Nuclear factor-kappa B in signal conduction of protein kinase C in T lymphocytes from an asthmatic guinea pig model

Abstract

Objective: To explore the role of nuclear factor-kappa B (NF-kappa B) 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-kappa B inhibitor pyrrolidine dithiocarbamate (PDTC), respectively. The expressions of NF-kappa B, 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-kappa B, 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-kappa B 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-kappa B and apoptosis of T lymphocytes (r = 0.62, P < 0.001).

Conclusions: NF-kappa B may participate in the signal conduction of PKC regulated proliferation, apoptosis and expression of IL-4 and IL-5 of T lymphocytes in asthma. The activation of NF-kappa B in PKC signal conduction pathway of T lymphocytes may play an important role in the pathogenesis of asthma.