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1.
用放射免疫分析方法测定了45峰双峰驼血清样品中类人乙型肝炎表面抗原(HBsAg)、乙型肝炎表面抗体(抗-HBs)、乙型肝炎核心抗原(HBcAg)、乙型肝炎核心抗体(抗-HBc.IgM)、乙型肝炎e抗原(HBeAg)和乙型肝炎e抗体(抗-HBe),结果仅检测到1例抗-HBs阳性样品,总阳性率为2.11%,其SX/NcX=12.233。  相似文献   

2.
禽类血管活性肠肽与乙肝病毒核心抗原融合基因的构建   总被引:2,自引:0,他引:2  
在制备以禽类血管活性肠肽(VIP)为基础的基因工程疫苗工作中,选择乙肝病毒核心抗原(HBcAg)作为载体来提高鹅VIP的免疫原性,首先将克隆于鹅VIP cDNA和HBc基因第1至435bp的序列片段先后插入到质粒pRSET A的BamH I/EcoR I和Nhe I/BamH I克隆位点之间,构建成VIP序列位于HBc序列之后的VIP融合基因的重组质粒pHBc-VIP,其次将HBc第1至225bp序列的扩增片段和HBc第244bp之间包括VIP的充列经扩增,EcoR I酶切,连接,再扩增的片段先后插入到质粒pBSKS /-的BamH\Pst和Pst\HindⅢ克隆位点,构建成VIP持入到HBc基因中间(HB cAg的第75和82位氨基酸之间)融合基因的重组质粒pVIP-HBc.  相似文献   

3.
Alteration of T-cell functions by infection with HTLV-I or HTLV-II   总被引:18,自引:0,他引:18  
Two functionally different types of human T-cell clones, one with helper function and two with specific activity, were infected with different isolates of HTLV-I and HLTV-II. Both types of human T cells showed alterations in specific function after infection with either of the HTLV subgroups. Before HTLV infection, the T-cell clone with helper function proliferates and provides help to B cells only in the presence of both a specific soluble antigen (keyhole limpet hemocyanin) and histocompatible antigen-presenting cells. After HTLV infection, these cells respond with increased proliferation and indiscriminant stimulation of polyclonal immunoglobulin production by B cells, regardless of the histocompatibility of the antigen-presenting cells or the presence of the soluble antigen. Infection of the normal cytotoxic T-cell clones led to a dimunition or loss of the cytotoxic function. The results of these studies suggest some possible mechanisms for induction of immune deficiency and of polyclonal B-cell activation by viruses of the HTLV family.  相似文献   

4.
A model is proposed to explain the presence of the e antigen (HBeAg) of hepatitis B virus (HBV) in the serum of individuals infected with this virus. The e antigen, which has only recently been characterized, is a fragment of the virus core, or nucleocapsid, protein. Serum HBeAg is a valuable clinical marker for active HBV infection because its appearance correlates both with virus replication in the liver and with the presence of circulating virions. In this study a protease-like amino acid sequence was identified at the amino terminus of the core protein sequence. Experimental evidence indicates that HBeAg may be produced by proteolytic self-cleavage of the core protein.  相似文献   

5.
ELISA法与FQ-PCR对HBV三种血清标志物检测结果的比较   总被引:1,自引:1,他引:0  
为了探讨与评价联合检测乙型肝炎HBeAg和Pre-S1Ag、HBV-DNA等血清免疫标志物在乙型病毒性肝炎临床诊断、治疗中的意义,利用酶联免疫吸附试验(ELISA)和荧光实时定量聚合酶链式反应(FQ-PCR),对619例疑似或确诊乙肝患者的血清样本分别进行乙肝免疫标志物HBeAg、Pre-S1Ag和HBV-DNA的联合检测。结果表明,血清乙肝免疫标志物HbeAg检测为阴性时,不能完全表明患者乙肝病毒复制终止或病毒血症的消失;血清Pre-S1Ag检测结果有助于乙型肝炎的早期诊断,也可以作为乙肝病毒DNA复制的指标之一;而FQ—PCR检测血清HBVDNA结果则有助于乙型肝炎病毒的抗原或抗体血清滴度较低时肝炎的诊断。  相似文献   

