RT Journal Article ID 441d521978b67aeb A1 Boothby, Mark A1 Mora, Ana L. A1 Stephenson, Linda M. T1 Lymphokine-Dependent Proliferation of T-Lymphoid Cells: Regulated Responsiveness and Role In Vivo JF Critical Reviews™ in Immunology JO CRI YR 2001 FD 2001-12-01 VO 21 IS 6 OP 36 AB The discovery of lymphokines stemmed from their ability to promote T-lymphocyte proliferation in vitro. Even after 20 years of in tensive investigation , crucial aspects remain to be c larified about the role of specific lymphokines in T-cell proliferation and the biochemical mechanisms by which they play these roles, particularly in vivo. The present review focuses on conventional populations of TCRab T cells. Older findings and new insights into the function of specific lymphokines in T-lymphocyte proliferation in vivo are summarized along with unanswered questions raised by these observations. Vital contributions of lymphokines to clonal proliferation arise from two processes: the protection of cells against apoptosis and the activation of cell cycling. Findings are underscored indicating that the activity of a particular lymphokine depends on the subset of T cells (CD4 vs. CD8; naive vs. memory) to which it binds, and that point to potential pitfalls of extrapolating from tissue culture-adapted models to the regulation of T cells in vivo. After summaries of signaling mechanisms related to the proliferative activity of lymphokines, recent findings are highlighted suggesting that such signaling is a regulated and plastic process rather than one fixed schema of action. PB Begell House LK https://www.dl.begellhouse.com/journals/2ff21abf44b19838,62ccbe1309cc811b,441d521978b67aeb.html