Epitopes are present on a single HLA (private epitope) or shared by multiple antigens (public epitope). 83R. Figure D. Epitope 423 shared by the AB-loci Bw4 associated antigens A23, A25, A32, B2705, B37, B38, B44, B47, B49, B51, B52, B53, B57, B58, B59, B63, B77 (A24, B13 Negative) and CHMFL-ABL-039 defined by 83R+144Q+145R. Figure E. Epitope 246 shared by BC-loci antigens B46, B73, Cw1, Cw7, Cw8, Cw9, Cw10, Cw12, Cw14, Cw16 and defined by 76V+80N. Figure F. Epitope 5024 shared by the HLA class I B-locus antigens B7, B42, B54, B55, B56, B67, B81, B82 and defined by 66I+70Q. Reactions strength of the antibody is stronger with the unobstructed epitope after dissociation of the peptide. Figure G. Epitope 5037 shared by the HLA C-locus antigens Cw4, Cw6, Cw17, Cw18 and defined by 73A+77N. Antibody reaction strength increases with the CHMFL-ABL-039 unobstructed epitope after removal of the peptide. Figure H HLA class II DQB epitope 2007 shared by DQ4,5,6 antigens and define by 52P+55R on the beta chain of the DQ antigens. Figure I. Serum from renal transplant patient with mismatch has two antibodies. One antibody targets epitope 2017 (defined by 52H) on the DQA1?02:01 alpha chain and the other targets epitope 2001 (defined by 52L) on the DQB1?02:02 beta chain. Figure J. Epitope 2018 shared by the alpha chains of the DQ4, 5, 6 antigens and defined by Glutamine (Q) at position 53. Figure K. Epitope 2002 shared exclusively by the beta chains of the DQ4 antigen and defined by Leucine (L) in position 56. Figure L. Epitope 2010 shared by the beta chains of DQ antigens DQ4, 5, 6, 8, 9 and defined by 45G+46V. Figure M. Epitope 2022 exclusive to DQB1?05:01 chain on the DQ5 antigen and defined by 125S+126Q. Figure N. Epitope 2006 shared by DQB1?03:01 (DQ7), DQB1?03:02 (DQ8), DQB1?03:03 (DQ9) and defined by Proline (P) at position 55 on the beta chains of the DQ antigens. 3406230.f1.pptx (78K) GUID:?D3B994CF-058D-4CCE-B1A2-6A94C3C809D8 3406230.f2.pptx (51K) GUID:?01512840-1B44-4BF8-999A-F98BD1B4CAD7 3406230.f3.pptx (737K) GUID:?6CA457FC-E69F-480A-9423-4CE2D7549DF2 3406230.f4.pptx (405K) GUID:?F6B7F224-0F97-47C1-B954-F3571B04D19D 3406230.f5.pptx (329K) GUID:?A29F25BC-DDC8-4A3F-9766-CEA52E8D996D 3406230.f6.pptx (399K) GUID:?ECE9F39A-E877-4F3C-B096-BF211095B832 3406230.f7.pptx (467K) GUID:?79956685-30C4-4F83-A91C-28DA0F182D48 3406230.f8.pptx (634K) GUID:?715EB6F2-D2A9-4CC9-9FBC-F82C9A842196 3406230.f9.pptx (578K) GUID:?818BC0C5-B072-4641-8AD1-76C0109C39DC 3406230.f10.pptx (364K) GUID:?1B94F298-9FDD-499E-8940-291E5B98EF25 3406230.f11.pptx (393K) GUID:?2793FC0F-4C39-4F36-B21D-836562EE7269 3406230.f12.pptx (289K) GUID:?4EBC6470-1859-4724-8786-A963955AA5EA 3406230.f13.pptx (331K) GUID:?8DEC9D12-F480-4342-8AB6-4EE5E53F4B16 3406230.f14.pptx (330K) GUID:?C5F2D934-76DB-4F7F-8FA1-5176CE8EFDD7 3406230.f15.pptx (300K) GUID:?4C4633D4-51E0-4EB9-B946-887FC51B72D3 3406230.f16.pptx (340K) GUID:?98004A7E-7C6F-4B9E-B800-6803572BD4D1 Abstract Sensitization to human leukocyte antigens (HLA) in organ transplant patients causes graft rejection, according to the humoral theory of transplantation. Sensitization is almost ubiquitous as anti-HLA antibodies are found in almost all sera of transplant recipients. Advances in testing assays and amino acid sequencing of HLA along with computer software contributed further to the understanding of antibody-antigen reactivity. It is commonly understood that antibodies bind to HLA antigens. With current knowledge of epitopes, it is more accurate to describe that antibodies bind to their target epitopes on the surface of HLA molecular chains. Epitopes are present on a single HLA (private epitope) or shared by multiple antigens (public epitope). The phenomenon of cross-reactivity in HLA testing, often explained as cross-reactive groups (CREGs) of antigens with antibody, can be clearly explained now by public epitopes. Since 2006, we defined and reported 194 HLA class I unique epitopes, including 56 cryptic epitopes on dissociated HLA class I heavy chains, 83 HLA class II epitopes, 60 epitopes on HLA-DRB1, 15 epitopes on HLA-DQB1, 3 epitopes on HLA-DQA1, 5 epitopes on HLA-DPB1, and 7 MICA epitopes. In this paper, we provide a summary of our findings. 1. Introduction Sensitization to HLA antigens in organ transplant patients causes graft rejection, according to the humoral theory of transplantation . Sensitization is almost ubiquitous as it is evident in the detection of anti-HLA antibodies in the sera of recipientsin one study, almost all patients waiting for regraft of a kidney transplant have anti-HLA antibodies . Determining specificity of the anti-HLA antibody has advanced in recent years using recombinant CHMFL-ABL-039 HLA single antigens (SA) coated on color-coded Luminex beads . The reactivity of anti-HLA antibodies with HLA antigens and the phenomenon of cross-reactivity has been the subject of investigation for decades. Amino acid sequences of the HLA molecules which greatly contributed to our understanding of antibody and antigen reactivity has been introduced since 1963 [4C12]. Antibodies are commonly described as binding to SUV39H2 HLA antigens; however, it is more accurate to describe the reactivity of the antibody as binding to specific epitopes on the surface of HLA antigensepitopes are conformational amino acid arrangements and are the targets of antibodies. Some epitopes are private, found exclusively on one antigen; others are public epitopes shared by two or more antigens. The phenomenon of cross-reactivity in HLA testing, often explained as cross-reactive groups (CREGs), of antigens with antibody can be clearly explained now by public epitopesan antibody targeting a public epitope shows positive reaction with all antigens sharing the epitope. Since 2006,.
- T-cell epitopes are peptides derived from antigens and identified by the T-cell receptor (TCR) when bound to MHC molecules displayed within the cell surface of APCs
- Cloning of gene fragments encoding diagnostic antigens
- Epitopes are present on a single HLA (private epitope) or shared by multiple antigens (public epitope)
- Spleens were harvested in 1 (C) or 2 wpi (B, C) and cells were analyzed by movement cytometry in comparison to na?ve mice
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