6.
T-cell tumor elimination as a result of T-cell receptor-mediated activation   总被引:5,自引:0,他引:5  
It has recently been shown that activation of murine T-cell hybridomas with antigen inhibits their growth in vitro. The "suicide" of these neoplastic T cells upon stimulation with antigen suggested the possibility that activation via the antigen-specific receptor could also inhibit the growth of neoplastic T cells in vivo. To test this, mice were subcutaneously inoculated with antigen-specific T-cell hybridomas and then treated intraperitoneally with antigen. Administration of the appropriate antigen immediately after inoculation with the T-cell hybridoma abrogated tumor formation; antigen administered after tumors had become established decreased the tumor burden and, in a substantial fraction of animals, led to long-term survival. The efficacy of antigen therapy was due to both a direct inhibitory effect on tumor growth and the induction of host immunity. These studies demonstrate the utility of cellular activation as a means of inhibiting neoplastic T-cell growth in vivo and provide a rationale for studying the use of less selective reagents that can mimic the activating properties of antigen, such as monoclonal antibodies, in the treatment of T-cell neoplasms of unknown antigen specificity.  相似文献   

7.
8.
Specific expression of hepatitis B surface antigen (HBsAg) in transgenic mice   总被引:27,自引:0,他引:27  
Two transgenic mice were obtained that contain in their chromosomes the complete hepatitis B virus (HBV) genome except for the core gene. These mice secrete particles of HBV surface antigen (HBsAg) in the serum. In one mouse, HBV DNA sequences that had integrated at two different sites were shown to segregate independently in the first filial generation (F1) and only one of the sequences allowed expression of the surface antigen. Among these animals the males produced five to ten times more HBsAg than the females. A 2.1-kilobase messenger RNA species comigrating with the major surface gene messenger RNA is expressed specifically in the liver in the two original mice. The results suggest that the HBV sequences introduced into the mice are able to confer a tissue-specific expression to the S gene. In addition, the HBV transgenic mice represent a new model for the chronic carrier state of hepatitis B virus infection.  相似文献   

9.
New method for detecting cellular transforming genes   总被引:24,自引:0,他引:24  
Tumor induction in athymic nude mice can be used to detect dominant transforming genes in cellular DNA. Mouse NIH 3T3 cells freshly transfected with either cloned Moloney sarcoma proviral DNA or cellular DNA's derived from virally transformed cells induced tumors when injected into athymic nu/nu mice. Tumors were also induced by cells transfected with DNA from two tumor-derived and one chemically transformed human cell lines. The mouse tumors induced by human cell line DNA's contained human DNA sequences, and DNA derived from these tumors was capable of inducing both tumors and foci on subsequent transfection. Tumor induction in nude mice represents a useful new method for the detection and selection of cells transformed by cellular oncogenes.  相似文献   

10.
目的:观察乙型肝炎病毒(HBV)与戊型肝炎病毒(HEV)重叠感染对HBV复制的影响。方法:以血清HBsAg和抗HEV均阳性患者36例作为重叠组,以单纯HBV感染患者36例作为对照组。两组病例抗HAV-IgM和抗HCV均为阴性。采用ELISA法测定两组的HBV-M。结果:重叠组血清HBeAg的阳性率明显低于对照组(P<0.001),抗HBe阳性率明显高于对照组(P<0.05)。结论:HBV与HEV重叠感染后,HBV的复制受到一定程度的抑制  相似文献   

11.
In an attempt to establish a model of the healthy carrier state in hepatitis B virus (HBV) infections, transgenic mice expressing HBV genes were produced. Fertilized one-cell eggs were microinjected with subgenomic fragments of HBV DNA containing the coding regions for the HBV surface antigen (HBsAg) and pre-S and X antigens. Either the normal (HBV) or metallothionein promoters were used to obtain expression of the HBV genes. There was no evidence of viral replication or tissue pathology. The integrated HBV DNA sequences were inherited in a normal Mendelian fashion. Three of 16 transgenic mice expressed HBV-encoded gene products to which they were immunologically tolerant. Expression was not tissue specific and may be influenced by the genomic integration site and cellular factors. Both HBsAg and pre-S antigen were detectable within the cytoplasm of hepatocytes and renal tubular epithelial cells. High serum concentrations of HBsAg were detectable and the secreted product appeared authentic as judged by mean density, morphology, mean particle diameter, polypeptide composition, and antigenicity. The absence of tissue pathology in these immunologically tolerant animals supports the hypothesis that cellular injury under these conditions is not a direct consequence of expression of the pre-S or HBs regions of the HBV genome.  相似文献   

