Innate and adaptive immunity at mucosal surfaces of the female reproductive tract: stratification and integration of immune protection against the transmission of sexually transmitted infections

Association between heavy metal exposure and bacterial vaginosis: A cross-sectional study

Bacterial vaginosis (BV) is a prevalent cause of vaginal symptoms in women of reproductive age. With the widespread of heavy metal pollutants and their harmful function on women's immune and hormonal systems, it is necessary to explore the association between heavy metal exposure and BV. This study investigates the potential relationship between serum heavy metals and bacterial vaginosis in a cohort of American women. The present study employed a cross-sectional analysis of 2,493 women participating in the 2001-2004 National Health and Nutrition Examination Survey (NHANES). Multivariable logistic regression models were utilized in the study to assess the correlation between these variables. A stratified analysis was performed to investigate the relationship among different population groups further, and smooth curve fittings were conducted to intuitively evaluate the correlation. According to the current cross-sectional study results, a significant correlation was identified between the high levels of lead and cadmium in the serum and the likelihood of developing bacterial vaginosis. We found that serum lead (OR = 1.35, 95% CI: 1.06-1.72, p = 0.016) and serum cadmium (OR = 1.41, 95% CI: 1.01-1.98, p = 0.047) increased the risk of bacterial vaginosis by 35% and 41%, respectively, in the highest level group in comparison to the lowest level group in the fully adjusted model. Furthermore, the research discovered no statistically significant association between the levels of total mercury in the serum and a heightened susceptibility to bacterial vaginosis (OR = 0.96, 95% CI: 0.75-1.23, p = 0.763). Results of our study indicated an inverse association between serum heavy metals and bacterial vaginosis risk, including lead and cadmium. Reducing exposure to heavy metals could be vital to preventing and managing bacterial vaginosis.

Study repair function of mucin-2 on the tight junction protein of uterine epithelial cells under bacterial endotoxins

To analysis repair function of mucin-2(MUC2) and glycoprotein particles on the tight junction protein of uterus under bacterial endotoxins. In this experiment, we showed that the thicker mucus layer of the uterus is used to prevent the translocation of endotoxin at 21d postdelivery. When endotoxin acts on the uterus to thin its mucous layer, the cells in the lamina propria of the uterus secrete a large number of glycoprotein particles at 27d postdelivery. Due to a significantly decrease in the expression of glycosyltransferase, the glycoprotein particles are incompletely glycosylation MUC2, which can interact with the cell membrane and are released in large quantities in the form of exocytosis. These glycoprotein particles can significantly repair tight junction proteins in the inter-cellular space and significantly increase the expression of Claudin-1, JAM (Junction adhesion molecule-A), E-cadherin, ZO-1(Zonula occludens-1) and desmosome proteins after endotoxin treatment. The results of the present study show that endotoxins can thin the uterine mucus layer and accelerate the release of incompletely glycosylated MUC2 from lamina propria cells. In inter-cellular spaces, MUC2 can increase its expression levels and distribution area to repair the tight junction structure of cells with larger gaps. Further strengthening of the barrier prevents endotoxin translocation by repairing the tight junction structure of uterine epithelial cells.

Effects of vaginal microbiota on human papillomavirus infection and its related diseases

With the knowledge of female reproductive tract microbiota gradually increasing, the connection between vaginal microbiota (VMB) and its related diseases is increasingly highlighted. Manifestation of VMB keeps changing with various dominated bacteria, which can affect the immune response of mucosal barrier and the entrance of pathogens. Human papillomavirus (HPV), as an oncogenic virus, is closely related to viral-associated cancer, such as cervical cancer. According to HPV infection status, VMB can transform into different types, and result in accelerating or restraining the progression of diseases, which have exposed the inner link between VMB and HPV. Therefore, probiotics therapy promises to be a new complementary therapy to rebuild a healthy VMB for patients, but there's still a long way to go before its ready for the clinic. This review focuses on composition, immune response, and application of VMB in HPV and its associated diseases and aims to provide the new ideas and directions for the research on VMB.

Effects of Ellagic Acid on Vaginal Innate Immune Mediators and HPV16 Infection In Vitro

Ellagic acid (EA) is a phenolic phytochemical found in many plants and their fruits. Vaginal epithelial cells are the first line of defense against pathogen invasion in the female reproductive tract and express antimicrobial peptides, including hBD2 and SLPI. This study investigated the in vitro effects of EA (1) on vaginal innate immunity using human vaginal epithelial cells, and (2) on HPV16 pseudovirus infection. Vaginal cells were cultured in the presence or absence of EA, and the expression of hBD2 and SLPI was determined at both transcriptional and translational levels. In addition, secretion of various cytokines and chemokines was measured. Cytotoxicity of EA was determined by CellTiter-blue and MTT assays. To investigate the ability of EA to inhibit HPV16 infection, EA was used to treat HEK-293FT cells in pre-attachment and adsorption steps. We found significant increases in both hBD2 mRNA (mean 2.9-fold at 12.5 µM EA, p < 0.001) and protein (mean 7.1-fold at 12.5 µM EA, p = 0.002) in response to EA. SLPI mRNA also increased significantly (mean 1.4-fold at 25 µM EA, p = 0.01), but SLPI protein did not. Secretion of IL-2 but not of other cytokines/chemokines was induced by EA in a dose-dependent manner. EA was not cytotoxic. At the pre-attachment step, EA at CC20 and CC50 showed a slight trend towards inhibiting HPV16 pseudovirus, but this was not significant. In summary, vaginal epithelial cells can respond to EA by producing innate immune factors, and at tested concentrations, EA is not cytotoxic. Thus, plant-derived EA could be useful as an immunomodulatory agent to improve vaginal health.

Role of the epithelium in human papillomavirus and human immunodeficiency virus infections in the female genital tract

Background

Two-thirds of people living with human immunodeficiency virus type 1 (HIV-1) infection reside in Sub-Saharan Africa, where there are the highest prevalence and incidence rates of human papillomavirus (HPV) infection. Both infections are sexually transmitted and enter the body via the epithelium. This review describes the extent of involvement of the epithelium in each infection in the female genital tract.

Methods

A narrative review was conducted on the role of the epithelium in HPV and HIV-1 infections.

Results

An intact epithelial barrier is the predominant form of protection against viral entry and infection, including from HIV-1 and HPV. HPV is an intraepithelial pathogen, and thus, its growth and amplification, which are dependent on squamous cell differentiation, occur in the epithelium. It gains entry to the basal cells of the stratified squamous epithelium via micro-abrasions or other epithelial injuries that expose the basement membrane. HIV-1, conversely, passes through the epithelium to infect subepithelial tissues. Following deposition of the HIV-1-containing inoculum into the lumen, the virus enters the mucosa through breaks in the epithelial barrier within hours of infection. Further, HIV-1 penetrates the epithelium via various mechanisms, including paracellular passage or across epithelial cells through transcytosis. The capture of the virus from the mucosal surface by intraepithelial and/or subepithelial target cells has also been documented.

Conclusions

Epithelial disruption is the major pathogenetic pathway in HIV-1 and HPV infections. Therefore, biochemical compounds that strengthen the epithelial barrier must be prioritized to prevent these infections.

Intra-horn insemination in the alpaca Vicugna pacos: Copulatory wounding and deep sperm deposition

Alpacas (Vicugna pacos) are reported to be the rare mammal in which the penis enters the uterus in mating. To date, however, only circumstantial evidence supports this assertion. Using female alpacas culled for meat, we determined that the alpaca penis penetrates to the very tips of the uterine horns, abrading the tract and breaking fine blood vessels. All female alpacas sacrificed one hour or 24 hours after mating showed conspicuous bleeding in the epithelium of some region of their reproductive tract, including the hymen, cervix and the tips of each uterine horn, but typically not in the vagina. Unmated females showed no evidence of conspicuous bleeding. Histological examination of mated females revealed widespread abrasion of the cervical and endometrial epithelium, injuries absent in unmated females. Within one hour of mating, sperm were already present in the oviduct. The male alpaca's cartilaginous penis tip with a hardened urethral process is likely responsible for the copulatory abrasion. The entire female reproductive tract interacts with the penis, functioning like a vagina. Alpacas are induced ovulators, and wounding may hasten delivery of the seminal ovulation-inducing factor beta-NGF into the female's blood stream. There is no evidence of sexual conflict in copulation in alpaca, and thus wounding may also be one of a variety of mechanisms devised by mammals to induce a beneficial, short-term inflammatory response that stimulates blastocyst implantation, the uterine remodeling associated with placental development, and thus the success of early pregnancy.

