The impact of pregnancy on anti-HIV activity of cervicovaginal secretions

Mass spectrometry-based proteomic analysis of biological stains identifies body fluids specific markers

The identification of biological stains and their tissue resource is an important part of forensic research. Current methods suffer from several limitations including poor sensitivity and specificity, trace samples, and sample destruction. In this study, we profiled the proteomes of menstrual blood, peripheral blood, saliva, semen, and vaginal fluid with mass spectrometry technology. Tissue-enhanced and tissue-specific proteins of each group have been proposed as potential biomarkers. These candidate proteins were further annotated and screened through the combination with the Human Protein Atlas database. Our data not only validates the protein biomarkers reported in previous studies but also identifies novel candidate biomarkers for human body fluids. These candidates lay the foundation for the development of rapid and specific forensic examination methods.

Dynamic states of cervical epithelia during pregnancy and epithelial barrier disruption

The cervical epithelium undergoes changes in proliferation, differentiation, and function that are critical to ensure fertility and maintain pregnancy. Here, we identify cervical epithelial subtypes in non-pregnant, pregnant, and in labor mice using single-cell transcriptome and spatial analysis. We identify heterogeneous subpopulations of epithelia displaying spatial and temporal specificity. Notably in pregnancy, two goblet cell subtypes are present in the most luminal layers with one goblet population expanding earlier in pregnancy than the other goblet population. The goblet populations express novel protective factors and distinct mucosal networks. Single-cell analysis in a model of cervical epithelial barrier disruption indicates untimely basal cell proliferation precedes the expansion of goblet cells with diminished mucosal integrity. These data demonstrate how the cervical epithelium undergoes continuous remodeling to maintain dynamic states of homeostasis in pregnancy and labor, and provide a framework to understand perturbations in epithelial health that increase the risk of premature birth.

Changes in concentrations of cervicovaginal immune mediators across the menstrual cycle: a systematic review and meta-analysis of individual patient data

BACKGROUND

Hormonal changes during the menstrual cycle play a key role in shaping immunity in the cervicovaginal tract. Cervicovaginal fluid contains cytokines, chemokines, immunoglobulins, and other immune mediators. Many studies have shown that the concentrations of these immune mediators change throughout the menstrual cycle, but the studies have often shown inconsistent results. Our understanding of immunological correlates of the menstrual cycle remains limited and could be improved by meta-analysis of the available evidence.

METHODS

We performed a systematic review and meta-analysis of cervicovaginal immune mediator concentrations throughout the menstrual cycle using individual participant data. Study eligibility included strict definitions of the cycle phase (by progesterone or days since the last menstrual period) and no use of hormonal contraception or intrauterine devices. We performed random-effects meta-analyses using inverse-variance pooling to estimate concentration differences between the follicular and luteal phases. In addition, we performed a new laboratory study, measuring select immune mediators in cervicovaginal lavage samples.

RESULTS

We screened 1570 abstracts and identified 71 eligible studies. We analyzed data from 31 studies, encompassing 39,589 concentration measurements of 77 immune mediators made on 2112 samples from 871 participants. Meta-analyses were performed on 53 immune mediators. Antibodies, CC-type chemokines, MMPs, IL-6, IL-16, IL-1RA, G-CSF, GNLY, and ICAM1 were lower in the luteal phase than the follicular phase. Only IL-1α, HBD-2, and HBD-3 were elevated in the luteal phase. There was minimal change between the phases for CXCL8, 9, and 10, interferons, TNF, SLPI, elafin, lysozyme, lactoferrin, and interleukins 1β, 2, 10, 12, 13, and 17A. The GRADE strength of evidence was moderate to high for all immune mediators listed here.

CONCLUSIONS

Despite the variability of cervicovaginal immune mediator measurements, our meta-analyses show clear and consistent changes during the menstrual cycle. Many immune mediators were lower in the luteal phase, including chemokines, antibodies, matrix metalloproteinases, and several interleukins. Only interleukin-1α and beta-defensins were higher in the luteal phase. These cyclical differences may have consequences for immunity, susceptibility to infection, and fertility. Our study emphasizes the need to control for the effect of the menstrual cycle on immune mediators in future studies.

