Expression of HLA-E molecules in the placental tissue of women infected with HIV-1 and uninfected women.

INTRODUCTION: Expression of HLA-E molecule in the placental extravillous trophoblast is associated with immune system cell inhibition, resulting in immune tolerance to fetus during pregnancy. HIV-1 can infect trophoblast cells and modify the expression of HLA-E, which may inhibit the cytotoxic activity of the immune system. AIM: The aim of this study was to evaluate HLA-E expression in third trimester placental tissue of women infected with HIV-1 and uninfected women. METHODS: We performed an immunohistochemistry assay to evaluate HLA-E staining in the placental tissue of 99 HIV-1 infected and 85 uninfected women. A pathologist analyzed and classified the HLA-E expression in the placental cells. RESULTS: Irrespective of the HIV status, HLA-E staining was observed in the extravillous trophoblast cells, endothelial cells and Hofbauer cells, but not in the syncytiotrophoblast. HLA-E staining showed no significant difference between the placental tissue of women infected with HIV-1 and uninfected women (P = 0.76). Considering HIV-1 infected women, HLA-E staining was not influenced by HIV-1 viral load (P = 0.48), CD4+ T-cell count (P = 0.10) and antiretroviral therapy used during pregnancy (P = 0.54). DISCUSSION: Despite the presence of HIV-1 infection, the expression of HLA-E molecules in the placental tissue was not modified when the infection was under antiretroviral therapy control.

Greater expression of the human leukocyte antigen-G (HLA-G) and interleukin-17 (IL-17) in cervical intraepithelial neoplasia: analytical cross-sectional study / Aumento da expressão do antígeno leucocitário humano-G (HLA-G) e interleucina-17 (IL-17) em neoplasia intraepitelial cervical: estudo transversal analítico

CONTEXT AND OBJECTIVE:Impaired local cell immunity seems to contribute towards the pathogenesis and progression of cervical intraepithelial neoplasia (CIN), but the underlying molecular mechanisms promoting its progression remain unclear. Identification of new molecular markers for prognosis and diagnosis of early-stage CIN may aid in decreasing the numbers of CIN cases. Several novel immunoregulatory molecules have been discovered over the past few years, including the human leukocyte antigen G (HLA-G), which through interaction with its receptors exerts important tolerogenic functions. Several lines of evidence suggest that T-helper interleukin-17 (IL-17)-producing cells (Th17 cells) may play a role in antitumor immunity. However, recent reports have implicated Th17 cells and their cytokines in both pro and anti-tumorigenic processes. The aim of the study was to evaluate the roles of HLA-G and Th17 in the immunopathogenesis of CIN I.DESIGN AND SETTING:Analytical cross-sectional study with a control group using 58 cervical specimens from the files of a public university hospital providing tertiary-level care.METHODS:We examined HLA-G and IL-17 expression in the cervical microenvironment by means of immunohistochemistry, and correlated these findings with clinical and pathological features.RESULTS:There was a greater tendency towards HLA-G and IL-17 expression in specimens that showed CIN I, thus suggesting that these molecules have a contribution towards cervical progression.CONCLUSION:These findings suggest that HLA-G and IL-17 expression may be an early marker for assessing the progression of cervical lesions.

CONTEXTO E OBJETIVO:A deficiência na imunidade celular localizada parece contribuir para a patogênese e progressão das neoplasias intraepiteliais cervicais (NIC), no entanto, ainda não está totalmente esclarecido o mecanismo molecular fundamental nesse processo de progressão. A identificação de novos marcadores moleculares de prognóstico e diagnóstico das NIC em estágios precoces pode ajudar a diminuir a quantidade de casos de NIC. Várias novas moléculas com função imunorregulatória foram descobertas nos últimos anos, inclusive o antígeno leucocitário humano G (HLA-G), que, através de interação com os receptores, tem importantes funções tolerogênicas. Diversas linhas de evidência sugerem que as células T-ajudantes produtoras de interleucina-17 (IL-17, células Th17), podem desempenhar um papel na imunidade antitumoral. Porém, recentes relatos implicaram as células Th17 e suas citocinas tanto em processos pro- quanto anti-tumorigênicos. O objetivo do estudo foi avaliar o papel do HLA-G e Th17 na imunopatogênese das NIC I.TIPO DE ESTUDO E LOCAL:Estudo transversal analítico com grupo controle em 58 espécimes cervicais dos arquivos de um hospital universitário público com assistência prestada no nível terciário.MÉTODOS:Avaliamos a expressão de HLA-G e IL-17 por imunoistoquímica no microambiente cervical, associando esses achados com as características clínico-patológicas.RESULTADOS:Houve tendência aumentada da expressão de HLA-G e IL-17 em espécimes que apresentaram NIC I, sugerindo que essas moléculas têm contribuição na progressão cervical.CONCLUSÃO:Estes resultados sugerem que a expressão do HLA-G e da IL-17 pode ser um marcador precoce para avaliar a progressão das lesões cervicais.

Greater expression of the human leukocyte antigen-G (HLA-G) and interleukin-17 (IL-17) in cervical intraepithelial neoplasia: analytical cross-sectional study.

