Contribution of lung-resident T cell proliferation to the overall magnitude of the antigen-specific CD8 T cell response in the lungs following murine influenza virus infection

摘要

Following influenza-virus infection, CD8 T cells encounter mature, antigen-bearing dendritic cells within the draining lymph nodes (LN) and undergo activation, programmed proliferation and differentiation to effector cells prior to migrating to the lungs to mediate viral clearance. However, it remains unclear if CD8 T cells continue their proliferation after arriving in the lungs. To address this question, we have developed a novel, in vivo dual-label system using intranasal CFSE and BrdU administration to identify virus-specific CD8 T cells that are actively undergoing cell division while in the lungs. With this technique we demonstrate that a high frequency of virus-specific CD8 T cells incorporate BrdU while in the lungs and that this lung-resident proliferation contributes significantly to the magnitude of the antigen-specific CD8 T cell response following influenza-virus infection.