HLA class I epitopes: recognition of binding sites by mAbs or eluted alloantibody confirmed with single recombinant antigens.
Development of beads coated with single recombinant HLA antigens has permitted the confirmation and further definition of HLA class I epitopes. In this study, monoclonal antibodies (mAbs) or alloantibodies eluted from recombinant cell lines were tested for reactivity with Luminex beads individually coated with 79 recombinant HLA class I single antigen (rHLA SA). Published amino acid sequences were used to map epitopes common to sets of antigens reactive with each antibody. While several epitopes have already been demonstrated, this study confirmed them by adsorption of allosera with transfectants or SA beads having a single HLA antigen and specific binding of the eluted antibody on SA beads. The allosera and mAbs used in this study recognized a total of at least 58 HLA class I epitopes, as demonstrated by their different adsorption/reactivity patterns. Of these, 25 epitopes were characterized by a single unique common amino acid, 30 shared 2 signature amino acids in close proximity, and 3 epitopes involved 3 specific amino acids in a non-linear sequence. Since these epitopes may be targets for antibody-mediated allograft rejection, epitope analysis should complement HLA and CREG assignment for defining complex antibodies and identifying suitable donors for highly sensitized transplant patients.
El-Awar
Nadim
N
One Lambda Inc., Canoga Park, CA 90064, USA. nelawar@onelambda.com
Lee
Jar-How
JH
Tarsitani
Christine
C
Terasaki
Paul I
PI
D000328:Adult; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D001665:Binding Sites; D018604:Epitope Mapping; D000939:Epitopes / Q000276:immunology*; D005260:Female; D015234:HLA-A Antigens / Q000276:immunology*; D015235:HLA-B Antigens / Q000276:immunology*; D006801:Humans; D007106:Immune Sera; D007163:Immunosorbent Techniques; D007518:Isoantibodies / Q000276:immunology*; D051379:Mice; D008863:Microspheres; D010298:Parity; D010920:Placenta / Q000276:immunology; D011247:Pregnancy; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000276:immunology; D020539:Sequence Analysis, Protein
D000596:Amino Acids; D000911:Antibodies, Monoclonal; D000939:Epitopes; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D007106:Immune Sera; D007518:Isoantibodies; D011994:Recombinant Proteins