Aim To demonstrate the promoting-proliferation effects of re-combinant human interleukin-4(rhIL-4)on lymphocyte subsets from normal indivaduals and its radiopro tection on lymphocytes irradiated b yγ-rays in vitro.Methods MTT colorimetric assay,immunohistochemical staining with alkaline phosphatase and TdT-mediated dUTP nick end la-beling(TUNEL)technique were used to detect the lym phocyte prolifera-tion,T and B lymphocyte subsets and t he lymphocyte apoptosis.Results(1)In the presence of adequate concentr ation of pokeweed mitogen(PWM),a definite concentration of rhIL-4could promote markedly the peripheral lymphocyte proliferati on of normal indivaduals,and displa yed stronger effects in serum-free cult ure system and 24h after culturing;(2)It is confirmed that the proliferati on of T cell subsets and B cells in-duced by rhIL-4might be major account for the proliferation of periphera llymphocytes.(3)A definite concentration of rhIL-4c ould obviously suppress the reduction of total lymp hocytes,T H ,T S subsets and B cells caused by 6Gy γ-irradiation.;and(4)It was also found that rhIL-4could inhibit distinctively abundant lymphocyte apoptosis induced by a -cute irradiation,suggesting that t his might be the major cause to alle-viate the radiation injury of lymphocytes and improve the immunological function of body.Conclusion rhIL-4can increase the number of pe-ripheral T and B lymphocytes from normal indivaduals,and demon-strated evident inhibition on the ly mphocytic reduction induced by leth al dose irradiation.
