CD3--Induced T--Cell Proliferation and Interleukin--2 Secretion is Modulated by the CD45 Antigen.

In the present study we have investigated the effect of CD45, CD45RA and CD45RO monoclonal antibodies (MoAbs) on the CD3 receptor-mediated proliferation of human T lymphocytes, It is shown that CD3-induced proliferation of purified resting T cells and quiescent T lymphoblasts (QTL) is promoted via all of the investigated CD45-associatcd epitopes. lt is also shown that the CD45 molecules are required to be cross-linked for costimulation. The MoAbs enhance the jnterleukin-2 (IL-2) production of CD3-stimulaled QTL, The elevation of the IL-2 production correlates with the increase in CD3-induced cell proliferation suggesting that the CD45-driven regulation of T lymphocyte activation is linked to the IL-2 pathway. [ABSTRACT FROM AUTHOR]