Endogenous erythroid colony formation in myeloproliferative diseases does not depend on T cells.
We investigated the influence of T-cell depletion on BFU-E and CFU-GM colony growth in vitro from normal individuals and patients with chronic granulocytic leukemia (CGL), idiopathic myelofibrosis (MF), and polycythemia vera (PV). Preincubation of mononuclear cells with the complement-fixing monoclonal antibody OKT11A, which is cytotoxic to T-lymphocytes, significantly reduced the number of erythropoietin (epo)-dependent BFU-E colonies cultured from normal bone marrow and normal peripheral blood, as well as from the blood of patients with CGL, PV, and MF. In contrast, the numbers of epo-independent ("endogenous") BFU-E colonies cultured from the blood of PV and MF patients were the same before and after T-cell depletion. The blood and marrow of CGL patients and normal individuals produced no epo-independent BFU-E proliferation. The growth of day-7 and day-14 CFU-GM was not significantly influenced by T-cell depletion in the majority of experiments. We conclude that T cells promote the growth of epo-dependent BFU-E colonies in vitro, but they do not influence the growth of "endogenous" BFU-E colonies from patients with myeloproliferative disorders.
D000328:Adult; D000911:Antibodies, Monoclonal; D003114:Colony-Forming Units Assay; D004912:Erythrocytes / Q000166:cytology*; D006098:Granulocytes / Q000166:cytology; D006410:Hematopoiesis; D006801:Humans; D007951:Leukemia, Myeloid / Q000097:blood; D008264:Macrophages / Q000166:cytology; D009196:Myeloproliferative Disorders / Q000097:blood*; D011087:Polycythemia Vera / Q000097:blood; D055728:Primary Myelofibrosis / Q000097:blood; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology*
D000911:Antibodies, Monoclonal