Interferon-epsilon is a novel regulator of NK cell responses in the uterus

The uterus is a unique mucosal site where immune responses are balanced to be permissive of a fetus, yet protective against infections. Regulation of natural killer (NK) cell responses in the uterus during infection is critical, yet no studies have identified uterine-specific factors that control NK cell responses in this immune-privileged site. We show that the constitutive expression of IFNε in the uterus plays a crucial role in promoting the accumulation, activation, and IFNγ production of NK cells in uterine tissue during Chlamydia infection. Uterine epithelial IFNε primes NK cell responses indirectly by increasing IL-15 production by local immune cells and directly by promoting the accumulation of a pre-pro-like NK cell progenitor population and activation of NK cells in the uterus. These findings demonstrate the unique features of this uterine-specific type I IFN and the mechanisms that underpin its major role in orchestrating innate immune cell protection against uterine infection.

Enhanced expression of miR-204 attenuates LPS stimulated inflammatory injury through inhibiting the Wnt/β-catenin pathway via targeting CCND2

One of the most common bacterial diseases of the reproductive system in dairy cows is endometritis, which will cause huge economic loss. Here, we investigate the mechanisms of miR-204 on LPS-stimulated endometritis in vitro and in vivo. Experiments displayed that the expression of miR-204 was lower in bovine uterine tissue samples or bovine endometrial epithelial cell line (BEND) that stimulated by LPS. Compared with the negative group, miR-204 treatment significantly suppressed the production of proinflammatory factors and the Wnt/β-catenin pathway activation. Additionally, the result of the dual luciferase assay showed that miR-204 targeted cyclin D2. More importantly, up-regulation of miR-204 alleviated LPS induced uterine injury was confirmed in vivo studies. Molecular experiments indicated that the expression level of tight junctional proteins Claudin3 and cadherin1 were both enchanced by miR-204 treatment. Accordingly, miR-204 may serve as a new measure to prevent and treat endometritis caused by LPS.

Association between serum carotenoids and bacterial vaginosis infection among American women

BACKGROUND

Bacterial vaginosis (BV) is a widely occurring vaginal inflammation in women of childbearing age caused by dysbiosis of the vaginal flora. Few studies have investigated the effect of serum carotenoids on the development and pathogenesis of BV. This study thus aimed to explore the correlation between serum carotenoids and BV in American women.

METHOD

The analysis included 1252 participants with BV from the National Health and Nutrition Examination Survey (NHANES) between 2001 and 2004. Multiple logistic regression was conducted to explore the correlation between BV and serum carotenoids, while smooth curve fitting was utilized to examine potential nonlinear correlations. Furthermore, stratified subgroup analyses and sensitivity analyses were conducted. ORs reflected the correlation between BV and serum carotenoids.

RESULT

Results of multiple logistic regression indicated that total serum carotenoids and BV had an inverse correlation. In the fully adjusted model II, the quartile with the highest levels of α-carotene and β-cryptoxanthin had a substantially lower incidence of BV. Smooth curve fitting revealed a significant negative linear correlation between serum carotenoids and the incidence of BV. The negative correlation between serum carotenoids and BV was relatively stable in stratified analyses. Moreover, in sensitivity analyses, the association between serum carotenoids and BV persisted, and β-carotene became significantly negatively correlated with BV.

CONCLUSION

This study found an inverse correlation between serum carotenoids and the prevalence of BV.

PEDV promotes the differentiation of CD4+T cells towards Th1, Tfh, and Treg cells via CD103+DCs

Porcine epidemic diarrhea virus (PEDV) can infect all ages of pigs, particularly newborn piglets with a mortality almost reaching to 80-100%, causing significant economic losses to the global pig industry. The mucosal immune response is crucial for PEDV prevention, in which specific dendritic cells (DCs) and differentiated T cells play vital roles. In this study, CD103+DCs were differentiated successfully with retinoic acid (RA) treatment in vitro. PEDV could not replicate efficiently in differentiated CD103+DCs but could promote maturation of CD103+DCs by up-regulating the expression of SLA-DR, CD1a, CD86, and cytokines of IL-1β and IL-10. In addition, PEDV-infected CD103+DCs and CD4+T cells were co-cultured, and the results showed that the differentiation of CD4+T cells toward Th1, Tfh, and Treg, but not Th2. These results demonstrate that PEDV-infected CD103+DCs could promote the differentiation of CD4+T cells, which provided the basis for further study of mucosal response induced by PEDV via CD103+DCs.

Comparing the therapeutic potentials of Lactobacillus johnsonii vs. Lactobacillus acidophilus against vulvovaginal candidiasis in female rats: an in vivo study

Background

Vulvovaginal candidiasis (VVC) is a highly prevalent illness affecting women globally. Lactobacilli, which make up the majority of healthy vaginal microbiota (VMB), serve as a powerful barrier against infections. Probiotic therapy has been recommended for the treatment or prevention of VVC.

Aim of work

To compare the in vivo therapeutic effects of Lactobacillus johnsonii (B-2178) vs. Lactobacillus acidophilus (LA-5^®) on VVC in a rat model, particularly highlighting the immune response of the host vaginal epithelium.

Methods

In total, 30 female Sprague-Dawley rats were divided into 5 groups; Group 1: no intervention, Group 2: ovariectomy group, while animals in Groups 3-5 were subjected to ovariectomy and an intravaginal inoculation of Candida albicans (C. albicans) to establish VVC. The animals in Groups 4 and 5 received intravaginal lactobacilli treatment with L. acidophilus (LA-5^®) and L. johnsonii (B-2178) strains, respectively, for 7 days. C. albicans load was measured in a vaginal lavage 1, 3, and 7 days after the stoppage of the treatment. Histological, morphometric, and immunohistochemical studies of the vaginal tissues were done. IFN-γ, IL-4, and IL-17 were measured in the vaginal tissue.

Results

Both L. johnsonii and L. acidophilus significantly reduced C. albicans vaginal load (250 ± 77.46 and 133.33 ± 40.82 CFU/mL) compared to the count before treatment in both groups (4,850 ± 1419.51 and 4966.67 ± 852.45 CFU/mL) even after 7 days of stoppage of lactobacilli treatment. A statistically significant reduction of the pro-inflammatory cytokines IL-17 and IFN-γ was reported in both treated groups compared to the infected untreated group. L. johnsonii has a significant effect on the reduction of hyphae formation of C. albicans as well as the nuclear factor kappa B (NF-κB) immunostaining density of vaginal tissue compared to L. acidophilus. Moreover, treatment with L. johnsonii significantly minimized the epithelium damage triggered by C. albicans infection and restored normal vaginal architecture as evidenced by the histologic and morphometric studies when compared to L. acidophilus.

Conclusion

Through maintaining an immune tolerant state in the vaginal epithelium and ameliorating the undesirable uncontrolled inflammatory response in the vaginal tissue, L. johnsonii (B-2178) has the potential to be utilized alone or in combination with other lactobacilli species in probiotic clinical trials to treat or prevent VVC.

The Role of Hydrogen-Peroxide (H2O2) Produced by Vaginal Microbiota in Female Reproductive Health

Female reproductive health is strongly associated with healthy vaginal microbiota, which is thought to be ensured by the dominance of certain Lactobacillus species. Lactobacilli control the vaginal microenvironment through several factors and mechanisms. One of them is their ability to produce hydrogen peroxide (H₂O₂). The role of Lactobacillus-derived H₂O₂ in the vaginal microbial community has been intensively investigated in several studies with many designs. However, results and data are controversial and challenging to interpret in vivo. Defining the underlying mechanisms responsible for a physiological vaginal ecosystem is crucial since it could directly affect probiotic treatment attempts. This review aims to summarize current knowledge on the topic, focusing on probiotic treatment possibilities.

