Abstract:

Objective To investigate the alteration of expression and activity of arginase from monocytic-type myeloid-derived suppressor cells（M-MDSC） in BALB/c mice infected with Echinococcus granulosus. Methods Twelve BALB/c female mice were randomly divided into control and infected groups. The mice were injected intraperitoneally with 2 000 live protoscoleces or an equivalent volume of normal saline. After 120 days, peripheral blood was collected through venae orbitaeta, and mice were sacrificed for pathological examination. The spleen was collected under aseptic conditions and single-cell suspension was prepared for M-MDSC isolation using the magnetic bead separation technology. Total RNA was extracted from M-MDSC, cDNA was generated, and genes with differential expression without and with infection were screened using the chip hybridization method. The resulting genes were further validated using real-time PCR. The activity of arginase from peripheral blood was also measured. Results Single cyst was formed within the abdomen and internal organs 120 days after infection. Chip hybridization and real-time PCR showed that the relative expression of arginase from M-MDSC in the infected group （7.92±0.85 and 11.97±5.39, respectively） was significantly higher than that in the control group （1.65±0.19 and 1.00±0.57, respectively） （P<0.05）. The activity of arginase was also significantly higher in the infected group ［（3.83±0.44）U/L］ than in the control ［（1.57±0.57）U/L］. Conclusion The expression and activity of arginase from mouse M-MDSC both increase significantly after infection with Echinococcus granulosus.

Key words: Echinococcus granulosus, Arginase, QPCR, Chip hybridization, Myeloid-derived suppressor cell