To reveal the underlying mechanisms involved in the suppression of T cell responses by type I IFN responses during the acute phase of bacterial infection, we performed in vitro infection assays using antigen-presenting phagocytes, BMDMs and BMDCs, from wild type and IFNAR KO mice and measured the levels of inflammatory cytokines produced upon O. tsutsugamushi infection (Figure 6A). This evidence concerns the gene IFNAR1 and bacterial infectious disease.