were collected after 48-h culture, and co-cultured with the protoscoleces of E. granulosus (about 5 000 protoscoleces in each group). Protoscoleces of the control group were cultured with serum-free medium only. On days 1, 3, 5 and 7 of culture, 50 μl of the suspension was taken from each group for trypan blue staining to count dead cells by light microscopy, and the survival rate was calculated. On day 7 after culture, the ultrastructure of protoscoleces was observed under a scanning electron microscope, and ELISA was performed to determine the activity of caspase-3 of the four groups. SPSS 20.0 software was used for variance analysis on the measured data. Results Trypan blue staining showed that the survival rate of the protoscoleces continuously decreased with prolonged culture in each group. On day 5 of culture, the survival rate of protoscoleces in the serum-free group, Huh7 group, Hepa1-6 group, and HepG-2 group decreased to (46.54 ± 1.11)%, (46.19 ± 3.60)%, (55.90 ± 2.33)%, and (68.73 ± 1.06)%, respectively. On day 7, the survival rate of protoscoleces in the Hepa1-6 and HepG2 group was (36.09 ± 0.95)% and (45.69 ± 0.40)%, respectively, which were significantly lower than that from control group [(17.99 ± 1.52)%, P < 0.01], while that of the Huh7 group [(19.04 ± 1.70)%] was not significantly different from the control group (P > 0.05). On day 7 of culture, light microscopy indicated more blue-stained protoscoleces with poor light transmittance and more disintegrated and necrotic debris in the control and Huh7 groups; higher numbers of stained protoscoleces but moderate light transmittance and less necrotic debris in the Hepa1-6 group; and small number of stained protoscoleces, high light transmittance and few necrotic debris in the HepG-2 group. Scanning electron microscopy showed that the morphology of the protoscoleces of the control group and Huh7 group was glargely destroyed, and the ultrastructures of microhairs and acetabula were disrupted and disintegrated. The protoscoleces of the Hepa1-6 and HepG2 groups showed a plump and smooth surface as well as clear and intact ultrastructure. The enzyme activity unit of Caspase-3 of the Hepa1-6 group and HepG2 group was (20.51 ± 0.61) and (17.51 ± 0.59) on day 7, which were statistically different from the control group (22.15 ± 1.14) (P < 0.05, 0.01). There was no statistically significant difference in enzymatic activity between the Huh7 group (22.67 ± 0.96) and the control group (P > 0.05). Conclusion The supernatant of hepatocarcinoma cell culture can improve the vitality of E. granulosus protoscoleces under serum-free culture in vitro, and particularly, culture presents more obvious effect.

Analysis of genetic polymorphisms of merozoite surface protein-1 and circumsporozoite protein of Plasmodium vivax

JIN Hang-yi, ZHANG Ling-ling, ZHU Su-juan, XU Wei-min, CHEN Jun-fang, RUAN Wei, YAO Li-nong, CHEN Hua-liang

2020, 38(3):  323-331.  doi:10.12140/j.issn.1000-7423.2020.03.011

Asbtract ( )   HTML ( )   PDF (11581KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective This study aimed to conduct descriptive analysis of the genetic polymorphisms of Plasmodium vivax gene merozoite surface protein-1 (PvMSP-1) and circumsporozoite protein (PvCSP) in vivax malaria cases in Hangzhou City. Methods Blood samples and epidemiological information of vivax malaria cases reported in Hangzhou during 2008-2019 were collected. P. vivax genomic DNA was extracted by QIAamp DNA blood mini kit. Pvmsp-1 and Pvcsp were amplified by nested PCR and the amplification products were sequenced. The amino-acid sequences were analyzed using DNAStar and MEGA 6.0 softwares and the phylogenetic tree was constructed using the neighbor-joining method. The descriptive and inductive analysis of genetic polymorphism and place of infection origin were performed using SPSS 17.0. Results Fifty-six vivax malaria cases were sampled, of whom 44 and 54 samples were successfully sequenced for Pvmsp-1 and Pvcsp, respectively. Sequence analysis indicated that 44 Pvmsp-1 sequences were clustered into four genotypes: SalⅠ(18 samples), Belem (8), R-Ⅲ (17) and R-Ⅳ (1); 54 Pvcsp sequences were devided into two genotypes: VK210 (52 samples) and VK247 (2). Analysis of the genotyping and place of infection origin of Pvmsp-1 gene showed that the SalⅠtype was widely distributed in East China, Southeast Asia, India, and Ethiopia. The main type of Pvmsp-1 in East China was R-Ⅲ. In addition, the R-Ⅲ type was also distributed in South Asia and Southeast Asia. The Belem type was mainly distributed in Southeast Asia, South Asia and Ethiopia. Analysis of Pvcsp gene polymorphism and place of infection origin revealed four types of polymorphism with some regional features. Conclusion The Pvmsp-1 and Pvcsp genes in vivax malaria cases reported in Hangzhou during 2008-2019 were characterized being highly polymorphic, with some genotypes having certain regional features.

