Monoclonal antibodies to HLA-A,B, and Ia-like antigens inhibit colony formation by human myeloid progenitor cells.
Hybridomas derived from the fusion of murine myeloma cells with splenocytes from mice immunized with human cultured lymphoid cells secreted monoclonal antibodies to human cell surface antigens. Serologic and immunochemical assays showed that 4 monoclonal antibodies (Ab Q2/47, Q2/61, Q2/70, Q2/80) recognize framework determinants of Ia-like antigens and 1 monoclonal antibody (Ab Q1/28) reacts with determinants expressed on the heavy chain of HLA-A,B antigens. Both anti-HLA-A,B and anti-Ia-like antigen monoclonal antibodies caused complement-dependent inhibition of granulocyte-macrophage colony formation by human bone marrow grown in soft agar. Mixing experiments excluded the possibility of an indirect effect on progenitor cells by lysis of auxiliary cells. These results indicate that human myeloid progenitor cells express HLA-A,B and Ia-like antigens.
D000818:Animals; D000961:Antilymphocyte Serum / Q000494:pharmacology; D002999:Clone Cells / Q000276:immunology; D003114:Colony-Forming Units Assay; D003165:Complement System Proteins; D000939:Epitopes; D006680:HLA Antigens; D006412:Hematopoietic Stem Cells / Q000276:immunology; D000949:Histocompatibility Antigens Class II; D006801:Humans; D007518:Isoantibodies; D051379:Mice; D011817:Rabbits
D000961:Antilymphocyte Serum; D000939:Epitopes; D006680:HLA Antigens; D000949:Histocompatibility Antigens Class II; D007518:Isoantibodies; D003165:Complement System Proteins