title: Modulation of in vitro BFU-E growth by normal Ia-positive T cells is restricted by HLA-DR.
abstract: The in vitro growth of immature erythroid precursors, assayed as burst forming units (BFU-E), can be enhanced by co-culturing with normal T cells. The growth enhancing effect of normal T cells, however, was shown to be the outcome of at least two functionally distinct subpopulations, one that enhances burst formation and one that limits it. It appears that the T cell population limiting growth enhancement of the erythroid precursors expresses 'Ia-like' antigen (Ia+) because treatment of T cells with anti-Ia antibody and complement significantly increased the ability of the remaining T cells to stimulate antologous BFU-E growth. As BFU-E also seem to express Ia, the inhibiting effect of certain T cells on BFU-E growth may involve the Ia molecule. We show here that the inhibitory effect of Ia+ T cells on BFU-E growth is genetically restricted to cell combinations which are phenotypically identical for at least one HLA-DR (Ia-like) antigen.
mesh_terms: D000328:Adult; D000818:Animals; D000906:Antibodies; D001769:Blood; D001853:Bone Marrow / Q000378:metabolism; D002648:Child; D003165:Complement System Proteins / Q000276:immunology; D004920:Erythropoiesis; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D009000:Monocytes / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology*
chemical_list: D000906:Antibodies; D000949:Histocompatibility Antigens Class II; D003165:Complement System Proteins