Genital inflammation is a key determinant of HIV transmission, and may increase HIV-susceptible target cells and alter epithelial integrity. Several genital conditions that increase HIV risk are more prevalent in African, Caribbean and other black (ACB) women, including bacterial vaginosis and Herpes simplex type-2 (HSV-2) infection. Therefore, we assessed the impact of the genital microbiota on mucosal immune cells and cytokines in ACB women, as well as HSV-2 interactions.


Cervico-vaginal secretions and endocervical cells were collected by cytobrush and Instead Softcup, respectively. T cell and dendritic cells were assessed by flow cytometry, cytokines by multiplex ELISA, and the microbiota by 16S rRNA gene sequencing.


The cervico-vaginal microbiota of 51 participants was composed of community state types (CSTs) showing diversity (20/51; 39%) or predominated by Lactobacillus iners (22/51; 42%), L. crispatus (7/51; 14%) or L. gasseri (2/51; 4%). High diversity CSTs and specific bacterial phyla (G. vaginalis and P. bivia) were strongly associated with cervico-vaginal inflammatory cytokines, but not with altered endocervical immune cells. However, cervical CD4+ T cell number was associated with HSV-2 infection and a distinct cytokine profile.


This suggests that the genital microbiota and HSV-2 infection may influence HIV susceptibility through independent biological mechanisms.

Author notes

Correspondence. Dr. Rupert Kaul and/or Mr. Brett Shannon, Department of Medicine, University of Toronto, Medical Sciences Building #6356, Toronto, Ontario, Canada, M5S 1A8. Tel: (1–416) 978–8607; Fax: (1–416) 978–8765. Email: rupert.kaul@utoronto.ca; brett.shannon@utoronto.ca