肥胖基因及其产物

肥胖基因及其产物Ｌｅｐｔｉｎ在肥胖的发生中起重要作用，人们已定位克隆了ｏｂ基因并对ｏｂ基因及其调控序列，ｏｂ基因的产物及其功能，各种因素对ｏｂ基因及其产物表达的影响等方面作了深入研究，并提出了机体调节体重的可能途径。本就以上几个方面作一综述。     

中国北方汉族人群TNF-α、VDR基因间交互作用与HBV感染结局相关

目的 探讨肿瘤坏死因子α(TNF-α)和维生紊D受体(VDR)基因多态位点交互作用与2型肝炎病毒(HBV)感染慢性化的关系.方法 391例慢性乙型肝炎(CHB)患者为病例组和212例乙型肝炎病毒自限性感染者为对照组,应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法检测TNF-α基因启动子区-238G/A、-857C/T、-863C/A、VDR-TaqⅠT/C和FokⅠC/T位点的基因型,采用相乘模型分析基因-基因问的交互作用.结果 TNF-α-238 GA与VDR-FokⅠCT/CC(ORint=4.04)、TNF-α-863 CC与-857CC(ORint=1.26)、VDR-FokⅠCT/CC与TNF-α-857CC的基因间(ORint=1.37)均为正交互作用,增加HBV感染发展为慢性乙型肝炎的风险;TNF-α-238 GA与-857 CC(ORint=0.92)、VDR-FokⅠCT/CC与TNF-α-863 CC基因间(ORint=0.95)为负交互作用,降低HBV感染发展为慢性乙型肝炎的风险.结论 TNF-α和VDR基因间交互作用可能影响HBV感染结局.     

NUP98基因融合的研究进展

基因融合是白血病发生的重要原因之一 ,其中涉及多种不同的基因 ,产生多种不同的致癌效应。 NU P98是一种主要参与调节核内外蛋白质和 RNA转运的基因 ,其野生型不具有致癌能力。但当 NU P98与伴侣基因发生融合后 ,其产物具有恶性转化能力 ,目前已发现这类伴侣基因有 13种。本文主要综述 NU P98的生物学特征、NU P98基因融合的种类及其在白血病中的作用机制     

TCRαβ基因结构与重排

ＴＣＲαβ基因是由Ｖ，（Ｄ），Ｊ，Ｃ等不同基因片段组成的，α和β链编码基因在结构上各有其特点，ＴＣＲαβ基因的重排与分子表达是在胸腺内完成的，这一过程受等位基排斥等机制的严格调控，从而确保了Ｔ细胞只能产生来自一个等位基因重排编码的克隆特异的αβＴＣＲ分子。     

肿瘤基因治疗

利用细胞工程技术将外源目的基因导入人体靶细胞或组织以取代有缺陷的基因，通过其正常表达，以达到防治肿瘤的目的。肿瘤基因治疗基本策略主要有以下几种方式：基因替代（gene replacement）、基因修饰（gene modification）、基因添加（gene addition）、基因补充（gene supplement）、基因封闭（gene block）。     

Evi1和MDS1基因

Evil基因在小鼠逆转录病毒诱发的急性髓系白血病(AML)中,是病毒常见的插入位点,在AML发病中起重要作用。MDS基因位于Evil上游,通过选择性剪接,可形成MDS1-Evil基因。本文就Evi-1和MDS1基因的研究近况作一综述。     

心肌梗塞大鼠心肌I,Ⅲ型胶原基因表达的变化

本文使用人胶原α１（Ⅰ）、α２（Ⅱ）及α１（Ⅲ）链ｃＤＮＡ探针，采用斑点杂交法动态观察了心肌梗塞（ＭＩ）大鼠心室各部位Ｉ、Ⅲ型胶原ｍＲＮＡ比值〔Ⅰ／Ⅲ（Ｒ）〕的变化。发现心室各部位Ｉ／Ⅲ（Ｒ）表现出不同的时相变化过程。Ｉ／Ⅲ（Ｒ）的变化与ＩⅢ型胶原蛋白的比值〔Ⅰ／Ⅲ（Ｐ）〕的变化一致。本研究提示ＭＩ后心脏胶原网架的生化改变与基因表达水平的改变有关。     

控制正常人身高的主要基因多态性研究现状

人的身高是基于多种基因的表达调控和环境影响的复杂性状。随着分子生物学的进展,发现相关基因的多态性影响着正常人的终身高。GH1基因、VDR基因、CYP19基因、雌激素受体基因以及Y染色体均与人的身材高矮有密切联系。本文综述了目前对以上基因的多态性与正常成人终身高之间关系的研究现状。     

