Roles of vaginal flora in human papillomavirus infection, virus persistence and clearance

Cervical microbiota dysbiosis associated with high-risk Human Papillomavirus infection

High-risk Human Papillomavirus (HR-HPV) genotypes, specifically HPV16 and HPV18, pose a significant risk for the development of cervical intraepithelial neoplasia and cervical cancer. In the multifaceted cervical microenvironment, consisting of immune cells and diverse microbiota, Lactobacillus emerges as a pivotal factor, wielding significant influence in both stabilizing and disrupting the microbiome of the reproductive tract. To analyze the distinction between the cervical microbiota and Lactobacillus-dominant/non-dominant status of HR-HPV and non-infected healthy women, sixty-nine cervical swab samples were analyzed, included 44 with HR-HPV infection and healthy controls. All samples were recruited from Human Papillomavirus-based cervical cancer screening program and subjected to 16s rRNA sequencing analysis. Alpha and beta diversity analyses reveal no significant differences in the cervical microbiota of HR-HPV-infected women, including 16 and 18 HPV genotypes, and those with squamous intraepithelial lesion (SIL), compared to a control group. In this study we identified significantly lower abundance of Lactobacillus mucosae in women with HR-HPV infection compared to the control group. Furthermore, changes in bacterial diversity were noted in Lactobacillus non-dominant (LND) samples compared to Lactobacillus-dominant (LD) in both HR-HPV-infected and control groups. LND samples in HR-HPV-infected women exhibited a cervical dysbiotic state, characterized by Lactobacillus deficiency. In turn, the LD HR-HPV group showed an overrepresentation of Lactobacillus helveticus. In summary, our study highlighted the distinctive roles of L. mucosae and L. helveticus in HR-HPV infections, signaling a need for further research to demonstrate potential clinical implications of cervical microbiota dysbiosis.

Cervicovaginal microbiota: a promising direction for prevention and treatment in cervical cancer

Cervical cancer is a common malignancy in women, with high incidence rate and mortality. Persistent infection of high-risk human papillomavirus (HPV) is the most important risk factor for cervical cancer and precancerous lesions. Cervicovaginal microbiota (CVM) plays an essential role in the defense of HPV infections and prevention of subsequent lesions. Dominance of Lactobacillus is the key of CVM homeostasis, which can be regulated by host, exogenous and endogenous factors. Dysbiosis of CVM, including altered microbial, metabolic, and immune signatures, can contribute to persist HPV infection, leading to cervical cancer. However, there is no evidence of the causality between CVM and cervical cancer, and the underlying mechanism remains unexplored. Considering the close correlation between CVM dysbiosis and persistent HPV infection, this review will overview CVM, its role in cervical cancer development and related mechanisms, and the prospects for therapeutic applications.

Human papillomavirus and cervical cancer in the microbial world: exploring the vaginal microecology

The vaginal microbiota plays a crucial role in female reproductive health and is considered a biomarker for predicting disease outcomes and personalized testing. However, its relationship with human papillomavirus (HPV) infection and cervical cancer is not yet clear. Therefore, this article provides a review of the association between the vaginal microbiota, HPV infection, and cervical cancer. We discuss the composition of the vaginal microbiota, its dysbiosis, and its relationship with HPV infection, as well as potential mechanisms in the development of cervical cancer. In addition, we assess the feasibility of treatment strategies such as probiotics and vaginal microbiota transplantation to modulate the vaginal microbiota for the prevention and treatment of diseases related to HPV infection and cervical cancer. In the future, extensive replication studies are still needed to gain a deeper understanding of the complex relationship between the vaginal microbiota, HPV infection, and cervical cancer, and to clarify the role of the vaginal microbiota as a potential biomarker for predicting disease outcomes, thus providing a theoretical basis for personalized testing.

