Roles of cytokines and TLRs in lymphocyte activation and differentiation

To investigate IL-5-producing cells in the peripheral tissues, we succeeded to generate IL-5/GFP knock-in mice. IL-5/GFP^+ cells were distributed mainly in the lung and intestinal tissues and they were CD3^- c-kit^- cells but not CD3^+ T cells. We also analyzed RP105 signals in B cell activation and found that RP105 was required for TLR4-dependent plasma cell differentiation and IgM production. Finally, we demonstrated that an interferon-inducible gene Iigp1 had a crucial role in Th1-dependent antigen cross-presentation.