Immunomodulatory effects of natural killer cells on the CD4⁺ T cell subset in mice with cerebral malaria

YAN Jin, LI Dan-ni, FU Wei-xin

2020, 38(3):  332-338.  doi:10.12140/j.issn.1000-7423.2020.03.012

Asbtract ( )   HTML ( )   PDF (10159KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To explore the immunomodulatory effects of natural killer (NK) cells on the CD4⁺T cell subset in mice with cerebral malaria. Methods Female C57BL/6 mice were randomly divided into the health control group, infection group and NK elimination group, 14 mice in each. The mice in the infection group and NK elimination group were injected intraperitoneally with 1 × 10⁶ Plasmodium berghei ANKA (PbA)-infected red cells. The mice in NK elimination group were intraperitoneally injected with anti-Asialo GM-1(15 μl), a blocking antibody against NK cells, on day 1 before and day 2 after infection, while the mice in the health control and infection groups were injected with equal volumes of PBS. From day 3 on post-infection, blood was collected from the tail vein to make blood smears for examining parasitemia, and death of mine was recorded. On days 3 and 5 after infection, 3 mice were sacrificed in each group. The spleens were taken to make single cell suspensions for assaying Th1 type cells and regulatory T cells (Tregs) by flow cytometry. The spleen cells were cultured in vitro for 48 h, then the culture supernatant was collected to assay the levels of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin 10 (IL-10) by ELISA. On day 6 after infection, 3 mice each group received Evans blue (EB) intravenously, brain tissues were incubated in vitro for 48 h, supernatant was collected and the EB content passing through the blood-brain barrier of the mice was detected by microplate reader. Results In the infection group, mice deaths began to occur on day 6 after infection, accompanied by neurological symptoms, and all died on day 8. In the NK elimination group, deaths began to occur on day 7 after infection, and all mice died on day 12. On day 7 after infection, mice in the NK elimination group had significantly higher parasitemia (5.2%-10.5%) than those in the infection group (2.4%-5.0%) (P < 0.05). On day 5 after infection, the percentage and absolute counts of Th1 type cells were (2.65 ± 0.06)% and (2.09-2.25) × 10⁶in the infection group, which were significantly higher than those in the health control group (1.37 ± 0.02)% and (0.41-0.47) × 10⁶ (P < 0.01). and those in the NK elimination group [(1.82 ± 0.07)% and (1.48-1.86) × 10⁶] were significantly lower than those in the infection group (P < 0.01 or P < 0.05). The percentages of Tregs on days 3 and 5 in the infection group were(1.21 ± 0.06)% and (1.70 ± 0.13)%, respectively, which were significantly higher than those in the health control group[(0.90 ± 0.01)% and (0.91 ± 0.02)%] (P < 0.01). The absolute counts of Tregs in the infection group on day 3 and 5 post-infection were (0.63-0.73) × 10⁶ and (1.39-1.62) × 10⁶, respectively, which were higher than those in the health control group[(0.27-0.31) × 10⁶ and (0.47-0.56) × 10⁶] (P < 0.01); the percentages of Tregs in the NK elimination group were (1.86 ± 0.07)% and (2.15 ± 0.04)%, and the absolute counts were (0.77-0.90) × 10⁶ and (1.68-2.15) × 10⁶, respectively, all significantly higher than those in the infection group (P < 0.01 or P < 0.05). On days 3 and 5 after infection, the concentrations of IFN-γ in the cultural supernatant of splenocytes in the infection group were (790.75 ± 84.80) and (989.58 ± 199.59) pg/ml, respectively, and the TNF-α concentrations were (2 637.47 ± 283.50) and (3 124.58 ± 964.70) pg/ml, respectively, which were higher than those in the health control group [(73.69 ± 16.67) and (75.19 ± 15.97) pg/ml, (290.01 ± 187.46) and (290.51 ± 186.76) pg/ml respectively] (P < 0.01 or P < 0.05). In the NK elimination group, the IFN-γ concentrations were (15.83 ± 4.27) and (266.63 ± 108.62) pg/ml, and the TNF-α concentrations were (165.89 ± 71.02) and (842.77 ± 311.94) pg/ml, respectively, which were lower than those in the infection group (P < 0.01 or P < 0.05). On day 3 after infection, the IL-10 concentration in the NK elimination group was (3 588.20 ± 1 436.38) pg/ml, which was higher than that in the infection group [(1 255.77 ± 190.01) pg/ml] (P < 0.05). On day 5 after infection, the IL-10 concentration in the infection group was (4 991.36 ± 1 030.89) pg/ml, which was higher than that in the health control group as (848.50 ± 501.79) pg/ml (P < 0.05). In the NK elimination group, the IL-10 concentration was (9 317.95 ± 1 077.89) pg/ml, which was higher than that in the infection group (P < 0.05). On day 6 after infection, the EB content in the brain tissue of the infection group was (4.02 ± 0.10) μg/ml, which was higher than that in the health control group [(2.09 ± 0.06) μg/ml] (P < 0.05), and the EB content in the NK elimination group was (3.14 ± 0.02) μg/ml, which was lower than that in the infection group (P < 0.05). Conclusion The elimination of NK cells weakens the Th1 immune response, enhances the Tregs immune response, reduces the blood-brain barrier permeability and prolongs the survival time of mice with cerebral malaria.