Progesterone and its receptor signaling in cervical remodeling: Mechanisms of physiological actions and therapeutic implications

The remodeling of the cervix from a closed rigid structure to one that can open sufficiently for passage of a term infant is achieved by a complex series of molecular events that in large part are regulated by the steroid hormones progesterone and estrogen. Among hormonal influences, progesterone exerts a dominant role for most of pregnancy to initiate a loss of tissue strength yet maintain competence in a phase termed softening. Equally important are the molecular events that abrogate progesterone function in late pregnancy to allow a loss of tissue competence and strength during cervical ripening and dilation. In this review, we focus on current understanding by which progesterone receptor signaling for the majority of pregnancy followed by a loss/shift in progesterone receptor action at the end of pregnancy, collectively ensure cervical remodeling as necessary for successful parturition.

Defensins: defenders of human reproductive health

BACKGROUND

Reproductive tract infection is an important factor leading to male and female infertility. Among female infertility factors, microbial and viral infections are the main factors affecting female reproductive health and causing tubal infertility, ectopic tubal pregnancy and premature delivery. Among male infertility factors, 13-15% of male infertility is related to infection. Defensins are cationic antibacterial and antiviral peptides, classified into α-defensins, β-defensins and θ-defensins. Humans only have α-defensins and β-defensins. Apart from their direct antimicrobial functions, defensins have an immunomodulatory function and are involved in many physiological processes. Studies have shown that defensins are widely distributed in the female reproductive tract (FRT) and male reproductive tract (MRT), playing a dual role of host defence and fertility protection. However, to our knowledge, the distribution, regulation and function of defensins in the reproductive tract and their relation to reproduction have not been reviewed.

OBJECTIVE AND RATIONALE

This review summarizes the expression, distribution and regulation of defensins in the reproductive tracts to reveal the updated research on the dual role of defensins in host defence and the protection of fertility.

SEARCH METHODS

A systematic search was conducted in PubMed using the related keywords through April 2022. Related data from original researches and reviews were integrated to comprehensively review the current findings and understanding of defensins in the human reproductive system. Meanwhile, female and male transcriptome data in the GEO database were screened to analyze defensins in the human reproductive tracts.

OUTCOMES

Two transcriptome databases from the GEO database (GSE7307 and GSE150852) combined with existing researches reveal the expression levels and role of the defensins in the reproductive tracts. In the FRT, a high expression level of α-defensin is found, and the expression levels of defensins in the vulva and vagina are higher than those in other organs. The expression of defensins in the endometrium varies with menstrual cycle stages and with microbial invasion. Defensins also participate in the local immune response to regulate the risk of spontaneous preterm birth. In the MRT, a high expression level of β-defensins is also found. It is mainly highly expressed in the epididymal caput and corpus, indicating that defensins play an important role in sperm maturation. The expression of defensins in the MRT varies with androgen levels, age and the status of microbial invasion. They protect the male reproductive system from bacterial infections by neutralizing lipopolysaccharide and downregulating pro-inflammatory cytokines. In addition, animal and clinical studies have shown that defensins play an important role in sperm maturation, motility and fertilization.

WIDER IMPLICATIONS

As a broad-spectrum antimicrobial peptide without drug resistance, defensin has great potential for developing new natural antimicrobial treatments for reproductive tract infections. However, increasing evidence has shown that defensins can not only inhibit microbial invasion but can also promote the invasion and adhesion of some microorganisms in certain biological environments, such as human immunodeficiency virus. Therefore, the safety of defensins as reproductive tract anti-infective drugs needs more in-depth research. In addition, the modulatory role of defensins in fertility requires more in-depth research since the current conclusions are based on small-size samples. At present, scientists have made many attempts at the clinical transformation of defensins. However, defensins have problems such as poor stability, low bioavailability and difficulties in their synthesis. Therefore, the production of safe, effective and low-cost drugs remains a challenge.

HIV Pathogenesis in the Human Female Reproductive Tract

PURPOSE OF REVIEW

Women remain disproportionately affected by the HIV/AIDS pandemic. The primary mechanism for HIV acquisition in women is sexual transmission, yet the immunobiological factors that contribute to HIV susceptibility remain poorly characterized. Here, we review current knowledge on HIV pathogenesis in women, focusing on infection and immune responses in the female reproductive tract (FRT).

RECENT FINDINGS

We describe recent findings on innate immune protection and HIV target cell distribution in the FRT. We also review multiple factors that modify susceptibility to infection, including sex hormones, microbiome, trauma, and how HIV risk changes during women's life cycle. Finally, we review current strategies for HIV prevention and identify barriers for research in HIV infection and pathogenesis in women. A complex network of interrelated biological and sociocultural factors contributes to HIV risk in women and impairs prevention and cure strategies. Understanding how HIV establishes infection in the FRT can provide clues to develop novel interventions to prevent HIV acquisition in women.

