Expression Of Human Antigen Research Articles

Animal models of autoimmune hepatitis

Animal models of autoimmune hepatitis have been important in defining pathogenic mechanisms, and they promise to aid in the evaluation of new molecular and cellular treatments. They have evolved from models based on crude liver homogenates that produced a transient hepatitis to models that express antibodies to human antigens, manifest liver-infiltrating T cells, persist for at least 3 months and develop fibrosis. Animal models allow the study of autoimmune hepatitis from its inception, and they can detail the progression of pathological events. Key imbalances in counter-regulatory mechanisms can be isolated and manipulated. Models can be humanized by the insertion of human genetic promoters and the expression of human antigens. Genetic engineering and preconditioning have been milestones in the evolution of animal models. Vaccination or infection of murine models with viral vectors carrying human antigens are the most recent developments. Animal models promise to extend the knowledge of etiological agents and improve treatment algorithms.

The expression of human antigen R and vascular endothelial growth factor-C and their significance in non-small cell lung cancer

Vascular endothelial growth factor-C(VEGF-C) plays a critical role in tumor-induced lymphangiogenesis and contributes to lymph node metastasis.Human antigen R(HuR) is one of the firstly identified RNA-binding proteins.It can increase the stability of a variety of growth factors and cytokines and upregulate protein expression.The aim of this study is to investigate the expression of HuR and VEGF-C protein in non-small cell lung cancer(NSCLC),and explore the relationship between the expression of HuR and VEGF-C and clinicopathological factors. HuR and VEGF-C protein levels were detected in 81 NSCLC tissues and 15 control benign pulmonary lesion tissues by immunohistochemistry method(SP method). In NSCLC tissues,positive rate of cytoplasmic HuR,nuclear HuR and VEGF-C was 45.7%(37/81),82.7%(67/81) and 70.4%(57/81),respectively.There was a significant difference in positive expression of HuR and VEGF-C between NSCLC and benign pulmonary lesion tissues(P < 0.05).The expression of cytoplasmic HuR was closely related to pTNM stages,differentiation degree and lymph node metastasis(P < 0.05),but not correlated with sex,age and histological classification(P > 0.05).Furthermore,cytoplasmic immunoreactivity for HuR protein(P < 0.05) but not nuclear HuR expression(P > 0.05) was associated with high VEGF-C expression. Cytoplasmic HuR and VEGF-C are overexpressed in NSCLC,and are related to tumor development.HuR may mediate the modulation of VEGF-C gene expression in NSCLC.

Cell fusion of human and mouse cells as a source for new cells retaining human markers

Flow cytometry and ultrastructural morphometry were used to study some characteristics of cells obtained by fusion with polyethylene-glycol 4000 between mouse fibroblasts 3T3.4E and normal keratinocytes (3T3.4E x NHK) or hand wart human keratinocytes (3T3.4E x HWK), at late passages. The cell cycle and the expression of human beta 2-microglobulin, human EGF-receptors (EGF-r), vimentin were simultaneously studied by flow cytometry. Epithelial CaSki cells, derived from a human uterine carcinoma, expressing high levels of beta 2-microglobulin, EGF-r and vimentin, were used as a positive control. In mouse fibroblasts 3T3.4E only vimentin was expressed whereas in cells derived from fusion, human beta 2-microglobulin, human EGF-r and vimentin were detected. The cell cycle analysis revealed that the peak position of G0/G1 differed with the cells (channel 11 for 3T3.4E cells, 13 for 3T3.4E x HWK and 15 for 3T3.4E x NHK). The area of the cell compartments from each cell type was also different by quantitative ultrastructural morphometry. The hybrid phenotype was maintained in late passages in cells (3T3.4E x NHK) and (3T3.4E x HWK), as shown by the expression of human antigens, differences in DNA contents and nuclear area. Flow cytometry may be a very accurate and precise tool for studying low antigenic expression. The combination of different methods including analysis of DNA content, antigenic expression and ultrastructural morphometry confirmed that 3T3.4E, 3T3.4E x NHK and 3T3.4E x HWK cells are different cell types. These techniques are complementary to cell phenotype analysis.(ABSTRACT TRUNCATED AT 250 WORDS)