Feijó G C, Sabbaga J, Carneiro C R, Brígido M M
Department of Cell Biology, University of Brasília, Brazil.
Immunology. 1997 Jul;91(3):479-85. doi: 10.1046/j.1365-2567.1997.00280.x.
Staphylococcal protein A is a cell wall-attached polypeptide that acts as a B-lymphocyte superantigen. This activation correlates with specific VH gene segment usage in the B-cell receptor. B-cell receptor assembled from members of the VH3 family in humans, or S107 family in mice, has an intrinsic affinity for protein A. Human VH3-derived antibodies bind to domain D of protein A. We have characterized a mouse IgM monoclonal antibody that binds protein A. The sequencing of the variable region suggests an almost germline-encoded VH derived from S107 family and a V kappa 8-derived VL. The binding specificity of the monoclonal antibody was tested with various recombinant constructions derived from protein A. We show that, unlike human VH3-derived antibody, mouse S107-derived immunoglobulin binds to the B domain of the bacterial superantigen.
葡萄球菌蛋白A是一种附着于细胞壁的多肽，可作为B淋巴细胞超抗原。这种激活与B细胞受体中特定VH基因片段的使用相关。由人类VH3家族成员或小鼠S107家族成员组装而成的B细胞受体对蛋白A具有内在亲和力。源自人类VH3的抗体与蛋白A的D结构域结合。我们鉴定了一种能结合蛋白A的小鼠IgM单克隆抗体。可变区测序表明，它有一个几乎由种系编码的源自S107家族的VH和一个源自Vκ8的VL。用源自蛋白A的各种重组构建体测试了该单克隆抗体的结合特异性。我们发现，与源自人类VH3的抗体不同，源自小鼠S107的免疫球蛋白与细菌超抗原的B结构域结合。
