Oncogenic Virome Benefits from the Different Vaginal Microbiome-Immune Axes

Roles of the Microbiota of the Female Reproductive Tract in Gynecological and Reproductive Health

The microbiome of the female reproductive tract defies the convention that high biodiversity is a hallmark of an optimal ecosystem. Although not universally true, a homogeneous vaginal microbiome composed of species of Lactobacillus is generally associated with health, whereas vaginal microbiomes consisting of other taxa are generally associated with dysbiosis and a higher risk of disease. The past decade has seen a rapid advancement in our understanding of these unique biosystems. Of particular interest, substantial effort has been devoted to deciphering how members of the microbiome of the female reproductive tract impact pregnancy, with a focus on adverse outcomes, including but not limited to preterm birth. Herein, we review recent research efforts that are revealing the mechanisms by which these microorganisms of the female reproductive tract influence gynecologic and reproductive health of the female reproductive tract.

Association between common vaginal and HPV infections and results of cytology test in the Zhoupu District, Shanghai City, China, from 2014 to 2019

Background

HPV (human papillomavirus) is an important cause of cervical cancer. Cervical-vaginal infection with pathogens, such as herpes simplex virus (HSV), bacterial vaginosis Trichomonas vaginalis and vaginal candidiasis could be a cofactor. This study aimed to assess the relationship between vaginal infection with HPV genotype and cytology test results and analyze the relationship between vaginal and HPV infections and cervical cancer.

Methods

We performed a district-based study to elucidate the relationship among the vaginal and HPV infections and cervical cancer. We collected the cervical exfoliation data of 23,724 women admitted to the Shanghai Zhoupu Hospital and received ThinPrep cytology test (TCT) and HPV detection between 2014 and 2019.

Results

Total vaginal infection rate was 5.3%, and the HPV-positive group had a slightly higher vaginal infection rate than the HPV-negative group (P < 0.01). The incidence rate of cervical intraepithelial neoplasia or cervical cancer with vaginal infection was higher than without vaginal infection (P < 0.001).

Conclusion

HPV/vaginal infection-positive women tended to have abnormal results of TCT. Women with vaginal infection were more likely to develop HPV infection. HSV combined with HPV infection was noted as a causal factor for HSIL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-022-01850-x.

SARS-CoV-2 and Prevotella spp.: friend or foe? A systematic literature review

During this global pandemic of the COVID-19 disease, a lot of information has arisen in the media and online without scientific validation, and among these is the possibility that this disease could be aggravated by a secondary bacterial infection such as Prevotella, as well as the interest or not in using azithromycin, a potentially active antimicrobial agent. The aim of this study was to carry out a systematic literature review, to prove or disprove these allegations by scientific arguments. The search included Medline, PubMed, and Pubtator Central databases for English-language articles published 1999-2021. After removing duplicates, a total of final eligible studies (n=149) were selected. There were more articles showing an increase of Prevotella abundance in the presence of viral infection like that related to Human Immunodeficiency Virus (HIV), Papillomavirus (HPV), Herpesviridae and respiratory virus, highlighting differences according to methodologies and patient groups. The arguments for or against the use of azithromycin are stated in light of the results of the literature, showing the role of intercurrent factors, such as age, drug consumption, the presence of cancer or periodontal diseases. However, clinical trials are lacking to prove the direct link between the presence of Prevotella spp. and a worsening of COVID-19, mainly those using azithromycin alone in this indication.

Cervicovaginal DNA Virome Alterations Are Associated with Genital Inflammation and Microbiota Composition

While the link between the cervicovaginal bacterial microbiome, human papillomavirus (HPV) infection, and cervical cancer is recognized (P. Łaniewski, D. Barnes, A. Goulder, H. Cui, et al., Sci. Rep. 8:7593, 2018, http://dx.doi.org/10.1038/s41598-018-25879-7; A. Mitra, D. A. MacIntyre, Y. S. Lee, A. Smith, et al., Sci. Rep. 5:16865, 2015, http://dx.doi.org/10.1038/srep16865; A. Mitra, D. A. MacIntyre, J. R. Marchesi, Y. S. Lee, et al., Microbiome 4:58, 2016, http://dx.doi.org/10.1186/s40168-016-0203-0; J. Norenhag, J. Du, M. Olovsson, H. Verstraelen, et al., BJOG, 127:171-180, 2020, http://dx.doi.org/10.1111/1471-0528.15854; E. O. Dareng, B. Ma, A. O. Famooto, S. N. Adebamowo, et al., Epidemiol. Infect. 144:123-137, 2016, http://dx.doi.org/10.1017/S0950268815000965; A. Audirac-Chalifour, K. Torres-Poveda, M. Bahena-Roman, J. Tellez-Sosa et al., PLoS One 11:e0153274, 2016, http://dx.doi.org/10.1371/journal.pone.0153274; M. Di Paola, C. Sani, A. M. Clemente, A. Iossa, et al., Sci. Rep. 7:10200, 2017, http://dx.doi.org/10.1038/s41598-017-09842-6), the role of the cervicovaginal virome remains poorly understood. In this pilot study, we conducted metagenomic next-generation sequencing of cervicovaginal lavage specimens to investigate the relationship between the cervicovaginal DNA virome, bacterial microbiome, genital inflammation, and HPV infection. Specific virome alterations were associated with features of the local microenvironment related to HPV persistence and progression to cervical cancer. Cervicovaginal viromes clustered distinctly by genital inflammation state. Genital inflammation was associated with decreased virome richness and alpha diversity and an increased abundance of Anelloviridae species from the genus Alphatorquevirus. Lactobacillus bacteriophages were closely associated with increased Lactobacillus abundance, consistent with phage-host relationships. Interestingly, bacteria-bacteriophage transkingdom interactions were linked to genital inflammation and showed specific interactions with bacterial vaginosis-associated bacteria, including Gardnerella, Prevotella, and Sneathia. Taken together, our results reveal prominent virome interactions with features of the cervicovaginal microenvironment that are associated with HPV and cervical cancer. These findings expand our understanding of the cervicovaginal host-microbiome interactions in women's health. IMPORTANCE HPV infection is an established risk factor for cervical cancer. However, more broadly, the role of the cervicovaginal virome in cervical cancer progression is not well understood. Here, we identified cervicovaginal DNA virome alterations associated with local microenvironment factors (vaginal microbiota and genital inflammation) that influence HPV persistence and progression to cervical cancer. These findings indicate that the cervicovaginal virome plays an important role in women's health.

