Pregnancy associates with alterations to the host and microbial proteome in vaginal mucosa.

ABSTRACT

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.