The role of the CD95, CD38 and TGFβ1 during active human cytomegalovirus infection in liver transplantation

AimHuman cytomegalovirus (HCMV) has highly evolved mechanisms for avoiding detection by the host immune system. The aim of this study was to analyze the expression levels of TGFβ1, soluble form of CD95, CD95 ligand (sCD95 and sCD95L, respectively) in plasma and CD95 expression on CD3+ cells, CD38 expression on CD8+ cells in liver transplanted recipients with active HCMV infection.MethodsBlood samples were collected from 15 liver transplanted recipients with active HCMV infection and 15 recipients without HCMV infection. CD95 expression on CD3+ cells and CD38 expression on CD8+ cells were quantitatively detected with two-color fluorescence activated cell sorter (FACS) analysis. Lymphocyte surface phenotypes of CD4 and CD8 were detected with FACS analysis. Plasma sCD95, sCD95L and TGFβ1 levels were determined with enzyme linked-immuno-sorbent assay (ELISA). The results were compared with that from 15 healthy individuals.ResultsCD95 expression on CD3+ T-cells and CD38 expression on CD8+ cells were significantly increased in active HCMV infection group compared with that in stable group or healthy group (P < 0.01). No significant difference was seen between stable group and healthy group (P > 0.05). The percentages of CD4+ T-cell and CD4/CD8 ratio in active HCMV infection group were significantly lower than the values in stable group and healthy group (P < 0.05). Plasma levels of TGFβ1 and sCD95 were significantly increased in active HCMV infection group compared to stable group and healthy group (P < 0.05). In contrast, plasma levels of sCD95L in healthy group were not significantly different from that expressed in active HCMV infection group and stable group (P > 0.05).ConclusionHCMV suppress proliferation of activated T cells by apoptosis and by releasing immunosuppressive cytokine TGFβ1. This may provide an important clue to a better understanding of the pathogenesis in liver transplanted recipients with active HCMV infection.