Or R, Renz H, Terada N, Gelfand E W
Department of Pediatrics, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206.
Clin Immunol Immunopathol. 1994 Jul;72(1):141-9. doi: 10.1006/clin.1994.1118.
We established a system for induction of competence in B cells following brief (45 min) exposure to either the combination of phorbol 12,13-dibutyrate (PDB) and ionomycin (I) (PDB/I) or PDB/anti-IgM. B cells, rendered competent in this fashion, were able to respond to PDB in the second or progression phase of culture but did not proliferate on their own. In addition, competent B cells were IL-2- or IL-4-responsive, due to up-regulation of their respective receptors following competence induction. IL-4 was found to have the most effective role in the progression phase to promote DNA synthesis and was able to enhance both IL-2 and IL-4 receptor expression. Whereas provision of IL-4 could induce IgM, IgG, and IgA in the absence of T cells, it did not result in IgE production. IgE production was only achieved in the presence of activated T cells (competent) together with competent B cells. These results indicate that IL-4 has a major role in B-cell immune responses following initial activation and trigger the cells, in the absence of T cells or other factors, to proliferate and differentiate into Ig-secreting cells. For IgE production in competent B cells, however, IL-4 alone could not overcome the requirement for activated T cells.
我们建立了一个系统，在B细胞短暂（45分钟）暴露于佛波醇12,13 - 二丁酸酯（PDB）和离子霉素（I）（PDB/I）或PDB/抗IgM的组合后诱导其产生应答能力。以这种方式获得应答能力的B细胞，能够在培养的第二阶段或进展阶段对PDB作出反应，但自身不会增殖。此外，由于在诱导应答能力后其各自受体的上调，有应答能力的B细胞对IL - 2或IL - 4有反应。发现IL - 4在促进DNA合成的进展阶段发挥最有效的作用，并且能够增强IL - 2和IL - 4受体的表达。虽然在没有T细胞的情况下提供IL - 4可以诱导IgM、IgG和IgA的产生，但不会导致IgE的产生。只有在活化的T细胞（有应答能力）与有应答能力的B细胞共同存在时才能实现IgE的产生。这些结果表明，IL - 4在初始激活后的B细胞免疫反应中起主要作用，并且在没有T细胞或其他因素的情况下触发细胞增殖并分化为分泌Ig的细胞。然而，对于有应答能力的B细胞产生IgE，单独的IL - 4无法克服对活化T细胞的需求。
