Characterization of an HLA-A3 restricted human kidney specific T cell clone

Background. The tissue specificity of a cytolytic T lymphocyte is determine d by the MHC class I bound peptide it recognizes. We have developed an allo restricted human CTL clone, DBS 1.5, that recognizes an epitope found on HL A-A3+ kidney epithelial cells but not on HLA identical B-lymphoblastoid cel ls. The peptide recognized by this clone has been isolated from HPLC separa ted, acid eluted peptides from purified HLA class I molecules from HLA-A3kidney tissue. This peptide shares no sequence homology with any known prot ein. Methods. To confirm the tissue specificity of the HLA-A3 restricted cl one and the peptide it recognizes we have transfected the gene for HLA-A3 i nto a number of tumor cell lines both human and murine not expressing this antigen. The resulting transfected lines, confirmed by immunofluorescent st aining, were used as targets to determine ii expression of HLA-A3 alone was sufficient to allow recognition and lysis by the HLA-A3 restricted T cell clone. Results.. The HLA-A3 restricted T cell clone recognized HLA-A3 when expressed on human kidney epithelial cells and to a lesser extent on human lung epithelium and human epidermal cells. Of the tumor lines transfected w ith HLA-A3 only the human kidney tumor cell line was lysed at a level equal to the original kidney epithelial cell used to develop the clone. Conclusi on. These results confirm that this allorestricted human CTL clone is tissu e specific recognizing a peptide found in human epithelial tissue that must be presented in the context of HLA-A3 for recognition. (C) American Societ y for Histocompatibility and Immunogenetics, 1999. Published by Elsevier Sc ience Inc.