MHC class I-related chain A and B ligands are differentially expressed in human cervical cancer cell lines

<p>Abstract</p> <p>Background</p> <p>Natural killer (NK) cells are an important resource of the innate immune system directly involved in the spontaneous recognition and lysis of virus-infected and tumor cells. An exquisite balance of inhibitory and activating receptors tightly controls the NK cell activity. At present, one of the best-characterized activating receptors is NKG2D, which promotes the NK-mediated lysis of target cells by binding to a family of cell surface ligands encoded by the MHC class I chain-related (MIC) genes, among others. The goal of this study was to describe the expression pattern of MICA and MICB at the molecular and cellular levels in human cervical cancer cell lines infected or not with human papillomavirus, as well as in a non-tumorigenic keratinocyte cell line.</p> <p>Results</p> <p>Here we show that MICA and MICB exhibit differential expression patterns among HPV-infected (SiHa and HeLa) and non-infected cell lines (C33-A, a tumor cell line, and HaCaT, an immortalized keratinocyte cell line). Cell surface expression of MICA was higher than cell surface expression of MICB in the HPV-positive cell lines; in contrast, HPV-negative cells expressed lower levels of MICA. Interestingly, the MICA levels observed in C33-A cells were overcome by significantly higher MICB expression. Also, all cell lines released higher amounts of soluble MICB than of soluble MICA into the cell culture supernatant, although this was most pronounced in C33-A cells. Additionally, Real-Time PCR analysis demonstrated that MICA was strongly upregulated after genotoxic stress.</p> <p>Conclusions</p> <p>This study provides evidence that even when MICA and MICB share a high degree of homology at both genomic and protein levels, differential regulation of their expression and cell surface appearance might be occurring in cervical cancer-derived cells.</p

Substantial increase in the frequency of circulating CD4+NKG2D+ T cells in patients with cervical intraepithelial neoplasia grade 1

Abstract Background The NKG2D receptor confers important activating signals to NK cells via ligands expressed during cellular stress and viral infection. This receptor has generated great interest because not only is it expressed on NK cells, but it is also seen in virtually all CD8+ cytotoxic T cells and is classically considered absent in CD4+ T cells. However, recent studies have identified a distinctive population of CD4+ T cells that do express NKG2D, which could represent a particular cytotoxic effector population involved in viral infections and chronic diseases. On the other hand, increased incidence of human papillomavirus-associated lesions in CD4+ T cell-immunocompromised individuals suggests that CD4+ T cells play a key role in controlling the viral infection. Therefore, this study was focused on identifying the frequency of NKG2D-expressing CD4+ T cells in patients with cervical intraepithelial neoplasia (CIN) 1. Additionally, factors influencing CD4+NKG2D+ T cell expansion were also measured. Results Close to 50% of patients with CIN 1 contained at least one of the 37 HPV types detected by our genotyping system. A tendency for increased CD4+ T cells and CD8+ T cells and decreased NK cells was found in CIN 1 patients. The percentage of circulating CD4+ T cells co-expressing the NKG2D receptor significantly increased in women with CIN 1 versus control group. Interestingly, the increase of CD4+NKG2D+ T cells was seen in patients with CIN 1, despite the overall levels of CD4+ T cells did not significantly increase. We also found a significant increase of soluble MICB in CIN 1 patients; however, no correlation with the presence of CD4+NKG2D+ T cells was seen. While TGF-beta was significantly decreased in the group of CIN 1 patients, both TNF-alpha and IL-15 showed a tendency to increase in this group. Conclusions Taken together, our results suggest that the significant increase within the CD4+NKG2D+ T cell population in CIN 1 patients might be the result of a chronic exposure to viral and/or pro-inflammatory factors, and concomitantly might also influence the clearance of CIN 1-type lesion

Substantial increase in the frequency of circulating CD4+

BACKGROUND: The NKG2D receptor confers important activating signals to NK cells via ligands expressed during cellular stress and viral infection. This receptor has generated great interest because not only is it expressed on NK cells, but it is also seen in virtually all CD8(+) cytotoxic T cells and is classically considered absent in CD4(+) T cells. However, recent studies have identified a distinctive population of CD4(+) T cells that do express NKG2D, which could represent a particular cytotoxic effector population involved in viral infections and chronic diseases. On the other hand, increased incidence of human papillomavirus-associated lesions in CD4(+) T cell-immunocompromised individuals suggests that CD4(+) T cells play a key role in controlling the viral infection. Therefore, this study was focused on identifying the frequency of NKG2D-expressing CD4(+) T cells in patients with cervical intraepithelial neoplasia (CIN) 1. Additionally, factors influencing CD4(+)NKG2D(+) T cell expansion were also measured. RESULTS: Close to 50% of patients with CIN 1 contained at least one of the 37 HPV types detected by our genotyping system. A tendency for increased CD4(+) T cells and CD8(+) T cells and decreased NK cells was found in CIN 1 patients. The percentage of circulating CD4(+) T cells co-expressing the NKG2D receptor significantly increased in women with CIN 1 versus control group. Interestingly, the increase of CD4(+)NKG2D(+) T cells was seen in patients with CIN 1, despite the overall levels of CD4(+) T cells did not significantly increase. We also found a significant increase of soluble MICB in CIN 1 patients; however, no correlation with the presence of CD4(+)NKG2D(+) T cells was seen. While TGF-beta was significantly decreased in the group of CIN 1 patients, both TNF-alpha and IL-15 showed a tendency to increase in this group. CONCLUSIONS: Taken together, our results suggest that the significant increase within the CD4(+)NKG2D(+) T cell population in CIN 1 patients might be the result of a chronic exposure to viral and/or pro-inflammatory factors, and concomitantly might also influence the clearance of CIN 1-type lesion

Bacterial Translocation Is Linked to Increased Intestinal IFN-γ, IL-4, IL-17, and mucin-2 in Cholestatic Rats

Background and rationale for the study. Bacterial translocation is an important triggering factor of infection and mortality in cirrhosis. In a rat model using bile duct ligation (BDL), bacterial translocation appears within 24 h after ligation. The dynamic between TH1/TH2/TH17 cytokines and the integrity of the colonic mucosa in the context of cirrhosis is little known. This study aims to determine the link between bacterial translocation and intestinal inflammation in a cholestasis model. Additionally, alterations of the colonic mucus layer and the bacterial load were also addressed.Results. Bacterial translocation detected by microbiological cultures and MALDI-TOF showed that Escherichia coli predominates in mesenteric lymph nodes of BDL rats. Intestinal bacterial load analyzed by qPCR indicates a dramatic Escherichia/Shigella overgrowth at 8 and 30 days post-BDL. IFN-γ, IL-4, and IL-17 evaluated by Western blotting were increased at 8 and 30 days in the small intestine. In the colon, in contrast, only IFN-γ was significantly increased. The colonic mucus layer and mucin-2 expression determined by Alcian blue staining and immunohistochemistry surprisingly showed an increase in the mucus layer thickness related to increased mucin-2 expression during the entire process of liver damage. Hepatic enzymes, as well as collagen I, collagen III, TNF-α, and IL-6 liver gene expression were increased.In conclusion, bacterial overgrowth associated with bacterial translocation is linked to the over-expression of IFN-γ, IL-4, IL-17 and mucin-2. These molecules might facilitate the intestinal permeability through exacerbating the inflammatory process and disturbing tight junctions, leading to the perpetuation of the liver damage