Herpes simplex virus evades natural killer T cell recognition by suppressing CD1d recycling

Nature Immunology 7, 835-842 (2006)

Speaker：黃炫榕                         Time：13:10 ~ 14:00, October 4, 2006

Commentator：蕭璦莉 老師                Place：Room 601

Abstract:

          Natural killer T cells (NKT) play an important role in bridging innate and adaptive immune response during viral infection. Several viruses evolved strategies to evade NKT cell immunosurveillance, but detailed mechanisms remain unclear. In this study, the authors demonstrated that herpes simplex virus type 1 (HSV-1) evades NKT immunosurveillanceby reducing CD1d surface expression on antigen-presenting cells. CD1d molecules are group II CD1 family, which are antigen presenting molecules homologous to MHC class I, with the unique ability to present lipid antigens to NKT cells. At first, the authors showed that CD1d surface expression was specifically downregulated in human dendritic cells and CD1d-transfected HeLa cells after HSV-1 infection, the effect was not caused by inhibiting host protein synthesis and such HSV-1-mediated CD1d downregulation inhibited NKT cells activation. Furthermore, the CD1d molecules were normally transported to the cell surface and endocytosed into endosomes, but reappearance of CD1d from late endosomalcompartments back to the cell surface was impaired in cells infected with HSV-1. The immuno-electron microscopy data also indicated that the CD1d molecules in uninfected cells were located mainly in internal vesicles of multivesicular lysosomes, whereas CD1d molecules located mainly at the limiting membrane of the lysosomes in cells infected with HSV-1. These results showed that HSV-1 may inhibit surface re-expression of recycled CD1d by trapping them in the lysosome limiting membrane. This paper revealed a HSV-1 immune evasion strategy to subvert NKT cells recognition by suppressing CD1d recycling, but what HSV-1 genes involved in this mechanism is needed further investigation.

References:

1、           Yuan, W., Dasgupta, A. & Cresswell, P. Herpes simplex virus evades natural killer T cell recognition by suppressing CD1d recycling. Nat. Immunol. 7, 835–842 (2006).

2、           Brigl, M. & Brenner, M.B. CD1: antigen presentation and T cell function. Annu. Rev. Immunol. 22, 817–890 (2004).