Lafrenz D, Teale J M, Klinman N R, Strober S
J Immunol. 1986 Mar 15;136(6):2076-9.
Our previous studies indicated that a large proportion of surface IgG+-primed B cells give rise to clones secreting IgM antibodies. Due to the implications of this result relative to molecular mechanisms of class switching, it was important to document that the surface IgG had been endogenously synthesized by the surface IgG+ cells and was not present as a result of cytophilic IgG. Therefore, spleen cells from immunized mice were treated sequentially with anti-immunoglobulin and protease which removed greater than 99% of surface immunoglobulin. After overnight incubation to allow resynthesis of surface immunoglobulin, the treated cells were sorted for surface IgG-bearing cells and were transferred to carrier-primed, irradiated adoptive recipients for analysis in the splenic focus assay. It was found that the majority of antibody-secreting clones derived from these surface IgG+ B cells still synthesized IgM. These data are discussed relative to current concepts of molecular mechanisms of immunoglobulin class switching.
我们之前的研究表明，很大一部分表面IgG +致敏的B细胞会产生分泌IgM抗体的克隆。鉴于这一结果与类别转换的分子机制相关，证明表面IgG是由表面IgG +细胞内源性合成的，而不是由于亲细胞性IgG的存在，这一点很重要。因此，对免疫小鼠的脾细胞依次用抗免疫球蛋白和蛋白酶处理，去除了超过99%的表面免疫球蛋白。经过过夜孵育以允许表面免疫球蛋白重新合成后，将处理过的细胞分选以获得携带表面IgG的细胞，并转移到经载体致敏、照射过的过继受体中，用于脾灶测定分析。发现这些表面IgG + B细胞衍生的大多数抗体分泌克隆仍合成IgM。相对于免疫球蛋白类别转换分子机制的当前概念，对这些数据进行了讨论。