Systemic, Mucosal Immune Activation and Psycho-Sexual Health in ART-Suppressed Women Living with HIV: Evaluating Biomarkers and Environmental Stimuli

Gender medicine is now an approach that can no longer be neglected and must be considered in scientific research. We investigated the systemic and mucosal immune response in a population of women living with HIV (WLWH) who were receiving successful ART and the sexual and psychological repercussions of HIV infection on the women's health. As control group, healthy women (HW) matched for age and sex distribution, without any therapy, were included. In summary, our study highlighted the persistence of immune-inflammatory activation in our population, despite virological suppression and a normal CD4 cell count. We found a hyperactivation of the systemic monocyte and an increase in inflammatory cytokine concentrations at the systemic level. The analysis carried out showed a significantly higher risk of HPV coinfection in WLWH compared to HW. Furthermore, our data revealed that WLWH have a profile compatible with sexual dysfunction and generalized anxiety disorders. Our study underlines that patients living with HIV should be evaluated by multidisciplinary teams. These findings also support the idea that more and different immunological markers, in addition to those already used in clinical practice, are needed. Further studies should be carried out to clarify which of these could represent future therapy targets.

Immune activation of vaginal human Langerhans cells increases susceptibility to HIV-1 infection

Vaginal inflammation increases the risk for sexual HIV-1 transmission but underlying mechanisms remain unclear. In this study we assessed the impact of immune activation on HIV-1 susceptibility of primary human vaginal Langerhans cells (LCs). Vaginal LCs isolated from human vaginal tissue expressed a broad range of TLRs and became activated after exposure to both viral and bacterial TLR ligands. HIV-1 replication was restricted in immature vaginal LCs as only low levels of infection could be detected. Notably, activation of immature vaginal LCs by bacterial TLR ligands increased HIV-1 infection, whereas viral TLR ligands were unable to induce HIV-1 replication in vaginal LCs. Furthermore, mature vaginal LCs transmitted HIV-1 to CD4 T cells. This study emphasizes the role for vaginal LCs in protection against mucosal HIV-1 infection, which is abrogated upon activation. Moreover, our data suggest that bacterial STIs can increase the risk of HIV-1 acquisition in women.

The initial interplay between HIV and mucosal innate immunity

Human Immunodeficiency Virus (HIV) is still one of the major global health issues, and despite significant efforts that have been put into studying the pathogenesis of HIV infection, several aspects need to be clarified, including how innate immunity acts in different anatomical compartments. Given the nature of HIV as a sexually transmitted disease, one of the aspects that demands particular attention is the mucosal innate immune response. Given this scenario, we focused our attention on the interplay between HIV and mucosal innate response: the different mucosae act as a physical barrier, whose integrity can be compromised by the infection, and the virus-cell interaction induces the innate immune response. In addition, we explored the role of the mucosal microbiota in facilitating or preventing HIV infection and highlighted how its changes could influence the development of several opportunistic infections. Although recent progress, a proper characterization of mucosal innate immune response and microbiota is still missing, and further studies are needed to understand how they can be helpful for the formulation of an effective vaccine.

Morphological Characteristics of Genital Organ-Associated Lymphoid Tissue in the Vaginal Vestibule of Goats and Pigs

Mucosa-associated lymphoid tissue (MALT) is a specialized form of peripheral lymphoid tissue (LT), which is found on mucosal surfaces exposed to the environment. However, morphological data of these tissues in farm animals are scarce. This study investigated the gross anatomical and histological features of genital organ-associated lymphoid tissues (GOALTs) in the vaginal vestibule (VV) of healthy, non-pregnant, adult goats and pigs. Their VVs were composed of stratified squamous, non-keratinized epithelium, and various-sized dark-blue hematoxylin-positive spots were observed in whole-mount specimens, which were diffusely distributed throughout the mucosal surfaces. These spots were histologically identified as LTs and consisted of lymphatic nodules (LNs) or diffuse lymphoid tissue (DLTs). Both LNs and DLTs contained B cells, T cells, macrophages, dendritic cells, plasma cells, and high endothelial venules. Only the numbers of B cells were significantly higher in both the LNs and DLTs of pigs compared to goats. Furthermore, the surface of the VV epithelium covering the LTs was partially disrupted with a large intercellular space containing abundant connective tissue fibers with numerous lymphocytes. In conclusion, GOALTs in the VV appear to be common local immunological barriers in both examined animals. This knowledge is crucial for understanding the structures and disorders of female reproductive organs in farm animals.

Antifungal Activity of Plant Secondary Metabolites on Candida albicans: An Updated Review

Fungal infections have been increasing continuously worldwide, especially in immunocompromised individuals. Fungi, regarded as eukaryotic pathogens, have many similarities to the host cells, which inhibit anti-fungal drug development progress. Various fungal model systems have been studied, and it was concluded that Candida spp. is the most common disease-causing fungus. Candida species are well known to cause infections not only in our mouth, skin, and vagina, but they are also a frequent cause of life-threatening hospital bloodstream infections. The morphological and developmental pathways of Candida have been studied extensively, providing insight into the fungus development. Candida albicans is known to be the most pathogenic species responsible for a variety of infections in humans. Conventional anti-fungal drugs, mainly azoles drugs available in the market, have been used for years developing resistance in C. albicans. Hence, the production of new anti-fungal drugs, which require detailed molecular knowledge of fungal pathogenesis, needs to be encouraged. Therefore, this review targets the new approach of "Green Medicines" or the phytochemicals and their secondary metabolites as a source of novel anti-fungal agents to overcome the drug resistance of C. albicans, their mechanism of action, and their combined effects with the available anti-fungal drugs.

Interactions between microbiota and cervical epithelial, immune, and mucus barrier

The female reproductive tract harbours hundreds of bacterial species and produces numerous metabolites. The uterine cervix is located between the upper and lower parts of the female genital tract. It allows sperm and birth passage and hinders the upward movement of microorganisms into a relatively sterile uterus. It is also the predicted site for sexually transmitted infection (STI), such as Chlamydia, human papilloma virus (HPV), and human immunodeficiency virus (HIV). The healthy cervicovaginal microbiota maintains cervical epithelial barrier integrity and modulates the mucosal immune system. Perturbations of the microbiota composition accompany changes in microbial metabolites that induce local inflammation, damage the cervical epithelial and immune barrier, and increase susceptibility to STI infection and relative disease progression. This review examined the intimate interactions between the cervicovaginal microbiota, relative metabolites, and the cervical epithelial-, immune-, and mucus barrier, and the potent effect of the host-microbiota interaction on specific STI infection. An improved understanding of cervicovaginal microbiota regulation on cervical microenvironment homeostasis might promote advances in diagnostic and therapeutic approaches for various STI diseases.

Candida albicans can foster gut dysbiosis and systemic inflammation during HIV infection

Candida albicans (C. albicans) is a ubiquitous fungal commensal component of the human microbiota, and under certain circumstances, such as during an immunocompromised state, it may initiate different types of infection. Moreover, C. albicans continuously and reciprocally interacts with the host immune system as well as with other elements of the gut microbiota, thus contributing significantly to both gut homeostasis and host immunity. People living with HIV (PLWH), including those receiving antiretroviral therapy, are characterized by a depletion of CD4 + T-cells and dysbiosis in their gut. C. albicans colonization is frequent in PLWH, causing both a high prevalence and high morbidity. Gut barrier damage and elevated levels of microbial translocation are also fairly common in this population. Herein, we take a closer look at the reciprocity among C. albicans, gut microbiota, HIV, and the host immune system, thus throwing some light on this complex interplay.

Role of the human vaginal microbiota in the regulation of inflammation and sexually transmitted infection acquisition: Contribution of the non-human primate model to a better understanding?

