The interleukin-7 receptor alpha chain transmits distinct signals for proliferation and differentiation during B lymphopoiesis.

摘要: The interleukin 7 receptor (IL7R), which contains a unique alpha chain and gamma shared by other cytokine receptors, is indispensable for normal lymphocyte development. basis this role poorly understood. Here we show that the IL7R not only causes progenitors to proliferate, but also has distinct activity in inducing differentiation. First, identify single cytoplasmic tyrosine residue essential cell cycle entry proliferation dependent on phosphatidylinositol 3-kinase. We use mutant been altered reconstitute B lymphopoiesis retrovirus-mediated gene transfer cultures of bone marrow from mice deficient chain. mutation abrogates B-lymphocyte progenitors, reveals novel function promoting immunoglobulin heavy rearrangement leading B-cell This lost (but sustained) when domain replaced corresponding sequences IL2R, despite similarity their signalling mechanisms. Thus, signals mediate differentiative are specific those causing proliferation.