Objective To explore the role of nuclear factor κB (NF κB) in the signal conduction of protein kinase C (PKC) regulated proliferation, apoptosis and expression of Th2 cytokines - interleukin 4 (IL 4) and interleukin 5 (IL 5) of T lymphocytes in the bronchial alveolus lavage fluid (BALF) Methods T lymphocytes were isolated and purified from BALF of asthmatic guinea pigs in normal and asthmatic groups, and were stimulated with PKC agitator phorbol 12 myristate 13 acetate (PMA) and NF κB inhibitor pyrrolidine dithiocarbamate (PDTC), respectively The expressions of NF κB, IL 4 and IL 5 mRNA and protein, the proliferation and apoptosis of T lymphocytes were observed by immunohistochemistry, in situ hybridization, ELISA, MTT and TUNEL, respectively Results The activation of NF κB, proliferation response, and expression of IL 4 and IL 5 mRNA and protein in T lymphocytes stimulated by PMA were significantly higher than those of their blank control ( P <0 01), while those indexes of T lymphocytes stimulated by PMA and PDTC simultaneously were significantly lower than those stimulated by PMA alone ( P <0 01) The apoptotic index of T lymphocytes stimulated with PMA were significantly lower than that of their blank control ( P <0 01), and the apoptotic index of asthmatic guinea pig T lymphocytes stimulated with PMA and PDTC simultaneously were significantly higher than that stimulated by PMA alone ( P <0 01) The significant positive correlations were found between the activation of NF κB and the proliferation ( r =0 64, P <0 001), and the expression of IL 4 and IL 5 mRNA and protein of T lymphocytes, respectively ( r =0 55-0 68, P <0 001) There was also significant negative correlation between the activation of NF κB and apoptosis of T lymphocytes ( r =0 62, P <0 001) Conclusions NF κB may participate in the signal conduction of PKC regulated proliferation, apoptosis and expression of IL 4 and IL 5 of T lymphocytes i