The human vaginal microbiota has a central role in the regulation of the female reproductive tract (FRT) inflammation. Indeed, on one hand an optimal environment leading to a protection against sexually transmitted infections (STI) is associated with a high proportion of Lactobacillus spp. (eubiosis). On the other hand, a more diverse microbiota with a high amount of non-Lactobacillus spp. (dysbiosis) is linked to a higher local inflammation and an increased STI susceptibility. The composition of the vaginal microbiota is influenced by numerous factors that may lead to a dysbiotic environment. In this review, we first discuss how the vaginal microbiota composition affects the local inflammation with a focus on the cytokine profiles, the immune cell recruitment/phenotype and a large part devoted on the interactions between the vaginal microbiota and the neutrophils. Secondly, we analyze the interplay between STI and the vaginal microbiota and describe several mechanisms of action of the vaginal microbiota. Finally, the input of the NHP model in research focusing on the FRT health including vaginal microbiota or STI acquisition/control and treatment is discussed.

Antiviral lectin Q-Griffithsin suppresses fungal infection in murine models of vaginal candidiasis

Resistance to antifungal agents in vulvovaginal candidiasis has resulted in increasing morbidity among women globally. It is therefore crucial that new antimycotic agents are developed to counter this rising challenge. Q-Griffithsin (Q-GRFT) is a red algal lectin, manufactured in Nicotiana benthamiana. Griffithsin has well characterized broad spectrum antiviral activity and has demonstrated potent in vitro activity against multiple strains of Candida, including C. albicans. We have been working to incorporate Q-GRFT into topical microbicide products to prevent HIV-1 and HSV-2 transmission. The goal of this study was to evaluate the efficacy of a prototype Q-GRFT dosage form in prophylactic and therapeutic murine models of vaginal candidiasis, through microbiologic, histopathologic, and immune studies. In a preventive model, in comparison with infected controls, Q-GRFT treatment resulted in a lower fungal burden but did not alter the number of vaginal neutrophils and monocytes. In a therapeutic model, Q-GRFT enhanced fungal clearance when compared with infected untreated controls. Finally, histopathology demonstrated lower vaginal colonization with C. albicans following Q-GRFT treatment. Our results demonstrate that Q-GRFT has significant preventive and therapeutic activity in vaginal candidiasis offering additional benefit as a topical microbicide for prevention of HIV-1 and HSV-2 transmission.

The Mucoadhesive Nanoparticle-Based Delivery System in the Development of Mucosal Vaccines

Mucosal tissue constitutes the largest interface between the body and the external environment, regulating the entry of pathogens, particles, and molecules. Mucosal immunization is the most effective way to trigger a protective mucosal immune response. However, the majority of the currently licensed vaccines are recommended to be administered by intramuscular injection, which has obvious shortcomings, such as high production costs, low patient compliance, and lack of mucosal immune response. Strategies for eliciting mucosal and systemic immune responses are being developed, including appropriate vaccine adjuvant, delivery system, and bacterial or viral vectors. Biodegradable mucoadhesive nanoparticles (NPs) are the most promising candidate for vaccine delivery systems due to their inherent immune adjuvant property and the ability to protect the antigen from degradation, sustain the release of loaded antigen, and increase the residence time of antigen at the administration site. The current review outlined the complex structure of mucosa, the mechanism of interaction between NPs and mucosa, factors affecting the mucoadhesion of NPs, and the application of the delivery system based on mucoadhesive NPs in the field of vaccines. Moreover, this review demonstrated that the biodegradable and mucoadhesive NP-based delivery system has the potential for mucosal administration of vaccines.

Cervicovaginal Complement Activation and Microbiota During Pregnancy and in Parturition

Background

Vaginal microbiome and the local innate immune defense, including the complement system, contribute to anti- and proinflammatory homeostasis during pregnancy and parturition. The relationship between commensal vaginal bacteria and complement activation during pregnancy and delivery is not known.

Objective

To study the association of the cervicovaginal microbiota composition to activation and regulation of the complement system during pregnancy and labor.

Study design

We recruited women during late pregnancy (weeks 41 + 5 to 42 + 0, n=48) and women in active labor (weeks 38 + 4 to 42 + 2, n=25). Mucosal swabs were taken from the external cervix and lateral fornix of the vagina. From the same sampling site, microbiota was analyzed with 16S RNA gene amplicon sequencing. A Western blot technique was used to detect complement C3, C4 and factor B activation and presence of complement inhibitors. For semiquantitative analysis, the bands of the electrophoresed proteins in gels were digitized on a flatbed photo scanner and staining intensities were analyzed using ImageJ/Fiji win-64 software. Patient data was collected from medical records and questionnaires.

Results

The vaginal microbiota was Lactobacillus-dominant in most of the samples (n=60), L. iners and L. crispatus being the dominant species. L. gasseri and L. jensenii were found to be more abundant during pregnancy than active labor. L. jensenii abundance correlated with C4 activation during pregnancy but not in labor. Gardnerella vaginalis was associated with C4 activation both during pregnancy and labor. The amount of L. gasseri correlated with factor B activation during pregnancy but not during labor. Atopobium vaginae was more abundant during pregnancy than labor and correlated with C4 activation during labor and with factor B activation during pregnancy. Activation of the alternative pathway factor B was significantly stronger during pregnancy compared to labor. During labor complement activation may be inhibited by the abundant presence of factor H and FHL1.

Conclusions

These results indicate that bacterial composition of the vaginal microbiota could have a role in the local activation and regulation of complement-mediated inflammation during pregnancy. At the time of parturition complement activation appears to be more strictly regulated than during pregnancy.

The roles and therapeutic applications of cytokines in endometrial cancer

Endometrial cancer (EC) is a common gynecological cancer globally and the most frequent gynecologic malignancy in industrialized countries. Patients are typically diagnosed when the disease is still restricted to the uterus. 5-year overall survival ranges from 70 % to 90 % in patients without metastatic disease; however, the metastatic form of the disease affects 16 % of EC patients, with a 5-year survival rate of 16.8 %. The immune system can detect abnormal cells as non-self in the early stages of carcinogenesis, producing the appropriate pro-inflammatory environment to eliminate cancer cells. In a second phase, cancer cells use various immune-editing systems to alter the profile of the immune response from pro to anti-inflammatory, resulting in immune escape. The directors of this immune switching mechanism are cytokines. Studies have reported the increased expression of several pro-and anti-inflammatory cytokines in EC tissues and cell lines, including Interleukin (IL)- 6, IL-8, IL-31, IL-33, IL-10, TGF-β, VEGF, and IL-1Ra. Immune cells producing these cytokines have also been reported to be present in EC tissues. Therefore, in this study, we aimed to show the possible mechanisms of the mentioned cytokines on EC progression, as well as the most current and prospective advancements in cytokine-based therapeutic applications.

Molecular Regulatory Mechanisms Drive Emergent Pathogenetic Properties of Neisseria gonorrhoeae

Neisseria gonorrhoeae is the causative agent of the sexually transmitted infection (STI) gonorrhea, with an estimated 87 million annual cases worldwide. N. gonorrhoeae predominantly colonizes the male and female genital tract (FGT). In the FGT, N. gonorrhoeae confronts fluctuating levels of nutrients and oxidative and non-oxidative antimicrobial defenses of the immune system, as well as the resident microbiome. One mechanism utilized by N. gonorrhoeae to adapt to this dynamic FGT niche is to modulate gene expression primarily through DNA-binding transcriptional regulators. Here, we describe the major N. gonorrhoeae transcriptional regulators, genes under their control, and how these regulatory processes lead to pathogenic properties of N. gonorrhoeae during natural infection. We also discuss the current knowledge of the structure, function, and diversity of the FGT microbiome and its influence on gonococcal survival and transcriptional responses orchestrated by its DNA-binding regulators. We conclude with recent multi-omics data and modeling tools and their application to FGT microbiome dynamics. Understanding the strategies utilized by N. gonorrhoeae to regulate gene expression and their impact on the emergent characteristics of this pathogen during infection has the potential to identify new effective strategies to both treat and prevent gonorrhea.

