?d T Cells Provide Protective Function in Highly Pathogenic Avian H5N1 Influenza A Virus Infection

Dong, Peng; Ju, Xiangwu; Yan, Yiwu; Zhang, Siya; Cai, Menghua; Wang, Huaishan; Chen, Hui; Hu, Yu; Cui, Lianxian; Zhang, Jianmin; He, Wei

Unlike αβ T cells, γδ T cells constitute only a small proportion (1-10%) of the T lymphocytes in the peripheral blood and organs. One of the most important features of γδ T cells is their tropism for epithelial surfaces, including those of the skin and liver as well as the mucosae of respiratory, reproductive and digestive organs; γδ T cells migrate to these surfaces during their early development and persist there as resident cells (28) . In addition, γδ T cells acquire a preactivated phenotype that allows the rapid induction of effector functions following the detection of cellular stress and infection. Previous reports described the role of γδ T cells in influenza infection in a mouse model. The number of γδ T cells resident in the lung was increased after influenza A virus (H3N2) infection (10) . Dr. Mozammal Hoq et al further reported that after γδ T cells depletion in vivo, the resistance of mice to influenza A virus (H3N2 and H1N1) infection was abrogated (11) . Recent studies demonstrated that IPP-expanded γδ T cells originating from PBMCs could kill monocyte-derived macrophages infected with human (H1N1) and avian (H9N2 or (15, 16) . γδ T cells in PBMCs could be rapidly activated by influenza virus (H1N1, H2N2, and H3N2) infection via a mechanism related to the mevalonate pathway (17) . However, the in vivo role of γδ T cells in HPAI H5N1 infection and the direct effects of HPAI H5N1 viruses on human γδ T cells have not yet been reported.