Inhibition of an allospecific T cell hybridoma by soluble class I proteins and peptides: estimation of the affinity of a T cell receptor for MHC.
To investigate the molecular basis of the interaction between the T cell receptor and the MHC class I antigen in an allogeneic response, a soluble counterpart of the murine class I molecule, H-2Kb, was genetically engineered. Cells secreting this soluble molecule, H-2Kb/Q10b, inhibited stimulation of an H-2Kb-reactive T cell hybridoma by cells transfected with H-2Kbm10, a weak stimulus, but not by H-2Kb- or H-2Kbm6-transfected cells. Soluble purified H-2Kb/Q10b protein also blocked T cell stimulation. In addition, a peptide from the wild-type H-2Kb molecule spanning the region of the bm10 mutation specifically inhibited activation of the T cell hybridoma by H-2Kbm10 cells, thus suggesting that amino acid residues 163-174 of H-2Kb define a region important for T cell receptor binding. An estimate for the Kd of the T cell receptor for soluble H-2Kb/Q10b was 10(-7) M, while the Kd for soluble peptide 163-174 was 10(-4) M.
Molecular Biology Section, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
J
J
Schneck
W L
WL
Maloy
J E
JE
Coligan
D H
DH
Margulies
D000818:Animals; D006183:H-2 Antigens / Q000235:genetics / Q000276:immunology*; D066298:In Vitro Techniques; D007739:L Cells; D008213:Lymphocyte Activation; D008285:Major Histocompatibility Complex; D051379:Mice; D010455:Peptides / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D012995:Solubility; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection
D006183:H-2 Antigens; D010455:Peptides; D011948:Receptors, Antigen, T-Cell