Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
J Reprod Immunol. 2009 Dec;83(1-2):196-200. doi: 10.1016/j.jri.2009.07.005. Epub 2009 Oct 23.
The male and female genital tracts are protected by a local immune system that displays features distinguishing them from other mucosal sites. In contrast to the intestinal tract, where locally produced IgA is the dominant Ig, secretions of the male and female genital tract contain predominantly IgG of both local and systemic origin. Genital tract tissues also lack mucosal lymphoepithelial inductive sites analogous to intestinal Peyer's patches; consequently, local immunization or infections with sexually transmitted pathogens induce low immune responses. Human immunodeficiency virus 1 (HIV-1) infection must be primarily considered as a mucosal disease with extensive involvement of the systemic immune compartment. Although the majority of infections is acquired through the genital mucosa, a high rate of virus replication and profound CD4(+) T cell depletion occurs in the intestinal mucosa and other mucosal tissues shortly after infection. Evaluation of HIV-specific antibodies in sera and external secretions, including vaginal washes and semen, unexpectedly revealed a selective lack of IgA responses. Moreover, specific antibody-secreting cells in peripheral blood were of the IgG isotype, even in mucosally infected individuals. Whether humoral responses to previously or newly encountered antigens are compromised in HIV-1-infected persons is under current investigation.
男性和女性生殖道受到局部免疫系统的保护，该系统具有与其他黏膜部位区分开来的特征。与肠道不同，肠道中局部产生的 IgA 是主要的 Ig，男性和女性生殖道的分泌物主要含有局部和全身来源的 IgG。生殖道组织也缺乏类似于肠道派尔集合淋巴结的黏膜淋巴上皮诱导部位；因此，局部免疫或性传播病原体感染会引起低免疫反应。人类免疫缺陷病毒 1（HIV-1）感染必须主要被视为一种黏膜疾病，广泛涉及全身免疫区室。尽管大多数感染是通过生殖道黏膜获得的，但在感染后不久，肠道黏膜和其他黏膜组织中就会发生高病毒复制和严重的 CD4(+)T 细胞耗竭。对血清和外分泌液（包括阴道冲洗液和精液）中的 HIV 特异性抗体的评估出人意料地显示出 IgA 反应的选择性缺乏。此外，外周血中的特异性抗体分泌细胞是 IgG 同种型，即使是在黏膜感染的个体中也是如此。HIV-1 感染者对先前或新遇到的抗原的体液反应是否受损正在进行研究。
