The study of the HLA system was primarily initiated to understand the basis for the histocompatibility between recipients and tissue donors. HLA typing methods are being continuously improved and biochemical and molecular typing, in particular, are expected to provide precise typing of the HLA system. Conventional HLA typing methods can define antigen specificities, while biochemical and molecular methods will provide direct allele typing that is based on the actual sequence polymorphism. The precise tissue typing will definitely improve the outcome of transplantation. Structural studies have revealed the highly polymorphic nature of the HLA system and given insight to understanding the molecular basis of the HLA polymorphism. One big immunological puzzle remaining to be answered is how T-cell receptor molecules recognize peptide antigen in conjunction with the HLA molecule. The crystallization of the T-cell receptor molecule, an experiment currently underway, will eventually reveal the structural basis of the trimolecular interaction.
Animals ; Genes, MHC Class I ; Genes, MHC Class II ; Histocompatibility Antigens Class I/analysis/chemistry/*physiology ; Histocompatibility Antigens Class II/analysis/chemistry/*physiology ; Human ; Polymorphism (Genetics) ; Protein Conformation

Animals ; Female ; Genes, MHC Class I ; Genes, MHC Class II ; Lung ; immunology ; pathology ; Mice ; Mice, Inbred C57BL ; Ovalbumin ; immunology ; Polymerase Chain Reaction ; RNA, Messenger ; analysis

Molecular characterization of swine leukocyte antigen (SLA) genes is important for elucidating the immune responses between swine-donor and human-recipient in xenotransplantation. Examination of associations between alleles of SLA class I genes, type of pig genetic modification, porcine endogenous retrovirus (PERV) viral titer, and PERV subtypes may shed light on the nature of xenograft acceptance or rejection and the safety of xenotransplantation. No significant difference in PERV gag RNA level between transgenic and non-transgenic pigs was noted; likewise, the type of applied transgene had no impact on PERV viremia. SLA-1 gene profile type may correspond with PERV level in blood and thereby influence infectiveness. Screening of pigs should provide selection of animals with low PERV expression and exclusion of specimens with PERV-C in the genome due to possible recombination between A and C subtypes, which may lead to autoinfection. Presence of PERV-C integrated in the genome was detected in 31.25% of specimens, but statistically significant increased viremia in specimens with PERV-C was not observed. There is a need for multidirectional molecular characterization (SLA typing, viremia estimation, and PERV subtype screening) of animals intended for xenotransplantation research in the interest of xeno-recipient safety.
Alleles ; Animals ; Endogenous Retroviruses ; Genes, MHC Class I ; Genes, MHC Class II ; Genome ; Heterografts ; Leukocytes ; Mass Screening ; Recombination, Genetic ; Retroviridae ; RNA ; Swine ; Transgenes ; Transplantation, Heterologous ; Viremia

The antigen (phenotype), gene (allele) and haplotype frequencies of HLA class I were analysed in 4,622 Koreans. With allele frequencies of over 0.05, the most frequent HLA-A,-B and -C antigens were A2, A24, A33, A11, A26, A31; B62, B51, B44, B54, B61, B35, B58, B60; Cw3, Cw1, Cw4, Cw7. Of these A2, A24, Cw1 and Cw3 were present in very high frequencies, respectively (0.3211, 0.2200, 0.2204, and 0.3737). The most common haplotypes with frequencies larger than 0.02 were A2-Blank, A33-B44, A33-B58, A11-B62, A24-B51, A24-B54, A2-B27, B54-Cw1, B58-Cw3, B51-Blank, B61-Cw3, B62-Cw4, B35-Cw3, B44-Blank, B60-Cw3, B27-Cw1, A2-Cw3, A2-Cw1, A24-Cw1, A33-Cw3, A26-Cw3, and A11-Cw4. A significant negative linkage disequilibrium was found for the haplotypes of A2-B7, A2-B44, A2-B58, A24-B13, A24-B27, A33-B54 and A33-B62, of which frequencies were larger than 0.003. The B-C and A-C haplotypes which showed the significant negative linkage disequilibrium were B44-Cw1, B51-Cw1, B44-Cw3,B62-Blank, A2-Cw4, A2-Blank, A11-Cw3, A11-Blank and A33-Cw1 and had frequencies higher than 0.01. The findings presented here could be used per se to estimate the populational relationships or as the control data for HLA-disease investigation. Furthermore they could provide the scope for the definition of new antigens.
*Alleles ; Gene Frequency ; *Genes, MHC Class I ; *Haplotypes ; Humans ; Korea ; Linkage Disequilibrium