To B or not to B: role of B cells in pathogenesis of arthritis in HLA transgenic mice

Population studies have shown that amongst all the genetic factors linked with autoimmune disease development, MHC class II genes are the most significant. Experimental autoimmune arthritis resembling human rheumatoid arthritis (RA) can be induced in susceptible strains of mice following immunization with type II collagen (CIA). We generated transgenic mice lacking endogenous class II molecules and expressing various HLA genes including RA-associated, HLA-DRB1*0401 and HLA-DQ8, and RA-resistant, DRB1*0402, genes. The HLA molecules in these mice are expressed on the cell surface and can positively select CD4+ T cells expressing various Vβ T cell receptors. Endogenous class II invariant chain is required for proper functioning of the class II transgene. Arthritis development in transgenic mice is CD4+ and B cells dependent. Studies in humanized mice showed that B cells are required as antigen presenting cells in addition to antibody producing cells for the development of CIA. The transgenic mice expressing *0401 and *0401/DQ8 genes developed sex-biased arthritis with predominantly females being affected, similar to that of human RA. Further, the transgenic mice produced autoantibodies like rheumatoid factor and anti-cyclic antibodies. Antigen presentation by B cells leads to a sex-specific immune response in DRB1*0401 mice suggesting a role of B cells and HLA-DR in rendering susceptibility to develop arthritis in females.     

DRB1*0402 may influence arthritis by promoting naive CD4+ T‐cell differentiation in to regulatory T cells

HLA‐DRB1*0401 expression in humans has been associated with a predisposition to developing rheumatoid arthritis (RA) and collagen‐induced arthritis (CIA), while HLA‐DRB1*0402 is not associated with susceptibility. Here, we determined if mice transgenic (Tg) for human *0401 have a CD4⁺ T‐cell repertoire that predetermines proinflammatory cytokine production. The data show that both *0401 and *0402 Tg mice can produce TH1/TH17 cytokines, although the kinetics of response may be different. However, in the context of antigen‐specific responses in a CIA model, *0402 Tg mice generate a TH2 response that may explain their resistance to developing arthritis. In addition, a significant subset of naïve CD4⁺ T cells from *0402 Tg mice can be activated in polarizing conditions to differentiate into Treg cells that produce IFN‐γ. *0401 Tg mice harbor memory CD4⁺ T cells that differentiate into IL‐17⁺ cells in various polarizing conditions. Our data suggest that *0401 Tg mice generate a strong immune response to lipopolysaccharide and may be efficient in clearing infection, and may *0401 have been evolutionarily selected for this ability. Autoimmunity, such as RA, could likely be a bystander effect of the cytokine storm that, along with the presence of low Treg‐cell numbers in *0401 Tg mice, causes immune dysregulation.     

T cell epitope spreading to myelin oligodendrocyte glycoprotein in HLA-DR4 transgenic mice during experimental autoimmune encephalomyelitis

Epitope spreading has been implicated in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and human multiple sclerosis (MS). T cell epitope spreading has been demonstrated in rodents for myelin basic protein (MBP) and proteolipid protein (PLP) determinants, but not for myelin oligodendrocyte glycoprotein (MOG), another important myelin antigen. Moreover, the role of human autoimmunity-associated MHC molecules in epitope spreading, including HLA-DR2 and DR4, has not been formally examined. To address these questions, we investigated epitope spreading to MOG determinants in HLA-DR4 (DRB1*0401) transgenic mice during EAE. The data show that upon induction of EAE in HLA-DR4 transgenic mice with the immunodominant HLA-DR4-restricted MOG peptide 97-108 (MOG(97-108); TCFFRDHSYQEE), the T cell response diversifies over time to MOG(181-200) (core: MOG(183-191); FVIVPVLGP) and MBP. The spreading epitope MOG(181-200) binds with high affinity to HLA-DRB1*0401 and is presented by human HLA-DRB1*0401+antigen presenting cells. Moreover, this epitope is encephalitogenic in HLA-DRB1*0401 transgenic mice. This study demonstrates intra- and intermolecular epitope spreading to MOG and MBP in "humanized" HLA-DR4 transgenic mice.     

