Endogenous SEMA4D in control of proliferation and apoptosis of T-lymphocytes

Semaphorin IV class Sema4D is a molecule widely represented in the immune system. It is constitutively expressed by T-lymphocytes, and when activated, it passes into a soluble form while retaining functional activity. The molecule realizes its effects in the immune system via Sema4D / CD72-dependent regulation of target cells. In the present work, we have shown that T-lymphocytes can act not only as a source of semaphorin, but also as a target for it. In particular, the stimulating effect of endogenous Sema4D on the proliferative response of T cells and, on the contrary, the inhibitory effect on the apoptosis of these cells was demonstrated. The revealed effects indicate the direct involvement of endogenous semaphorin in the control of early stages of T-lymphocyte activation.