McHeyzer-Williams M G
Walter and Eliza Hall Institute of Medical Research, Victoria, Australia.
Eur J Immunol. 1989 Nov;19(11):2025-30. doi: 10.1002/eji.1830191109.
Immunoglobulin (Ig) production by lipopolysaccharide (LPS)-stimulated cells in the presence of various combinations of interleukin (IL)2, IL4 and IL5 was examined. IgG1, IgM and IgE secretion was studied using a 3T3-fibroblast filler cell-supported B cell culture system, either at low cell density to support maximal Ig secretion, or at limiting dilution to determine isotype-specific precursor frequencies. In the presence of optimal concentrations of IL5 (2%) and IL2 (3 U/ml), the addition of 1 U/ml of IL4 resulted in the production of 4 ng of IgG1 per input B cell. In contrast, 1000 U/ml of IL4 alone was required to produce equivalent levels of IgG1. IL5 and IL2 increased both the precursor frequency and the amount of IgG1 secreted per clone in the presence of low levels of IL4. On the other hand, IgM secretion was decreased 10-fold by the addition of 10 U/ml IL4 or greater. This was not seen when IL5 was present. The IgM-secreting precursor frequency was unaffected by any of the lymphokines, either singly or in combination. The inhibition of IgM production and subsequent relief of this with IL5 was shown to affect the amount of IgM secreted per clone. IgE secretion was shown to be highly IL4 dependent with only minor reduction in the required concentration following addition of IL5 and IL2. At the clonal level, the majority of IgE-secreting clones (93%) at high IL4 concentrations (200 U/ml) arose from precursors which were able to produce IgM and IgG1. Furthermore, only 3% of the clones secreted IgG1 alone, with a further 3% secreting IgE alone. These results suggest that B cells in vivo are predominantly uncommitted in terms of isotype to be produced, the choice of isotype secreted being dependent on the nature of the stimulus. Overall, this work shows that the isotype secreted by B cells can be regulated using combinations of IL2, IL4 and IL5, and that major effects can be achieved by very small quantities of lymphokines acting in synergy.
研究了在白细胞介素（IL）-2、IL-4和IL-5的各种组合存在下，脂多糖（LPS）刺激的细胞产生免疫球蛋白（Ig）的情况。使用3T3成纤维细胞填充细胞支持的B细胞培养系统研究IgG1、IgM和IgE的分泌，该系统要么在低细胞密度下以支持最大Ig分泌，要么在有限稀释下以确定同种型特异性前体频率。在最佳浓度的IL-5（2%）和IL-2（3 U/ml）存在的情况下，添加1 U/ml的IL-4导致每个输入B细胞产生4 ng的IgG1。相比之下，单独需要1000 U/ml的IL-4才能产生同等水平的IgG1。在低水平IL-4存在的情况下，IL-5和IL-2增加了前体频率以及每个克隆分泌的IgG1量。另一方面，添加10 U/ml或更高剂量的IL-4会使IgM分泌减少10倍。当存在IL-5时未观察到这种情况。分泌IgM的前体频率不受任何一种细胞因子单独或联合作用的影响。IL-5对IgM产生的抑制作用以及随后的缓解作用显示会影响每个克隆分泌的IgM量。结果表明，IgE分泌高度依赖IL-4，添加IL-5和IL-2后所需浓度仅略有降低。在克隆水平上，高IL-4浓度（200 U/ml）下大多数分泌IgE的克隆（93%）来自能够产生IgM和IgG1的前体。此外，只有3%的克隆单独分泌IgG1，另有3%的克隆单独分泌IgE。这些结果表明，体内B细胞在要产生的同种型方面主要是未定向的，分泌的同种型选择取决于刺激的性质。总体而言，这项工作表明，可以使用IL-2、IL-4和IL-5的组合来调节B细胞分泌的同种型，并且极少量的细胞因子协同作用就能产生主要影响。
