T cell line specific for bacterial peptidoglycan subunit: possible role of the COOH-terminal amino acid of the disaccharide tetrapeptide in binding to the T cell receptor.
The T cell line specific for a bacterial cell wall peptidoglycan subunit, disaccharide tetrapeptide of diaminopimelic acid type, was examined for epitope specificity in elicitation of delayed-type hypersensitivity (DTH) in X-irradiated Lewis rats, using pairs of analogs different in optical configuration of the COOH-terminal amino acid. The test cell line induced DTH against analogs with the COOH-terminal D-amino acid but not against those with the L-amino acid at the COOH terminus. A close correlation was found between the T cell line-induced DTH reaction in vivo and the proliferative response in vitro, in terms of clear discrimination of the optical configuration of COOH-terminal amino acid of disaccharide tetrapeptide. The L-isomers (non-stimulatory analogs of T cell proliferation) competitively inhibited the proliferation of the T cell line by the corresponding D-isomers. Thus the L-isomers appear to interact with Ia molecules on antigen-presenting cells. We conclude that COOH-terminal D-amino acid of the disaccharide tetrapeptide could be involved in binding to the T cell receptor, induction of T cell proliferation, and elicitation of DTH.
Katsuki
M
M
Department of Biochemistry, Kyushu University School of Dentistry, Fukuoka, Japan.
Iribe
H
H
Kakimoto
K
K
Kotani
S
S
Kawata
S
S
Koga
T
T
D000596:Amino Acids / Q000276:immunology*; D000818:Animals; D002460:Cell Line; D005260:Female; D006968:Hypersensitivity, Delayed / Q000209:etiology; D008213:Lymphocyte Activation; D010457:Peptidoglycan / Q000276:immunology*; D051381:Rats; D011917:Rats, Inbred Lew; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D013237:Stereoisomerism; D013601:T-Lymphocytes / Q000276:immunology*
D000596:Amino Acids; D010457:Peptidoglycan; D011948:Receptors, Antigen, T-Cell