12.
目的:了解健康人群HBV感染及获得性免疫的状况,为更好的防治乙型肝炎提供客观依据.方法:采用ELISA法检测健康体检人群血清中HBsAg、HBsAb、HBeAg、HBeAb、HBcAb五项指标并对结果进行统计学分析.结果:8995例健康人群血清中HBV抗原抗体系统五项指标阴性者为48.4%,抗-HBs阳性者为44.7%,感染指标阳性者为6.9%,出现10种感染模式:五项指标均阴性;抗-HBs阳性;HBsAg阳性;抗-HBe阳性;HBsAg、HBeAg、HBcAb三项阳性;HBsAg、HBeAb、HBcAb三项阳性;HBsAg、HBeAb两项阳性;HBsAb、HBeAb、HBcAb三项阳性;HBeAb、HBcAb两项阳性和HBsAg、HBcAb两项阳性.结论:健康人群HBV感染近年来明显下降而免疫力明显上升,但尚有近1/2的人缺乏免疫力,并存在少数传染性强的乙型肝炎患者;应提倡健康人群普种乙肝疫苗,即使注射了乙肝疫苗也要注意自身一般性预防,常规检测乙肝五项指标,及时发现病情及早治疗.  相似文献   

13.
Immunodominant, disulfide-bond independent epitopes recognized by human antibodies to hepatitis B virus (HBV) are located within the 55-residue amino terminal portion (coded for by the pre-S region of HBV DNA) of minor HBV envelope components larger than the major protein constituents encoded by the S gene. A peptide having the sequence of the first 26 amino acids from the amino terminal methionine was synthesized and elicited antibodies (at dilutions of greater than or equal to 1 to 10(5) ) to the HBV envelope. These antibodies can be utilized for diagnostic tests. The immunogenicity of the peptide was substantially increased by covalent attachment to liposomes. The disulfide bond-independent determinants on sequences coded for by the pre-S gene may be more easily mimicked by peptide analogs than "conformational" determinants on the S-gene product.  相似文献   

14.
用PCR和ELISA方法分析奶牛血清和奶中类乙型肝炎病毒   总被引:4,自引:0,他引:4  
用人乙型肝炎病毒(HBV)表面抗原(HBsAg)和e抗原(HBeAg)ELISA试剂盒检测85份奶牛血清和93份奶样。结果测出33份血清为HBsAg阳性,其中4价亦为HBeAg阳性;22份奶样为HBsAg阳性,其中11份亦为HBsAg阳性。7个双阳性的样本,用针对HBV表面抗原基因不同部位的两对引物作PCR分析,结果未能扩增出特异片段,排除了奶牛HBV血清学阳性是由人HBV感染所致。  相似文献   

15.
In this study, we introduced the bovine immunoglobulin μ heavy-chain gene (the orphaned gene on BTA11) into mouse germline cells. Bovine IgM was highly expressed in selected transgenic lines, and it largely inhibited rearrangements of the endogenous immunoglobulin heavy chain (IgH) genes in these lines. The forced expression of bovine IgM resulted in reduced numbers of pro- and pre-B cells but increased the number of immature B cells in the transgenic mice. Bovine IgM-expressing B cells can migrate from the bone marrow to the spleen, but most of the cells are arrested at the T1 transitional B cell stage, leading to a significantly lower number of T2 transitional and mature B cells in the spleen. Although the serum concentrations of endogenous IgM and IgG in the transgenic mice were significantly decreased, the IgA levels were slightly increased compared to the WT mice. The bovine IgM level in the serum was only one-tenth to one-fifth of that of endogenous mouse IgM, suggesting that most of the serum immunoglobulin were contributed by endogenous IgH gene-expressing B cells. These transgenic mice also exhibited a lower frequency of unique complementarity determining region 3 (CDR3) sequences in their VH repertoire and Vκ repertoire but exhibited an increased frequency of unique CDR3 in their Vλ repertoire. Compared to the WT mice, the transgenic mice had a significantly higher percentage of mouse IgM-expressing B cells that expressed λ chains. Finally, we showed that the transgenic mice were deficient in a specific antibody response to antigen stimulation.  相似文献   

