Is endogenous TGF-beta activation by reactive oxygen species key to Foxp3 induction in TCR-stimulated and HIV-1-infected human CD4+CD25- T cells?
Several conclusions can be drawn from this work: (1) TCR and CD28-induced Foxp3 expression is a late event following TCR stimulation; (2) TGF-beta serves as a link in Foxp3 induction in human CD4+CD25- T cells following TCR stimulation, which induces not only latent, but also active TGF-beta; (3) the activation of TGF-beta requires reactive oxygen species; (4) HIV infection results in an increase in Foxp3 expression in TCR-activated CD25- T cells, which is also associated with TGF-beta. Taken together, our findings reinforce a definitive role of TGF-beta not only in the generation of Tregs with respect to normal immune responses, but also is critical in immune diseases such as HIV-1 infection.
LMP1 mediates serine phosphorylation of Annexin I via PKC pathway.