Prevalence of visceral leishmaniasis in China during 2015-2018

ZHOU Zheng-bin, LI Yuan-yuan, ZHANG Yi, LI Shi-zhu

2020, 38(3):  339-345.  doi:10.12140/j.issn.1000-7423.2020.03.013

Asbtract ( )   HTML ( )   PDF (8786KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Objective To understand the prevalence of visceral leishmaniasis (VL) in China during 2015-2018, providing scientific basis for formulating strategies and measures for prevention and control. Methods Information of VL cases reported during 2015-2018 from the web-based National Diseases Reporting Information System (NDRIS) operated by the Chinese Center for Disease Control and Prevention was collected. A database was established after excluding suspected cases, duplicate cases and cutaneous leishmaniasis cases. The three-compartment distribution of VL cases was analyzed with descriptive statistics using Microsoft Excel 2016. Results During 2015-2018, a total of 1 194 VL cases were reported in 177 counties (cities) of 16 provinces (autonomous regions and municipalities). They were mainly distributed in Xinjiang (669 cases), Gansu (271 cases) and Sichuan Province (79 cases). Of the 177 counties (cities), 73 were endemic areas, reporting 1 064 indigenous cases, while the other 104 counties (cities) were non-endemic areas, reporting 130 imported VL cases. In particular, Jiashi County (497 cases), Zhouqu county (94 cases), Dangchang county (49 cases) and Wudu district (71 cases) were major endemic regions; the number of cases reported in the 4 areas accounted for 59.5% (711/1 194) of the grand total reported. During 2015-2018, VL recurrence occurred in 9 counties of 4 provinces including Gansu, Shanxi, Shaanxi and Henan Provinces, where 25 indigenous cases were reported. The onset of VL peaked during October-November, with a male/female ratio of 1: 0.7. Infants and farmers were high-risk populations of VL, accounting for 67.3% (803/1 194) and 18.8% (224/1 194) of total cases, respectively. The VL cases were mainly distributed within ages of 0-2 years (727 cases). The age distribution of different epidemiological types of VL obviously varied. The desert-type zoonotic and anthroponotic types of VL were mainly distributed within ages of 0-2 years (557 cases and 30 cases), while the mountain-type zoonotic VL was mainly distributed at ages ≥15 years (198 cases). Conclusion Visceral leishmaniasis endemic in China displays a status of low prevalence, but the endemic area shows a trend of expansion.

