Teale J M
Fed Proc. 1982 Jul;41(9):2497-501.
The isotypes secreted by the progeny of individual antigenically stimulated murine B cells were studied to determine the extent to which B cells exhibit class commitment. The study includes an analysis of B lymphocytes at different maturational states as well as an analysis of B cells selected on the basis of their surface isotype. All B cell subsets were analyzed under optimal stimulation conditions by the T-dependent splenic focus assay. From these studies it was found that the majority of B cells are not committed to a particular isotype that on antigenic stimulation would give rise to all progeny that secrete solely the one immunoglobulin class. The results indicate that the major influence attributable to the B cells themselves with regard to isotype commitment stems from the maturational state of the B cell. Thus, immature B cells from fetal liver and spleen give rise to clones secreting IgM and/or IgA, but not IgG; secondary B cells that lack surface mu appear unable to produce IgM-secreting clones on stimulation. However, most mature B cells (both primary and secondary) have the potential to give rise to clones secreting multiple immunoglobulin classes including IgE. Therefore, the predominant form of regulation regarding isotype expression is more likely to be controlled at the T cell level rather than separate lineages of B cells committed to a particular isotype prior to antigenic exposure.
研究了单个经抗原刺激的鼠源B细胞后代分泌的同种型，以确定B细胞表现出类别定向的程度。该研究包括对处于不同成熟状态的B淋巴细胞的分析，以及对基于其表面同种型选择的B细胞的分析。通过T细胞依赖的脾集落测定法，在最佳刺激条件下对所有B细胞亚群进行了分析。从这些研究中发现，大多数B细胞并不定向于某一特定同种型，即在抗原刺激下会产生仅分泌一种免疫球蛋白类别的所有后代。结果表明，B细胞自身对同种型定向的主要影响源于B细胞的成熟状态。因此，来自胎肝和脾脏的未成熟B细胞产生分泌IgM和/或IgA但不分泌IgG的克隆；缺乏表面μ链的二级B细胞在受到刺激时似乎无法产生分泌IgM的克隆。然而，大多数成熟B细胞（包括一级和二级）有产生分泌包括IgE在内的多种免疫球蛋白类别的克隆的潜力。因此，关于同种型表达的主要调节形式更可能是在T细胞水平上受到控制，而不是在抗原暴露之前就存在定向于某一特定同种型的B细胞的不同谱系。
