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Problem: Pregnant women are at increased risk of HIV acquisition, but the biological mechanisms contributing to this observation are not well understood. Method of Study: Here, we assessed host immune and microbiome differences in the vaginal mucosa of healthy pregnant and non‐pregnant women using a metaproteomics approach. Cervicovaginal lavage (CVL) samples were collected from 23 pregnant and 25 non‐pregnant women. Results: Mass spectrometry analysis of CVL identified 550 human proteins and 376 bacterial proteins from 11 genera. Host proteome analysis indicated 56 human proteins (10%) were differentially abundant (P <.05) between pregnant and non‐pregnant women, including proteins involved in angiogenesis (P = 3.36E‐3), cell movement of phagocytes (P = 1.34E‐6), and permeability of blood vessels (P = 1.27E‐4). The major bacterial genera identified were Lactobacillus, Gardnerella, Prevotella, Megasphaera, and Atopobium. Pregnant women had higher levels of Lactobacillus species (P =.017) compared with non‐pregnant women. Functional pathway analysis indicated that pregnancy associated with changes to bacterial metabolic pathway involved in energy metabolism, which were increased in pregnant women (P =.035). Conclusion: Overall, pregnant women showed differences in the cervicovaginal proteome and microbiome that may be important for HIV infection risk. [ABSTRACT FROM AUTHOR]

The mucosal surface of the female genital tract contains physiological, immunological, and microbial components that collectively comprise a functioning “mucosal system” that is critical for reproductive health. Alterations or imbalances to any of these components can have significant consequences for susceptibility to sexually transmitted infections, such as HIV. In recent years the advent of advanced systems biology technologies, such as metaproteomics, has provided new toolsets to studying mucosal systems. Studies have linked an altered mucosal proteome to many HIV risk factors including mucosal inflammation, bacterial vaginosis, hormonal contraceptives, and reduced efficacy of antiretroviral drugs for HIV prevention. Herein we will discuss how metaproteomics has been used to study mucosal system components, including epithelial barriers, inflammation, and the microbiome, with a focus on what alterations may contribute to increased HIV transmission risk in women. [ABSTRACT FROM AUTHOR]

Problem: Susceptibility to HIV is associated with the menstrual cycle and vaginal microbiome, but their collective impact on vaginal inflammation remains unclear. Here, we characterized the cervicovaginal proteome, inflammation, and microbiome community structure and function during the menstrual cycle. Method of study: Cervicovaginal secretions were collected from regularly cycling women (n = 16) at median day 10, 16, and 24 of each menstrual cycle and analyzed by mass spectrometry, 16S rRNA gene sequencing, and a multiplex bead array immunoassay. Follicular, ovulatory, and luteal phases were defined by serum sex hormone levels. Results: Ovulation showed the largest mucosal proteome changes, where 30% and 19% of the 406 human proteins identified differed compared to the luteal and follicular phases, respectively. Neutrophil/leukocyte migration pathways were lowest during ovulation and peaked in the luteal phase, while antimicrobial and epithelial barrier promoting proteins were highest during ovulation. Vaginal microbial community structure and function did not vary significantly during the menstrual cycle, with the majority consistently Lactobacillus‐dominant (63%) or non‐Lactobacillus‐dominant (25%). Fluctuations in the epithelial barrier protein RPTN between the ovulatory and luteal phase were amplified in women with Gardnerella vaginalis and anaerobic bacteria and reduced when Lactobacillus was dominant. Conclusion: This small study demonstrates that sex hormones modulate neutrophil/leukocyte inflammation, barrier function, and antimicrobial pathways in the female genital tract with the strongest changes occurring during ovulation. The data further suggest a microbiome context for hormone‐driven changes in vaginal immunity which may have implications for HIV susceptibility. [ABSTRACT FROM AUTHOR]

Problem: Cervical insufficiency is a precursor of preterm birth. Treatment with emergency cervical cerclage is contraindicated in the presence of intra‐amniotic infection. Detecting infection with Gram stain and culture of amniotic fluid lacks sensitivity. Proteomic profiling of amniotic fluid in cervical insufficiency may help identify pregnancies best suited for emergency cerclage. Method of study: Thirty‐two pregnant women underwent amniocentesis for routine genetic testing (n = 22) or after diagnosis of cervical insufficiency (n = 10). The proteomic profiles of the amniotic fluid samples were compared in a cross‐sectional fashion, including sub‐analyses of women with cervical insufficiency and latency periods of <1 week and >1 week post‐diagnosis. Results: Mean gestational age at diagnosis of cervical insufficiency was 21.4 weeks (95% CI 20.6‐22.1). Proteomic analysis yielded 40 (7.2%, P < 0.05) differentially expressed proteins between women with delivery <1 week (n = 6) vs. >1 week (n = 4). Women who delivered <1 week had activated inflammatory response (z = 2.3, P = 6.71E−09), chemotaxis of immune cells (z = 2.9, P = 2.01E−08), and inhibited bacterial growth (z = ‐2.2, P = 5.82E−05). A multivariate model of eight biomarkers positively associated with cases of <1 week latency and distinguished cases from controls (97.8%, cross‐validation accuracy 92.7%, P = 0.0009). Conclusion: In this pilot study, significant differences in the amniotic fluid proteomic profiles in cases of cervical insufficiency compared to genetic amniocentesis were observed. Proteomic signatures were predictive of achieving latency > 1 week after diagnosis of cervical insufficiency. These preliminary findings suggest that proteomic analysis may be of value in predicting outcome following cervical insufficiency and warrants further validation in larger studies. [ABSTRACT FROM AUTHOR]