Strikingly, we detected a significantly reduced relative number of CD4+ T cells producing IFNγ in addition to a partial reduction of CD69+ and granzyme B+ CD4+ T cells in DT-treated and P. yoelii-infected CD169DTR mice, suggesting that MMMΦ and/or MZMΦ contribute, at least in part, to the activation of CD4+ T cells during infection. This evidence concerns the gene CD4 and infection.