Heterologous prime-boost vaccination based on Polymorphic protein D protects against intravaginal Chlamydia trachomatis infection in mice

The control of the worldwide spread of sexually transmitted Chlamydia trachomatis (Ct) infection urgently demands the development of a preventive vaccine. In this work, we designed a vaccine based on a fragment of polymorphic protein D (FPmpD) that proved to be immunogenic enough to generate a robust systemic and mucosal IgG humoral immune response in two strains of mice. We used a heterologous prime-boost strategy, including simultaneous systemic and mucosal administration routes. The high titers of anti-PmpD antibodies elicited by this immunization scheme did not affect murine fertility. We tested the vaccine in a mouse model of Ct intravaginal infection. Anti-PmpD antibodies displayed potent neutralizing activity in vitro and protective effects in uterine tissues in vivo. Notably, the humoral immune response of PmpD-vaccinated mice was faster and stronger than the primary immune response of non-vaccinated mice when exposed to Ct. FPmpD-based vaccine effectively reduced Ct shedding into cervicovaginal fluids, bacterial burden at the genitourinary tract, and overall infectivity. Hence, the FPmpD-based vaccine might constitute an efficient tool to protect against Ct intravaginal infection and decrease the infection spreading.

Local Innate Markers and Vaginal Microbiota Composition Are Influenced by Hormonal Cycle Phases

Background

The female reproductive tract (FRT) mucosa is the first line of defense against sexually transmitted infection (STI). FRT environmental factors, including immune-cell composition and the vaginal microbiota, interact with each other to modulate susceptibility to STIs. Moreover, the menstrual cycle induces important modifications within the FRT mucosa. Cynomolgus macaques are used as a model for the pathogenesis and prophylaxis of STIs. In addition, their menstrual cycle and FRT morphology are similar to women. The cynomolgus macaque vaginal microbiota is highly diverse and similar to dysbiotic vaginal microbiota observed in women. However, the impact of the menstrual cycle on immune markers and the vaginal microbiota in female cynomolgus macaques is unknown. We conducted a longitudinal study covering three menstrual cycles in cynomolgus macaques. The evolution of the composition of the vaginal microbiota and inflammation (cytokine/chemokine profile and neutrophil phenotype) in the FRT and blood was determined throughout the menstrual cycle.

Results

Cervicovaginal cytokine/chemokine concentrations were affected by the menstrual cycle, with a peak of production during menstruation. We observed three main cervicovaginal neutrophil subpopulations: CD11bhigh CD101+ CD10+ CD32a+, CD11bhigh CD101+ CD10- CD32a+, and CD11blow CD101low CD10- CD32a-, of which the proportion varied during the menstrual cycle. During menstruation, there was an increase in the CD11bhigh CD101+ CD10+ CD32a+ subset of neutrophils, which expressed higher levels of CD62L. Various bacterial taxa in the vaginal microbiota showed differential abundance depending on the phase of the menstrual cycle. Compilation of the factors that vary according to hormonal phase showed the clustering of samples collected during menstruation, characterized by a high concentration of cytokines and an elevated abundance of the CD11bhigh CD101+ CD10+ CD32a+ CD62L+ neutrophil subpopulation.

Conclusions

We show a significant impact of menstruation on the local environment (cytokine production, neutrophil phenotype, and vaginal microbiota composition) in female cynomolgus macaques. Menstruation triggers increased production of cytokines, shift of the vaginal microbiota composition and the recruitment of mature/activated neutrophils from the blood to the FRT. These results support the need to monitor the menstrual cycle and a longitudinal sampling schedule for further studies in female animals and/or women focusing on the mucosal FRT environment.

Progesterone and Inflammatory Response in the Oviduct during Physiological and Pathological Conditions

Progesterone has been shown to be a potent suppressor of several inflammatory pathways. During pregnancy, progesterone levels increase, allowing for normal pregnancy establishment and maintenance. The dysregulation of progesterone, as well as inflammation, leads to poor pregnancy outcomes. However, it is unclear how progesterone imbalance could impact inflammatory responses in the oviduct and subsequently result in early pregnancy loss. Therefore, in this review, we describe the role of progesterone signaling in regulating the inflammatory response, with a focus on the oviduct and pathological conditions in the Fallopian tubes.

Interaction of cervical microbiome with epigenome of epithelial cells: Significance of inflammation to primary healthcare

One pillar of the predictive, preventive, and personalized medicine framework strategies is the female health. The evaluation of women's lifestyle and dietary habits in context with genetic and modifiable risk factors may reflect the prevention of cervical cancer before the occurrence of clinical symptoms and prediction of cervical lesion behavior. The main aim of this review is to analyze publications in the field of precision medicine that allow the use of research knowledge of cervical microbiome, epigenetic modifications, and inflammation in potential application in clinical practice. Personalized approach in evaluating patient's risk of future development of cervical abnormality should consider the biomarkers of the local microenvironment characterized by the microbial composition, epigenetic pattern of cervical epithelium, and presence of chronic inflammation. Novel sequencing techniques enable a more detailed characterization of actual state in cervical epithelium. Better understanding of all changes in multiomics level enables a better assessment of disease prognosis and selects the eligible targeted therapy in personalized medicine. Restoring of healthy vaginal microflora and reversing the outbreak of cervical abnormality can be also achieved by dietary habits as well as uptake of prebiotics, probiotics, synbiotics, microbial transplantation, and others.

Tissue Models for Neisseria gonorrhoeae Research—From 2D to 3D

Neisseria gonorrhoeae is a human-specific pathogen that causes gonorrhea, the second most common sexually transmitted infection worldwide. Disease progression, drug discovery, and basic host-pathogen interactions are studied using different approaches, which rely on models ranging from 2D cell culture to complex 3D tissues and animals. In this review, we discuss the models used in N. gonorrhoeae research. We address both in vivo (animal) and in vitro cell culture models, discussing the pros and cons of each and outlining the recent advancements in the field of three-dimensional tissue models. From simple 2D monoculture to complex advanced 3D tissue models, we provide an overview of the relevant methodology and its application. Finally, we discuss future directions in the exciting field of 3D tissue models and how they can be applied for studying the interaction of N. gonorrhoeae with host cells under conditions closely resembling those found at the native sites of infection.

Evidence for HPV DNA in the placenta of women who resorted to elective abortion

BACKGROUND

It is believed that HPV infection can result in the death of placental trophoblasts and cause miscarriages or preterm birth. In clinical cases of placental villi positive for HPV DNA reported by other authors, contamination is suspected in the act of crossing the cervical canal. We analyzed placental samples of women who resorted to elective abortion obtained by hysterosuction of ovular material, bypassing any contact with the cervical canal and vagina.

METHODS

We studied the chorionic villi of the placenta of 64 women who resorted to voluntary termination of pregnancy, in the first trimester. To avoid contamination of the villi by the cervical canal, we analyzed placental samples obtained by hysterosuction of ovular material, bypassing any contact with the cervical canal and vagina. All samples of chorionic villi were manually selected from the aborted material and subjected to research for HPV DNA.

RESULTS

HPV DNA was detected in 10 out of 60 women (16.6%). The HPV DNA identified in the placenta belonged to genotypes 6, 16, 35, 53, and 90.

CONCLUSION

The study shows that papillomavirus DNA can infect the placenta and that placenta HPV infection can occur as early as the first trimester of pregnancy.

Production and characterization of a human antisperm monoclonal antibody against CD52g for topical contraception in women

BACKGROUND

Approximately 40% of human pregnancies are unintended, indicating a need for more acceptable effective contraception methods. New antibody production systems make it possible to manufacture reagent-grade human monoclonal antibodies (mAbs) for clinical use. We used the Nicotiana platform to produce a human antisperm mAb and tested its efficacy for on-demand topical contraception.

METHODS

Heavy and light chain variable region DNA sequences of a human IgM antisperm antibody derived from an infertile woman were inserted with human IgG₁ constant region sequences into an agrobacterium and transfected into Nicotiana benthamiana. The product, an IgG₁ mAb ["Human Contraception Antibody" (HCA)], was purified on Protein A columns, and QC was performed using the LabChip GXII Touch protein characterization system and SEC-HPLC. HCA was tested for antigen specificity by immunofluorescence and western blot assays, antisperm activity by sperm agglutination and complement dependent sperm immobilization assays, and safety in a human vaginal tissue (EpiVaginal™) model.

