McGarey D J, Barbet A F, Palmer G H, McGuire T C, Allred D R
Department of Infectious Diseases, University of Florida, Gainesville 32611.
Infect Immun. 1994 Oct;62(10):4594-601. doi: 10.1128/iai.62.10.4594-4601.1994.
Genes for the MSP1a and MSP1b subunits of the Anaplasma marginale surface antigen complex MSP1 were previously cloned and expressed in Escherichia coli. We report here the localization of MSP1a and MSP1b polypeptides on the surface of recombinant E. coli by using a live cell indirect immunofluorescent antibody assay. Recombinant E. coli cells expressing the msp1 alpha gene or the msp1 beta gene encoding the MSP1a and MSP1b polypeptide subunits, respectively, were shown by a culture recovery adhesion assay and by direct microscopic examination to specifically adhere to bovine erythrocytes. This adhesion was more than additive when both genes were coexpressed in a single recombinant construct. Similarly, these recombinants hemagglutinated bovine erythrocytes in a microtiter hemagglutination assay. Inhibition of recombinant E. coli adhesion to bovine erythrocytes and hemagglutination inhibition were observed in the presence of homologous monospecific polyclonal antiserum raised against purified MSP1a or MSP1b polypeptide. These data suggest that the MSP1a and MSP1b polypeptides have functions as adhesins on A. marginale initial bodies, probably during erythrocyte invasion.
边缘无形体表面抗原复合物MSP1的MSP1a和MSP1b亚基的基因先前已被克隆并在大肠杆菌中表达。我们在此报告，通过活细胞间接免疫荧光抗体试验，MSP1a和MSP1b多肽在重组大肠杆菌表面的定位。分别表达编码MSP1a和MSP1b多肽亚基的msp1α基因或msp1β基因的重组大肠杆菌细胞，通过培养回收黏附试验和直接显微镜检查显示能特异性黏附于牛红细胞。当两个基因在单个重组构建体中共表达时，这种黏附作用具有叠加性。同样，这些重组体在微量滴定血凝试验中能使牛红细胞发生血凝。在存在针对纯化的MSP1a或MSP1b多肽产生的同源单特异性多克隆抗血清的情况下，观察到重组大肠杆菌对牛红细胞的黏附抑制和血凝抑制。这些数据表明，MSP1a和MSP1b多肽可能在红细胞入侵过程中作为边缘无形体初始小体上的黏附素发挥作用。