INFORMATION EXCHANGES

Analysis of demands for trainings related to malaria control in Asia-Pacific countries

HUANG Lu-lu, DING Wei, SHI Dan-dan, LI Hong-mei, MA Xue-jiao, DUAN Lei, QIAN Ying-jun, WANG Duo-quan, GUAN Ya-yi

2020, 38(3):  350-353.  doi:10.12140/j.issn.1000-7423.2020.03.014

Asbtract ( )   HTML ( )   PDF (7171KB) ( )  

Figures and Tables | References | Related Articles | Metrics

This study was performed to understand the demands of attendees for trainings related to malaria control and prevention in Asia-pacific countries including Vietnam, Papua New Guinea, Laos, and Cambodia, and to provide reference for future international training courses. Questionnaire survey was conducted among attendees of four international training courses held by the National Institute of Patristics Diseases, Chinese Centers for Disease Control and Prevention in 2017-2019. There were totally 78 attendees trained during 2017-2019; they were from 7 countries: Vietnam, Papua New Guinea, Laos, Cambodia, Philippines, Thailand and Indonesia. Of them, 60.3% (48/78) were from English-speaking countries. The trainees were mainly (88.5%, 69/78) from national-level research institutions, working as scientific researchers (78.2%, 61/78) and health administrators (21.8%, 17/78). The training needs were largely focused on malaria diagnostic techniques and disease control strategies (both 91.0%, 71/78). Other needs are related to laboratory molecular biological tests (65.4%, 51/78), international cooperation project management (50.0%, 39/78), and English writing (52.6%, 41/78). It is recognized that the international training courses of malaria control that have held are able to conform the demand of trainees from related countries, but there remain considerable room for improvement in training content and approach.

Analysis on safety of albendazole in the treatment of echinococcosis

LIU Ke-xin, ZHANG Wei, JIN Zhao-hui, QIN Zhou, ZHAXI Qun-zong, XU Ting

2020, 38(3):  354-359.  doi:10.12140/j.issn.1000-7423.2020.03.015

Asbtract ( )   HTML ( )   PDF (6643KB) ( )  

Figures and Tables | References | Related Articles | Metrics

This study aimed to investigate the probability of adverse effects of albendazole in the treatment of echinococcosis and assess the drug safety, providing reference for its safe medication in clinical practice. Literature search was performed in PubMed, EMBase, China Biology Medicine disc(CBMdisc), China National Knowledge Infrastructure(CNKI) and Wanfang Databases to obtain studies on the use of albendazole in the treatment of echinococcosis. Eligible studies were included according to the inclusion and exclusion criteria, and the reported adverse effects of albendazole were statistically analyzed. This review analyzed 26 eligible studies included, and found that the studies were mostly performed in Xinjiang, while considerably fewer performed in Tibet. According to the literature available, the occurrence rate of severe adverse effects was not high, and the adverse effects often involved digestive system, skin rash, and blood system, with transient presentation in most cases. The data indicates that the studies on the adverse side effects of albendazole is apparently limited. Although the current study results currently available suggest that albendazole is rather safe in clinical use, scale-up clinical trials remain imperative to verify this safety and address the drug safety.