FINDINGS

HCA was obtained at concentrations ranging from 0.4 to 4 mg/ml and consisted of > 90% IgG monomers. The mAb specifically reacted with a glycan epitope on CD52g, a glycoprotein produced in the male reproductive tract and found in abundance on sperm. HCA potently agglutinated sperm under a variety of relevant physiological conditions at concentrations ≥ 6.25 µg/ml, and mediated complement-dependent sperm immobilization at concentrations ≥ 1 µg/ml. HCA and its immune complexes did not induce inflammation in EpiVaginal™ tissue.

INTERPRETATION

HCA, an IgG1 mAb with potent sperm agglutination and immobilization activity and a good safety profile, is a promising candidate for female contraception.

FUNDING

This research was supported by grants R01 HD095630 and P50HD096957 from the National Institutes of Health.

Vaginal Lactobacilli and Vaginal Dysbiosis-Associated Bacteria Differently Affect Cervical Epithelial and Immune Homeostasis and Anti-Viral Defenses

Persistent infection with High Risk-Human Papilloma Viruses (HR-HPVs) is a primary cause of cervical cancer worldwide. Vaginal-dysbiosis-associated bacteria were correlated with the persistence of HR-HPVs infection and with increased cancer risk. We obtained strains of the most represented bacterial species in vaginal microbiota and evaluated their effects on the survival of cervical epithelial cells and immune homeostasis. The contribution of each species to supporting the antiviral response was also studied. Epithelial cell viability was affected by culture supernatants of most vaginal-dysbiosis bacteria, whereas Lactobacillus gasseri or Lactobacillus jensenii resulted in the best stimulus to induce interferon-γ (IFN-γ) production by human mononuclear cells from peripheral blood (PBMCs). Although vaginal-dysbiosis-associated bacteria induced the IFN-γ production, they were also optimal stimuli to interleukin-17 (IL-17) production. A positive correlation between IL-17 and IFN-γ secretion was observed in cultures of PBMCs with all vaginal-dysbiosis-associated bacteria suggesting that the adaptive immune response induced by these strains is not dominated by T_H1 differentiation with reduced availability of IFN-γ, cytokine most effective in supporting virus clearance. Based on these results, we suggest that a vaginal microbiota dominated by lactobacilli, especially by L. gasseri or L. jensenii, may be able to assist immune cells with clearing HPV infection, bypasses the viral escape and restores immune homeostasis.

Immunotherapy in endometrial cancer: rationale, practice and perspectives

Tumor immunotherapy has attracted more and more attention nowadays, and multiple clinical trials have confirmed its effect in a variety of solid tumors. Immune checkpoint inhibitors (ICIs), cancer vaccines, adoptive cell transfer (ACT), and lymphocyte-promoting cytokines are the main immunotherapy methods. Endometrial cancer (EC) is one of the most frequent tumors in women and the prognosis of recurrent or metastatic EC is poor. Since molecular classification has been applied to EC, immunotherapy for different EC subtypes (especially POLE and MSI-H) has gradually attracted attention. In this review, we focus on the expression and molecular basis of the main biomarkers in the immunotherapy of EC firstly, as well as their clinical application significance and limitations. Blocking tumor immune checkpoints is one of the most effective strategies for cancer treatment in recent years, and has now become the focus in the field of tumor research and treatment. We summarized clinical date of planned and ongoing clinical trials and introduced other common immunotherapy methods in EC, such as cancer vaccine and ACT. Hormone aberrations, metabolic syndrome (MetS) and p53 mutant and that affect the immunotherapy of endometrial cancer will also be discussed in this review.

Observational cohort study of the effect of a single lubricant exposure during transvaginal ultrasound on cell-shedding from the vaginal epithelium

The outer layers of the vaginal epithelium (VE) are important because they accumulate glycogen which, under optimal conditions, Lactobacillus spp. consume to grow and acidify the vaginal microenvironment with lactic acid. We hypothesized that exposure to lubricant, for example in the conduct of a transvaginal ultrasound (TVUS), may contribute to the shedding of mature epithelial cells, exposing immature cells. Cervicovaginal fluid (CVF) was sampled at four time points by menstrual cup (Softdisc™) from 50 women referred for TVUS, during which a controlled volume of lubricant was applied to the TVUS wand. Samples were collected (1) immediately before TVUS and (2) 6-12 hours, (3) within one week, and (4) two weeks after TVUS. Clinical vaginal lubricants are similar to commercial lubricants, and often have a high osmolality or pH, and contain bactericides such as methylparaben and propylparaben. The number and maturity of epithelial cells in each CVF sample were measured by quantitative and differential fluorimetry (maturity index, MI). Comparisons of cell-counts and maturity were made by paired Wilcoxon signed-rank tests. Among women with a high pre-TVUS MI (> 3), there was a decrease in median cell-count and mean MI in the sample collected 6-12 hours after TVUS (p<0.001, n = 26 and p < 0.001, n = 26, respectively). For these women, cell-count and MI remained lower in the sample collected within the subsequent week (p<0.001, n = 29 and p<0.01, n = 29, respectively), and MI remained lower in the sample collected within two weeks of TVUS (p<0.01, n = 25), compared to the pre-TVUS sample. Among participants with a low pre-TVUS MI (< 3), cell-count was higher in the sample collected within two weeks of TVUS compared to the pre-TVUS sample (p = 0.03, n = 15), but no significant changes in MI were observed. Results were similar when restricted to reproductive-age women. This preliminary data indicates hypertonic vaginal lubricants may increase vaginal epithelial cell shedding.

Immunological response of fallopian tube epithelial cells to spermatozoa through modulating cytokines and chemokines

BACKGROUND

Spermatozoa interactions with fallopian tubes may influence fertilization. The purpose was to investigate cytokines, chemokines and growth factors expression from human fallopian tube epithelial cells (OE-E6/E7) exposed to spermatozoa.

METHODS

Fresh semen samples were obtained from 10 healthy normozoospermic men. Sperms were prepared and co-cultured with OE-E6/E7. The cell line without spermatozoa was considered as the control group. Afterwards, Expression of 84 cytokines from OE-E6/E7 cell line in the presence and absence of spermatozoa were measured using PCR-array. Quantitative PCR was performed on seven genes to confirm the results of PCR-array analysis. Differentially expressed genes were subjected to www.geneontology.org and www.pantherdb.org to perform GO enrichment and panther pathway analysis. The concentration of IL-8, IL-10, IL-1B and BMP-4 in culture medium were analyzed by ELISA.

RESULTS

Sperm interaction with the epithelial cells resulted in a significant increase in expression of TGF-β2, BMP-4, IL-10, IL-9, and CD40LG markers. Moreover, expression of IL-16, IL-17F, SPP-1, CXCL-13, MSTN, IL-1A, IL-1B, IL-8, BMP-7, CSF-2, CSF-3, VEGF-A, OSM, LTA, TNF, TNFRSF11B, TNFSF11, CCL-11, CCL-20, CCL-24, CCL-3, CCL-8, CX3CL1 and CXCL-9 were considerably reduced in presence of spermatozoa. Panther pathway analysis discovered 3 pathways for upregulated genes including gonadotropin-releasing hormone receptor, TGF-beta and interleukin signaling pathways. Furthermore, 9 pathways were detected for down-regulated genes. Inflammation signaling pathway which is mediated by chemokine and cytokine contains the most number of genes.

CONCLUSION

This study indicates that sperm modifies expression of cytokines, chemokines and growth factors from OE-E6/E7. Moreover, altered genes expression are toward higher survival chance of the spermatozoa.

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.

