Gibbs A, Buggert M, Ranefall P, Introini A, Cheuk S, Eidsmo L, Hirbod T, Ball T, Kimani J, Kaul R, Karlsson AC, Wählby C, Broliden K, Tjernlund A
Conference on HIV Research for Prevention (HIV R4P), 2016, October 17–20, Chicago - (-) - [2016-10-17]
Background: Tissue resident memory (TRM) cells are characterized by the expression of several markers including αE(CD103)β7 integrin and by their preferential localization in the epithelium of mucosal surfaces. However, little is known about the presence of TRM cells in the human female reproductive tract (FRT), and their eventual role in protecting the host against HIV infection therein. In this study, we compared the distribution of CD103, as a surrogate marker of tissue-residency, on CD8+ T cells between the FRT and blood of HIV-infected and uninfected women. Methods: Blood and ectocervical tissue biopsies were collected from HIV-seropositive (n = 19) and HIV-seronegative (n = 17) Kenyan female sex workers as well as HIV-seronegative lowerrisk women (n = 21). Flow cytometry was used to assess the phenotype of circulating CD103+ CD8+ T cells, while in situ staining with image analysis were performed to enumerate CD8+ CD103+ cells in ectocervical biopsies. Results: The HIV-infected women displayed a significantly lower proportion of circulating CD103+cells within CD8+ T cells as compared to uninfected women. Circulating CD103+CD8+ T cells from the HIV-infected women were highly activated and enriched within the effector memory pool. Similar to blood, the proportion of cervical CD103+ cells among CD8+ cells was significantly lower in the HIV-infected versus uninfected women, even though the absolute count of these cells was increased in the HIV-infected women. Conclusions: Our data suggests that CD8+ T cells with the potential of residing within mucosal sites in virtue of their CD103 expression may be actively recruited to/or expanded in the FRT of chronically HIV-infected sex workers. This data poses the basis for further analysis of the phenotype and function of CD103+ CD8+ T cells residing in the FRT as TRM, and their eventual changes in the course of HIV infection.