Achievements and challenges of China-UK-Tanzania Pilot Project on Malaria Control

MA Xue-jiao, DING Wei, WANG Duo-quan, DUAN Lei, HUANG Lu-lu, WANG Bei, LI Hong-mei, QIAN Ying-jun, GUAN Ya-yi, XIAO Ning, ZHOU Xiao-nong

2020, 38(3):  360-365.  doi:10.12140/j.issn.1000-7423.2020.03.016

Asbtract ( )   HTML ( )   PDF (5888KB) ( )  

Figures and Tables | References | Related Articles | Metrics

To summarize the primary achievements and challenges of China-UK-Tanzania Pilot Project on Malaria Control (referred to as “Pilot Project” hereafter) and explore new modes of China-Africa public health cooperation. Information concerning main achievements, challenges, measures to overcome challenges, and suggestions on sustainable development of the Pilot Project was collected via questionnaires from relevant personnel in 11 institutions and/or organizations directly involved in the Pilot Project. Data were analyzed based on the frequencies of keywords. The results showed that the main achievements of the Pilot Project were “reducing malaria burden” and “sharing and transforming Chinese experience”, and on the other hand the main challenges were “unsmooth exchanging” and “insufficient support from governments”. This Pilot Project demonstrates the feasibility of Chinese malaria-control experience applying in Africa local, and indicates that strengthening the capacity building of Chinese personnel and the government support can promote the sustainability of international cooperation project in public health.

A survey on the needs and evaluation of global health trainings for provincial centers for disease prevention and control and institutions for parasitic disease control in China

DUAN Lei, YANG Fan, HUANG Lu-lu, DING Wei, WANG Bei, LI Hong-mei, QIAN Ying-jun, MA Xue-jiao, WANG Duo-quan, XIAO Ning, ZHOU Xiao-nong, GUAN Ya-yi

2020, 38(3):  365-370.  doi:10.12140/j.issn.1000-7423.2020.03.017

Asbtract ( )   HTML ( )   PDF (5211KB) ( )  

Figures and Tables | References | Related Articles | Metrics

This study was performed to understand the needs of global health trainings for professionals in provincial centers for disease control and prevention (CDC) and institutions for parasitic disease prevention and control, and evaluate the efficacy of training courses with suggestions, to provide reference for further improving the design of global health training. A total of 132 participants joined the global health training held by Chinese Center for Disease Control and Prevention (China CDC) and the National Institute Parasitic Diseases of China CDC were surveyed. They were from 30 provincial CDCs (or CDCs at levels of municipality and autonomous regions excluding Tibet) and 7 provincial (Yunnan, Anhui, Jiangsu, Jiangxi, Hubei, Hunan and Shandong) parasitic disease control and prevention institutions. Questionnaires containing information on gender, age, positional title, institution category, the intention and main reasons to attend global health training, gaps on foreign aid work, content of training, and efficacy evaluations and suggestions for training courses. A total of 119 respondents completed the questionnaire, with a response rate of 90.2% (119/132). Of the 119 respondents 73.9% (88/119) showed willingness to attend global health training, and only 16.8% (20/119) of the respondents answered that their institutions or centers had held global health training. The proportions of those willing to participate in foreign aid work and those who had participated in foreign aid work were 95.8% (114/119) and 9.2% (11/119), respectively. In addition, 46.2% (55/119) of the respondents regarded improvement of professional competence and communication skills as the most pressing reasons for attending global health training. The most important gap for foreign aid work, according to the respondents (40.3%, 48/119), was the insufficiency of experience. Further, 66.4% (71/107) of the respondents were satisfied with the overall efficacy of global health training. There is a strong need to participate in global health trainings among professionals in provincial CDCs and institutions. The effectiveness of the previous training courses is quite well. Improvements in training time and content are expected for future training courses.

REVIEWS

Research progress on combined medications for schistosomiasis

ZHAO Jin-ying, LIU Peng, LI Yan-wei, WANG Shi-ping

2020, 38(3):  370-377.  doi:10.12140/j.issn.1000-7423.2020.03.018

Asbtract ( )   HTML ( )   PDF (4578KB) ( )  

References | Related Articles | Metrics

Currently, the praziquantel (PZQ) remains the drug of choice for schistosomiasis treatment. Despite its effectiveness in killing adult schistosomes, PZQ is ineffective for schistosomula, and monotherapy using PZQ cannot reverse the pathological damage associated with the infection. With the emerging PZQ-resistant strains, it is imperative to find out alternatives for PZQ. At present, the research and development of new anti-schistosomiasis drugs is moving slowly, but pre-clinical and clinical trials found that combined medication of PZQ and various antimalarial drugs has shown good schistosomicidal effects. Also, synergistic effects have been exerted by combined use of PZQ and auxiliary drugs in the treatment of schistosomiasis. This article provides a review on the research progress in this field.