Human β-defensin-3 participates in intra-amniotic host defense in women with labor at term, spontaneous preterm labor and intact membranes, and preterm prelabor rupture of membranes

Objective: Human β-defensin-3 (HBD-3) has a broad spectrum of antimicrobial activity, and activity and, therefore, plays a central role in host defense mechanisms against infection. Herein, we determined whether HBD-3 was a physiological constituent of amniotic fluid during midtrimester and at term and whether the concentration of this defensin was increased in amniotic fluid of women with spontaneous preterm labor and intact membranes and those with preterm prelabor rupture of membranes (pPROM) with intra-amniotic inflammation or intra-amniotic infection.Methods: Amniotic fluid was collected from 219 women in the following groups: (1) midtrimester who delivered at term (n = 35); (2) with or without spontaneous labor at term (n = 50); (3) spontaneous preterm labor with intact membranes who delivered at term (n = 29); (4) spontaneous preterm labor with intact membranes who delivered preterm with or without intra-amniotic inflammation or intra-amniotic infection (n = 69); and (5) pPROM with or without intra-amniotic infection (n = 36). Amniotic fluid HBD-3 concentrations were determined using a sensitive and specific ELISA kit.Results: (1) HBD-3 is a physiological constituent of amniotic fluid; (2) the amniotic fluid concentration of HBD-3 did not change with gestational age (midtrimester versus term not in labor); (3) amniotic fluid concentrations of HBD-3 were higher in women with spontaneous labor at term than in those without labor; (4) in the absence of intra-amniotic inflammation, amniotic fluid concentrations of HBD-3 were similar between women with spontaneous preterm labor who delivered preterm and those who delivered at term; (5) among patients with spontaneous preterm labor who delivered preterm, amniotic fluid concentrations of HBD-3 were greater in women with intra-amniotic infection than in those without this clinical condition; (6) among patients with spontaneous preterm labor, amniotic fluid concentrations of HBD-3 were higher in women with intra-amniotic inflammation or intra-amniotic infection who delivered preterm than in those without these clinical conditions who delivered at term; and (7) women with pPROM and intra-amniotic infection had higher median amniotic fluid concentrations of HBD-3 than those without this clinical condition.Conclusion: Human β-defensin-3 is a physiological constituent of amniotic fluid and increases during the process of labor at term. Amniotic fluid concentrations of HBD-3 were increased in women with spontaneous preterm labor with intact membranes or pPROM with intra-amniotic inflammation or intra-amniotic infection, indicating that this defensin participates in the host defense mechanisms in the amniotic cavity against microorganisms or danger signals. These findings provide insight into the soluble host defense mechanisms against intra-amniotic inflammation and intra-amniotic infection.

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

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.

The Pre-clinical Toolbox of Pharmacokinetics and Pharmacodynamics: in vitro and ex vivo Models

Prevention strategies against sexual transmission of human immunodeficiency virus (HIV) are essential to curb the rate of new infections. In the absence of a correlate of protection against HIV infection, pre-clinical evaluation is fundamental to facilitate and accelerate prioritization of prevention candidates and their formulations in a rapidly evolving clinical landscape. Characterization of pharmacokinetic (PK) and pharmacodynamic (PD) properties for candidate inhibitors is the main objective of pre-clinical evaluation. in vitro and ex vivo systems for pharmacological assessment allow experimental flexibility and adaptability at a relatively low cost without raising as significant ethical concerns as in vivo models. Applications and limitations of pre-clinical PK/PD models and future alternatives are reviewed in the context of HIV prevention.

The estrogen-macrophage interplay in the homeostasis of the female reproductive tract

BACKGROUND

Estrogens are known to orchestrate reproductive events and to regulate the immune system during infections and following tissue damage. Recent findings suggest that, in the absence of any danger signal, estrogens trigger the physiological expansion and functional specialization of macrophages, which are immune cells that populate the female reproductive tract (FRT) and are increasingly being recognized to participate in tissue homeostasis beyond their immune activity against infections. Although estrogens are the only female gonadal hormones that directly target macrophages, a comprehensive view of this endocrine-immune communication and its involvement in the FRT is still missing.

