No abstract

A specific immune response to human papillomavirus (HPV) in the cervical microenvironment plays a key role in eradicating infection and eliminating mutated cells. However, high-risk HPVs modulate immune cells to create an immunosuppressive microenvironment, and induce these immune cells to produce interleukin 10 (IL-10). This production of IL-10, in conjunction with HPV infection, contributes to the appearance of cervical neoplastic lesions. We sought to characterize the IL-10-producing cellular phenotype, and investigate the influence of host and HPV factors upon the induction of an immunosuppressive microenvironment. Immunohistochemical analysis demonstrated an increase in IL-10 production by keratinocytes, macrophages and Langerhans cells in high-grade cervical lesions and cervical cancer. This increase was more pronounced in patients older than 30 years, and was also correlated with high viral load, and infection with a single HPV type, particularly high-risk HPVs. Our results indicate the existence of a highly immunosuppressive microenvironment composed of different IL-10-producing cellular phenotypes in cervical cancer samples, and samples classified as high-grade cervical lesions (cervical intraepithelial neoplasia stages II and III). The immunosuppressive microenvironment that developed for these different cellular phenotypes favours viral persistence and neoplastic progression.

No abstract

We analyzed 87 cervical samples from Campo Grande, Mato Grosso do Sul, with a PGMY/GP+ nested PCR system. Positive samples were typed using E7 type-specific primer pairs for HPV 6/11, 16, 18, 45 and 66. Eighteen samples (22%) were infected with HPV6/11, 18 samples (22%) with HPV66, 13 samples (15.9%) with HPV45, 8 samples (9.8%) with HPV18 and 7 samples (8.5%) with HPV16. Seventeen samples (20.7%) were infected by two HPV types, and five samples (6.1%) by three HPV types. We conclude that infection with multiple types is present at a high frequency in our population and that there is a relation between some types and cytological finds.

Persistent infection by high-risk human papillomavirus (HR-HPV) is the main cause of cervical cancer and its precursor lesions. While some cytokines help immune cells in virus clearance, others contribute to the persistence of infection and neoplastic progression. Here, the levels of interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-10, IL-6, IL-4, and IL-2 were quantified in the serum and exfoliated cervical cells (ECCs) of patients with HR-HPV, and the presence of IL-6+ cells was investigated in uterine cervix biopsies. Cytokine levels in the serum and ECCs of 26 HR-HPV DNA-positive patients and 18 HPV DNA-negative patients were measured using flow cytometry. Fifteen uterine cervix biopsy samples embedded in paraffin were subjected to immunohistochemical analysis for the detection of IL-6+ cells. HR-HPV-positive patients showed increased IL-6 and IL-10 in the ECCs and serum, respectively. Compared with HPV DNA-positive patients, HPV DNA-negative patients had higher levels of IL-6 in ECCs. Patients with multiple infections of HPV had higher levels of IL-6 in their ECCs than those with a single infection. Immunostaining of uterine cervix biopsy samples revealed no differences in IL-6 expression between the different classes of histopathological lesions. However, differences were observed in the expression levels of IL-6 and IL-10 at the systemic and local levels in HR-HPV-positive patients without cervical lesions. Considering the functional characteristics of these cytokines, it can be inferred that such patients are prone to persistent HPV infection.