Mucosal Immunity in the Human Female Reproductive Tract

Cervicovaginal Microbiome: Physiology, Age-Related Changes, and Protective Role Against Human Papillomavirus Infection

Background/Objectives: Persistent high-risk human papillomavirus (HPV) infections are the leading cause of cervical cancer. Developing evidence suggests that the cervicovaginal microbiome plays a significant role in modulating HPV persistence and progression to cervical neoplasia. This review synthesizes the current knowledge on the interplay between the cervicovaginal microbiome and local immunity in HPV infections, emphasizing microbial diversity, immune responses, and potential therapeutic implications. Methods: A thorough review of the literature was performed using Embase, PubMed, Scopus, and Google Scholar, encompassing studies published between 2000 and 2024. Studies examining the composition of the microbiome, immune responses, and HPV-related outcomes were evaluated and synthesized into a comprehensive review. Results: A Lactobacillus-dominant microbiome, particularly with L. crispatus, creates a protective environment through lactic acid production, maintenance of low pH, and anti-inflammatory immune modulation, facilitating HPV clearance. Dysbiosis, often characterized by a dominance of L. iners and overgrowth of anaerobic bacteria, fosters chronic inflammation, cytokine imbalance, and a microenvironment conducive to HPV persistence and progression. Hormonal changes and menopause exacerbate these microbial shifts, increasing the risk of cervical lesions. Studies suggest that cytokine profiles and antimicrobial peptides significantly influence local immune responses, further modulating infection outcomes. Conclusions: The cervicovaginal microbiome is a critical determinant in HPV infection outcomes, with therapeutic potential for modulating the microbiome to enhance immune responses and prevent cervical cancer. Personalized microbiome-targeted therapies may offer a novel avenue for managing HPV and reducing cervical cancer incidence.

Comparative genomics between Trichomonas tenax and Trichomonas vaginalis: CAZymes and candidate virulence factors

Introduction

The oral trichomonad Trichomonas tenax is increasingly appreciated as a likely contributor to periodontitis, a chronic inflammatory disease induced by dysbiotic microbiota, in humans and domestic animals and is strongly associated with its worst prognosis. Our current understanding of the molecular basis of T. tenax interactions with host cells and the microbiota of the oral cavity are still rather limited. One laboratory strain of T. tenax (Hs-4:NIH/ATCC 30207) can be grown axenically and two draft genome assemblies have been published for that strain, although the structural and functional annotation of these genomes is not available.

Methods

GenSAS and Galaxy were used to annotate two publicly available draft genomes for T. tenax, with a focus on protein-coding genes. A custom pipeline was used to annotate the CAZymes for T. tenax and the human sexually transmitted parasite Trichomonas vaginalis, the most well-characterized trichomonad. A combination of bioinformatics analyses was used to screen for homologs of T. vaginalis virulence and colonization factors within the T. tenax annotated proteins.

Results

Our annotation of the two T. tenax draft genome sequences and their comparison with T. vaginalis proteins provide evidence for several candidate virulence factors. These include candidate surface proteins, secreted proteins and enzymes mediating potential interactions with host cells and/or members of the oral microbiota. The CAZymes annotation identified a broad range of glycoside hydrolase (GH) families, with the majority of these being shared between the two Trichomonas species.

Discussion

The presence of candidate T. tenax virulence genes supports the hypothesis that this species is associated with periodontitis through direct and indirect mechanisms. Notably, several GH proteins could represent potential new virulence factors for both Trichomonas species. These data support a model where T. tenax interactions with host cells and members of the oral microbiota could synergistically contribute to the damaging inflammation characteristic of periodontitis, supporting a causal link between T. tenax and periodontitis.

Semenogelin, a coagulum macromolecule monitoring factor involved in the first step of fertilization: A prospective review

Human male infertility affects approximately 1/10 couples worldwide, and its prevalence is found more in developed countries. Along with sperm cells, the secretions of the prostate, seminal vesicle and epididymis plays a major role in proper fertilization. Many studies have proven the functions of seminal vesicle secretions, especially semenogelin protein, as an optimiser for fertilization. Semenogelin provides the structural components for coagulum formation after ejaculation. It binds with eppin and is found to have major functions like motility of sperm, transporting the sperm safely in the immune rich female reproductive tract until the sperm cells reach the egg intact. The capacitation process is essential for proper fertilization and semenogelin involved in mediating capacitation in time. Also, it has control of events towards the first step in the fertilization process. It is a Zn ions binding protein, and Zn ions act as a cofactor that helps in the proper motility of sperm cells. Therefore, any imbalance in protein that automatically affect sperm physiology and fertility status. This review sheds a comprehensive and critical view on the significant functions of semenogelin in fertilization. This review can open up advanced proteomics research on semenogelin towards unravelling molecular mechanisms in fertilization.

