Basophils can directly present or cross-present antigen to CD8 lymphocytes and alter CD8 T cell differentiation into IL-10-producing phenotypes.
There is increasing evidence suggesting that basophils play a critical role in developing Th2-type immunity both in vitro and in vivo. We previously reported that basophils cocultured with naive CD4 T cells stimulated with Ag promote the differentiation of the T cells into IL-4-producing Th2 cells. In the present study, we examined the roles of basophils during CD8 T cell activation. Although stimulating OVA-specific OT-I CD8 T cells with OVA peptide-pulsed splenic dendritic cells primarily induced the production of IFN-gamma, adding basophils into the coculture induced IL-10 production. Surprisingly, basophils were capable of directly presenting peptide Ag or of cross-presenting protein Ag to CD8 T cells. CD28-mediated costimulation dramatically enhanced T cell IL-10 production, yet neither ICOS nor CD86 was involved in IL-10 production. Basophil-mediated IL-10 induction was greatly diminished without IL-4 or IL-6, indicating that these cytokines are necessary for programming CD8 T cell IL-10 production. Adding IL-4 or IL-6 into CD8/APC coculture was not sufficient to induce IL-10 production; however, the presence of both cytokines significantly induced IL-10 production without basophils. Finally, CD8 T cells producing IL-10 induced by basophils did not display regulatory cell functions. Collectively, these results suggest a novel function of basophils that act as professional APCs to present Ag to CD8 T cells, thus inducing IL-10 production.
Kim
Sohee
S
Department of Immunology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Shen
Tao
T
Min
Booki
B
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D000938:Antigen-Presenting Cells / Q000276:immunology* / Q000378:metabolism; D001491:Basophils / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology*; D002478:Cells, Cultured; D045142:Cross-Priming / Q000276:immunology*; D016130:Immunophenotyping; D016753:Interleukin-10 / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000502:physiology; D015850:Interleukin-6 / Q000502:physiology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic
D015850:Interleukin-6; D016753:Interleukin-10; D015847:Interleukin-4