Svenstrup Helle Friis, Nielsen Pernille K, Drasbek Mette, Birkelund Svend, Christiansen Gunna
Department of Medical Microbiology and Immunology, Bartholin Building, University of Aarhus, DK-8000 Aarhus C and *Loke Diagnostics ApS, Science Park, Gustav Wiedsvej 10C, DK-8000 Aarhus C, Denmark.
J Med Microbiol. 2002 May;51(5):361-373. doi: 10.1099/0022-1317-51-5-361.
Adhesion of Mycoplasma pneumoniae and the closely related M. genitalium to HEp-2 cells was investigated. The main surface proteins known to be involved in adhesion are P1 of M. pneumoniae and its homologue, MgPa, of M. genitalium. Both proteins are also immunodominant proteins. Protein P116 is another immunodominant protein of M. pneumoniae. These immunogenic proteins were investigated for their surface exposure and involvement in adhesion to host epithelial cells. Immunofluorescence microscopy (IFM) was used to detect M. pneumoniae and M. genitalium adhering to HEp-2 cells. Monospecific antibodies were produced against fragments of the surface proteins lacking tryptophan stop codons and were used for adhesion detection, surface exposure and adhesion inhibition IFM assays. Three monospecific antibodies were made against MgPa covering regions in the N-terminal, the middle and the C- terminal part; two monospecific antibodies were produced against P1 covering regions of the N- and the C-terminal part and one monospecific antibody was made against most of P116. Only the C-terminal parts of P1 and MgPa were surface exposed and blocking of these regions with the monospecific antibody resulted in inhibition of cytadsorption. Protein P116 was shown to be surface exposed and an essential protein involved in adhesion because the anti-P116 antibody prevented attachment of M. pneumoniae to the HEp-2 cells independently of P1. This study adds to the understanding of the molecular biology of M. genitalium and M. pneumoniae and presents a method to study the proteins involved in adhesion of these mycoplasmas.
研究了肺炎支原体及密切相关的生殖支原体对人喉癌上皮细胞（HEp-2细胞）的黏附情况。已知参与黏附的主要表面蛋白是肺炎支原体的P1及其生殖支原体的同源物MgPa。这两种蛋白也是免疫显性蛋白。蛋白P116是肺炎支原体的另一种免疫显性蛋白。对这些免疫原性蛋白的表面暴露情况及其在与宿主上皮细胞黏附中的作用进行了研究。采用免疫荧光显微镜（IFM）检测黏附于HEp-2细胞的肺炎支原体和生殖支原体。制备了针对缺乏色氨酸终止密码子的表面蛋白片段的单特异性抗体，并将其用于黏附检测、表面暴露及黏附抑制IFM分析。制备了三种针对MgPa的单特异性抗体，分别覆盖其N端、中间和C端区域；制备了两种针对P1的单特异性抗体，分别覆盖其N端和C端区域，还制备了一种针对大部分P116的单特异性抗体。只有P1和MgPa的C端区域暴露于表面，用单特异性抗体封闭这些区域会导致细胞吸附抑制。结果表明蛋白P116暴露于表面且是黏附中的必需蛋白，因为抗P116抗体可独立于P1阻止肺炎支原体黏附于HEp-2细胞。本研究增进了对生殖支原体和肺炎支原体分子生物学的理解，并提出了一种研究这些支原体黏附相关蛋白的方法。
