Abundant and Superficial Expression of C-Type Lectin Receptors in Ectocervix of Women at Risk of HIV Infection

Objectives: Dendritic cells (DCs) are among the first cells to encounter HIV after mucosal exposure and can bind virus via C-type lectin receptors (CLRs). Here, we characterized the distribution of various DC subtypes and the density of the CLRs, DC-SIGN, langerin, and mannose receptor in the ectocervix of HIV-seronegative women with low- and high-risk behavior for acquiring HIV. Material and Methods: Cryosections from ectocervical biopsies, collected from sexually active low-risk healthy HIV immunoglobulin G-negative women (n = 10) and HIV immunoglobulin G-negative commercial sex workers (n = 8), were assessed by computerized image analysis. Results: We identified various distinct DC populations. CD11c(-)CD1a(+)langerin(+) cells were localized in the epithelium, whereas CD11c(+)CD1a(-)DC-SIGN(+) and CD11c(-)CD1a(-)CD68(+)DC-SIGN(+) mannose receptor(+) cells were restricted to the lamina propria of the ectocervix. CD123(+) cells were found at low incidence and did not express any of the investigated CLRs. The density of CLR expression was significantly higher in the high-risk as compared with the low-risk women. Conclusions: The superficial and abundant presence of potential HIV target cells makes the ectocervix a likely site for HIV transmission. The detected variations in density and localization of potential HIV receptors should be considered when developing topical prophylactic measures.