杀伤细胞免疫球蛋白样受体3DL1(KIR3DL1)阳性NK细胞在慢性HIV-1感染中的作用研究

Role of killer Cell immunoglobulin like receptor 3DL1 (KIR3DL1) expressing NK cells in chronic HIV-1 infection

目的了解杀伤细胞免疫球蛋白样受体3DL1(KIR3DL1)阳性自然杀伤细胞(NK细胞)在急性和慢性1型艾滋病病毒(HIV-1)感染中的作用。方法用流式技术检测急、慢性HIV-1感染者KIR3DL1受体在NK细胞的表达,CD38、HLA-DR在NK细胞的共表达,及NK细胞分泌CD107a和TNF-α的水平。结果1)急、慢性HIV-1感染者KIR3DL1+NK细胞比例与正常对照者相当,但是慢性感染者KIR3DL1+NK细胞数量与病毒载量成反比(r=-0.439,P=0.009)。2)急、慢性HIV-1感染者KIR3DL1+NK细胞共表达CD38和HLA-DR的比例均显著高于正常对照(P<0.0001),且其总NK以及KIR3DL1+NK、KIR3DL1-NK细胞共表达CD38和HLA-DR的水平与HIV-1病毒载量均成正比、与CD4^+T淋巴细胞(简称CD4细胞)计数及CD4/CD8细胞比值均成反比(P均<0.05)。3)急、慢性感染者和正常对照分泌CD107a的KIR3DL1+NK细胞比例均低于其各自的KIR3DL1-NK细胞(P<0.01)。急、慢性感染者KIR3DL1+NK细胞分泌CD107a的水平与正常对照相当,但是KIR3DL1-NK细胞分泌CD107a的水平均小于正常对照者,差异有统计学意义(急性:P=0.016;慢性:P=0.045)。4)急、慢性感染者和正常对照者分泌肿瘤坏死因子(TNF-α)的KIR3DL1-NK细胞比例与KIR3DL1+NK细胞相当,且急、慢性HIV-1感染者KIR3DL1+NK细胞分泌TNF-α的水平与正常对照相当。慢性HIV-1感染者总NK包括KIR3DL1+和KIR3DL1-细胞分泌TNF-α的水平与病毒载量、CD4细胞计数均呈负相关性(P均<0.05)。结论慢性HIV-1感染者KIR3DL1+NK和KIR3DL1-NK细胞均参与抑制病毒复制,可能与其分泌的TNF-α有关。然而CD38和HLA-DR在KIR3DL1+NK和KIR3DL1-NK细胞共表达上调可不利于抑制病毒复制。

Objective To study the protective functions of KIR3 DL1-positive(KIR3 DL1+)NK cells during acute and chronic HIV-1 infection.Methods Individuals with acute or chrom’c HIV-1 infection were enrolled in this study.The frequency of KIR3 DL1+NK cells and the levels of activated NK cells were detected by flow cytometry.The levels of CD107 a and cytokine TNF-αproduced by NK cells including KIR3 DL1+NK and KIR3 DL1-NK cells were measured by intracellular cytokine staining technique.Results 1.The frequencies of KIR3 DL1+NK cells in individuals with acute HIV-1 infection and those with chronic HIV-1 infection were comparable to that in HIV-1 negative donors.Whereas,the proportion of KIR3 DL1+NK cells in individuals with chronic HIV-1 infection was inversely associated with HIV-1 viral load(r=-0.439,P=0.009).2.The frequencies of CD38+HLA-DR+NK cells in HIV-1 individuals at the stage of acute and chronic infection were significantly higher than that in HIV-1 negative donors(P<0.0001).Moreover,the activation capacities of total NK cells,KIR3 DL1+NK and KIR3 DL1-NK cells were positively associated with viral load and inversely associated with CD4 T-cell count and the ratio of CD4:CD8 in HIV-1 individuals during acute infection and chronic infection(all P<0.05).3.Among both HIV-1 individuals and HIV-1 negative donors,the levels of KIR3 DL1+NK cells producing CD107 a were significantly lower than those of KIR3 DL1-NK cells(P<0.01).The proportion of KIR3 DL1+NK cells producing CD107 a in individuals with acute and chronic infection were comparable to that in HIV-1 negative donors,but the proportion of KIR3 DL1-NK cells producing CD107 a were significantly lower than that in HIV-1 negative donors(acute:P=0.016;chronic:P=0.045).4.Among both HIV-1 individuals and HIV-1 negative donors,the amounts of KIR3 DL1+NK cells producing TNF-αwere comparable to those of KIR3 DL1-NK cells.The amounts of KIR3 DL1+NK cells secreting TNF-αin HIV-1 individuals with acute and chronic infection were comparable to that in HIV-1 negative donors.However,the levels of KIR3 DL1+NK cells and KIR3 DL1-NK cells secreting TNF-αin HIV-1 individuals with chronic infection were inversely associated with viral loads and CD4 T-cell counts(all P<0.05).Conclusion Our study shows that KIR3 DL1+NK and KIR3 DL1-NK cells are involved in inhibiting HIV-1 replication,especially in chronic infection,which may be related to the secretion of TNF-α.However,the co-expression of CD38 and HLADR in KIR3 DL1+NK and KIR3 DL1-NK cells is upregulated,which is not conducive to the inhibition of virus replication.