Immunometabolic Analysis of Mobiluncus mulieris and Eggerthella sp. Reveals Novel Insights Into Their Pathogenic Contributions to the Hallmarks of Bacterial Vaginosis

The cervicovaginal microbiome plays an important role in protecting women from dysbiosis and infection caused by pathogenic microorganisms. In healthy reproductive-age women the cervicovaginal microbiome is predominantly colonized by protective Lactobacillus spp. The loss of these protective bacteria leads to colonization of the cervicovaginal microenvironment by pathogenic microorganisms resulting in dysbiosis and bacterial vaginosis (BV). Mobiluncus mulieris and Eggerthella sp. are two of the many anaerobes that can contribute to BV, a condition associated with multiple adverse obstetric and gynecological outcomes. M. mulieris has been linked to high Nugent scores (relating to BV morphotypes) and preterm birth (PTB), whilst some bacterial members of the Eggerthellaceae family are highly prevalent in BV, and identified in ~85-95% of cases. The functional impact of M. mulieris and Eggerthella sp. in BV is still poorly understood. To determine the individual immunometabolic contributions of Eggerthella sp. and M. mulieris within the cervicovaginal microenvironment, we utilized our well-characterized human three-dimensional (3-D) cervical epithelial cell model in combination with multiplex immunoassays and global untargeted metabolomics approaches to identify key immune mediators and metabolites related to M. mulieris and Eggerthella sp. infections. We found that infection with M. mulieris significantly elevated multiple proinflammatory markers (IL-6, IL-8, TNF-α and MCP-1) and altered metabolites related to energy metabolism (nicotinamide and succinate) and oxidative stress (cysteinylglycine, cysteinylglycine disulfide and 2-hydroxygluatrate). Eggerthella sp. infection significantly elevated multiple sphingolipids and glycerolipids related to epithelial barrier function, and biogenic amines (putrescine and cadaverine) associated with elevated vaginal pH, vaginal amine odor and vaginal discharge. Our study elucidated that M. mulieris elevated multiple proinflammatory markers relating to PTB and STI acquisition, as well as altered energy metabolism and oxidative stress, whilst Eggerthella sp. upregulated multiple biogenic amines associated with the clinical diagnostic criteria of BV. Future studies are needed to evaluate how these bacteria interact with other BV-associated bacteria within the cervicovaginal microenvironment.

Selected Uterine Immune Events Associated With the Establishment of Pregnancy in the Dog

In the dog, implantation takes place at approximately 17 days of embryonal life and, while exposed to relatively high circulating progesterone concentrations, embryos presence is required for the formation of decidua. Furthermore, a balance between pro- and anti-inflammatory responses in conceptus-maternal communication is crucial for the onset of pregnancy. Strikingly, the understanding of such immune mechanisms in canine reproduction is still elusive. Here, canine uterine samples from pre-implantation (day 10-12, E+) and corresponding non-pregnant controls (E-), implantation (day 17, Imp) and post-implantation (day 18-25, Post-Imp) stages of pregnancy were used to investigate the expression and localization of several immune-related factors. The most important findings indicate increased availability of CD4, MHCII, NCR1, IDO1, AIF1, CD25, CCR7, and IL6 in response to embryo presence (E+), while FoxP3 and CCL3 were more abundant in E- samples. Implantation was characterized by upregulated levels of FoxP3, IL12a, ENG, and CDH1, whereas CD4, CCR7, IL8, and -10 were less represented. Following implantation, decreased transcript levels of TNFR1, MHCII, NCR1, TLR4, CD206, FoxP3, and IL12a were observed concomitantly with the highest expression of IL6 and IL1β. MHCII, CD86, CD206, CD163, TNFα, IDO1, and AIF1 were immunolocalized in macrophages, CD4 and Nkp46 in lymphocytes, and some signals of IDO1, AIF1, and TNF-receptors could also be identified in endothelial cells and/or uterine glands. Cumulatively, new insights regarding uterine immunity in the peri-implantation period are provided, with apparent moderated pro-inflammatory signals prevailing during pre-implantation, while implantation and early trophoblast invasion appear to be associated with immunomodulatory and rather anti-inflammatory conditions.