Vaginal candida infection is associated with host molecular signatures of neutrophil activation in the adjacent ectocervical mucosa in Kenyan sex workers

Problem: Overgrowth of candida species in the human vaginal mucosa causes inflammation, which could render the mucosal barrier more susceptible to HIV infection. Here, we investigated whether this condition also affects the ectocervical mucosa, a potential site of HIV entry, in women at high risk of HIV infection. Method of study: Retrospective medical data and ectocervical tissue samples were obtained from a cohort of Kenyan sex workers. Among 108 women, seven had signs of vaginal candida infection by wet smear microscopy and/or the presence of characteristic discharge. Women lacking these two criteria served as controls. Host transcriptomic profiling and quantitative in situ image analysis of epithelial barrier markers and CD4+ cell distribution were performed. Results: The candida group had 162 differentially expressed genes out of 15 435 genes as compared with the control group. Among these 162 genes, 147 were upregulated and 15 were downregulated. Gene expression pathway analysis indicated associations with an upregulated inflammatory response, defined primarily by markers of neutrophil activation. Transcription factor analysis revealed upregulation of pathways related to RELA/REL/NFKB1, JUN and STAT1 in the candida group. In situ image analysis of ectocervical tissue samples showed no differences between groups in terms of epithelial height, expression of epithelial junction proteins (E-cadherin, claudin-1, zonula occludens 1, and desmoglein-1), or epithelial CD4+ cell distribution. Conclusions: Vaginal candida infection was associated with inflammation and neutrophil infiltration, but not with severe epithelial disruption or CD4+ cell infiltration, in the ectocervical mucosa.