Jelinek D F, Splawski J B, Lipsky P E
J Immunol. 1986 Jan;136(1):83-92.
Highly purified human peripheral blood B cells stimulated with Cowan I Staphylococcus aureus (SA) and mitogen-activated T cell supernatants (T supt) generated large numbers of immunoglobulin (Ig)-secreting cells (ISC), whereas fewer ISC developed in cultures containing T supt in the absence of SA. To determine whether surface Ig isotype expression defined responsive B cell subsets, IgD+ and IgD- B cells were prepared with the fluorescence-activated cell sorter. Whereas both the IgD+ and IgD- B cells responded to SA + T supt, only the IgD- subset generated substantial numbers of ISC in response to T supt alone. Analysis of secreted Ig revealed that IgG and IgA were the predominant isotypes secreted by IgD- B cells in response to T supt or SA + T supt. By contrast, the IgD+ cells secreted predominantly IgM in response to SA + T supt but not to T supt alone. When responsiveness to pokeweed mitogen (PWM) was examined in the presence of supplemental T cells, the IgD- subset was found to be greatly enriched for responsive cells, and again, IgG and IgA were the predominant isotypes secreted, although these cells were also capable of secreting some IgM. The magnitude of the response induced by PWM from IgD- B cells was usually greater than that induced by SA + T supt. Although IgD+ B cells responded poorly to PWM, the differentiation of a small number of IgM-secreting cells was routinely stimulated by this polyclonal activator in the presence of T cells. The magnitude of the PWM response by IgD+ B cells was always greatly diminished compared with that stimulated by SA + T supt. Cell cycle analysis after acridine orange staining, cell volume measurement, and staining for expression of activation antigens (transferrin receptor and 4F2) indicated that the IgD- B cells were largely resting, but did contain a population of activated cells. Removal of activated 4F2+ cells from the IgD- subset diminished but did not abolish their capacity to generate ISC in response to SA + T supt or PWM in the presence of T cells. These results suggest that the IgD- population contains both an activated 4F2+ and a resting 4F2- subset. The data emphasize that multiple subpopulations of peripheral blood B cells contain precursors of ISC. Moreover, the responsiveness of the subsets to various stimuli and the Ig isotype subsequently secreted appear to be intrinsic features of each subset.
用考恩I型金黄色葡萄球菌（SA）和丝裂原激活的T细胞上清液（T supt）刺激高度纯化的人外周血B细胞，可产生大量分泌免疫球蛋白（Ig）的细胞（ISC），而在不含SA的含T supt的培养物中，产生的ISC较少。为了确定表面Ig同种型表达是否定义了反应性B细胞亚群，用荧光激活细胞分选仪制备了IgD +和IgD - B细胞。虽然IgD +和IgD - B细胞对SA + T supt均有反应，但只有IgD -亚群在单独对T supt反应时产生大量ISC。对分泌的Ig的分析表明，IgG和IgA是IgD - B细胞在对T supt或SA + T supt反应时分泌的主要同种型。相比之下，IgD +细胞在对SA + T supt反应时主要分泌IgM，但对单独的T supt无反应。当在补充T细胞的存在下检测对商陆丝裂原（PWM）的反应性时，发现IgD -亚群中反应性细胞大大富集，同样，IgG和IgA是分泌的主要同种型，尽管这些细胞也能够分泌一些IgM。来自IgD - B细胞的PWM诱导的反应强度通常大于SA + T supt诱导的反应强度。虽然IgD + B细胞对PWM反应较差，但在T细胞存在下，这种多克隆激活剂通常会刺激少量分泌IgM的细胞的分化。与SA + T supt刺激的反应相比，IgD + B细胞的PWM反应强度总是大大降低。吖啶橙染色后的细胞周期分析、细胞体积测量以及激活抗原（转铁蛋白受体和4F2）表达的染色表明，IgD - B细胞大多处于静止状态，但确实含有一群活化细胞。从IgD -亚群中去除活化的4F2 +细胞会降低但不会消除它们在T细胞存在下对SA + T supt或PWM产生ISC的能力。这些结果表明，IgD -群体包含活化的4F2 +和静止的4F2 -亚群。数据强调外周血B细胞的多个亚群包含ISC的前体。此外，亚群对各种刺激的反应性以及随后分泌的Ig同种型似乎是每个亚群的固有特征。
