Increased levels of inflammatory cytokines in the female reproductive tract are associated with altered expression of proteases, mucosal barrier proteins, and an influx of HIV-susceptible target cells

Abstract

Elevated inflammatory cytokines (EMCs) at mucosal surfaces have been associated with HIV susceptibility, but the underlying mechanisms remain unclear. We characterized the soluble mucosal proteome associated with elevated cytokine expression in the female reproductive tract. A scoring system was devised based on the elevation (upper quartile) of at least three of seven inflammatory cytokines in cervicovaginal lavage. Using this score, HIV-uninfected Kenyan women were classified as either having EMC (n=28) or not (n=68). Of 455 proteins quantified in proteomic analyses, 53 were associated with EMC (5% false discovery rate threshold). EMCs were associated with proteases, cell motility, and actin cytoskeletal pathways, whereas protease inhibitor, epidermal cell differentiation, and cornified envelope pathways were decreased. Multivariate analysis identified an optimal signature of 16 proteins that distinguished the EMC group with 88% accuracy. Three proteins in this signature were neutrophil-associated proteases that correlated with many cytokines, especially GM-CSF (granulocyte-macrophage colony-stimulating factor), IL-1β (interleukin-1β), MIP-3α (macrophage inflammatory protein-3α), IL-17, and IL-8. Gene set enrichment analyses implicated activated immune cells; we verified experimentally that EMC women had an increased frequency of endocervical CD4(+) T cells. These data reveal strong linkages between mucosal cytokines, barrier function, proteases, and immune cell movement, and propose these as potential mechanisms that increase risk of HIV acquisition.

Distinct Effects of the Cervicovaginal Microbiota and Herpes Simplex Type 2 Infection on Female Genital Tract Immunology

“…Mucosal inflammation may increase HIV risk in at least 2 ways. Proinflammatory cytokines such as IL-1α and TNF-α are produced after stimulation of innate immune receptors on both epithelial cells and local dendritic cells [35], and directly disrupt mucosal epithelial barrier function both in vitro and in vivo, potentially facilitating HIV entry [7,36]; furthermore, inflammation is associated with an influx of activated CD4 + T cells that fuels local HIV replication [8]. Our analyses now suggest that these 2 mechanisms can operate independently of each other.…”

“…Prior studies have also associated Nugentdefined BV with increased proinflammatory cytokines, particularly IL1α and IL1β, as well as decreased levels of IP-10 [11,46]. However, while vaginal proinflammatory cytokines have been associated with increased mucosal CD4 + T-cell numbers [6,7], a direct association between the vaginal microbiome and cervical CD4 + T cells has not been shown [6].…”

“…Of the 14 genital cytokines assayed, 3 were detectable in all participants (IL-1α, IL-8, MCP-1), and others in a subset: Our primary analysis assessed the relationship of the genital microbiota with the presence or absence of genital inflammation (predefined based on cytokine levels [7]). Overall, 13/51 (25.5%) of participants demonstrated genital inflammation: 45% (9/20) of participants within CST-IV, 18.2% (4/22) within CST-III, and 0% (0/9) within CST-I/II (LR = 9.5; P = .024, Figure 2A).…”

“…Elevated genital proinflammatory cytokines ("genital inflammation") was predefined as having ≥3/7 proinflammatory cytokines (IL-1α, IL-8, MIP-3α, RANTES, IL-1β, MIP-1β, and TNF-α) in the upper quartile [7]. The association between specific phyla and genital inflammation was determined using general additive models and ordinary logistic regression linear and spline models.…”

Multipurpose tenofovir disoproxil fumarate electrospun fibers for the prevention of HIV-1 and HSV-2 infections in vitro

“…Studies have shown that increased expression of cytokines such as IL-6, IL-8, as well as IL-1α and β is strongly associated with increased susceptibility to HIV infection [66, 67]. Nonoxynol-9, once a promising microbicide candidate against HIV, was shown to increase the rate of HIV infection in clinical studies due to its pro-inflammatory properties and disruption of the reproductive epithelium [68, 69].…”