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1.
Neuroblastoma cell lines can have very low MHC Ag expression. The cell lines are insensitive to allo-killing by primed CTL, but are sensitive to non-MHC-restricted cytotoxicity. IFN-gamma increased class I expression, but the cells remained insensitive to CTL. Susceptibility to nonrestricted effectors was preserved. Class I+ glioma cell lines behaved similarly. The CTL resistance was localized to the recognition phase. Neuroblastoma lines did not form conjugates with primed T cells, but were lysed if they were coupled to the effectors via lectins. The levels of class I expression, and resistance to CTL, were constant over a range of IFN doses. HLA-A,B,C structure and distribution were studied more intensively on one cell line, CHP-100. HLA-A2 and -A3 were present on greater than or equal to 99% of the cells, in a unimodal distribution. After IFN treatment, the levels were similar to B cell controls. In two-dimensional gel electrophoresis, the molecules co-migrated with those of B cell controls. The defect may thus be in accessory proteins that are necessary for T cell recognition or binding, rather than in the structure or distribution of the HLA-A,B,C proteins.  相似文献   

2.
Gur'ev IP 《Genetika》2004,40(4):560-564
Published data on two cases of linkage disequilibrium in Yakuts are analyzed. These are the disequilibria between loci HLA-A and HLA-B and between the mutation of gene SCA1 responsible for type 1 spinocerebellar ataxia and its flanking microsatellites D6S274 and D6S89. Both cases are regarded as consequences of the founder effect. The genetic archeological approach has been used to calculate the historical period when the mutant SCA1 gene and the HLA-A1\B17 haplotype spread in the population. It has been found that this was approximately 60-70 generations (1500-1750 years) ago in both cases. The time of the segregation of haplotype HLA-A1\B17 has also been calculated for some other populations. Caucasoids have proved to be the oldest carriers of this gene, which agrees with the well-known notion that HLA-A1 originated in Indo-Europeans. The general distribution of HLA genes in Yakuts is similar to that in east-central Asian Mongoloids; therefore, it is concluded that that Yakuts are east-central Asian Mongoloids by origin, except for the founder that had haplotype A1\B17. Historically, the time of the appearance of this haplotype coincided with the period when Saks conquered east-central Asia; therefore, it is hypothesized that the aforementioned founder was a Sak.  相似文献   

3.
The distribution of the antigens of the HLA system in 517 erysipelas patients, constant residents of Voroshilovgrad and the adjoining region (the Ukrainian SSR), has been studied. The HLA system has been found to take part in the formation of predisposition to erysipelas and its clinical forms. Predisposition to erysipelas infection has a polygenic nature and is associated with antigens HLA-A2, B5, B12, Bw35. The specific features of HLA-A10, Aw12, B7, B8 have, seemingly, a protective character. The most pronounced connection between the disease and histocompatibility antigens has been detected in patients with frequent and multiple relapses of erysipelas.  相似文献   

4.
Diversity and diversification of HLA-A,B,C alleles   总被引:20,自引:0,他引:20  
The nucleotide sequences encoding 14 HLA-A,B,C and 5 ChLA-A,B,C molecules have been determined. Combining these sequences with published data has enabled the polymorphism in 40 HLA-A,B,C and 9 ChLA-A,B,C alleles to be analyzed. Diversity is generated through assortment of point mutations by recombinational mechanisms including gene and allelic conversions. The distribution and frequency of silent and replacement substitutions indicate that there has been positive selection for allelic diversity in the 5' part of the gene (exons 1 to 3) and for allelic homogenization and locus specificity in the 3' part of the gene (exons 4 to 8). These differences may correlate with the lengths of converted sequences in the two parts of the gene and frequency of the CpG dinucleotide. Locus-specific divergence of HLA-A,B, and C demonstrates that recombinational events involving alleles of a locus have been more important than conversion between loci. This contrasts with the predominance of gene conversion events in the evolution of mutants of the H-2Kb gene. However, a striking example of gene conversion involving HLA-B and C alleles of an oriental haplotype has been found. Comparison of human and chimpanzee alleles reveals extensive sharing of polymorphisms, confirming that diversification is a slow process, and that much of contemporary polymorphism originated in ancestral primate species before the emergence of Homo sapiens. There is less polymorphism at the HLA-A locus compared to HLA-B, with greater similarity also being seen between HLA-A and ChLA-A alleles than between HLA-B and ChLA-B alleles. Although greater diversity is seen in the 5' "variable" exons of HLA-B compared to HLA-A, there is increased heterogeneity in the 3' "conserved" exons of HLA-A compared to HLA-B.  相似文献   