A rapid HLA-DRB1*04 subtyping method using PCR and DNA heteroduplex generators

We describe here a rapid polymerase chain reaction (PCR)-based method for the identification of HLA-DRB1*0401-*0412 alleles. The method is based on the generation of specific DNA heteroduplex patterns between PCR products derived from selective group-specific amplification of the various DRB1*04 alleles and PCR products derived from two synthetic DNA heteroduplex generator (DHG) molecules following non-denaturing polyacrylamide minigel electrophoresis. One DHG was designed to detect DRB1*0401, *0405, *0407, *0408, and *0409 alleles, whilst the other was designed to detect DRB1*0402, *0403, *0404, *0406, *0410, *0411, and *0412 alleles. Characteristic heteroduplex patterns were obtained for all DRB1*04 alleles tested both in homozygous and heterozygous situations. Both DHG and PCR-SSP (sequence-specific primer) typing were performed on 41 DRB1*04 positive DNAs from Singaporean Chinese blood donors and complete concordance in results was obtained. HLA-DRB1*0403, *0405, and *0406 were found to account for 95% of the DRB1*04 alleles in the population studied. The DHG technique described is technically simple and rapid since it essentially involves only two PCR amplifications per individual subtyping. The technique is particularly useful for resolving DRB1*04 combinations which are indistinguishable by PCR-SSO (sequence-specific oligonucleotide) or PCR-SSP subtyping.     

中国湖北汉族HLA—Ⅱ类等痊基因频率的群体调查

调查中国湖北汉族人群ＨＬＡ－Ⅱ类基因频率。方法,用聚合酶链反应／序列特异性引物和聚合酶链反应／限制性片段长度多态性技术,对中国湖北汉族１６８名正常个体进行了ＨＬＡ－ＤＲＢ１（ｎ＝１６８）、ＨＬＡ－ＤＱＢ１（ｎ＝１６０）、ＨＬＡ－ＤＰＢ１（ｎ＝９３）基因的多态性检测。结果共检出３９种ＤＲＢ１、１５种ＤＱＢ１和１７种ＤＰＢ１等位基因型别,等位基因频率较高的分别是：ＤＲＢ１＊０９０１（ｇｅｎｅｆｒｅｑｕ     

Specificity of an HLA-DRB1*0401-restricted T cell response to type II collagen

A panel of HLA-DRB1*0401-restricted CD4⁺ mouse T cell hybridomas specific for bovine type II collagen were generated from transgenic mice expressing the human HLA-DRA1*0101/-DRB1*0401 and CD4 molecules. The vast majority recognized a single peptide determinant corresponding to residues 261–273 (CII 261–273). This determinant was rapidly defined by the use of a predictive algorithm for peptide binding to DRB1*0401. CII 261–273 is conserved in bovine and human type II collagen and overlaps with an important I-A^q-restricted T cell determinant in mice with collagen-induced arthritis. This study demonstrates how HLA-DR and human CD4-transgenic mice can be used to identify a T cell epitope in a potential or candidate autoantigen.     

HLA-DQ and DRB1 polymorphism and susceptibility to type 1 diabetes in Jamaica.

Genetic susceptibility to type 1 diabetes is determined by a combination of HLA-DQ and DRB1 alleles. In the present study, HLA associations with type 1 diabetes were investigated in the Jamaican population. DRB1 and DQ genotyping was performed on 45 type 1 diabetic patients and 132 control subjects born and resident in Jamaica. The small number of patients available for study reflected the low prevalence of type 1 diabetes in Jamaica. The results were compared with those from other African heritage populations and white Caucasians. The highest relative risk was associated with the DRB1*03-DQ2/DRB1*04-DQ8 genotype. Both DRB1*0401-DQ8 and DRB1*0408-DQ8 were positively associated with disease. DRB1*0408-DQ8 is uncommon amongst white Caucasians, where DRB1*0401-DQ8 is the major predisposing haplotype. The DRB1*1503-DQ6 haplotype was associated with protection from diabetes in the Jamaican population. This haplotype is rare amongst white Caucasians, where DRB1*1501-DQ6 is the protective haplotype. Data from African heritage populations suggest that DRB1*1503-DQ6 might be less protective than DRB1*1501-DQ6. DRB1*03-DQA1*0401-DQB1*0402 was associated with protection from diabetes in the Jamaican population, whereas in white Caucasians DRB1*08-DQA1*0401-DQB1*0402 is predisposing. These data demonstrate that comparison of genetic associations with type 1 diabetes in races with population-specific DRB1-DQ haplotypes provides new information as to the exact determinants of disease susceptibility. Further support is provided for roles of the DQ genes and the DRB1 gene (or a gene in linkage disequilibrium with it) in determining susceptibility to type 1 diabetes.     

