Epigenetic regulatory effects of the methylation of CpG island shore on the expression of lag3 gene in various human T cell lines / 中华微生物学和免疫学杂志

Objective To investigate the effects of DNA methylation on the expression of lympho-cyte activation gene 3 (lag3) in different human T cell lines.Methods A quantitative PCR and a flow cy-tometry analysis were performed to measure the expression of lag3 gene in various T cell lines at mRNA and protein levels.The distribution of CpG sites within the promoter and body of lag3 gene was detected to locate the potential regulatory region(s) (CpG island and CpG island shore).The levels of DNA methylation in each cell line were analyzed.The T cell lines were demethylated with 5-Aza-2′-deoxycytidine (5-Aza-2′-dc) for further investigation on the changes of lag3 gene expression and DNA methylation.Results Jurkat E6-1 cells showed the highest expression level of lag3 gene as compared with J.CaM1.6 and CEM cells.Hyperm-ethylated CpG islands were detected in cells of each cell line.The methylation levels of CpG island shore in J.CaM1.6 and CEM cells were higher than that in Jurkat E6-1 cells.Treatment of J.CaM1.6 and CEM cells with 5-Aza-2′-dc significantly promoted the expression of lag3 gene at mRNA and protein levels as well as the demethylation of CpG island shore.No significant differences with the expression of lag3 gene and the methylation of CpG island were observed in Jurkat E6-1 cells with or without 5-Aza-2′-dc stimulation.Con-clusion Methylation and demethylation of CpG island shore played important roles in regulating the tran-scription of lag3 gene.

Cloning of human LIGHT gene and expression of the cloned molecule on 293T cells / 第三军医大学学报

Objective To clone the full length cDNA of human LIGHT and to construct the recombinant eukaryotic expression plasmid pCI neo LIGHT for the stable expression on 293T cells. Methods Human LIGHT cDNA was cloned from a normal human activated T cell cDNA library phAD.CAD by PCR. After sequencing, LIGHT cDNA was inserted into plasmid pCI neo for the construction of the eukaryotic expression. The recombinant was transfected into 293T cells by electroporation. The expression of LIGHT on the surface of 293T cells was detected by flow cytometry after screening with G418. Results Sequencing confirmed that ORF of LIGHT gene was intact and right. Restrictive enzyme digestion proved that LIGHT gene was inserted into the recombinant plasmid of LIGHT pCI neo correctly. FACS analysis revealed that about 78.69% 293T cells expressed LIGHT protein on the cell surfaces at 3 months after screening with G418. Conclusion LIGHT gene has been cloned successfully, and a 293T cell line expressing LIGHT protein on its membrane surface has been obtained.

Perturbation of host responses by Porphyromonas gingivalis biofilm / 대한치주과학회지

The present study was performed to evaluate how cellular and humoral immune responses were perturbed by immunization of mixed periodontal bacterial biofilms. Each group of mice was immunizared with 1) Porphyromonas gingivalis (P. gingivalis) grown as a planktonic culture, 2) Fusobacterium nucleatum (F. nucleatum), 3) P. gingivalis grown as a biofilm, or 4) mixed P. gingivalis plus F. nucleatum grown as a biofilm culture, respectively. Immune mouse sera were collected from each mouse. Spleens were harvested to isolate T cells and consequently stimulated with antigen presenting cells and P. gingivalis whole cell antigen to establish P. gingivalis-specific T cell lines. There were no significant differences in the mean anti-P. gingivalis IgG antibody titers among mouse groups. Immunization of mice with pure P. gingivalis biofilm or mixed P. gingivalis plus F. nucleatum biofilm resulted in significant reduction of antibody avidity and opsonophagocytosis function. INF-gammaproduction by P. gingivalis-specific T cell lines was also substantially reduced in mouse groups immunized with the biofilm. It was concluded that P. gingivalis biofilm perturbs the cellular and humoral immune responses in periodontal disease.

S Antigen Specific Rat Helper T Cell Line Induced Experimental Autoimmune Uveoretinitis / 대한면역학회지

No abstract available.

STUDIES ON THE ROLE OF SUPPRESSOR T CELL IN RESISTANCE TO EXPERIMENTAL AUTOIMMUNE ENCEPHALITOMYELITIS / 中国免疫学杂志

In order to test whether suppressor T cells are the responsible cell com-ponent in the induced resistance of Lewis rat against reinduction of Exp-erimental Autoimmune Encephalomyelitis(EAE)or not,attempts have beenmade to enrich a T cell population,which were functionally antagonistic tothe encephalitogenic activity of the EAE-inducing autoaggressive T cells,Lewis rats were passively induced for acute EaE by intravenous injectionof encephalitogenic,Myelin Basic Protein(MBP)-specific T line cell(S1cell). Nylon-wool-enriched spleen T cells recovered from animals passivelyinduced EAE,were cultured in vitro with irradiated encephalitogenic Tcells(S1)in the absence of antigen.The selective growth of T cell popula-tion with the phenotype of CD8 were found in the cultures.Functional ch-aracteristics of this cell population were studied both in vivo and in vitro.Thus,the S1-stimulated cells(Anti-S1 cells)are able to suppress both theantigen-and Con A-induced T cell proliferation of the antigenspecificT cell series.Studies on the in vivo activities of the Anti-Si cells couldhave shown that,pretreatment or posttreatment of the normal Lewis reci-pients with isolated Anti-Si cells are able to abolish or prevent thedisease-inducing activity of autoaggressive T cells.