5.
Three hundred forty-three Yakuts (mongoloids of central Asian type living in Siberia) were tested for HLA-A, -B, and -C loci. The HLA antigen distribution corresponds on the whole to a mongoloid population with high frequency of the HLA-A9, -B15, and -B40 antigens (phenotype frequencies .533, .367, and .405, respectively). At the same time a strikingly high frequency for the "Indo-European" HLA-A1 antigen (phenotype frequency .282) was detected, which in Yakuts is found exclusively with HLA-B17 (haplotype frequency x 1,000 = 87.0; linkage disequilibrium value x 1,000 = 63.8). The present paper deals with a new hypothesis of the Yakut ethnogenesis according to which ancient Aryan tribes formed the substratum which was later assimilated by the mongoloid and Turkic populations. Another hypothesis that I have advanced argues that from analysis of the HLA system the ancient Aryans formed, a local group within the Indo-European entity, with high frequency for HLA-A1 and -B17 antigens and for the HLA-A1,B17 haplotype and with a complete absence of or very low frequency for the HLA-B8 antigen and for the HLA-A1,B8 haplotype. Significant linkage disequilibrium, as it is found in Indians and Yakuts, etc., could have resulted from mixing of the Aryans with non-Indo-European tribes. No significant linkage disequilibrium between A1 and B8 characteristic of the European caucasoids was produced in the mixing.  相似文献   

6.
4个HLA等位基因在5个民族中分布的多样性研究   总被引:2,自引:1,他引:1  
肖文彦  褚嘉档  史磊  俞建昆  许绍斌 《遗传》2005,27(4):518-522
应用ARMS-SSP结合的方法调查与AIDS相关的HLA等位基因,即HLA-A*02,B*35,B*27,B*57四个基因在五个民族群体(云南汉族、彝族、傣族、新疆维吾尔族、广西壮族)中的分布情况,并进行了相应的遗传学分析。结果显示,HLA-A*02在壮族和汉族中检出的阳性样本频率非常高,在另外几个民族中的分布频率偏低;B*35基因在各民族中分布差异不大;B*27在傣族中的分布频率较高,汉族、彝族和壮族中分布的频率差异不大;B*57则在各民族中的分布差异不大;保护性的等位基因即A*02,B*27,B*57的基因型频率在5个民族中有极显著的差异。此课题增进了对我国部分AIDS流行地区AIDS相关HLA等位基因型遗传背景的了解,是对HLA与AIDS相关性研究资料的有益补充。  相似文献   

