RESTRICTED TCR V-BETA REPERTOIRE IN THE HUMAN MIXED LYMPHOCYTE-REACTION IS DETERMINED BY THE TCR ON THE RESPONDER CELL AND NOT BY THE STIMULATING ANTIGEN ON THE STIMULATOR CELL

The use of a restricted TCR repertoire has been reported in antigen-st imulated T cells, We have examined by flow cytometry and polymerase ch ain reaction the changes in the TCR variable beta (V beta) repertoire as they occur in the mixed leukocyte reaction. The HLA class I-negativ e lymphoblastoid B cell line, Daudi, an HLA class I-positive variant o f the Daudi cell line, and the homozygous typing cell line HTC 9062 we re used to stimulate HLA-mismatched responder cells from 8 individuals . The magnitude of HLA incompatibility in various combinations ranged from single DR10 and DR13 differences to full 6-antigen differences at the HLA-A, -B, and -DR loci, Using a panel of 19 V beta-specific olig onucleotide primers, changes in the level of TCR V beta mRNA were asse ssed, The observed V beta repertoire was not specific for the stimulat or cell antigens used. We did not find a correlation between the numbe r of mismatched HLA antigens and the number of V beta elements involve d, It rather appeared that individual responder cells displayed a unif orm V beta pattern following exposure to single and multiple HLA antig ens, We conclude that the V beta repertoire was largely determined by factors associated with the TCR on the responder cells, and not as obv iously influenced by the HLA antigen(s) on the stimulator cells.