Saturation mutagenesis of a major histocompatibility complex protein domain: identification of a single conserved amino acid important for allorecognition.
The interactive association between T lymphocytes and their target cells is an important system of cell-cell interactions. Major histocompatibility complex class I molecules are the cell surface structures recognized by cytolytic T lymphocytes. To define the molecular structures recognized by cytotoxic T lymphocytes, we have saturated the 270-base-pair alpha 1 exon of the H-2Dp gene with point mutations, rapidly producing a "library" of 2.5 x 10(3) independent mutants. The library contains enough recombinant clones (each clone encoding approximately one amino acid replacement mutation) to predict a mutation at each nucleotide position of the alpha 1 exon. The functional analysis of the first five transfected gene products tested has shown that mutation of a conserved tyrosine at position 27 to asparagine destroys recognition of the H-2Dp gene product by polyclonal alloreactive cytotoxic T lymphocytes. Recognition of the same mutant molecule by three monoclonal antibodies and H-2-restricted lymphocytic choriomenengitis virus-specific cytotoxic T lymphocytes is unaffected.
Murray
R
R
Department of Microbiology and Immunology, University of North Carolina, Chapel Hill 27599.
Hutchison
C A
CA
Frelinger
J A
JA
D000595:Amino Acid Sequence; D001216:Asparagine; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005805:Genes, MHC Class I; D006183:H-2 Antigens / Q000235:genetics*; D006680:HLA Antigens / Q000235:genetics*; D064532:Histocompatibility Antigen H-2D; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D011487:Protein Conformation; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014443:Tyrosine
D006183:H-2 Antigens; D006680:HLA Antigens; D064532:Histocompatibility Antigen H-2D; D014443:Tyrosine; D001216:Asparagine