title: Restricted expression of an MHC alloantigen in cells of the erythroid series: a specific marker for erythroid differentiation.
abstract: The spectrum of reactivity with various types of cells of a monoclonal antibody (CH-4) which detects a private MHC antigen of chickens was analysed. CH-4 agglutinates only RBCs that possess the B2 (MHC) haplotype. A new rosette-forming cell (RFC) assay was devised to detect individual cells (excluding RBCs) that possess the CH-4 specificity on their cell surfaces. RBCs that have CH-4 chemically coupled to their surfaces attach to, and form rosettes with, B2 antigen-bearing cells. Most non-RBC RFC were detected in active erythropoietic organs (adult bone marrow and embryonic spleen), and none were found in organs where erythropoiesis does not occur: adult thymus and bursa. Preincubation of bone marrow cells with CH-4 plus complement almost completely inhibits their capacity to form CFU-E without affecting their ability to form GM-CFU. In addition, CH-4 plus complement does not inhibit the capacity of B2/B2 lymphocytes to induce a graft-versus-host reaction under conditions where anti-B2 lymphocyte alloantisera are completely inhibitory. Our results strongly suggest that CH-4 monoclonal antibodies detect a private specificity on a gene product of the B-G locus whose expression is restricted to erythroid stem cells and erythrocytes.
mesh_terms: D000328:Adult; D000372:Agglutination Tests; D000818:Animals; D000936:Antigen-Antibody Complex; D001853:Bone Marrow / Q000276:immunology; D002454:Cell Differentiation; D002642:Chick Embryo; D002645:Chickens; D003114:Colony-Forming Units Assay; D003165:Complement System Proteins / Q000276:immunology; D004920:Erythropoiesis; D005838:Genotype; D006087:Graft vs Host Reaction; D006410:Hematopoiesis; D006801:Humans; D007519:Isoantigens / Q000235:genetics*; D012397:Rosette Formation
chemical_list: D000936:Antigen-Antibody Complex; D007519:Isoantigens; D003165:Complement System Proteins