Ia antigen is a differentiation marker on human eosinophils.
Evidence suggests that the "la-like" or antigen is a differentiation marker that is expressed on early human hematopoietic precursor cells, but is absent on their mature progeny. The eosinophil precursor cell (CFU-EO) is distinct from the granulocyte-monocyte colon-forming cell (CFU-C). We provide data that indicate that the ia antigen is expressed on the human eosinophil colony-forming cells and is absent on mature eosinophils. All CFU-EO were inhibited in the presence of rabbit la antiserum at a titer of 1:30. Cytotoxicity was complement-dependent. The metamyelocytic eosinophil and more mature eosinophil forms did not express the la antigen.
D000954:Antigens, Surface; D002454:Cell Differentiation; D003601:Cytotoxicity Tests, Immunologic; D004802:Eosinophilia / Q000276:immunology; D004804:Eosinophils / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006412:Hematopoietic Stem Cells / Q000276:immunology; D006649:Histocompatibility Antigens; D006801:Humans
D000954:Antigens, Surface; D006649:Histocompatibility Antigens