CONTEXT AND OBJECTIVE: Impaired local cell immunity seems to contribute towards the pathogenesis and progression of cervical intraepithelial neoplasia (CIN), but the underlying molecular mechanisms promoting its progression remain unclear. Identification of new molecular markers for prognosis and diagnosis of early-stage CIN may aid in decreasing the numbers of CIN cases. Several novel immunoregulatory molecules have been discovered over the past few years, including the human leukocyte antigen G (HLA-G), which through interaction with its receptors exerts important tolerogenic functions. Several lines of evidence suggest that T-helper interleukin-17 (IL-17)-producing cells (Th17 cells) may play a role in antitumor immunity. However, recent reports have implicated Th17 cells and their cytokines in both pro and anti-tumorigenic processes. The aim of the study was to evaluate the roles of HLA-G and Th17 in the immunopathogenesis of CIN I. DESIGN AND SETTING: Analytical cross-sectional study with a control group using 58 cervical specimens from the files of a public university hospital providing tertiary-level care. METHODS: We examined HLA-G and IL-17 expression in the cervical microenvironment by means of immunohistochemistry, and correlated these findings with clinical and pathological features. RESULTS: There was a greater tendency towards HLA-G and IL-17 expression in specimens that showed CIN I, thus suggesting that these molecules have a contribution towards cervical progression. CONCLUSION: These findings suggest that HLA-G and IL-17 expression may be an early marker for assessing the progression of cervical lesions.

Expression of the Classical and Nonclassical HLA Molecules in Breast Cancer.

Considering that downregulation of HLA expression could represent a potential mechanism for breast carcinogenesis and metastasis, the aim of the present study was to use immunohistochemical methods to analyze the expression of HLA-Ia, HLA-DR, HLA-DQ, HLA-E, and HLA-G in invasive ductal carcinoma (IDC) of the breast and to relate this HLA profile to anatomopathological parameters. Fifty-two IDC from breast biopsies were stratified according to histological differentiation (well, moderately, and poorly differentiated) and to the presence of metastases in axillary lymph nodes. The expression of HLA molecules was assessed by immunohistochemistry, using a computer-assisted system. Overall, 31 (59.6%) out of the 52 IDC breast biopsies exhibited high expression of HLA-G, but only 14 (26.9%) showed high expression of HLA-E. A large number (41, 78.8%) of the biopsies showed low expression of HLA-Ia, while 45 (86.5%) showed high expression of HLA-DQ and 36 (69.2%) underexpressed HLA-DR. Moreover, 24 (41.2%) of 52 biopsies had both low HLA-Ia expression and high HLA-G expression, while 11 (21.2%) had low HLA-Ia expression and high HLA-E expression. These results suggest that, by different mechanisms, the downregulation of HLA-Ia, HLA-E, and HLA-DR and the upregulation of HLA-G and HLA-DQ are associated with immune response evasion and breast cancer aggressiveness.

Upregulation of soluble and membrane-bound human leukocyte antigen G expression is primarily observed in the milder histopathological stages of chronic hepatitis C virus infection.

Chronic hepatitis C virus (HCV) infection is a worldwide health problem that may evolve to cirrhosis and hepatocellular carcinoma. Incompletely understood immune system mechanisms have been associated with impaired viral clearance. The nonclassical class I human leukocyte antigen G (HLA-G) molecule may downregulate immune system cell functions exhibiting well-recognized tolerogenic properties. HCV genotype was analyzed in chronic HCV-infected patients. Because HLA-G expression may be induced by certain viruses, we evaluated the presence of HLA-G in the liver microenvironment obtained from 89 biopsies of patients harboring chronic HCV infection and stratified according to clinical and histopathological features. Overall, data indicated that HCV genotype 1 was predominant, especially subgenotype 1a, with a prevalence of 87%. HLA-G expression was observed in 45 (51%) liver specimens, and it was more frequent in milder stages of chronic hepatitis (67.4%) than in moderate (27.8%; p = 0.009) and severe (36.0%; p = 0.021) stages of the disease. Altogether, these results suggest that the expression of HLA-G in the context of HCV is a complex process modulated by many factors, which may contribute to an immunologic environment favoring viral persistence. However, because the milder forms predominantly expressed HLA-G, a protective role of this molecule may not be excluded.

Alkaloids extracted from Pterogyne nitens induce apoptosis in malignant breast cell line.

In the present study, two alkaloids isolated from Pterogyne nitens, a plant native to Brazil, have been shown to induce apoptosis in human breast cancer cells. These compounds, pterogynine (PGN) and pterogynidine (PGD), were tested for their effect on a human infiltrating ductal carcinoma cell line (ZR-7531). The cell line was treated with each alkaloid at several concentrations. Time-dependence (with or without recuperation time) and concentration-dependence (in the range 0.25-10 mM) were investigated in cytotoxicity and apoptosis assays. The annexin assay indicated an apparently higher percentage of death by necrosis of malignant cells after 24 h exposure to both P. nitens extracts than the Hoechst assay. Thus, our results in the two tests demonstrated that the Hoechst assay can discriminate between late apoptotic cells and necrosis, whereas the flow cytometry-based annexin V assay cannot. We concluded that PGN and PGD have effective antineoplastic activity against human breast cancer cells in vitro, by inducing programmed cell death.