The Impact Of Murine Cytomegalovirus Early Infection On CD8~+ T,??t And NK Cell

Objective:The impact of MCMV on the phenotypes and function of spleen CD3+ T,y8T and NK cells were observed in vivo and in vitro of C57BL/6 mice.Methods:C57BL/6 mice were infected with 5×104 PFU or 5×105 PFU of MCMV Smith MSGV strain for 9 days,spleen lymphocytes were extracted.And derived spleen lymphocytes from C57BL/6 mice,infected them with 1×104 PFU,1×105 PFU and 1×106 PFU of MCMV in vitro for 24 h and 48 h,respectively.We used multi-color flow cytometry technology to detect the secretion level of cytokines(IFN-y,IL-2)and expression level of CD 107a and granzyme B of CD8+/CD4+ T,y8T and NK cells;NK1.1+CD49b+CD3-NK cell subsets(CD11b-KLRG1-,CD11b+KLRG1-and CD11b+KLRG1+ NK cell)were also measured;MCMV specific CTLs(CD3+CD8+Pentamer+)were detected by pentamer.Results:Compared with control group mice,IFN-y and IL-2 secretion and granzyme B expression of CD8+ T cells of mice infected with MCMV in vivo increased,granzyme B and CD 107a expressing by y8T cells significantly increased,CD 107a expressing by NK cells raised;increasing rate of MCMV specific CTLs as well as CD25+CD4+ T cells were observed in MCMV infected mice;CD25+CD4+ T cells dropped in 5×105 PFU MCMV infected mice than 5×104 PFU MCMV infected mice in vivo,while no significant differences were observed of others between different MCMV titers;the percentage of CD11b-KLRG1-NK cell subsets in MCMV infected mice reduced compared with the uninfected control group,the number of CD11b+KLRG1+ NK cell subsets was significantly increased.In vitro MCMV infected lymphocytes,after infected with different virus titer MCMV for 24 h and 48 h,the activated surface molecule CD69 of CD8+ T cells increased compared with the control group,and which was higher in 1×106 PFU group than 1×104 PFU and 1×105 PFU group after infected for 48 h;CD69 expression of CD4+ T cells was increased compared with the control group at 24 h after MCMV infection in vitro,and 1×105 PFU and 1×106 PFU infection groups were higher than that of 1×104 PFU infection group;post 24 h of MCMV infection in vitro,the IFN-y secreted by CD8+ T cells in the ×106 PFU infection group was higher than that in the control group,1×x104 PFU and 1×105 PFU infection groups;the higher levels of CD8+ T cells secreted TNF-a after MCMV infected for 24 h and 48 h in vitro than those of the control group were observed,and TNF-a secretion up-regulated with viral titer increased;TNF-a secreted by CD4+ T cells increased after in vitro infection for 24 h compared with the control group,and which was higher in 1×106 PFU group post 48 h infection than the control group and the other two infection groups;IL-2 secretion and granzyme B expression of CD8+ T cells and CD4+ T cells found no uptrend;compared with the control group,IL-2 and granzyme B levels of NK cells increased in the infection groups after 24 h and 48 h in vitro infection,and up-regulating expression and secretion levels of which in 1×106 PFU infection group than those of other infection groups were observed.Conclusion:In the early period of MCMV infection,the effector function of CD8+ T,??T cell and NK cell might be enhanced.