Gut Microbiome Homeostasis and the CD4 T- Follicular Helper Cell IgA Axis in Human Immunodeficiency Virus Infection

Human Immunodeficiency Virus (HIV) and Simian Immunodeficiency Virus (SIV) are associated with severe perturbations in the gut mucosal environment characterized by massive viral replication and depletion of CD4 T cells leading to dysbiosis, breakdown of the epithelial barrier, microbial translocation, immune activation and disease progression. Multiple mechanisms play a role in maintaining homeostasis in the gut mucosa and protecting the integrity of the epithelial barrier. Among these are the secretory IgA (sIgA) that are produced daily in vast quantities throughout the mucosa and play a pivotal role in preventing commensal microbes from breaching the epithelial barrier. These microbe specific, high affinity IgA are produced by IgA+ plasma cells that are present within the Peyer’s Patches, mesenteric lymph nodes and the isolated lymphoid follicles that are prevalent in the lamina propria of the gastrointestinal tract (GIT). Differentiation, maturation and class switching to IgA producing plasma cells requires help from T follicular helper (Tfh) cells that are present within these lymphoid tissues. HIV replication and CD4 T cell depletion is accompanied by severe dysregulation of Tfh cell responses that compromises the generation of mucosal IgA that in turn alters barrier integrity leading to commensal bacteria readily breaching the epithelial barrier and causing mucosal pathology. Here we review the effect of HIV infection on Tfh cells and mucosal IgA responses in the GIT and the consequences these have for gut dysbiosis and mucosal immunopathogenesis.

Reproductive Tract Infections in Dairy Cows: Can Probiotics Curb Down the Incidence Rate?

Postpartum uterine diseases are common in dairy cows and are a great concern for the dairy industry as they are associated with various consequences, including lower fertility, lower milk yield, and an overall negative impact on the host health. An infected uterus is a source of bacterial compounds and cytokines that spill into the systemic circulation, spreading inflammation to other organs. In this review article, we discuss a short overview of the anatomy of the reproductive tract of dairy cows and several infectious diseases of the uterus including metritis, endometritis, and pyometra. Additionally, we discuss the microbiome of the reproductive tract in health and during uterine diseases. As well, diagnostic criteria for metritis and endometritis and contributing factors for increased susceptibility to metritis infection are important topics of this review. To better understand how the uterus and reproductive tract respond to bacterial pathogens, a section of this review is dedicated to immunity of the reproductive tract. Both the innate and adaptive immunity systems are also discussed. We conclude the review with a factual discussion about the current treatments of uterine diseases and the new developments in the area of application of probiotics for uterine health. Mechanisms of actions of probiotics are discussed in detail and also some applications to prevent uterine infections in dairy cows are discussed.

TRIM26 Facilitates HSV-2 Infection by Downregulating Antiviral Responses through the IRF3 Pathway

Herpes simplex virus type 2 (HSV-2) is the primary cause of genital herpes which results in significant morbidity and mortality, especially in women, worldwide. HSV-2 is transmitted primarily through infection of epithelial cells at skin and mucosal surfaces. Our earlier work to examine interactions between HSV-2 and vaginal epithelial cells demonstrated that infection of the human vaginal epithelial cell line (VK2) with HSV-2 resulted in increased expression of TRIM26, a negative regulator of the Type I interferon pathway. Given that upregulation of TRIM26 could negatively affect anti-viral pathways, we decided to further study the role of TRIM26 in HSV-2 infection and replication. To do this, we designed and generated two cell lines derived from VK2s with TRIM26 overexpressed (OE) and knocked out (KO). Both, along with wildtype (WT) VK2, were infected with HSV-2 and viral titres were measured in supernatants 24 h later. Our results showed significantly enhanced virus production by TRIM26 OE cells, but very little replication in TRIM26 KO cells. We next examined interferon-β production and expression of two distinct interferon stimulated genes (ISGs), MX1 and ISG15, in all three cell lines, prior to and following HSV-2 infection. The absence of TRIM26 (KO) significantly upregulated interferon-β production at baseline and even further after HSV-2 infection. TRIM26 KO cells also showed significant increase in the expression of MX1 and ISG15 before and after HSV-2 infection. Immunofluorescent staining indicated that overexpression of TRIM26 substantially decreased the nuclear localization of IRF3, the primary mediator of ISG activation, before and after HSV-2 infection. Taken together, our data indicate that HSV-2 utilizes host factor TRIM26 to evade anti-viral response and thereby increase its replication in vaginal epithelial cells.

Hypothetical roadmap towards endometriosis: prenatal endocrine-disrupting chemical pollutant exposure, anogenital distance, gut-genital microbiota and subclinical infections

BACKGROUND

Endometriosis is a gynaecological hormone-dependent disorder that is defined by histological lesions generated by the growth of endometrial-like tissue out of the uterus cavity, most commonly engrafted within the peritoneal cavity, although these lesions can also be located in distant organs. Endometriosis affects ~10% of women of reproductive age, frequently producing severe and, sometimes, incapacitating symptoms, including chronic pelvic pain, dysmenorrhea and dyspareunia, among others. Furthermore, endometriosis causes infertility in ~30% of affected women. Despite intense research on the mechanisms involved in the initial development and later progression of endometriosis, many questions remain unanswered and its aetiology remains unknown. Recent studies have demonstrated the critical role played by the relationship between the microbiome and mucosal immunology in preventing sexually transmitted diseases (HIV), infertility and several gynaecologic diseases.

OBJECTIVE AND RATIONALE

In this review, we sought to respond to the main research question related to the aetiology of endometriosis. We provide a model pointing out several risk factors that could explain the development of endometriosis. The hypothesis arises from bringing together current findings from large distinct areas, linking high prenatal exposure to environmental endocrine-disrupting chemicals with a short anogenital distance, female genital tract contamination with the faecal microbiota and the active role of genital subclinical microbial infections in the development and clinical progression of endometriosis.

SEARCH METHODS

We performed a search of the scientific literature published until 2019 in the PubMed database. The search strategy included the following keywords in various combinations: endometriosis, anogenital distance, chemical pollutants, endocrine-disrupting chemicals, prenatal exposure to endocrine-disrupting chemicals, the microbiome of the female reproductive tract, microbiota and genital tract, bacterial vaginosis, endometritis, oestrogens and microbiota and microbiota-immune system interactions.

OUTCOMES

On searching the corresponding bibliography, we found frequent associations between environmental endocrine-disrupting chemicals and endometriosis risk. Likewise, recent evidence and hypotheses have suggested the active role of genital subclinical microbial infections in the development and clinical progression of endometriosis. Hence, we can envisage a direct relationship between higher prenatal exposure to oestrogens or estrogenic endocrine-disrupting compounds (phthalates, bisphenols, organochlorine pesticides and others) and a shorter anogenital distance, which could favour frequent postnatal episodes of faecal microbiota contamination of the vulva and vagina, producing cervicovaginal microbiota dysbiosis. This relationship would disrupt local antimicrobial defences, subverting the homeostasis state and inducing a subclinical inflammatory response that could evolve into a sustained immune dysregulation, closing the vicious cycle responsible for the development of endometriosis.

WIDER IMPLICATIONS

Determining the aetiology of endometriosis is a challenging issue. Posing a new hypothesis on this subject provides the initial tool necessary to design future experimental, clinical and epidemiological research that could allow for a better understanding of the origin of this disease. Furthermore, advances in the understanding of its aetiology would allow the identification of new therapeutics and preventive actions.

The Cervicovaginal Mucus Barrier

Preterm births are a global health priority that affects 15 million babies every year worldwide. There are no effective prognostic and therapeutic strategies relating to preterm delivery, but uterine infections appear to be a major cause. The vaginal epithelium is covered by the cervicovaginal mucus, which is essential to health because of its direct involvement in reproduction and functions as a selective barrier by sheltering the beneficial lactobacilli while helping to clear pathogens. During pregnancy, the cervical canal is sealed with a cervical mucus plug that prevents the vaginal flora from ascending toward the uterine compartment, which protects the fetus from pathogens. Abnormalities of the cervical mucus plug and bacterial vaginosis are associated with a higher risk of preterm delivery. This review addresses the current understanding of the cervicovaginal mucus and the cervical mucus plug and their interactions with the microbial communities in both the physiological state and bacterial vaginosis, with a focus on gel-forming mucins. We also review the current state of knowledge of gel-forming mucins contained in mouse cervicovaginal mucus and the mouse models used to study bacterial vaginosis.

