Keratinocyte-derived T cell costimulation induces preferential production of IL-2 and IL-4 but not IFN-γ

摘要: By using superantigens, we have found previously that keratinocytes activated by IFN-gamma could serve as accessory cells, providing costimulatory signals needed to induce T cell proliferation. Here, compared the profile of cytokines produced cells stimulated in presence with response seen professional APCs. When are used there is a specific defect production, whereas IL-2 and IL-4 induced at levels comparable those when APCs cells. Because express BB-1, CD28-ligand distinct from B7-1 or B7-2 (which on APCs), examined possibility production might be result nonproductive CD28 engagement. However, even pathway directly stimulatory mAb, no induction keratinocyte-supported cultures. In these same cultures increased 10-fold, thus demonstrating deficiency rather than failure respond stimulation. Analysis reverse transcriptase-PCR ELISA for inducible p40 chain IL-12 reveals produce little if any messenger RNA protein Addition rIL-12 restores present. Finally, restimulated analyzed later time points (10 14 days) find refinement cytokine profiles: Th1 IFN-gamma, only Th2 IL-4. The ability seems most closely linked their absence may important maintenance peripheral tolerance self-Ags immune exogenous Ags, pathogens, haptens encountered skin.