Alloantibodies can discriminate class I major histocompatibility complex molecules associated with various endogenous peptides.
Molecules encoded by a single major histocompatibility complex class I gene can associate with any one of a large number of peptide ligands. T-cell receptors have the capacity to discriminate among these peptide-class I complexes and in many cases bind only a single peptide-class I complex with sufficient affinity to trigger effector function. In contrast, it is generally assumed that class I-specific alloantibodies are indifferent to peptide heterogeneity, being directed toward allele-specific determinants on the molecule. In this report, three monoclonal antibodies were used to precipitate Kb molecules from cell lysates. Surprisingly, in each case a different set of peptides was found to be associated with Kb as detected by peptide-dependent Kb-specific alloreactive cytolytic T lymphocytes or by biochemical resolution. These results demonstrate that the affinity of binding by alloantibodies can be affected by the endogenous peptide ligand.
Sherman
L A
LA
Department of Immunology, Scripps Research Institute, La Jolla, CA 92037.
Chattopadhyay
S
S
Biggs
J A
JA
Dick
R F
RF
Bluestone
J A
JA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000941:Antigens / Q000378:metabolism*; D003602:Cytotoxicity, Immunologic; D006183:H-2 Antigens / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D007111:Immunity, Cellular; D066298:In Vitro Techniques; D007518:Isoantibodies / Q000276:immunology*; D046911:Macromolecular Substances; D051379:Mice; D008810:Mice, Inbred C57BL; D010455:Peptides / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D000911:Antibodies, Monoclonal; D000941:Antigens; D006183:H-2 Antigens; D007518:Isoantibodies; D046911:Macromolecular Substances; D010455:Peptides