Press J L, Klinman N R, McDevitt H O
J Exp Med. 1976 Aug 1;144(2):414-27. doi: 10.1084/jem.144.2.414.
The nonimmune adult spleen contains at least two B-cell subpopulations. The majority of primary B cells express cell surface Ia determinants and have the capacity to give rise to IgG antibody-producing clones after T-cell dependent antigenic stimulation. There is also a small subpopulation of primary B cells which are, by definition, Ia negative, since their activity is not eliminated by negative selection with anti-Ia serum and complement. The Ia-negative B cells give rise to clones that produce only IgM antibody. These B-cell subsets may form a continuum in B-cell maturation, or they may exist as discrete B-cell lineages. Since the cellular expression of Ia antigens appears to correlate with the ability of the B cell to generate IgG-producing clones, it is speculated that Ia molecules may have a role in the IgM to IgG B-cell switch mechanism.
非免疫的成年脾脏至少包含两个B细胞亚群。大多数初级B细胞表达细胞表面Ia决定簇，并且在依赖T细胞的抗原刺激后有能力产生产生IgG抗体的克隆。也有一小部分初级B细胞亚群，根据定义，它们是Ia阴性的，因为它们的活性不会被用抗Ia血清和补体进行的阴性选择所消除。Ia阴性B细胞产生仅产生IgM抗体的克隆。这些B细胞亚群可能在B细胞成熟过程中形成一个连续体，或者它们可能作为离散的B细胞谱系存在。由于Ia抗原的细胞表达似乎与B细胞产生产生IgG克隆的能力相关，因此推测Ia分子可能在IgM到IgG的B细胞转换机制中起作用。
