Evidence for specific association between class I major histocompatibility antigens and the CD8 molecules of human suppressor/cytotoxic cells.
Human T lymphocytes, metabolically labeled with 35S-cysteine and 35S-methionine, were reacted with the homobifunctional cross-linking reagent, dithiobis (succinimidyl propionate) (DSP). When detergent lysates from these cells were immunoprecipitated with a monoclonal antibody reactive with the CD8 antigen, a radiolabeled protein of approximately 44 kd was coprecipitated with the CD8 molecule. Immunoprecipitates from detergent lysates prepared without prior chemical cross-linking contained only the 33 kd CD8 molecule. Similar results were obtained when T lymphocytes or a cytotoxic T cell clone (T4T8Cl) were radiolabeled with 32P-orthophosphoric acid. The 44 kd CD8-associated protein was identified as the heavy chain of the class I major histocompatibility antigen by depletion in preclearing experiments with anti-class I MHC antibody and by peptide mapping. Further analyses indicated that the CD8-class I MHC association is due, in part at least, to disulfide bonding, which may be susceptible to cleavage during processing of cell lysates.
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Division of Tumor Immunology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115.
Craig
K A
KA
Anderson
P
P
Branton
K R
KR
Schlossman
S F
SF
D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D001345:Autoradiography; D016827:CD8 Antigens; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D006680:HLA Antigens / Q000032:analysis*; D006801:Humans; D007118:Immunoassay; D010449:Peptide Mapping; D010766:Phosphorylation; D011422:Propionates; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D003432:Cross-Linking Reagents; D006680:HLA Antigens; D011422:Propionates; C021749:N-succinimidyl propionate