The Inhibition of Cathepsin G on Endometrial Explants With Endometrosis in the Mare

Although proteases found in neutrophil extracellular traps (NETs) have antimicrobial properties, they also stimulate collagen type 1 (COL1) production by the mare endometrium, contributing for the development of endometrosis. Cathepsin G (CAT), a protease present in NETs, is inhibited by specific inhibitors, such as cathepsin G inhibitor I (INH; β-keto-phosphonic acid). Matrix metallopeptidases (MMPs) are proteases involved in the equilibrium of the extracellular matrix. The objective of this study was to investigate the effect of CAT and INH (a selective CAT inhibitor) on the expression of MMP-2 and MMP-9 and on gelatinolytic activity. In addition, the putative inhibitory effect of INH on CAT-induced COL1 production in mare endometrium was assessed. Endometrial explants retrieved from mares in follicular phase or midluteal phase were treated for 24 or 48 h with CAT, inhibitor alone, or both treatments. In explants, transcripts (quantitative polymerase chain reaction) of COL1A2, MMP2, and MMP9, as well as the relative abundance of COL1 protein (Western blot), and activity of MMP-2 and MMP-9 (zymography) were evaluated. The protease CAT induced COL1 expression in explants, at both estrous cycle phases and treatment times. The inhibitory effect of INH was observed on COL1A2 transcripts in follicular phase at 24-h treatment, and in midluteal phase at 48 h (P < 0.05), and on the relative abundance of COL protein in follicular phase and midluteal phase explants, at 48 h (P < 0.001). Our study suggests that MMP-2 might also be involved in an earlier response to CAT, and MMP-9 in a later response, mainly in the follicular phase. While the use of INH reduced CAT-induced COL1 endometrial expression, MMPs might be involved in the fibrogenic response to CAT. Therefore, in mare endometrium, the use of INH may be a future potential therapeutic means to reduce CAT-induced COL1 formation and to hamper endometrosis establishment.

Gardnerella and vaginal health: the truth is out there

The human vagina is a dynamic ecosystem in which homeostasis depends on mutually beneficial interactions between the host and their microorganisms. However, the vaginal ecosystem can be thrown off balance by a wide variety of factors. Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age but its etiology is not yet fully understood, with different controversial theories being raised over the years. What is generally accepted is that BV is often characterized by a shift in the composition of the normal vaginal microbiota, from a Lactobacillus species dominated microbiota to a mixture of anaerobic and facultative anaerobic bacteria. During BV, a polymicrobial biofilm develops in the vaginal microenvironment, being mainly composed of Gardnerella species. The interactions between vaginal microorganisms are thought to play a pivotal role in the shift from health to disease and might also increase the risk of sexually transmitted infections acquisition. Here, we review the current knowledge regarding the specific interactions that occur in the vaginal niche and discuss mechanisms by which these interactions might be mediated. Furthermore, we discuss the importance of novel strategies to fight chronic vaginal infections.

Distinct follicular and luteal transcriptional profiles in engineered human ectocervical tissue dependent on menstrual cycle phase

To investigate genomic pathways that may influence physiology and infectivity during the menstrual cycle, RNA sequence analysis was performed on patient-matched engineered ectocervical tissue after follicular and luteal phase (LP) hormone treatments. We developed distinct cellular, molecular, and biological profiles in ectocervical epithelium dependent on the menstrual cycle phase. Follicular phase hormones were associated with proliferation, transcription, and cell adhesion, while LP samples expressed genes involved in immune cell recruitment, inflammation, and protein modifications. Additionally, our analysis revealed mucins not previously reported in ectocervical tissue, which could play an important role in fertility and disease prevention. This study provides insight into the phenomenon of increased LP vulnerability to infection and identifies potential targets for future research.

Typologies of violence against women in Brazil: A latent class analysis of how violence and HIV intersect

We address the limited understanding around the overlap between violence and HIV in Brazil. Data was from two clinic-based samples of HIV-positive (n = 1534) and HIV-negative women (n = 1589) in São Paulo and Porto Alegre. We conducted latent class analysis and identified violence typologies by type of violence, life course timing, frequency, and perpetrator, stratified by city and HIV-status. Overall, HIV-positive women experienced more lifetime physical and sexual violence than HIV-negative women. Twelve unique violence latent classes were identified. In São Paulo, HIV-positive women were likely to have endured physical violence several times (Conditional Probability [CP]: 0.80) by an intimate partner (CP: 0.85), and sexual violence several times (CP: 0.46) by an intimate partner (CP: 0.62). In Porto Alegre, HIV-positive women endured physical violence several times (CP: 0.80) by an intimate partner (CP: 0.70) during childhood/adolescence (CP: 0.48), and sexual violence several times (CP: 0.54) by an intimate partner (CP: 0.60). Findings inform interventions to educate around gender equity, violence, and the health effects of violence including HIV, integrate HIV and violence services, and improve the provision of bio-medical HIV prevention among HIV-negative women who experience violence.

Asymptomatic Bacterial Vaginosis Is Associated With Depletion of Mature Superficial Cells Shed From the Vaginal Epithelium

Previous studies have described bacterial vaginosis (BV) as associated with increased cell-shedding from the cervicovaginal epithelium. Cell-shedding in excess of cell-proliferation is thought to decrease epithelial barrier function and increase susceptibility to infection. This study evaluated the number of shed cells in mid-vaginal smears from women with a diagnosis of symptomatic BV (sBV, n = 17), asymptomatic BV (aBV, n = 71), or no BV (n = 104) by Amsel criteria. The sBV smears contained significantly more shed cells (median 158/100X field) than no BV smears (median 91/100X field), p = 7.2e−9. However, we observed that aBV smears contained significantly fewer shed cells (median 35/100X field) than no BV smears, p = 22.0e−16. The sizes of cell-aggregates (cells shed in sometimes multilayered sections with intact cell-cell attachments) followed the same pattern. Cell-aggregates in sBV smears were significantly larger (median ~220,000 μm²) than those in no BV smears (median ~50,000 μm²), p = 1.8e−6, but cell-aggregates in aBV smears were significantly smaller (median ~7,000 μm²) than those in no BV smears, p = 0.0028. We also compared the superficial cell index (SCI), a measure of cervicovaginal epithelial cell maturity, in no BV and aBV smears with relatively low numbers of shed cells (≤50/100X field). The SCI of no BV smears was significantly higher (median 0.86) than that of aBV smears (median 0.35), p = 4.3e−98, suggesting a depletion of mature cells with exposure and shedding of underlying immature cells in aBV with low number of shed cells. These results indicate that aBV may contribute disproportionately to the increased susceptibility to reproductive tract infections associated with BV. Our findings remained true when considering only those smears in which the microbiota comprised a diverse set of strict and facultative anaerobic bacteria [Community State Type IV (n = 162)], thus excluding those dominated by Lactobacillus spp. This is consistent with our developing hypothesis that high-shedding sBV and low-shedding aBV could be temporally separated phases of the same condition, rather than two separate forms of BV. These findings might inform future work on clinical management of symptomatic and asymptomatic bacterial vaginosis.

Mechanisms linking bovine viral diarrhea virus (BVDV) infection with infertility in cattle

Bovine viral diarrhea virus (BVDV) is an important infectious disease agent that causes significant reproductive and economic losses in the cattle industry worldwide. Although BVDV infection is known to cause poor fertility in cattle, a greater part of the underlying mechanisms particularly associated with early reproductive losses are not clearly understood. Previous studies reported viral compromise of reproductive function in infected bulls. In females, BVDV infection is thought to be capable of killing the oocyte, embryo or fetus directly, or to induce lesions that result in fetal abortion or malformation. BVDV infections may also induce immune dysfunction, and predispose cattle to other diseases that cause poor health and fertility. Other reports also suggested BVDV-induced disruption of the reproductive endocrine system, and a disruption of leukocyte and cytokine functions in the reproductive organs. More recent studies have provided evidence of viral-induced suppression of endometrial innate immunity that may predispose to uterine disease. Furthermore, there is new evidence that BVDV may potentially disrupt the maternal recognition of pregnancy or the immune protection of the conceptus. This review brings together the previous reports with the more recent findings, and attempts to explain some of the mechanisms linking this important virus to infertility in cattle.