A novel approach to DNA probe hybridization and heteroduplex analysis, termed directed heteroduplex analysis (DHDA) is presented here to illustrate its utility in simplification of human lymphocyte antigen (HLA)-typing. By strategic labeling of single-stranded probe sequences, DHDA allows the identification of specific heteroduplex structures that contribute to the differentiation of DQA1 and DQB1 alleles. Because of the high degree of polymorphism among major histocompatibility complex class II second exon sequences, this analysis of 50 different heteroduplex molecules provides evidence of the importance of unpaired bases and mismatched base pairs and their effect on heteroduplex electrophoretic-mobility differences. This strategy is further used to genotype accurately a family for DQA1 which was previously analyzed by sequence specific oligonucleotide (SSO) probe hybridization. To differentiate by SSO-typing among the DQA1 and DQB1 alleles analyzed in this study requires the use of 23 different probes. Equivalent results are obtained by DHDA using only three probes. Therefore, this study suggests that accurate HLA-typing can be simplified by DHDA. Additionally, DHDA may be useful for differentiation of DNA sequence polymorphisms in other genetic systems.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC311187 | PMC |
http://dx.doi.org/10.1093/nar/21.19.4541 | DOI Listing |
Transpl Immunol
December 2024
Department of Transfusion Medicine, Histocompatibility and Molecular Biology, Jaypee Hospital, Noida, UP 201301, India.
Aim: Detection of anti-HLA antibodies is crucial for pre-transplant histocompatibility testing, donor selection, and graft survival. The aim of this study was to evaluate the spectrum of anti-HLA antibodies among live related renal transplant recipients from one of the largest transplant centers in north India.
Methods: In this study, retrospective data of transplant workup done in past four years were analyzed using GraphPad Prism 9 Version 9.
Long-term allograft survival is limited by humoral-associated chronic allograft rejection, suggesting inadequate constraint of humoral alloimmunity by contemporary immunosuppression. Heterogeneity in alloreactive B cells and the incomplete definition of which B cells participate in chronic rejection in immunosuppressed transplant recipients limits our ability to develop effective therapies. Using a double-fluorochrome single-HLA tetramer approach combined with single-cell culture, we investigated the B-cell receptor (BCR) repertoire characteristics, avidity, and phenotype of donor HLA-DQ reactive B cells in a transplant recipient with end-stage donor specific antibody (DSA)-associated cardiac allograft vasculopathy while receiving maintenance immunosuppression (tacrolimus, mycophenolate mofetil, prednisone).
View Article and Find Full Text PDFDiabetologia
December 2024
University of Miami Miller School of Medicine, University of Miami, Miami, FL, USA.
Aims/hypothesis: Many studies of type 1 diabetes pathogenesis focus on individuals with high-risk HLA haplotypes. We tested the hypothesis that, among islet autoantibody-positive individuals, lacking HLA-DRB1*04-DQA1*03-DQB1*0302 (HLA-DR4-DQ8) and/or HLA-DRB1*0301-DQA1*0501-DQB1*0201 (HLA-DR3-DQ2) is associated with phenotypic differences, compared with those who have these high-risk HLA haplotypes.
Methods: We classified autoantibody-positive relatives of individuals with type 1 diabetes into four groups based on having both HLA-DR4-DQ8 and HLA-DR3-DQ2 (DR3/DR4; n=1263), HLA-DR4-DQ8 but not HLA-DR3-DQ2 (DR4/non-DR3; n=2340), HLA-DR3-DQ2 but not HLA-DR4-DQ8 (DR3/non-DR4; n=1607) and neither HLA-DR3-DQ2 nor HLA-DR4-DQ8 (DRX/DRX; n=1294).
Int Immunol
December 2024
Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan.
The pandemic outbreak of SARS-CoV-2 has threatened human health worldwide. Among protective immune reactions, T cell responses are diverse among individuals, which is related to the differences in severity. A T cell subset, regulatory T (Treg) cells, is crucial for limiting excessive immune responses.
View Article and Find Full Text PDFHum Immunol
December 2024
Diagnostic Laboratories and Blood Research Institute, Versiti, Milwaukee, WI, USA. Electronic address:
Introduction: Donors for patients requiring hematopoietic cell transplant (HCT) are selected based on matching genetic sequences encoding the antigen recognition domain of specific HLA loci. However, differences in transplant outcomes in fully matched unrelated HCT compared with sibling HCT suggest that other genetic regions within the major histocompatibility complex (MHC) may contribute to HCT outcomes.
Methods: We sequenced the non-classical MHC loci (NCML) HLA-E, -F, -G, -H, MICA and MICB on a well-characterized retrospective cohort of 157 unrelated donor/recipient HCT pairs to determine the extent of MHC mismatching in matched pairs.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!