title: HLA-class II antigens on human hematopoietic progenitors.
abstract: A panel of alloindifferent monoclonal antibodies (MAB's) was used in complement-dependent lysis to characterize human myeloid, erythroid and multipotential progenitors (CFU-GM, BFU-E, CFU-GEMM) for their expression of MHC class II HLA-DR, -DP, and -DQ products. 7-16 donors were tested in each system. MAB Tü 34, detecting DR products, caused reduction of CFU-GM by a mean of 89%, whereas BFU-E and CFU-GEMM were reduced by 67% and 66% respectively. 35% of CFU-GM, 27% of BFU-E and 32% of CFU-GEMM were lysed by MAB B7/21, recognizing HLA-DP determinants, while Tü 22, binding HLA-DQ antigens, lysed 32% only of CFU-GM and did not lyse the other progenitors. Employing the "broad" MAB Tü 39, which binds at least DR and DP, inhibition of colony formation by CFU-GM was generally greater than that caused by Tü 34 alone or even by combinations of Tü 34, Tü 22, and B7/21. This suggests that there may be a subset of DR-, DP-, DQ- hematopoietic progenitors, which nonetheless bind MAB Tü 39, previously proposed as a candidate for the recognition of novel class II antigens.
mesh_terms: D000911:Antibodies, Monoclonal; D000920:Antibody-Dependent Cell Cytotoxicity; D001853:Bone Marrow / Q000276:immunology; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003165:Complement System Proteins / Q000276:immunology; D000939:Epitopes / Q000032:analysis; D006681:HLA-D Antigens / Q000032:analysis*; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D006681:HLA-D Antigens; D003165:Complement System Proteins