16.
Proteosomes are hydrophobic, membranous, multimolecular preparations of meningococcal outer membrane proteins that are also B cell mitogens. These characteristics suggested that proteosomes may serve as carrier proteins and adjuvants to enhance peptide immunogenicity. Although high titers of malaria circumsporozoite (CS) antibodies protect against malaria, vaccines thus far tested in humans have been insufficiently immunogenic to be clinically useful. Here it is shown that synthetic CS peptides hydrophobically complexed to proteosomes by way of lauroyl-cysteine become highly immunogenic in mice without other adjuvants. The high titers of antibodies produced and the safety of proteosomes in humans suggest that this novel system is widely applicable for the development of peptide vaccines to protect against many diseases.  相似文献   

17.
In cats, infection with T-lymphotropic retroviruses can cause T-cell proliferation and leukemia or T-cell depletion and immunosuppression. In humans, some highly T4 tropic retroviruses called HTLV-I can cause T-cell proliferation and leukemia. The subgroup HTLV-II also induces T-cell proliferation in vitro, but its role in disease is unclear. Viruses of a third subgroup of human T-lymphotropic retroviruses, collectively designated HTLV-III, have been isolated from cultured cells of 48 patients with acquired immunodeficiency syndrome (AIDS). The biological properties of HTLV-III and immunological analyses of its proteins show that this virus is a member of the HTLV family, and that it is more closely related to HTLV-II than to HTLV-I. Serum samples from 88 percent of patients with AIDS and from 79 percent of homosexual men with signs and symptoms that frequently precede AIDS, but from less than 1 percent of heterosexual subjects, have antibodies reactive against antigens of HTLV-III. The major immune reactivity appears to be directed against p41, the presumed envelope antigen of the virus.  相似文献   

18.
Analysis of the cell culture fluid from two new human hepatoma-derived cell lines reveals that 17 of the major human plasma proteins are synthesized and secreted by these cells. One of these cell lines, Hep 3B, also produces the two major polypeptides of the hepatitis B virus surface antigen. When Hep 3B in injected into athymic mice, metastatic hepatocellular carcinomas appear. These cell lines provide experimental models for investigation of plasma protein biosynthesis and the relation of the hepatitis B viru genome to tumorigenicity.  相似文献   

19.
Tetanus-toxoid specific helper-inducer T-cell clones, which had been infected and transformed by human T-cell leukemia-lymphoma virus (HTLV-I), were obtained from an antigen-specific human T cell line by using a limiting dilution technique in the presence of the virus. These HTLV-I-infected T-cell clones proliferated specifically in response to soluble tetanus toxoid but, unlike normal T cells, they could do so in the absence of accessory cells. The HTLV-I-infected T-cell clones did not present the antigen to autologous antigen-specific T cells that were not infected with HTLV-I. The capacity of helper-inducer T cells to retain antigen-specific reactivity after infection by HTLV-I, while losing the normal T-cell requirement for accessory cells, has clinical and theoretical implications.  相似文献   

20.
Dependence of self-tolerance on TRAF6-directed development of thymic stroma   总被引:1,自引:0,他引:1  
The microenvironments of the thymus are generated by thymic epithelial cells (TECs) and are essential for inducing immune self-tolerance or developing T cells. However, the molecular mechanisms that underlie the differentiation of TECs and thymic compartmentalization are not fully understood. Here we show that deficiency in the tumor necrosis factor receptor-associated factor (TRAF) 6 results in disorganized distribution of medullary TECs (mTECs) and the absence of mature mTECs. Engraftment of thymic stroma of TRAF6(-/-) embryos into athymic nude mice induced autoimmunity. Thus, TRAF6 directs the development of thymic stroma and represents a critical point of regulation for self-tolerance and autoimmunity.  相似文献   

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