Smith L M, Laganas V, Pistole T G
Department of Microbiology, University of New Hampshire, Durham 03824-2617, USA.
FEMS Immunol Med Microbiol. 1998 Feb;20(2):89-97. doi: 10.1111/j.1574-695X.1998.tb01114.x.
Group B Streptococcus (GBS) is able to bind to human macrophages in vitro in the absence of exogenous opsonins. The exact mechanisms that mediate this attachment are unclear. This study was undertaken to determine what protein adhesins are present on the surface of GBS that mediate attachment to macrophages. We have identified a 21-kDa protein from the envelope of GBS type III that directly binds to macrophages as determined by Western blot analysis. Antiserum against this protein was able to inhibit binding of GBS to macrophages by greater than 80% as measured by flow cytometry. Antiserum against the 21-kDa protein cross-reacted with 21-kDa proteins from GBS type Ib, type II, type III (COH31 and MR732) and type IV, as well as Staphyloccus epidermidis, but not GBS type Ia, Listeria monocytogenes or Enterococcus faecalis. This protein may be important in mediating the attachment of GBS to macrophages in an opsonin-poor environment.
B族链球菌（GBS）在体外能够在没有外源性调理素的情况下与人巨噬细胞结合。介导这种附着的确切机制尚不清楚。进行这项研究是为了确定GBS表面存在哪些介导与巨噬细胞附着的蛋白质黏附素。我们从III型GBS的包膜中鉴定出一种21 kDa的蛋白质，通过蛋白质印迹分析确定其可直接与巨噬细胞结合。通过流式细胞术检测，针对该蛋白质的抗血清能够抑制GBS与巨噬细胞的结合达80%以上。针对21 kDa蛋白质的抗血清与来自Ib型、II型、III型（COH31和MR732）和IV型GBS以及表皮葡萄球菌的21 kDa蛋白质发生交叉反应，但与Ia型GBS、单核细胞增生李斯特菌或粪肠球菌不发生交叉反应。这种蛋白质可能在介导GBS在调理素缺乏的环境中与巨噬细胞的附着方面发挥重要作用。