7.
Increased frequencies of cells carrying mutations at several loci have been found in the blood cells of atomic-bomb (A-bomb) survivors upon testing four or five decades after the bombing. Interestingly, though, we have been unable to demonstrate any radiation-associated increases in the frequencies of mutant blood cells in which human leukocyte antigen (HLA)-A expression has been disrupted; this is true both of preliminary tests on the T cells of a small subset of A-bomb survivors and of the much more extensive study reported here in which we screened a much larger group of survivors for HLA-A2 loss mutations in B cells and granulocytes as well as in T cells. In attempting to explain our inability to detect any increases in HLA-A2-negative cell numbers in HLA-A2 heterozygous individuals exposed to A-bomb irradiation, we decided to test the hypothesis that HLA-A mutant lymphocytes might well have been induced by radiation exposure in much the same way as every other type of mutant we encountered, but may subsequently have been eliminated by the strong negative selection associated with their almost inevitable exposure to autologous natural killer (NK) cells in the bloodstream of each of the individuals concerned. We now report that mutant B lymphocyte cell lines that have lost the ability to express the HLA-A2 antigen do indeed appear to be much more readily eliminated than their parental heterozygous counterparts during co-culture in vitro with autologous NK cells. We make this claim first because we have observed that adding autologous NK cells to in vitro cultures of HLA-A2 heterozygous B or T cell lines appeared to cause a dose-dependent decrease in the numbers of HLA-A2-negative mutants that could be detected over a period of 3 days, and second because when we used peripheral blood HLA-A2 heterozygous lymphocyte cultures from which most of the autologous NK cells had been removed we found that we were able to detect newly-arising HLA-A2 mutant T cells in substantial numbers. Taken together, these results strongly support the hypothesis that autologous NK cells are responsible for eliminating mutant lymphocytes that have lost the ability to express self-HLA class I molecules in vivo, and may well therefore explain why we have been unable to detect increased frequencies of HLA-A2 mutants in samples from any of the 164 A-bomb survivors whose HLA-A2 heterozygote status made their lymphocytes suitable for our tests.  相似文献   

8.
9.
Ontogeny of human Ia antigens   总被引:1,自引:0,他引:1  
Indirect immunofluorescence (IIP) staining of tissues from human fetuses (ages ranging from 8 to 32 weeks of intrauterine life) with monoclonal antibodies (MoAb) to monomorphic determinants of Ia antigens and HLA-A,B,C antigens has shown that both types of antigens are already detectable in tissues of 8-week-old fetuses. Ia antigens and HLA-A,B,C antigens reach their almost-complete tissue distribution after 32 and 24 weeks of intrauterine life, respectively. The structure of Ia antigens synthesized by fetal thymus cells is similar to that of B-lymphoid cell-derived Ia antigens. Ia antigen-bearing thymic fetal cells can stimulate allogeneic lymphocytes in mixed lymphocyte reactions (MLRs). These reactions are blocked by monoclonal antibodies to monomorphic determinants of human Ia antigens and of HLA-A,B, antigens.  相似文献   

10.
The frequencies of HLA-A, -B, and -C antigens were studied in a tribal population of Koya from Andhra Pradesh in southern India. No other well-defined tribal population has been studied with which the present results may be compared. However, the HLA profile of Koya showed distinct differences from the general HLA distribution in India in the frequency of a large number of antigens both at the A and B loci. This study indicates the distinctiveness of this tribal population and suggests the potential importance of the study of HLA frequencies in tribal groups of India.  相似文献   

11.
Published data on two cases of linkage disequilibrium in Yakuts are analyzed. These are the disequilibria between loci HLA-A and HLA-Band between the mutation of gene SCA1 responsible for type 1 spinocerebellar ataxia and its flanking microsatellites D6S274 andD6S89. Both cases are regarded as consequences of the founder effect. The genetic archeological approach has been used to calculate the historical period when the mutant SCA1 gene and the HLA-A1\B17 haplotype spread in the population. It has been found that this was approximately 60–70 generations (1500–1750 years) ago in both cases. The time of the segregation of haplotype HLA-A1\B17 has also been calculated for some other populations. Caucasoids have proved to be the oldest carriers of this gene, which agrees with the well-known notion that HLA-A1 originated in Indo-Europeans. The general distribution of HLA genes in Yakuts is similar to that in east-central Asian Mongoloids; therefore, it is concluded that that Yakuts are east-central Asian Mongoloids by origin, except for the founder that had haplotype A1\B17. Historically, the time of the appearance of this haplotype coincided with the period when Saks conquered east-central Asia; therefore, it is hypothesized that the aforementioned founder was a Sak.  相似文献   