No abstract available.
Cytokines/pharmacology* ; Gene Expression Regulation ; Genes, MHC Class I* ; Histocompatibility Antigens Class I/biosynthesis* ; Interferons/pharmacology ; Lymphotoxin/pharmacology ; Models, Genetic ; Signal Transduction ; Tumor Necrosis Factor/pharmacology

The study was aimed to investigate the expression of HLA class I molecules and MHC class I chain-related molecules A/B (MICA/MICB) in K562 and adriamycin (ADM)-resistant K562 cell lines (K562/AO2) and their effect on cytotoxicity of NK cells. Expression of HLA class I molecules and MICA/MICB on the surface of K562 and K562/AO2 cell lines were analyzed by flow cytometry. Cytotoxicity of NK cells (isolated from 3 healthy persons) against K562 and K562/AO2 cells were detected by LDH releasing assay at different effect-to-target cell ratios (E:T). In blocking experiments, anti-MHC class I monoclonal antibody (McAb) (W6/32, a pan anti-HLA class I antibody) and anti-MHC class I chain-related molecules McAb (BAMO-1, specifically against MICA and MICB) were added to the target cells at E:T of 10:1. The results showed that the expression of MHC class I chain-related molecules on K562 was higher than that on K562/AO2 (P=0.000), and HLA class I molecules were not detectable on both cells. Cytotoxicities of NK cells against K562 and K562/AO2 cells were (29.32 +/- 0.12)%, (45.33 +/- 0.78)%, (58.37 +/- 0.87)%, (72.37 +/- 0.96)% and (12.47 +/- 0.91)%, (24.36 +/- 1.11)%, (33.29 +/- 1.03)%, (53.87 +/- 1.27)% at E:T ratios of 5:1, 10:1, 20:1 and 30:1 respectively (P=0.000), the cytotoxicity of NK cells on K562 cells was significantly higher than that on K562/A02 cells at different E:T ratios. Blocking experiments confirmed that at E:T of 10:1 killing of NK cells against K562 and K562/AO2 cells was efficiently inhibited by BAMO-1, whereas W6/32 had no effect on K562 and K562/AO2 cells. It is concluded that the expression of MHC class I chain-related molecules on K562 and K562/AO2 cells is correlated with NK cell-mediated lysis. NK cells display higher cytotoxicity against parental K562 cells than multi-drug resistant K562/AO2 cells. Down-regulation of MICA/B in multi-drug resistant tumor cell lines leads to reduction of susceptibility to NK lysis.
Cytotoxicity, Immunologic ; immunology ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; immunology ; Genes, MHC Class I ; genetics ; Histocompatibility Antigens Class I ; immunology ; Humans ; K562 Cells ; Killer Cells, Natural ; immunology

OBJECTIVEThe purpose of this study was to examine the expression of human major histocompatibility complex-I at different degrees of dysplasia leukoplakia, and to investigate local immune status and discuss their associations with oral leukoplakia.

METHODSThe monoclonal antibody of MHC class I antigen was employed in this study. There were 55 oral leukoplakias, 31 primary oral squamous cell carcinomas and 28 histologically normal oral epithelia were detected for the presence of the MHC class I molecule by using immunohistochemistry method.

RESULTSThe MHC class I antigen expression of the severe dysplasia and oral squamous cell carcinoma was significantly lower than that of the normal epithelia (P < 0.05). But their expression did not show statistically difference between the normal epithelia and other groups of oral leukoplakia (P > 0.05).

CONCLUSIONThe expression levels of the MHC class I antigen is reduced in oral leukoplakia, particularly in severe dysplasia oral leukoplakia, it is relevant to the degree of dysplasia.

Antibodies, Monoclonal ; Carcinoma, Squamous Cell ; genetics ; Genes, MHC Class I ; Histocompatibility Antigens Class I ; genetics ; Humans ; Immunohistochemistry ; Leukoplakia, Oral ; genetics ; Mouth Neoplasms ; genetics

OBJECTIVETo investigate the association of HLA class I and II alleles with generalized vitiligo in ethnic Han Chinese in north China.

METHODSBy employing polymerase chain reaction sequence-specific primer (PCR-SSP) procedure 34 generalized vitiligo patients in north China were studied for HLA I and II alleles and were compared with 102 healthy controls.

RESULTSThe allelic frequencies of HLA-A*30, Cw*06, DRB1*07, and DQB1*0201 were increased significantly in generalized vitiligo and especially in the patients without family history compared with the controls.

