CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES ›› 2023, Vol. 41 ›› Issue (3): 286-293.doi: 10.12140/j.issn.1000-7423.2023.03.004

• ORIGINAL ARTICLES • Previous Articles     Next Articles

Effect of excretory-secretory antigen TPx of Cysticercus cellulosae on activation of dendritic cells in piglets

YE Jingming(), HE Wei, LIU Huiyuan, YU Xiao, LUO Bo, LIU Meichen, ZHOU Biying*()   

  1. Department of Parasitology, Zunyi Medical University, Zunyi 563000, Guizhou, China
  • Received:2022-09-06 Revised:2023-12-29 Online:2023-06-30 Published:2023-06-20
  • Contact: *E-mail: zbyz101@126.com
  • Supported by:
    National Natural Science Foundation of China(81960378);Basic Research Program of the Department of Science and Technology of Guizhou Province (Qiankehe Foundation-ZK [2023] General 516);Undergraduate Innovation and Entrepreneurship Training Program of Guizhou Province(S202210661169);Zunyi City School Joint Fund ([2021]278);Special Project of Cultivating New Academic Seedlings and Innovative Exploration of Zunyi Medical University (Qian Sci Con Platform Talent[2020]-004);Project of Zunyi Medical University Graduate Education Innovation(ZYK70);Undergraduate Innovation and Entrepreneurship Training Program of Zunyi Medical University(ZYDC2021143)

Abstract:

Objective This study investigates the effect of thioredoxin peroxidase (TPx) in the excretory-secretory antigen (ESA) of Cysticercus cellulosae on activation of dendritic cell (DC) in piglets. Methods Healthy piglet medulla-derived DC were cultured in vitroo, in which lipopolysaccharide (LPS) was added at a final concentration of 100 ng/ml on 7 d for stimulation for 2 days, and then continuously cultured for 2 more days to collect immature DC (imDC) and mature DC (mDC) separately. The morphological changes of DCs were observed by light microscopy and scanning electron microscopy on 1 to 9 d of culture. The expression of surface markers CD1 and major histocompatibility complex (MHC-Ⅱ) was detected by flow cytometry. The 7 d imDC was used in the assay with the assigned groups of negative control, TPx, ESA and LPS positive control, to which RPMI 1640 medium, TPx (50 μg/ml), ESA (50 μg/ml) and LPS (100 ng/ml) was added, respectively, to stimulate for 48 h for examining the expression of DC surface markers MHC-Ⅱ, CD80 and CD86 using flow cytometry and for detecting secretion levels of tumor necrosis factor-α (TNF-α), interleukin (IL-6), IL-10, IL-12 in DC culture supernatant by ELISA. One-way ANOVA was used for comparison between multiple groups, and LSD-t test was used for two-way comparison between groups. Results Under ligth microscope, imDC were ovoid in shape with single form at the first day of culture; with the extension of culture time, DC increased in size, appeared pseudopods and spines and other features, and changed from ovoid to irregular shape. Scanning electron microscopy showed that compared with imDC, mDC had irregular morphology, roughly long shuttle shape, and numerous protrusions of different lengths radiating from the cytosol, which were distributed in a dendritic pattern, a typical dendritic structure. Flow cytometry showed that the expression of CD1 and MHC-Ⅱ in imDC was (0.113 ± 0.005)% and (0.430 ± 0.016)%, respectively, which was lower than that of mDC (21.400 ± 0.327)% and (21.333 ± 0.450)% (t = 130.341, 92.906, both P < 0.05). The expression levels of MHC-Ⅱ, CD80, and CD86 in the TPx group were (15.300 ± 0.245)%, (22.900 ± 0.374)% and (13.033 ± 0.249)%, respectively, which were lower than those in the LPS positive control group (19.000 ± 0.374)%, (31.600 ± 0.082)%, and (21.300 ± 0.245)% (t = 11.53, 46.32, 43.84, all P < 0.05) and the ESA group (18.365 ± 0.618)%, (40.400 ± 0.356)% and (30.300 ± 0.283)%] (t = 9.55, 93.17, 91.57, all P < 0.05). The MHC-Ⅱ expression level in the TPx group was higher than that of the negative control group (12.133 ± 0.492)% (t = 9.87, P < 0.05). ELISA results showed that IL-6 level in DC of the TPx group was 15.682 ± 0.660, which was ower than that of 21.041 ± 0.901 in the control group (t = 6.51, P < 0.05); TNF-α (35.711 ± 4.196), IL-6, IL-10 (22.216 ± 1.357) and IL-12 (16.799 ± 0.523) were all lower than those of the LPS positive control group 169.037 ± 7.823, 42.118 ± 1.932, 34.730 ± 1.772, 52.504 ± 2.431 (t = 36.79, 32.09, 13.09, 35.05, all P < 0.05); IL-12 level were lower than that of the ESA group at 23.854 ± 1.020 (t = 6.93, P < 0.05). Conclusion TPx mediates immune tolerance by inducing high expression of DC surface molecules MHC-Ⅱ, low expression of CD80 and CD86, and reducing the secretion levels of IL-6.

Key words: Cysticercus cellulosae, Excretory-secretory antigens, Thioredoxin peroxidase, Dendritic cell

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