TNF and infection: Analysis of CD8+ T cells by in vivo intracellular cytokine staining showed that A20AEC-KO mice displayed reduced numbers of Granzyme B, IFNγ and TNF expressing activated (CD62Llo) CD8+ T cells in the brochoalveolar space and to a lesser extend in the lung tissue at day 8 post infection with X-47 virus (Fig 3A and 3B).