Role of Natural Killer Cells in the Generation of Influenza Virus-Specific Cytotoxic T Cells

Recently we reported that natural killer (NK) cells are critical accessory cells required for the differentiation of alloantigen-stimulated CD8+T cells into effector cytotoxic T lymphocytes (CTL)in vitro.In this study we provide evidence that NK cells are also required for the generation of influenza virus-specific CTL. Depletion of NK cells from responder human peripheral blood mononuclear cells or mouse splenocytes abolished the induction of influenza A virus-specific CTL under culture conditions. Treatment of C57BL/6 mice with the NK cell-depleting NK1.1 monoclonal antibody (mAb) before primary or secondary immunization with influenza A virus abrogated the capacity of CTL precursors to differentiate into influenza virus-specific CTL effectorsin vivo.These results extend our previous findings and demonstrate that NK cells critically influence the induction of antigen-specific CTL, bothin vitroandin vivo.