Dieli F, Asherson G L, Sireci G, Lio D, Bonanno C T, Salerno A
Institute of General Pathology, University of Palermo, Italy.
Cell Immunol. 1995 Jul;163(2):309-13. doi: 10.1006/cimm.1995.1131.
Lymphonode cells from BALB/k mice, but not from BALB/c mice, immunized with picryl chloride (PCl) produce IL-5 when stimulated with the specific antigen in vitro and this correlates with picryl-specific IgA levels in vivo, which are 6 to 10 times higher in BALB/k mice. B lymphocytes from BALB/k mice cultured with PCl-immune T cells from BALB/k produce in vivo anti-PCl-IgA, while B lymphocytes from BALB/c mice, cultured with T cells from BALB/c mice, fail to produce appreciable amounts of anti-PCl IgA, unless IL-5 is added to cultures. B lymphocytes from both strains of mice produce similar amounts of total IgA antibodies when stimulated in vitro with lipopolysaccharide. In vivo administration of IL-5 to BALB/c mice increases significantly PCl-specific IgA levels to those observed in BALB/k mice and a dose-response analysis reveals that 500 units of IL-5 was the minimal effective dose, although a small increase in PCl-specific IgA levels was observed with 100 units of IL-5. Total IgA levels were increased in both strains of mice following in vivo injection of IL-5, but no significant difference in the values was observed. Our results therefore indicate that IL-5 in vivo enhances antigen-specific IgA production in MHC-determined low IL-5 responder mice and suggest an explanation for IgA deficiency in humans.
用苦味酰氯（PCl）免疫的BALB/k小鼠而非BALB/c小鼠的淋巴结细胞，在体外受到特异性抗原刺激时会产生白细胞介素-5（IL-5），这与体内苦味酰特异性IgA水平相关，BALB/k小鼠体内的该水平比BALB/c小鼠高6至10倍。用来自BALB/k小鼠的经PCl免疫的T细胞培养的BALB/k小鼠B淋巴细胞在体内产生抗PCl-IgA，而用来自BALB/c小鼠的T细胞培养的BALB/c小鼠B淋巴细胞，除非向培养物中添加IL-5，否则无法产生可观量的抗PCl IgA。当用脂多糖在体外刺激时，两种品系小鼠的B淋巴细胞产生的总IgA抗体量相似。向BALB/c小鼠体内注射IL-5可使PCl特异性IgA水平显著提高至BALB/k小鼠中观察到的水平，剂量反应分析表明500单位的IL-5是最小有效剂量，尽管用100单位的IL-5时也观察到PCl特异性IgA水平有小幅增加。体内注射IL-5后，两种品系小鼠的总IgA水平均升高，但未观察到数值上的显著差异。因此，我们的结果表明，体内IL-5可增强MHC决定的低IL-5反应小鼠中抗原特异性IgA的产生，并为人类IgA缺乏症提供了一种解释。
