Expression of HPV-16 E6 and E7 oncoproteins alters Chlamydia trachomatis developmental cycle and induces increased levels of immune regulatory molecules.

Introduction: Infection with Human Papillomavirus (HPV) is a recognized risk factor for Chlamydia trachomatis (CT) infection and vice versa. Coinfection of HPV and CT in women is a very common and usually asymptomatic finding that has been linked to increased risk of cervical cancer. It has been demonstrated that CT facilitates the entry of multiple high risk HPV genotypes, leading to damage of the mucosal barrier and interfering with immune responses and viral clearance, which ultimately favours viral persistence and malignant transformation. Although the facilitating effects elicited by CT infection on viral persistence have been reported, little is known about the consequences of HPV infection on CT development. Methods: Herein, we took advantage of a genetically modified human cervical cell line co-expressing HPV-16 major oncogenic proteins E6 and E7, as an experimental model allowing to investigate the possible effects that HPV infection would have on CT development. Results and discussion: Our results show that CT infection of HPV-16 E6E7 expressing cells induced an upregulation of the expression of E6E7 oncoproteins and host cell inhibitory molecules PD-L1, HVEM and CD160. Additionally, smaller chlamydial inclusions and reduced infectious progeny generation was observed in E6E7 cells. Ultrastructural analysis showed that expression of E6 and E7 did not alter total bacterial counts within inclusions but resulted in increased numbers of reticulate bodies (RB) and decreased production of infectious elementary bodies (EB). Our results indicate that during CT and HPV coinfection, E6 and E7 oncoproteins impair RB to EB transition and infectious progeny generation. On the other hand, higher expression of immune inhibitory molecules and HPV-16 E6E7 are cooperatively enhanced in CT-infected cells, which would favour both oncogenesis and immunosuppression. Our findings pose important implications for clinical management of patients with HPV and CT coinfection, suggesting that screening for the mutual infection could represent an opportunity to intervene and prevent severe reproductive health outcomes, such as cervical cancer and infertility.

Association between Human Papillomavirus and Chlamydia trachomatis genital infections in male partners of infertile couples.

The prevalence of HPV infection and its relationship with other sexually transmitted infections was analyzed in a cohort of 117 male partners of infertile couples from Cordoba, Argentina. Semen samples and urethral swabs were obtained and the infection with HPV, Chlamydia trachomatis, HSV1, HSV2, Mycoplasma hominis and Ureaplasma urealyticum was analyzed. A prevalence of HPV infection of 27.4% was found. Interestingly, infections by exclusively low risk HPV genotypes or high/intermediate risk HPV genotypes were present in 64.5% and 22.6% of cases, respectively. Low risk-HPV6 was the most frequently detected genotype. Remarkably, HPV and C. trachomatis infections were significantly associated to each other (OR: 11.55, 95% CI 1.14-117.06). No significant differences in sperm quality were found between HPV-positive and HPV-negative patients indicating that HPV male urogenital infection does not impair sperm quality. Our results show a high prevalence of HPV urogenital infection among male partners of infertile couples, and that HPV and C. trachomatis infections are reciprocal risk factors of their co-infection. Moreover, our results suggest that men constitute a reservoir for continued transmission of C. trachomatis and HPV to women highlighting the need for routine screening for these two pathogens in male partners of infertile couples.

Sexually transmitted infections in oral cavity lesions: Human papillomavirus, Chlamydia trachomatis, and Herpes simplex virus.

Objective: Provide evidence of HPV, C. trachomatis, and HSV infection in the oral cavity from patients with different types of stomatological lesions. Materials and Methods: Oral swabs samples were collected from a total of 318 patients. The infectious agents were analyzed using the PCR technique. HPV genotyping and HSV type were studied using the RFLP method. Results: We studied 137 benign lesions (B), 96 potentially malignant disorders (PMD) and 85 oral squamous cell carcinomas (OSCC). The prevalence of HPV was 34%. The most frequently genotypes detected were 6 low risk and 16 high risk. The prevalence of C. trachomatis was 16% and HSV 3%. Co-infections were detected mostly in benign lesions as following: HPV-C. trachomatis in 4%, C. trachomatis- HSV in 1.8% and HPV-HSV in 0.3%. Conclusion: This report is the first contribution to the identification and genotype characterization of HPV in a scenario little studied in our area, and it also contributes to improving our understanding on sexually transmitted infectious agents and their associations with the oral cavity. Besides, we detect the presence of C. trachomatis and HSV and co-infection with HPV in the oral cavity, which they should be taken into account for diagnostic and treatment purposes.

Mutation detection of E6 and LCR genes from HPV 16 associated with carcinogenesis.

Human papillomavirus (HPV) is responsible for one of the most frequent sexually transmitted infections. The first phylogenetic analysis was based on a LCR region fragment. Nowadays, 4 variants are known: African (Af-1, Af-2), Asian-American (AA) and European (E). However the existence of sub-lineages of the European variant havs been proposed, specific mutations in the E6 and LCR sequences being possibly related to persistent viral infections. The aim of this study was a phylogenetic study of HPV16 sequences of endocervical samples from Cordoba, in order to detect the circulating lineages and analyze the presence of mutations that could be correlated with malignant disease. The phylogenetic analysis determined that 86% of the samples belonged to the E variant, 7% to AF-1 and the remaining 7% to AF-2. The most frequent mutation in LCR sequences was G7521A, in 80% of the analyzed samples; it affects the binding site of a transcription factor that could contribute to carcinogenesis. In the E6 sequences, the most common mutation was T350G (L83V), detected in 67% of the samples, associated with increased risk of persistent infection. The high detection rate of the European lineage correlated with patterns of human migration. This study emphasizes the importance of recognizing circulating lineages, as well as the detection of mutations associated with high-grade neoplastic lesions that could be correlated to the development of carcinogenic lesions.