Advances in research on schistosome-host interactions mediated by extracellular vesicles

SUN Cheng-song, HU Wei, WANG Tian-ping

2020, 38(3):  378-382.  doi:10.12140/j.issn.1000-7423.2020.03.019

Asbtract ( )   HTML ( )   PDF (3587KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Extracellular vesicles are lipid-bilayer vesicles that are released by cells into the extracellular space. They contain bioactive molecules such as proteins, lipids, DNA and RNA, and can transfer effector molecules via binding to receptors of target cells or by direct fusing to, thus exerting biological function. Extracellular vesicles as a new type of intercellular signal transduction mechanism, play a critical role in regulating interaction between schistosome and host. This review underlines the researches advance on extracellular vesicles in regard to the classification, origin, structure and functions, and the role to mediate the parasite-host interactions upon secreted from schistosomes at different developmental stages, thus providing new ideas for researches on the prevention and control of schistosomiasis.

Research progress on new formulations of albendazole against echinococcosis

YANG Lin-chuan, TIAN Yi-jiang, ZENG Zhu-lin, ZENG Ren-quan

2020, 38(3):  383-389.  doi:10.12140/j.issn.1000-7423.2020.03.020

Asbtract ( )   HTML ( )   PDF (2976KB) ( )  

References | Related Articles | Metrics

Albendazole is the first-option drug for treatment of echinococcosis, with various new formulations including solid dispersion, liposomes, self-microemulsifying, precursor micelles, microspheres and nanodrug. Albendazole liposome formulations have been studied earlier, with its preparation technique being matured, and the formulation have commenced clinical application, however, the shortcomings in carrier modification and drug storage are being improved. Albendazole nanoformulation has wide application prospect, and the reaches in this regard have been growing year by year. Other new formulations of albendazole remain at the laboratory study stage. To be noted, some new albendazole formulations can largely improve the targeting property and bioavailability of the crude drug, and thus expectedly, the new formulations could play important role in reducing adverse effects and improving the bioavailability and therapeutic efficacy of the original crude drug. This review summarizes the researches in recent 10 years on new formulations of albendazole.

Advances in research on Nod-like receptor protein 3 inflammasome in parasitic diseases

CHEN Cai-song, ZHANG Yao-gang, WANG Zhi-xin, FAN Hai-ning

2020, 38(3):  390-394.  doi:10.12140/j.issn.1000-7423.2020.03.021

Asbtract ( )   HTML ( )   PDF (2029KB) ( )  

References | Related Articles | Metrics

Inflammatory corpuscles are receptors of the innate immune system and participate in the stress responses against pathogenic organisms after activated. This review summarizes the basic structure and functions of Nod-like receptor protein 3 (NLRP3) inflammasome as well as the related researches on malaria, amoebic disease, trypanosomiasis, leishmaniasis, schistosomiasis, and vaginal trichomoniasis, aiming to analyze the role and mechanism of NLRP3 inflammasome in parasitic diseases and provide ideas for better interventions and treatment.

