Detection of regulatory T cell phenotypic markers and cytokines in patients with human papillomavirus infection.

Infection with human papillomavirus (HPV) is the main cause of cervical cancer. Viral persistence is considered the main risk factor for neoplastic progression and evidence suggests that regulatory T cells (Treg) play an important role in the failure of viral elimination. The aim of this study was to detect phenotypic markers of Treg and cytokines interleukin (IL)-10 and transforming growth factor (TGF)-ß, in the cervical microenvironment of HPV-infected patients. One hundred and one samples of uterine cervix embedded in paraffin were analyzed. We used immunohistochemistry to examine the coexpression of the CD25/FOXP3 and CD4/TGF-ß markers, and the expression of GITR and IL-10 in cells present in the cervical stroma. We detected a microenvironment composed of high proportions of CD25+ FOXP3+ , CD4+ TGFß+ , IL-10+ , and GITR+ cells in samples with high viral loads and severe lesions of HPV-infected patients. The abundance of these markers, indicative of the presence of Treg cells and immunosuppressive cytokines, was significantly associated with severe lesions and elevated viral loads in the examined samples. These results suggest that Treg cells may be involved in maintaining a microenvironment favorable for viral persistence and neoplastic progression. Our findings support those of previous studies that suggested that these markers could be used to predict HPV persistence and neoplastic progression, and as potential targets for immune response modulation.

Predominant overexpression of CD25/FOXP3, IFN-γ, and suppressive cytokines in high-grade lesion samples infected with human papillomavirus / PPredominância de superexpressão de CD25/FOXP3, IFN-γ e citocinas supressoras em amostras de lesão de alto grau infectadas pelo papilomavírus humano

ABSTRACT Introduction: Human papillomavirus (HPV) persistent infection is the leading cause of cervical cancer and its precursor lesions, and the inappropriate immune response is among the factors that contribute to viral persistence. This may be influenced by regulatory T (Treg) cells and the production of immunosuppressive cytokines, such as transforming growth factor beta (TGF-β) and interleukin-10 (IL-10). Objective: We established the profile of the predominant response, Th1 or immunosuppressive response, in the tissue microenvironment, by detecting interferon-gamma (IFN-γ), TGF-β, and IL-10, as well as the co-expression of IL-2 receptor alpha (CD25) and forkhead box P3 (FOXP3). Methods: Seventy-four samples from uterine cervix biopsies that underwent HPV deoxyribonucleic acid (DNA) detection and histopathology analysis were immunostained to detect CD25/FOXP3, IFN-γ and suppressive cytokines in lymphocytes. Results: The microenvironment of high-grade squamous intraepithelial lesion (HSIL) samples with high numbers of viral particles (≥ 10,000 copies/ml) contained high numbers of CD25/FOXP3+, TGF-β+, IL-10+, and IFN-γ+ cells. Conclusion: The co-expression of CD25/FOXP3 and the expression of TGF-β, and IL-10 in HSIL samples suggest the existence of Treg cells in these locations, although IFN-γ expression was observed in several cells in these samples. Our data suggest that this cytokine could be related to immunosuppressed microenvironment maintenance, favoring the persistent HPV infection and the progression to carcinoma.

RESUMO Introdução: A infecção persistente por papilomavírus humano (HPV) é a principal causa do câncer cervical e suas lesões precursoras, e a resposta imune inadequada está entre os fatores que contribuem para a persistência viral. Isso pode ser influenciado por células T regulatórias (Treg) e pela produção de citocinas imunossupressoras, como o fator de transformação de crescimento beta (TGF-β) e a interleucina 10 (IL-10). Objetivo: Estabelecemos o perfil de resposta predominante, resposta Th1 ou imunossupressora, no microambiente tecidual, pela detecção de interferon gama (IFN-γ), TGF-β, e IL-10, bem como a coexpressão do receptor da cadeia alfa da IL-2 (CD25) e do forkhead box P3 (FOXP3). Método: Setenta e quatro amostras de biópsias de cérvice uterina, submetidas à detecção do ácido desoxirribonucleico (DNA) de HPV e à análise histopatológica, foram utilizadas nas reações de imuno-histoquímica para detectar IFN-γ, TGF-β, IL-10 e CD25/FOXP3 em linfócitos. Resultados: O microambiente das amostras de lesões intraepiteliais escamosas de alto grau (HSIL) com elevado números de partículas virais (≥ 10.000 cópias/ml) continha elevado número de células CD25/FOXP3+, TGF-β+, IL-10+ e IFN-γ+. Conclusão: A coexpressão de CD25/FOXP3 e a expressão de TGF-β nas amostras HSIL sugerem a existência de células Treg nesses locais, embora a expressão de IFN-γ tenha sido observada em várias células. Nossos dados sugerem que essa citocina pode estar relacionada com a manutenção do microambiente imunossuprimido, favorecendo a infecção persistente por HPV e a progressão para carcinoma.