Identification of a novel HLA-B27 subtype by restriction analysis of a cytotoxic gamma delta T cell clone.
Seven HLA-B27 alleles are known, which share the same allospecificity, but differ by one to six amino acid substitutions. Herein, we describe a novel HLA-B27 allele, provisionally named B27-ci, which is expressed by an individual from whom a B27-restricted gamma delta T cell clone has been derived. This clone recognizes B cell lines from the proband and all of the other B27-positive members of the family, but does not lyse B cell lines that express other HLA-B27 alleles. The amino acid sequence deduced from three B27-ci cDNA clones was found to differ from the B*2705 sequence by one amino acid substitution (Asp to His) in position 116 of the alpha 2 domain. This position has been shown to lie in the floor of the F pocket, where it plays a key role in determining the nature of the amino acid side chain that will fit into this pocket. Moreover, the fact that the clone described here possesses a TCR-gamma delta indicates that this subset of cells not only can be HLA-restricted, but also can finely discriminate among classical class I molecules.
Del Porto
P
P
Department of Cellular Biology and Development, La Sapienza University, Rome, Italy.
D'Amato
M
M
Fiorillo
M T
MT
Tuosto
L
L
Piccolella
E
E
Sorrentino
R
R
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D002999:Clone Cells; D003001:Cloning, Molecular; D003602:Cytotoxicity, Immunologic; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D015796:HLA-B27 Antigen / Q000235:genetics*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010375:Pedigree; D017434:Protein Structure, Tertiary; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D017931:DNA Primers; D018076:DNA, Complementary; D015796:HLA-B27 Antigen; D016692:Receptors, Antigen, T-Cell, gamma-delta