CONCLUSIONThese alleles positively associated with generalized vitiligo in Chinese Han patients in north China, might provide clues to reveal the susceptibility gene(s) of vitiligo in Chinese and as well as the immunnogenetic mechanisms of disease.

Adult ; Aged ; Aged, 80 and over ; Alleles ; Asian Continental Ancestry Group ; genetics ; China ; Female ; Gene Frequency ; Genes, MHC Class I ; genetics ; Genes, MHC Class II ; genetics ; Genotype ; Humans ; Male ; Middle Aged ; Vitiligo ; ethnology ; genetics

HLA expression is altered in a large variety of human cancers. We performed immunohistochemical staining on tissues from normal, preinvasive, invasive and metastatic cervical cancer tissues using anti-HLA class I or class II antibody. In tissues from normal squamous epithelium, carcinoma in situ (CIS) and microinvasive carcinoma (MIC), the expressions of HLA-B, C heavy chains and class II heavy chain were significantly decreased as disease progressed. When the expression patterns were compared between primary and metastatic squamous cell carcinoma (SCC) lesions, statistically significant down-regulation of HLA class I and class II antigen in metastatic lesions was observed. The rates of HLA-B, C heavy chains and class II heavy chain expressions were all significantly down-regulated compared to the down-regulation rate of class I beta2-microglobulin (beta2m) in invasive squamous lesions, and the expressions of class II heavy chain in metastatic lesions was decreased further than that in primary lesions. Unlike SCC, the degree of HLA class I and class II loss was not evident as disease progressed in early stage of adenocarcinoma. In invasive adenocarcinoma lesions, only the expression of HLA-B, C heavy chains was decreased and no differences were seen in HLA-B, C heavy chain expression patterns between primary and metastatic lesions. These results suggest that alterations of HLA class I and II expressions seem to occur at a particular step in cervical cancer development and depend on tissue types: when the tumor becomes invasive and starts to metastasize.
Antibodies, Monoclonal ; Carcinoma in Situ/immunology/pathology/physiopathology ; Carcinoma, Squamous Cell/immunology/pathology/physiopathology ; Cervix Neoplasms/*immunology/pathology/physiopathology ; Disease Progression ; Female ; Genes, MHC Class I ; Genes, MHC Class II ; HLA Antigens/*analysis ; HLA-B Antigens/analysis ; Histocompatibility Antigens Class I/*analysis ; Histocompatibility Antigens Class II/*analysis ; Human ; Immunohistochemistry ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Support, Non-U.S. Gov't

BACKGROUND: A large number of diseases occur in association with specific HLA-B or-C alleles. Recently a new gene, termed maj or histocompatibility complex class I chain-related gene A (MICA), has been identified in close proximity to HLA-B. The function of this gene is still unknown. However, it is structurally similar to HLA class I genes. MICA gene is polymorphic and is potentially associated with several diseases. METHODS: To evaluate the association of MICA gene in Korean patient s with human immunodeficiency virus 1 (HIV-1) infections, Polymerase chain reaction-Sequence specific primer (PCR-SSP) was done for MICA alleles in the extracellular exons, and a microsatellite analysis for GCT repeat polymorphisms in the TM exon was also completed. RESULTS: In 199 Korean healthy controls, 7 alleles were observed and the frequencies for each allele were MICA008 (44.7%), MICA0 10 (34.2%), MICA002 (31.7%), MICA004 (23.6%), MICA0 12 (2 1.6%), MICA009 (19.6%), and MICA007 (6.5%). When 65 HIV seropositive patients were analyzed, MICA007 allele frequency was significantly higher than in controls (15.4% vs 6.5 %, RR=2.6, p<0.04). In contrast, the frequencies of other MICA alleles and microsatellite alleles in the transmembrane region of MICA gene were not significantly different between HIV seropositive patients and controls. The tight linkage between MICA alleles in the extracellular exons and GCT repeat polymorphisms in the TM exon was observed as follows; MICA002/A9, MICA004/A6, MICA007/A4, MICA008/A5. 1, MICA0 10/A5, and MICA0 12/A4 in both groups. No significant difference between patient s and controls was observed in the haplotype frequencies of MICA alleles in the extracellular exons and GCT repeat polymorphisms in the TM exon. CONCLUSION: The data suggest that immune functions related with MICA gene may affect a HIV infections.
Alleles ; Exons ; Gene Frequency ; Genes, MHC Class I ; Haplotypes ; HIV Infections* ; HIV* ; HIV-1 ; HLA-B Antigens ; Humans ; Major Histocompatibility Complex ; Microsatellite Repeats