?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

In this study, we demonstrate for the first time that γδ T cell deficiency results in a decreased survival rate and more severe lung injury following respiratory H5N1 infection, which indicates that γδ T cells play a critical role in the infection process. However, Xue et al. recently reported that the depletion of γδ T cells, especially the Vγ4+ γδ T cell subset, significantly rescued the weight loss induced by H1N1 infection and improved the survival rate by reducing IL-17A secretion and immunopathological injury (29) . These contradictory results are likely due to the use of different influenza virus strains and treatment methods. In our study, the mice were infected with the HPAI H5N1 virus, which likely induces more severe lung injury than does the H1N1 virus. Moreover, our animal experiments were conducted in TCR-δ −/− mice, which completely lack γδ T cells; however, γδ T cells may not have been completely depleted by the anti-mouse TCR γδ mAbs used in the later study.