Hajishengallis G, Nikolova E, Russell M W
Department of Microbiology, University of Alabama, Birmingham 35294.
Infect Immun. 1992 Dec;60(12):5057-64. doi: 10.1128/iai.60.12.5057-5064.1992.
The effect of human secretory immunoglobulin A (S-IgA) and serum antibodies to surface protein antigen (Ag) I/II on the adherence of Ag I/II-bearing Streptococcus mutans and of free Ag I/II to saliva-coated hydroxyapatite (SHA) was investigated. The inhibition by S-IgA of binding of both S. mutans and free Ag I/II to SHA was dependent on antibody to Ag I/II. Essentially no difference was found between S-IgA1 and S-IgA2 with respect to antibody-dependent inhibition of Ag I/II binding to SHA, but S-IgA1 inhibited S. mutans adherence more effectively than did either serum immunoglobulin A1 (IgA1) or IgG antibodies. The antiadherence effect of S-IgA was abrogated after cleavage by IgA1 protease. Purified Fab alpha fragments containing Ag I/II-binding activity enhanced the binding of free Ag I/II to SHA and showed greater binding to SHA than did intact S-IgA1. Despite its relative inability to interact with precoated SHA, S-IgA1 containing antibody to Ag I/II was readily incorporated into the salivary pellicle during coating, but this did not promote Ag I/II binding. These data suggest that S-IgA antibodies can inhibit the initial adherence of S. mutans to salivary pellicle-coated tooth surfaces in an adhesin-specific fashion, but the presence in the oral cavity of bacterial IgA1 proteases would potentially interfere with this antiadherence mechanism.
研究了人分泌型免疫球蛋白A（S-IgA）和针对表面蛋白抗原（Ag）I/II的血清抗体对携带Ag I/II的变形链球菌以及游离Ag I/II与唾液包被的羟基磷灰石（SHA）黏附的影响。S-IgA对变形链球菌和游离Ag I/II与SHA结合的抑制作用取决于针对Ag I/II的抗体。就抗体依赖性抑制Ag I/II与SHA的结合而言，S-IgA1和S-IgA2之间基本没有差异，但S-IgA1比血清免疫球蛋白A1（IgA1）或IgG抗体更有效地抑制变形链球菌的黏附。S-IgA的抗黏附作用在被IgA1蛋白酶切割后被消除。含有Ag I/II结合活性的纯化Fabα片段增强了游离Ag I/II与SHA的结合，并且比完整的S-IgA1与SHA的结合更强。尽管S-IgA1相对无法与预先包被的SHA相互作用，但含有针对Ag I/II抗体的S-IgA1在包被过程中很容易掺入唾液薄膜中，但这并未促进Ag I/II的结合。这些数据表明，S-IgA抗体可以以黏附素特异性方式抑制变形链球菌对唾液薄膜包被的牙齿表面的初始黏附，但口腔中细菌IgA1蛋白酶的存在可能会干扰这种抗黏附机制。
