An analysis of the physical properties of peptides that influence the pigeon cytochrome c specific T lymphocyte response.
The ability to modify T cell responses was analyzed using synthetic peptide analogues of the T cell determinant for pigeon cytochrome c. Although the B10.A T cell proliferative response is directed to residues 95-104, residues to the amino-terminal side of this determinant influence antigen-specific T cell recognition. The proposed role of this non-determinant leader sequence has been to stabilize the core determinant in a helical conformation. Previous studies from our laboratory, however, using non-native leader sequences that were designed to examine the changes to T cell recognition invoked when the determinant was made more or less helical, amphipathic, or lipid binding in character than the native determinant. The structure of each analogue in aqueous, non-polar (TFE) and lipid environments was determined by circular dichroism. The ability of each antigen analogue to bind to phospholipid membranes and to stimulate two different pigeon cytochrome c T cell hybridomas, 2B4 and 22.D11, was also investigated. Our findings suggest that neither helicity or amphipathicity are necessary features of T cell recognition but that electrostatic interactions involving either the lipid membrane or the I-Ek molecule may influence T cell stimulation.
Collawn
J F
JF
Department of Cancer Biology, Salk Institute, La Jolla, CA 92037.
Bhayani
H
H
Paterson
Y
Y
D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D010856:Columbidae; D003574:Cytochrome c Group / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D008213:Lymphocyte Activation; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology*; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology*
D003574:Cytochrome c Group; D000939:Epitopes; D010455:Peptides