Vaginal inoculation of rhesus macaques (RM) with simian immunodeficiency virus (SIV) has been used to study the biology of HIV transmission. Although the results of vaginal SIV transmission experiments could be affected by vaginal inflammation, studies to date have been conducted without regard to levels of pre-existing genital inflammation present in RM. We collected cevicovaginal secretions (CVS) from 33-36 RM during the mid menstrual cycle (day 10-20) at 2 time points approximately 8 months apart and characterized the mRNA and protein levels of inflammatory cytokines, chemokines and interferon-stimulated genes. There was extreme variability in the levels of inflammatory mediators (IFN-α, IFN-γ, IL-6, TNF, IL-1b, IP-10, MIG, IL-12 and IL-17). In most animals, the mRNA levels of the inflammatory mediators were similar in the 2 CVS samples collected 8 months apart, suggesting that genital inflammation is stable in a subset of captive female RM. At both time points the cervicovaginal microbiota had low levels of Lactobacillus and was relatively diverse with an average of 13 genera in the samples from the first time point (median 13, range 7-21) and an average of 11.5 genera in the samples from the second time point (median 11, range 5-20). Many of the macaques had similar microbiota in the samples collected 8 months apart. However, we found no correlation between specific bacterial genera and the mRNA or protein levels of the inflammatory mediators in the genital tract of RM in this study. It seems likely that results of published vaginal SIV transmission experiments in RM have been influenced by pre-existing inflammation in the animals used for the experiments.

Urogenital diseases, especially infection and cancer, are major causes of death and morbidity in females. Yet, millions of women in the developing world have no access to basic urogynecological care, and the diagnosis and treatment of widespread aberrant bacterial conditions (bacterial vaginosis [BV] and aerobic vaginitis [AV]) remain suboptimal the world over. Samples from women living in resource-disadvantaged and developed countries have been analyzed by high-throughput sequencing to reveal the diversity of bacteria in the vagina, how rapidly the bacterial population fluctuates over time, and how rapidly the switch occurs between healthy and aberrant conditions. Unfortunately, clinical diagnostic methods are inefficient and too often outdated therapies are administered. The net result is suboptimal care and recurrent disease that adversely affects the quality of life. This viewpoint outlines a scientific and translational road map designed to improve the cervicovaginal health and treatment of disease. This comprises (1) improving education of women and physicians on the vaginal microbiota; (2) having agencies target funding for research to improve diagnosis and test new therapies; and (3) making sure that new approaches are accessible in developing countries, empowering to women, and are acceptable and appropriate for different populations.

Background

 Bacterial vaginosis (BV) is characterized by low abundance of Lactobacillus species, high pH, and immune cell infiltration and has been associated with an increased risk of human papillomavirus (HPV) infection. We molecularly assessed the cervicovaginal microbiota over time in human immunodeficiency virus (HIV)-infected and HIV-uninfected women to more comprehensively study the HPV-microbiota relationship, controlling for immune status.

Methods

 16S ribosomal RNA gene amplicon pyrosequencing and HPV DNA testing were conducted annually in serial cervicovaginal lavage specimens obtained over 8-10 years from African American women from Chicago, of whom 22 were HIV uninfected, 22 were HIV infected with a stable CD4⁺ T-cell count of > 500 cells/mm³, and 20 were HIV infected with progressive immunosuppression. Vaginal pH was serially measured.

Results

 The relative abundances of Lactobacillus crispatus and other Lactobacillus species were inversely associated with vaginal pH (all P < .001). High (vs low) L. crispatus relative abundance was associated with decreased HPV detection (odds ratio, 0.48; 95% confidence interval, .24-.96; P_trend = .03) after adjustment for repeated observation and multiple covariates, including pH and study group. However, there were no associations between HPV and the relative abundance of Lactobacillus species as a group, nor with Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii individually.

Conclusions

 L. crispatus may have a beneficial effect on the burden of HPV in both HIV-infected and HIV-uninfected women (independent of pH).