A NOVEL HLA-A DETERMINANT RECOGNIZED BY A CYTOTOXIC HUMAN HYBRIDOMA IGG1 MONOCLONAL-ANTIBODY (TRJ14)

TrJ14 is a cytotoxic human IgG1 lambda hybridoma mAb that recognized a novel HLA-A epitope expressed by lymphoblastoid B cells that are homo - or heterozygous for A2, A3, A11, A30, A31, A33, A68 and A69. Based o n these results, the HLA type of cell line TEM (10w9057) was retyped a s A66. When peripheral blood T cells isolated freshly from 265 HLA-typ ed normal individuals served as targets, TrJ14 killed cells expressing two TrJ14-positive HLA-A alleles, as well as the majority of cells ha ving one TrJ14-positive and one TrJ14-negative HLA-A antigen. However, TrJ14 failed to recognize or reacted weakly with most HLA-A2 and A3 h eterozygous normal T cells when A2 or A3 was coexpressed together with a TrJ14-negative antigen. The serological reactivity of TrJ14 correla ted with the amino acid valine and aspartic acid at positions 76 and 7 7 of the alpha 1-domain helix. These amino acids were shared exclusive ly by all the identified TrJ14(+) alleles.