12.
Cytotoxic T cells specific for influenza virus A/HK or Epstein-Barr virus were used to study the heterogeneity of the HLA-A3 molecule. Variability of the recognition of HLA-A3 in both systems was observed. The hierarchy was both effector cell and target cell specific. An extreme example of the hierarchy of HLA-A3 recognition is the following. Virus-specific cytotoxic T lymphocytes of a given donor were found to recognize all HLA-A3-matched target cells, including target cells of a donor from whom the virus-specific effector cells did not recognize target cells of that given donor: Donor A recognizes target B but donor B does not recognize target A. Both will recognize a third HLA-A3-matched target cell C. Cold target inhibition studies confirmed that the recognition of target cell B by effector cell A involved the recognition of only HLA-A3. Examples of such asymmetric recognition were found in both influenza A and Epstein-Barr virus-specific cytotoxic T-lymphocyte responses but not one combination was asymmetric in both systems. This suggests that influenza virus A/HK-specific cytotoxic T lymphocytes recognize other HLA-A3 histotopes than do Epstein-Barr virus-specific cytotoxic T lymphocytes.  相似文献   

13.
The distribution of HLA-A, B, C antigens has been studied in 40 patients with systemic scleroderma and in 200 healthy individuals (all Russians). An increased frequency of the antigens B35 and Cw4 has been discovered in patients, as compared with control. When analysing different clinical and common parameters, lung affection in the systemic scleroderma patients was found to be associated with the antigen A10 (58.9% versus 21% in control, RR = 5.22, EF = 0.476, Pc = 0.0363), the presence of antinuclear antibodies being associated with the antigen B35 (50% versus 17% in control, RR = 4.8, EF = 0.396, Pc = 0.0354). The association with the antigen B8 most commonly mentioned in the literature was characteristic of the patients with an earlier onset of the disease (under 30 years) and those with the rheumatoid factor. The patients having D-penicillamine-induced complications were found to have an increased frequency of the antigen B8, as compared with the alternative group of patients (2P = 0.0430).  相似文献   

14.
HLA antigens in 841 healthy, unrelated Japanese from nine widely separated geographic localities were studied. The five most common antigens observed in order of decreasing frequency were for the HLA-A locus: HLA-A9, A2, A10, AW32 and A11; and for the HLA-B locus: HLA-'B5' (= HLA-B5+B17), BW40, B12, B14 and B8. The allelic frequency of undetected antigens of the HLA-A locus was .14-.37, and that of the HLA-B locus, .32-.67, indicating that there were serological difficulties in typing for Japanese antigens using antisera from Caucasians. Marked gene frequency clines were observed for HLA-A9 and HLA-A2 from south (Okinawa) to north (Nagoya). Two haplotypes, HLA-A9, B5 and HLA-A10, BW40 were shown to be in linkage disequilibrium in four of the nine subpopulations.  相似文献   

15.
Summary Antigen, gene, and haplotype frequencies as well as phenotype distribution of the HLA system were studied in a series of 213 individuals in northern Thailand. The series consisted of 160 northern Thais, 23 Thai individuals from various other regions of Thailand, and 25 persons of Chinese origin. Most frequently found were the alleles HLA-A11 and HLA-Bw40 and the haplotype HLA-A2, B-. Phenotype distribution followed a Hardy-Weinberg expectation. Significant differences were found especially between our results for the alleles of locus B and the results of a series from Bangkok reported by Chiewsilp and Chanarat (1976).  相似文献   

16.
Summary Quantitative changes in major histocompatibility class I antigen expression in tumour cells are believed to affect the host immune response against the tumour. In tumourigenic (TGrIII) human urothelial cell lines the apparent loss of polymorphic HLA-A,B epitopes has previously been demonstrated. In the present study, 3 non-tumourigenic (TGrII) and 6 tumourigenic (TGrIII) human urothelial cell lines have been investigated for their quantitative expression of monomorphic HLA-A,B,C and B2-microglobulin. Evidence is provided that an inverse correlation exists between tumourigenicity and HLA-A,B,C and B2-microglobulin expression. Furthermore, treatment of the cells with neuraminidase partly restored the expression of monomorphic HLA-A,B,C suggesting that at least some of the observed quantitative differences could be due to masking of the membrane bound HLA antigens by sialic acid-containing glycoconjugates.  相似文献   

