Characterization of the Syk-Dependent T Cell Signaling Response to an Altered Peptide.

Rheumatoid arthritis is an autoimmune disorder characterized by T cell dysregulation. We have shown that an altered peptide ligand (A9) activates T cells to use an alternate signaling pathway that is dependent on FcRγ and spleen tyrosine kinase, resulting in downregulation of inflammation. In the experiments described in this study, we have attempted to determine the molecular basis of this paradox.

Compensatory dendritic cell development mediated by BATF-IRF interactions.

The AP1 transcription factor Batf3 is required for homeostatic development of CD8α(+) classical dendritic cells that prime CD8 T-cell responses against intracellular pathogens. Here we identify an alternative, Batf3-independent pathway in mice for CD8α(+) dendritic cell development operating during infection with intracellular pathogens and mediated by the cytokines interleukin (IL)-12 and interferon-γ. This alternative pathway results from molecular compensation for Batf3 provided by the related AP1 factors Batf, which also functions in T and B cells, and Batf2 induced by cytokines in response to infection.