Different contribution of HLA-DR and -DQ genes in susceptibility and resistance to Insulin-dependent diabetes mellitus (IDDM)

Abstract: Previous studies have indicated that certain alleles of HLA-DR and -DQ genes were strongly associated with susceptibility and resistance to insulin-dependent diabetes mellitus (IDDM), and the role of DQ molecule in IDDM has been suggested. To further clarify the association of DQ alleles with IDDM, we determined the nucleotide sequences of full-length cDNA from 13 DQA1 alleles and 14 DQB1 alleles. The sequencing analysis revealed sequence polymorphisms outside the hypervariable region of DQ genes. We then analyzed the DQA1 and DQB1 polymorphisms along with that of DRB genes in 86 B-lymphoblastoid cell lines (B-LCLs) from various ethnic groups and in healthy unrelated Japanese and Norwegian individuals. The allelic and haplotypic distributions in each population revealed the characteristic haplotypic formation in the HLA class II region. HLA genes in 139 Japanese and 100 Norwegian IDDM patients were analyzed. DQB1*0301 was negatively associated with IDDM in both ethnic groups, irrespective of associated DRB1 and DQA1 alleles. In DQB1*0302 positive populations, which represented a positive association with IDDM in both ethnic groups, DRB1*0401, *0404, *0802 haplotypes increased in the patients, whereas DRB1*0406 haplotype decreased. Considering about the hierarchy in DRB1 alleles with IDDM susceptibility (DRB1*0401>*0404>*0403 in Norwegian and DRB1*0802>*0403>*0406 in Japanese), the genetic predisposition to IDDM is suggested to be defined by the combination of DR-associated susceptibility and DQ-associated susceptibility and by the DQ-associated resistance which is a dominant genetic trait.     

人Man2c1转基因小鼠模型的建立

目的 为在体内研究MAN2C1的生物学意义而建立转hMan2c1基因的小鼠。方法 构建pIRKS2-EGFP-hMan2c1重组表达载体，经体外转染实验鉴定转染的基因能在COS-7细胞表达后，注射人ICR小鼠受精卵，以制备转基因小鼠。用基因组PCR鉴定目的基因在宿主基因组DNA的整合。用RT-PCR和Westernblot分析hMan2c1在转基因小鼠的表达。结果 在116只原代小鼠中，有7只hMan2c1基因组PCR阳性。在所检测的20只F1代小鼠中，有9只hMan2c1基因组PCR阳性。在所检测的21只F2代小鼠中，有16只基因组PCR阳性。用鼠尾组织RT-PCR和Western blot检测hMan2c1基因表达，确定基因组PCR阳性的7个系中有4个系阳性。结论 建立了4个稳定表达hMan2c1的转基因小鼠系，为深入研究MAN2C1的生物学意义打下了基础。     

HLA-DR and HLA-DQ polymorphism in human thyroglobulin-induced autoimmune thyroiditis: DR3 and DQ8 transgenic mice are susceptible

In contrast to H2-based susceptibility to experimental autoimmune thyroiditis (EAT) induced with thyroglobulin (Tg), human leukocyte antigen (HLA) association with Hashimoto's thyroiditis, the human counterpart, is less clear, and determining association is further complicated by DR/DQ linkage disequilibrium. Previously, we addressed the controversial implication of HLA-DR genes by introducing HLA-DRA/DRB1*0301 (DR3) transgene into endogenous class II negative H2Ab(0) mice. EAT induction with either human (h) or mouse (m) Tg demonstrated the permissiveness of DR3 molecules for shared Tg epitopes. Here, we examined the participation of HLA-DQ genes by introducing DQA1*0301/DQB1*0302 (DQ8) transgene into class II negative Ab(0) or class I and II negative beta(2)m((-/-)) Ab(0) mice. About 50% and 80% of HLA-DQ8(+) Ab(0) and beta(2)m(-) Ab(0) mice, respectively, developed moderate EAT after hTg immunization, but only minimal response to mTg. The hTg presentation to hTg-primed cells was blocked by anti-DQ mAb in vitro. By contrast, HLA-DRB1*1502 (DR2) and *0401 (DR4) transgenes contributed little to hTg induction. Similarly, DQA1*0103/DQB1*0601 or DQA1*0103/DQB1*0602 (DQ6) transgenic Ab(0) mice were unresponsive to hTg induction and carried no detectable influence in DQ8/DQ6 double transgenic mice. Thus, both HLA-DR and -DQ polymorphism exists for hTg in autoimmune thyroiditis. The use of defined single or double transgenic mice obviates the complications seen in polygenic human studies.