Mercolino T J, Arnold L W, Hawkins L A, Haughton G
Department of Microbiology and Immunology, University of North Carolina, Chapel Hill 27514.
J Exp Med. 1988 Aug 1;168(2):687-98. doi: 10.1084/jem.168.2.687.
We have found that, in the peritoneums of normal adult mice, 5-15% of lymphocytes bind a fluorescent liposome probe. In ontogeny, cells with this specificity were shown to appear by 8 d after birth, and increase to the adult frequency by 2-3 wk. Some older mice contain an expanded population of these cells. We have shown that liposome binding occurs by cell surface IgM recognizing the common membrane phospholipid, phosphatidyl choline (PtC). Virtually all of these PtC-specific cells bear the cell surface marker Ly-1. Our results indicate that roughly 1 in 10 peritoneal Ly-1+ B cells has this single specificity. We have found that the precursors to all the cells that form plaques on protease-treated autologous erythrocytes (BrMRBC) are included in the PtC-specific population and can be isolated by FACS. We believe this is the first report of sorting large numbers of B cells with a single antigen specificity from normal, unimmunized animals. This method will allow for in vitro and in vivo studies of differentiative and proliferative properties of Ly-1+ B cells, which may help define their role in development and disease.
我们发现，在正常成年小鼠的腹膜中，15%的淋巴细胞可结合一种荧光脂质体探针。在个体发育过程中，具有这种特异性的细胞在出生后8天出现，并在2至3周时增加到成年时的频率。一些老年小鼠含有这些细胞的扩增群体。我们已经表明，脂质体结合是通过细胞表面IgM识别常见的膜磷脂磷脂酰胆碱（PtC）而发生的。几乎所有这些PtC特异性细胞都带有细胞表面标志物Ly-1。我们的结果表明，大约每10个腹膜Ly-1+B细胞中就有1个具有这种单一特异性。我们发现，所有能在经蛋白酶处理的自体红细胞（BrMRBC）上形成噬斑的细胞的前体都包含在PtC特异性群体中，并且可以通过荧光激活细胞分选术（FACS）分离出来。我们相信，这是首次从正常未免疫动物中筛选出具有单一抗原特异性的大量B细胞的报告。这种方法将允许对Ly-1+B细胞的分化和增殖特性进行体外和体内研究，这可能有助于确定它们在发育和疾病中的作用。