Polymicrobial Interactions Operative during Pathogen Transmission

Pathogen transmission is a key point not only for infection control and public health interventions but also for understanding the selective pressures in pathogen evolution. The “success” of a pathogen lies not in its ability to cause signs and symptoms of illness but in its ability to be shed from the initial hosts, survive between hosts, and then establish infection in a new host. Recent insights have shown the importance of the interaction between the pathogen and both the commensal microbiome and coinfecting pathogens on shedding, environmental survival, and acquisition of infection. Pathogens have evolved in the context of cooperation and competition with other microbes, and the roles of these cooperations and competitions in transmission can inform novel preventative and therapeutic strategies.

Significant and Conflicting Correlation of IL-9 With Prevotella and Bacteroides in Human Colorectal Cancer

Background and aim

Gut microbiota (GM) can support colorectal cancer (CRC) progression by modulating immune responses through the production of both immunostimulatory and/or immunosuppressive cytokines. The role of IL-9 is paradigmatic because it can either promote tumor progression in hematological malignancies or inhibit tumorigenesis in solid cancers. Therefore, we investigate the microbiota–immunity axis in healthy and tumor mucosa, focusing on the correlation between cytokine profile and GM signature.

Methods

In this observational study, we collected tumor (CRC) and healthy (CRC-S) mucosa samples from 45 CRC patients, who were undergoing surgery in 2018 at the Careggi University Hospital (Florence, Italy). First, we characterized the tissue infiltrating lymphocyte subset profile and the GM composition. Subsequently, we evaluated the CRC and CRC-S molecular inflammatory response and correlated this profile with GM composition, using Dirichlet multinomial regression.

Results

CRC samples displayed higher percentages of Th17, Th2, and Tregs. Moreover, CRC tissues showed significantly higher levels of MIP-1α, IL-1α, IL-1β, IL-2, IP-10, IL-6, IL-8, IL-17A, IFN-γ, TNF-α, MCP-1, P-selectin, and IL-9. Compared to CRC-S, CRC samples also showed significantly higher levels of the following genera: Fusobacteria, Proteobacteria, Fusobacterium, Ruminococcus2, and Ruminococcus. Finally, the abundance of Prevotella spp. in CRC samples negatively correlated with IL-17A and positively with IL-9. On the contrary, Bacteroides spp. presence negatively correlated with IL-9.

Conclusions

Our data consolidate antitumor immunity impairment and the presence of a distinct microbiota profile in the tumor microenvironment compared with the healthy mucosa counterpart. Relating the CRC cytokine profile with GM composition, we confirm the presence of bidirectional crosstalk between the immune response and the host’s commensal microorganisms. Indeed, we document, for the first time, that Prevotella spp. and Bacteroides spp. are, respectively, positively and negatively correlated with IL-9, whose role in CRC development is still under debate.

Lactobacillus iners and gasseri, Prevotella bivia and HPV Belong to the Microbiological Signature Negatively Affecting Human Reproduction

Infertile couples undergoing the use of assisted reproductive technology are a good study model to evaluate the microbiological signatures affecting reproductive health. We tested vaginal lavages, follicular fluids, embryo culture mediums, and seminal fluids from 47 couples for their microbiome composition and HPV infection. Twenty-five infertile couples were diagnosed with unexplained infertility, whereas 22 were diagnosed with explained infertility. Lactobacilli were dominant in the vaginal lavages of both patient groups, and the most abundant species was L. iners (CST III), which is linked to a decreased fertility rate. Besides this, L. gasseri—which is known to be associated with oocyte DNA fragmentation and decreased sperm mobility—was identified in the seminal fluids, follicular fluids, and embryo culture media of the unexplained infertility group. Prevotella was increased in the seminal fluids of the explained infertility group, along with HPV-positive seminal fluids: an infection commonly associated with infertility, especially male infertility. Prevotella has been described to negatively affect sperm motility. Taken together, these results suggest that the profiling of the reproductive tract microbiome can add new perspectives to human reproduction.

The Role of the Cervicovaginal Microbiome on the Genesis and as a Biomarker of Premalignant Cervical Intraepithelial Neoplasia and Invasive Cervical Cancer

The microbiome is able to modulate immune responses, alter the physiology of the human organism, and increase the risk of viral infections and development of diseases such as cancer. In this review, we address changes in the cervical microbiota as potential biomarkers to identify the risk of cervical intraepithelial neoplasia (CIN) development and invasive cervical cancer in the context of human papillomavirus (HPV) infection. Current approaches for clinical diagnostics and the manipulation of microbiota with the use of probiotics and through microbiota transplantation are also discussed.