Research progress on the in vitro culture model of Cryptosporidium species

NIU Zi-wen, CHANG Yan-kai, WANG Ke, ZHANG Long-xian

2020, 38(3):  394-399.  doi:10.12140/j.issn.1000-7423.2020.03.022

Asbtract ( )   HTML ( )   PDF (1552KB) ( )  

References | Related Articles | Metrics

Cryptosporidium is an important zoonotic protozoan parasite, which mainly parasitizes in intestinal epithelial cells, causing diarrhea in humans and animals. To date, there are no effective drugs or vaccines for control of cryptosporidiosis. Establishing an efficient culture model may provide experimental basis for studying the mechanisms of host cell invasion by Cryptosporidium and the development of vaccines and drug against Cryptosporidium. Comparing to common animal infection models, in vitro culture system has advantages of low cost and being able to simulate physiological status of hosts, compared to common animal models of infection, thus facilitating anti-Cryptosporidium drug screen. This article reviews the research progress on chicken embryo and chicken embryo organ culture models, the cell culture models, the cell-free culture model, the three-dimensional culture model and intestinal organoids culture model for Cryptosporidium, to provide reference for further understanding of pathogenic mechanisms of Cryptosporidium and the development of anti-Cryptosporidium drugs.

Research progress on malaria status among Chinese overseas labor personnel

BO Shan-shan, ZHANG Xiao-juan, WANG Xiao-chun, LIANG Xiao-feng

2020, 38(3):  400-404.  doi:10.12140/j.issn.1000-7423.2020.03.023

Asbtract ( )   HTML ( )   PDF (865KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Malaria is a worldwide insect-borne infectious disease that seriously impairs human health. With the development of international exchanges and labor export, the number of contract workers going abroad is increasing these years. The labor workers abroad are at the high risk of infectious diseases. In practical, it is significant to protect their health and resolve the risk of cross-border transmission of imported malaria. This article reviews recent literature on the status of malaria as well as the prevention and treatment of this disease among Chinese overseas labor personnel, in order to advance our understanding of progress in malaria elimination work and provide referable experience for elimination of malaria in the country.

SHORT COMMUNICATION

A survey on the status of important human parasitic diseases in Beijing in 2015

HE Zhan-ying, WANG Xiao-mei, WU Wen-ting, DU Dan, ZHANG Dai-tao, WANG Quan-yi

2020, 38(3):  345-349.  doi:10.12140/j.issn.1000-7423.2020.03.024

Asbtract ( )   HTML ( )   PDF (7728KB) ( )  

Figures and Tables | References | Related Articles | Metrics

In 2015, a survey on the status of important human parasitic diseases was carried out in 52 sites for soil-transmitted nematode infection and 7 sites for Clonorchis sinensis infection selected 13 districts of Beijing, using the stratified cluster sampling method, according to the National Survey Program and detailed implementation guidance. No less than 250 fecal samples from permanent residents were collected at each site. The eggs of soil-transmitted nematodes and other intestinal helminthes were examined using the modified Kato-Kats technique (one sample/two slides reading). The cellophane swab method was used to detect Enterobius vermicularis eggs in children aged 3-6 years. In addition, the residents were randomly sampled to complete a questionnaire concerning the knowledge of parasitic disease prevention and treatment. Data were analyzed using the SPSS 20.0 software. A total of 13 401 residents from the 52 sites were surveyed. Twelve of them were detected with Ascaris lumbricoides infection, of whom 4 showed mixed infection with Trichuris trichiura. Therefore, the overall infection rate of soil-transmitted nematode was 0.09% (12/13 401). A total of 622 children aged 3-6 years were examined and no Enterobius vermicularis infection was found. A total of 1 782 residents were examined in the 7 survey sites for Clonorchis sinensis, and no infection was found. The 12 residents with soil-transmitted nematode infection were from the Yanshan-Taihang Mountain ecological region, including a student and 11 farmers. The soil-transmitted nematode infection rate was 0.18% (12/6 673) in the Yanshan-Taihang Mountain ecological region, while no soil-transmitted nematode infection was detected in the Beijing-Tianjin-Tangshan ecological region, with significant difference between the two regions (P < 0.01). There was no significant difference in the infection rate between males and females, among age groups, or among different occupations (P > 0.05). A total of 1 876 questionnaires were collected. The awareness rate of parasitic disease was highest in residents in the suburb area, including 83.72% (607/725) aware of ascariasis and 56.83% (412/725) of clonorchiasis sinensis. In conclusion, the infection rate of soil-transmitted nematodes shows a significant decrease in Beijing. Residents aged 40 years and above in remote rural areas are the main targets of parasitic disease prevention and control.