Prolactin affects both survival and differentiation of T-cell progenitors

We have analysed the in vitro effects of prolactin on thymocyte development concluding that PRL favours the survival and differentiation of T-cell progenitors. Fetal, adult thymocytes and CD45+ fetal liver lymphoid progenitors express PRL-R. PRL induces survival, proliferation and differentiation of lymphoid progenitors whereas both an anti-PRL antiserum and an anti-PRL-R mAb block T-cell development accumulating CD25+DN (CD4−CD8−) cells. Furthermore, IL2 rescues the blockade of T-cell development in FTOC treated with anti-PRL antiserum but PRL does not recover cultures treated with an anti-IL2R α chain mAb, which drastically blocks the T-cell development. These results support IL2/IL2R mediation of PRL effects on developing thymocytes.