17.
HLA-A, B, C-polymorphism was characterized from a population sample taken in the north of the GDR (n = 1446). The frequencies obtained are representative for the GDR population. The data properly fit into the European distribution pattern of HLA antigens.  相似文献   

18.
Biosynthesis and regulation of expression of transplantation as detected by a monoclonal antibody to HLA-A,B,C antigens (human leucocytic antigen) and a polyclonal antiserum to beta 2-microglobulin have been investigated using radioactive amino acids and sugars to label human lymphoid cells. We found unbalanced synthesis of HLA heavy chains and beta 2-microglobulin, the latter being in excess and secreted to the extracellular medium. In DAUDI cells, which are defective in beta 2-microglobulin, no HLA-A,B,C could be detected intracellularly even in the presence of added beta 2-microglobulin. Treatment of BRI-8 cells with tunicamycin, an antibiotic which inhibits glycosylation of polypeptides, almost had no effect on the levels of beta 2-microglobulin, while it markedly decreased that of HLA heavy chains, both on the cell surface and intracellularly. Glycosylation of the HLA heavy chains appeared to be an essential requirement for the normal expression of HLA-A,B,C antigens. The translation in vitro in a messenger-dependent reticulocyte system with total polysomes obtained from BRI-8 cells showed that beta 2-microglobulin was synthesized as a precursor. This larger polypeptide was converted into mature beta 2-microglobulin when protein synthesis was performed with microsomes instead of polysomes.  相似文献   

19.
A human alloimmune cytotoxic T lymphocyte (CTL) clone (4E4) was generated against the HLA-A2 molecule. Lysis of 51Cr-labeled HLA-A2 target cells was blocked by monoclonal antibodies (mAb), including mAb PA2.1 (anti-HLA-A2), mAb BB7.2 (anti-HLA-A2), mAb 4B (anti-HLA-A2-plus-A28), mAb MA2.1 (anti-HLA-A2-plus-B17), and mAb W6/32 (anti-HLA-A,B,C), which are directed against different serologic epitopes on the HLA-A2 molecule. However, HLA-A2 mutant lines lacking the serologic epitope recognized by mAb BB7.2 (anti-HLA-A2) were efficiently lysed by CTL 4E4. Thus, although mAb may block cytolysis, the HLA-A2 epitope recognized the 4E4 CTL clone is distinct from the HLA-A2-specific epitope recognized by serologic reagents. Moreover, analysis of HLA-A2 population variants revealed that only the predominant HLA-A2.1 subtype molecule was recognized by CTL 4E4. No cross-reactivity on other, biochemically related HLA-A2 population subtypes was observed, including HLA-A2.2 cells (Hill, CVE, ZYL, M7), HLA-A2.3 cells (TENJ, DK1), or HLA-A2.4 cells (CLA, KNE). This CTL clone appears to recognize a single epitope and, like monoclonal antibody counterparts, can be used to discriminate among immunogenic cellular and serologic epitopes on closely related HLA-A2 molecules. On the basis of the known sequence changes in mutant and subtype HLA-A2 molecules, it appears that the sequence spanning residues 147 to 157 may be critical for cellular recognition of this Class I MHC molecule.  相似文献   

20.
A linkage between C2 deficiency and the HLA-A10,B18/BfS antigens has been found in a French family from the Strasbourg area. The propositus, suffering from a chronic glomerulonephritis, is homozygous forHLA-A10,B18/BfS and totally C2-deficient. The parents and the brother are heterozygous for C2 deficiency and share theHLA-A10,B18/BfS haplotype. MLC tests and HLA-D typing revealed that the homozygous C2-deficient patient is also homozygous at theHLA-D locus for the w2 specificity. Evidence was obtained for a heterogeneity of the HLA-Dw2 specificity. This observation confirms the remarkable association between C2 deficiency and theHLA-A10,B18,Dw2 haplotype.  相似文献   

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