| Objects1. Observing the changes of KIR gene and KIR ligand gene HLA-C frequency between CHC patients and healthy person in Chinese Han population, we hope to find the relationship between KIR gene, KIR ligand gene HLA-C and HCV persistent infection.2. Aiming to study the influence on the therapeutic effect of CHC gene in Chinese Han population, the variation of KIR gene and KIR ligand gene HLA-C frequency for different effects of treatment were observed after standard therapy.3. The meta-analysis of KIR2DL2on CHC treatment effection were analyzed and summarized, combining the research results on the effects of CHC therapeutic response by Pub-Med data.4. Through regulating the expression of KIR2DL2gene, and observing the characteristics of its effect on NK cell function, the analysis will be draw that how the treatment response of CHC was down-regulated by KIR2DL2. It provided the possible ways and new therapeutic target for CHC treatment and prognosis judgment.Methods1. In Chinese Han population, the CHC patients were defined by ALT detected by biochemical test, anti-hepatitis C virus ELISA, and quantified HCV RNA by realtime-PCR. Those patients excluding HAV, HBV, HDV, HEV, HIV virus infection, were detected by ELISA.2. Extracting DNA from anticoagulant of study subject by saturated salt method, amplifing KIR and HLA-C genotyping of samples with sequence specific primer PCR technology (PCR-SSP), and calculating gene frequency, the results were dealed with by statistical analysis and comparison of differences between CHC patients and healthy controls in Chinese Han population.3. After CHC patients in Chinese Han population received standard treatment at least6months, that is pegylated interferon-α (1.5g/kg body weight/week) and ribavirin (0.9g/day), All patients were divided into two outcome according to previous reported:sustained virological responders(SVR) and nonresponders(NR). Then we extracted DNA, used PCR-SSP to classific KIR and HLA-C, and analysed the differences between SVR and NR more by statistic method.4. The joint analysis of KIR-HLA ligands pairs (i.e., KIR2DL1and C2, KIR2DL2and Cl) revealed an association of both combinations with HCV infection and therapeutic response in Chinese Han population.5. In the PubMed database (1995.11-2013.4), we searched literature with "KIR2DL2" and "HCV" as a keyword, and flited by English writing, the same CHC diagnosis standard and international standard treatment methods, the same results judgment, reported the KIR2DL2genotype frequencies, Hepatitis C patients without other disease. The proper documents for Meta-analysis were determined by heterogeneity, publication bias; calculate the overall risk coefficient selection of the fixed effect model.6. After treating NK92cells with5-Aza-dc, those cells can express KIR2DL2molecules. Observing the effects of different concentration of antibody blocking KIR2DL2receptor, it was detected that NK cell killing ability of K562cells.7. Data are analysed by Statistical Package for Social Sciences (SPSS) version17.0.Results1. As genotyping results showed, the OR values of KIR2DL2, KIR2DS3are greater than1. It indicated two genes frequency of CHC patients are higher than the healthy control group in Chinese Han population, which may be the risk factors for CHC. Moreover, the OR values of HLA-Cw*06, HLA-Cw*15, are less than1. It suggested these genes in Chinese Han patients with CHC frequency is lower than that of healthy controls, these genes are likely to inhibit CHC.2. Accroding from the genotyping results of SVR and NR, it was implied that patients who carry KIR2DL2and HLA-Cw*03have poor effect for tratment of CHC in Chinese Han population.3. As KIR/HLA-C paired analysis described, the OR values of KIR2DL2/HLA-C group1matching was greater than1, while the frequency of the combination in patients with NR is higher than SVR. It suggested this combination could be conducive to the occurrence of CHC and treatment against CHC. However, KIR2DL1/HLA-C group1was on the contrary.4. The Meta analysis results also suggested negative effects of KIR2DL2on CHC therapy.5. After treatment of5-Aza-dc NK92cells, the cells can express higer KIR2DL2molecules. Blocking with20μg/ml KIR2DL2receptor antibody, NK cell killing activity of K562cells increased significantly. Conclusions1. KIR2DL2can inhibit the activity of NK cells;2. KIR2DL2and its receptor HLA-C group1might contribute to the occurrence of CHC and poor response of Peg1FN-alpha and ribavirin combination therapy;3. The frequency of KIR2DS3in CHC patients is higher than the healthy control group; this may be the risk factors of CHC;4. The frequency of HLA-Cw*06, HLA-Cw*15, KIR2DS4in CHC patients is lower than that of healthy controls; these genes are likely to inhibit CHC. |
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