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

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• Cytolytic T lymphocyte (CTL) specificity is dictated by MHC class I-bound peptides.
• An allorestricted human CTL clone, DBS 1.5, recognizes an epitope on HLA-A3+ kidney epithelial cells but not on HLA-identical B-lymphoblastoid cells.
• The recognized peptide, isolated from HLA class I molecules of HLA-A3+ kidney tissue, has no known protein homology.

Purpose of the Study:

• To confirm the tissue specificity of the HLA-A3 restricted CTL clone and its recognized peptide.
• To determine if HLA-A3 expression alone is sufficient for recognition and lysis by the CTL clone.

Main Methods:

• Transfection of HLA-A3 gene into various human and murine tumor cell lines lacking the antigen.
• Immunofluorescent staining to confirm HLA-A3 expression in transfected cell lines.
• Using transfected cell lines as targets to assess recognition and lysis by the HLA-A3 restricted T cell clone.

Main Results:

• The HLA-A3 restricted CTL clone recognized HLA-A3 on human kidney epithelial cells, human lung epithelium, and human epidermal cells.
• Among transfected tumor lines, only the human kidney tumor cell line showed lysis levels comparable to the original kidney epithelial cells.
• This indicates HLA-A3 expression on kidney epithelial cells is crucial for recognition.

Conclusions:

• The allorestricted human CTL clone exhibits tissue specificity.
• The clone recognizes a peptide present in human epithelial tissue, specifically presented in the context of HLA-A3.
• This finding has implications for understanding T cell recognition in specific tissues.