The role of Th17 cells in murine cytomegalovirus infection during the acute stage / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the nature of Th17 cells in murine cytomegalovirus(MCMV)infection during the acute stage,we characterized the frequency of IL-17A-producing CD4 T cells and the level of Th17 cytokines,IL-17A,in MCMV-infected mice.Methods BALB/c mice were randomly divided into two groups.One was infected with MCMV Smith for establishing disseminative infection; the other was sham-inoculated control.On day 3,7,14 and 28 of the experiment,three mice of each group were randomly chosen to be killed separately.Real-time PCR was used to detect MCMV loads in organs of MCMV-infected mice,the pathology of spleen was observed by HE staining.The frequency of CD4+IL-17A+ T cells in total splenocytes of mice was detected by flow cytometry.The level of IL-17A in culture supernatants of splenocytes was measured by double antibody sandwich ELISA.Results MCMV loads in salivary gland reached the peak on day 14 after MCMV infection,the most severe spleen injury was also shown on day 14,the frequencies of CD4+IL-17A+ T cells in total splenocytes increased significantly( all P＜0.01 ) in MCMV-infected mice than those in controls,and reached the peak on day 14 ( 1.14％ ±0.09％ vs 0.19％ ±0.04％,t =17.551,P=0.000).The levels of MCMV-specific IL-17A in culture supernatants were increased dramatically in MCMV-infected mice than those in controls on day 14 [ (81.98± 12.37) pg/ml vs (44.96±8.44)pg/ml,t=4.281,P=0.006].In MCMV-infected mice,correlation was positive between the levels of MCMV-specific IL-17A in culture supernatants and MCMV loads in salivary gland tissues (r=0.54,P＜0.05 ),the levels of IL-17 A in culture supernatants were higher in more severe spleen injury.Conclusion Thl7 cells and IL-17A were involved in the immunity response during acute MCMV infection.They may correlate with the persistence of MCMV and the pathology of spleen in infected mice.