Single and Multiple High-Risk Human Papillomavirus Infections in Histopathologically Confirmed Cervical Squamous Lesions: Incidences, Distribution, and Associated Detection Rates for Precancerous and Cancerous Lesions

Coinfection with multiple high-risk human papillomavirus (hrHPV) is frequently observed in cervical specimens; however, the clinical significance of concomitant multiple hrHPV infections is poorly understood, and the published results remain inconsistent. A retrospective study at a tertiary care institution was performed, evaluating Tellgenplex human papillomavirus (HPV) 27 genotyping or YanengBio HPV 23 genotyping results and immediate cervical histologic diagnosis (within 6 months after HPV genotyping), between November 2015 and October 2022. Among 49,299 cases with hrHPV genotyping and histologic diagnosis, 24,361 cases were diagnosed as cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma. Among women with cervical squamous lesions, 86.5% (21,070/24,361) had hrHPV infections, and concomitant multiple hrHPV infections accounted for 24.7% of hrHPV-positive cases (5210/21,070). The hrHPV-positive rates in these cervical squamous lesions increased progressively with disease severity; however, the percentages of concomitant multiple hrHPV infection rates among hrHPV-positive cases decreased significantly with increasing degree of squamous abnormalities. There was no increased detection rate of CIN3+ (CIN3 and squamous cell carcinoma) in cases with concomitant 2 or 3 hrHPV genotype infections when compared with those with corresponding single hrHPV infections. Conversely, some combinations of multiple hrHPV infections demonstrated a decrease in the detection rates of CIN3+ lesions. In this large cohort, our results demonstrated that multiple hrHPV infections do not carry an increased risk for developing CIN3+ lesions when compared to the corresponding single-genotype infection. The reduced risk of CIN3+ in women infected with some combinations of hrHPV genotypes compared to those with single-genotype infections supports the concept of intergenotypic competition of hrHPV genotypes in cervical squamous lesions.

Association between human papillomavirus infection and common sexually transmitted infections, and the clinical significance of different Mycoplasma subtypes

Introduction

Human papillomavirus (HPV) infection, especially persistent high-risk HPV, is associated with cervical cancer. Female reproductive tract microecological disorders and lower genital tract infections have been increasingly correlated with HPV infection and cervical lesions. Due to their common risk factors and transmission routes, coinfection with other sexually transmitted infections (STIs) has become a concern. Additionally, the clinical significance of Mycoplasma subtypes appear to vary. This study aimed to assess the correlations between common STIs and HPV infection, and to investigate the clinical significance of Mycoplasma subtypes.

Methods

We recruited 1,175 patients undergoing cervical cancer screening at the Peking University First Hospital gynecological clinic from March 2021 to February 2022 for vaginitis and cervicitis tests. They all received HPV genotyping and detection of STIs, and 749 of them underwent colposcopy and cervical biopsy.

Results

Aerobic vaginitis/desquamative inflammatory vaginitis and STIs (mainly single STIs) were found significantly more often in the HPV-positive group than in the HPV-negative group. Among patients with a single STI, rates of infection with herpes simplex virus type 2 or UP6 in the HPV-positive group were significantly higher than in the HPV-negative group (ORadj: 1.810, 95%CI: 1.211–2.705, P=0.004; ORadj: 11.032, 95%CI: 1.465–83.056, P=0.020, respectively).

Discussion

Through detailed Mycoplasma typing, a correlation was found between different Mycoplasma subtypes and HPV infection. These findings suggest that greater attention should be paid to detecting vaginal microecological disorders in those who are HPV-positive. Further, lower genital tract infections, including both vaginal infections and cervical STIs, are significantly more common among women who are HPV-positive and who thus require more thorough testing. Detailed typing and targeted treatment of Mycoplasma should become more routine in clinical practice.

The Female Reproductive Tract Microbiome and Cancerogenesis: A Review Story of Bacteria, Hormones, and Disease

The microbiota is the complex community of microorganisms that populate a particular environment in the human body, whereas the microbiome is defined by the entire habitat-microorganisms and their environment. The most abundant and, therefore, the most studied microbiome is that of the gastrointestinal tract. However, the microbiome of the female reproductive tract is an interesting research avenue, and this article explores its role in disease development. The vagina is the reproductive organ that hosts the largest number of bacteria, with a healthy profile represented mainly by Lactobacillus spp. On the other hand, the female upper reproductive tract (uterus, Fallopian tubes, ovaries) contains only a very small number of bacteria. Previously considered sterile, recent studies have shown the presence of a small microbiota here, but there are still debates on whether this is a physiologic or pathologic occurrence. Of particular note is that estrogen levels significantly influence the composition of the microbiota of the female reproductive tract. More and more studies show a link between the microbiome of the female reproductive tract and the development of gynecological cancers. This article reviews some of these findings.