Hussain L A, Lehner T
Division of Immunology, United Medical School, Guy's Hospital, London.
Immunology. 1995 Jul;85(3):475-84.
Human immunodeficiency virus (HIV) is commonly transmitted, during homosexual and heterosexual intercourse, through the rectal and cervicovaginal mucosa, foreskin and urethral epithelia. However, there is uncertainty about HIV transmission through the oral mucosa by oral sex. We have carried out a comparative immunohistological investigation of primate oral, cervicovaginal, foreskin, urethral and rectal epithelia for potential HIV receptors. We investigated epithelial tissues for CD4 glycoprotein, which is the principal receptor for HIV, Fc receptors of IgG for binding HIV-IgG antibody complexes, and HLA class II, which might enable HIV-bound CD4+ cells to gain access to the epithelial cells. CD4 glycoprotein was not found in oral, foreskin, urethral, vaginal or rectal epithelial cells, although CD4+ mononuclear cells were present in the lamina propria of each epithelium. Fc gamma II and Fc gamma III receptors were found in urethral, endocervical and rectal epithelia, and Fc gamma III and Fc gamma I receptors in the foreskin. However, Fc gamma receptors were not found in oral epithelium (buccal, labial, lingual or palatal) and only Fc gamma III receptors were detected in the gingival epithelial cells. HLA class II antigen was also not detected in foreskin, oral or rectal epithelium, but it was expressed by endocervical cells from most human specimens and in male urethral epithelia of non-human male primates. Langerhans' cells were found in all epithelia except those of the urethra and rectum, and they can express CD4 glycoprotein, Fc gamma receptors and HLA class II antigen. The mean number of Langerhans' cells expressing CD4 in the upper third of oral epithelium was significantly lower compared with vaginal epithelium or foreskin. The HIV-binding V1 domain of CD4 was significantly decreased in Langerhans' cells present in oral compared with vaginal epithelium. The results suggest that the foreskin in uncircumcised men and the cervicovaginal epithelium in females might become infected via the CD4+ Langerhans' cells. However, urethral infection might be mediated by HIV-antibody complexes binding to urethral epithelial Fc gamma receptors. The paucity of Langerhans' cells expressing the V1 domain of CD4, the absence of Fc gamma receptors, and a lack of expression of HLA class II antigens in most oral epithelial cells, argue against transmission of HIV through the normal intact oral mucosa.
人类免疫缺陷病毒（HIV）通常在同性恋和异性恋性交过程中，通过直肠和宫颈阴道黏膜、包皮和尿道上皮传播。然而，关于口交时HIV通过口腔黏膜传播尚存在不确定性。我们对灵长类动物的口腔、宫颈阴道、包皮、尿道和直肠上皮进行了潜在HIV受体的比较免疫组织学研究。我们研究了上皮组织中的CD4糖蛋白（HIV的主要受体）、用于结合HIV-IgG抗体复合物的IgG的Fc受体以及HLA-II类分子，后者可能使结合了HIV的CD4+细胞能够接触上皮细胞。在口腔、包皮、尿道、阴道或直肠上皮细胞中未发现CD4糖蛋白，尽管在每个上皮的固有层中存在CD4+单核细胞。在尿道、宫颈内膜和直肠上皮中发现了FcγII和FcγIII受体，在包皮中发现了FcγIII和FcγI受体。然而，在口腔上皮（颊、唇、舌或腭）中未发现Fcγ受体，仅在牙龈上皮细胞中检测到FcγIII受体。在包皮、口腔或直肠上皮中也未检测到HLA-II类抗原，但在大多数人类标本的宫颈内膜细胞以及非人雄性灵长类动物的男性尿道上皮中表达。除尿道和直肠上皮外，在所有上皮中均发现了朗格汉斯细胞，它们可表达CD4糖蛋白、Fcγ受体和HLA-II类抗原。与阴道上皮或包皮相比，口腔上皮上三分之一处表达CD4的朗格汉斯细胞的平均数量显著降低。与阴道上皮相比，口腔中存在的朗格汉斯细胞中CD4的HIV结合V1结构域显著减少。结果表明，未割包皮男性的包皮和女性的宫颈阴道上皮可能通过CD4+朗格汉斯细胞被感染。然而，尿道感染可能是由HIV抗体复合物与尿道上皮Fcγ受体结合介导的。大多数口腔上皮细胞中表达CD4 V1结构域的朗格汉斯细胞稀少、缺乏Fcγ受体以及缺乏HLA-II类抗原的表达，这表明HIV不太可能通过正常完整的口腔黏膜传播。