OBJECTIVE AND RATIONALE

Recent accomplishments encourage a revision of the literature on the ability of macrophages to respond to estrogens and induce tissue-specific functions required for reproductive events, with the aim to envision macrophages as key players in FRT homeostasis and mediators of the regenerative and trophic actions of estrogens.

SEARCH METHODS

We conducted a systematic search using PubMed and Ovid for human, animal (rodents) and cellular studies published until 2018 on estrogen action in macrophages and the activity of these cells in the FRT.

OUTCOMES

Our search identified the remarkable ability of macrophages to activate biochemical processes in response to estrogens in cell culture experiments. The distribution at specific locations, interaction with selected cells and acquisition of distinct phenotypes of macrophages in the FRT, as well as the cyclic renewal of these properties at each ovarian cycle, demonstrate the involvement of these cells in the homeostasis of reproductive events. Moreover, current evidence suggests an association between estrogen-macrophage signaling and the generation of a tolerant and regenerative environment in the FRT, although a causative link is still missing.

WIDER IMPLICATIONS

Dysregulation of the functions and estrogen responsiveness of FRT macrophages may be involved in infertility and estrogen- and macrophage-dependent gynecological diseases, such as ovarian cancer and endometriosis. Thus, more research is needed on the physiology and pharmacological control of this endocrine-immune interplay.

Highly Human Immunodeficiency Virus-Exposed Seronegative Men Have Lower Mucosal Innate Immune Reactivity

Risk of HIV acquisition varies, and some individuals are highly HIV-1-exposed, yet, persistently seronegative (HESN). The immunologic mechanisms contributing to this phenomenon are an area of intense interest. As immune activation and inflammation facilitate disease progression in HIV-1-infected persons and gastrointestinal-associated lymphoid tissue is a highly susceptible site for transmission, we hypothesized that reduced gut mucosal immune reactivity may contribute to reduced HIV-1 susceptibility in HESN men with a history of numerous rectal sexual exposures. To test this, we used ex vivo mucosal explants from freshly acquired colorectal biopsies from healthy control and HESN subjects who were stimulated with specific innate immune ligands and inactivated whole pathogens. Immune reactivity was then assessed via cytokine arrays and proteomic analysis. Mucosal immune cell compositions were quantified via immunohistochemistry. We found that explants from HESN subjects produced less proinflammatory cytokines compared with controls following innate immune stimulation; while noninflammatory cytokines were similar between groups. Proteomic analysis identified several immune response proteins to be differentially expressed between HIV-1-stimulated HESN and control explants. Immunohistochemical examination of colorectal mucosa showed similar amounts of T cells, macrophages, and dendritic cells between groups. The results of this pilot study suggest that mucosal innate immune reactivity is dampened in HESN versus control groups, despite presence of similar densities of immune cells in the colorectal mucosa. This observed modulation of the rectal mucosal immune response may contribute to lower risk of mucosal HIV-1 transmission in these individuals.

Comparison of Mucosal Markers of Human Immunodeficiency Virus Susceptibility in Healthy Premenopausal Versus Postmenopausal Women

The objective of this study was to characterize cervicovaginal (CV) mucosal factors modulating susceptibility to human immunodeficiency virus (HIV) acquisition in healthy premenopausal (PRE) and postmenopausal (POST) women before and after treatment with estradiol (E2). We compared CV mucosal epithelial histology and immune cells, vaginal microbiota, antimicrobial activity of and soluble mucosal protein concentrations in the CV fluid lavage (CVL), and p24 antigen production after ex vivo infection of ectocervical tissues with HIV-1_BaL among PRE women (n = 20) in the follicular and luteal phases of the menstrual cycle and POST women (n = 17) at baseline and after ∼1 month of treatment with 0.01% vaginal E2 cream. Compared to PRE women, we measured higher levels of p24 antigen after ex vivo infection in tissues from POST women. POST women had a significantly thinner vaginal epithelium with decreased tight junction proteins and a higher density of mucosal immune T cells and lower levels of CD1a antigen-presenting cells, antimicrobial peptides, and inflammatory cytokines in the CVL (p values <.05). POST women had higher vaginal pH and lower vaginal Lactobacilli (p values <.05) than PRE women. After vaginal E2 therapy, CV endpoints and ex vivo HIV replication in POST tissues were similar to those observed in PRE tissues. The CV mucosa in POST women is thinned and compromised, with increased HIV-target immune cells and decreased antimicrobial factors, being more susceptible to HIV infection. After POST women receive topical E2 treatment, mucosal endpoints are similar to PRE levels.