concanavalin-a and Anemia--Aplastic

Human retroviruses have recently been linked with T cell lymphoproliferative disorders and with the acquired immune deficiency syndrome. We investigated the mechanisms for acquired pure red cell aplasia and cutaneous anergy in a patient with the chronic T gamma-lymphoproliferative disease (T gamma-LPD) syndrome. Patient marrow erythroid progenitors (BFU-E) were 17 +/- 9% of control and were selectively increased to 88-102% of control after marrow T cell depletion. Patient Leu 2+ suppressor T cells spontaneously produced high titers of human gamma-interferon and resulted in a concentration-dependent selective inhibition (74-91%) of BFU-E when co-cultured with autologous or allogeneic marrow. Conditioned media (CM) derived from patient Leu 2+ T cells similarly inhibited growth of autologous or allogeneic marrow BFU-E. The inhibitory factor derived from patient CM was acid-labile (pH 2) and sensitive to trypsin; prior treatment of patient T cells with anti-HLA-DR monoclonal antibody plus complement abrogated the suppressive effect of T cell-derived CM. Patient peripheral blood mononuclear cells (PBMC) were unable to support growth of cultured interleukin 2 (IL 2)-dependent T cells, but responded to exogenous IL 2 in vitro with a 16-21-fold augmentation, relative to control, in mitogen-induced proliferation. Antibodies to HTLV-I core proteins p19 and p24 but not to HTLV-III proteins were detected in patient serum by Western blotting; patient cultured PBMC stained (7-11%) with antibodies to p19 and p24. Patient cultured PBMC demonstrated integrated HTLV-I genomic sequences by the Southern technique and expressed both specific HTLV-I genomic sequences by RNA dot blot plus reverse transcriptase activity. Utilizing a cloned DNA probe for the beta chain of the T cell receptor gene, patient PMBC demonstrated gene rearrangements providing presumptive evidence for clonality. The presence in serum of HTLV-I p19 and p24 antibodies, the expression of p19 and p24 core antigens on patient mononuclear cells, the evidence of HTLV-I proviral integration sequences and the expression of HTLV-I genomic sequences in patient cells, indicates infection with HTLV-I and raises the possibility of an etiologic link between human retrovirus infection and some instances of large granular lymphocytic leukemia (T gamma-LPD).

Topics: Anemia, Aplastic; Antigens, Differentiation; Concanavalin A; Deltaretrovirus Infections; Erythropoiesis; Humans; Interleukin-2; Lymphocyte Activation; Lymphoproliferative Disorders; Male; T-Lymphocytes, Regulatory; Viral Proteins

Bone marrow and peripheral blood T cells were obtained from 15 normal individuals by E rosetting and cultured in round-bottomed microwells for 7 days in RPMI or in RPMI supplemented with mitogens (pokeweed mitogen, phytohemagglutinin or concanavalin A). Supernatants and cells were harvested on days 1, 2, 3, 4 and 7 and co-cultured with normal marrow cells in semi-solid agar to test their CFU-c suppressor activity. The results of this study indicate that (a) RPMI treated cells and their supernatants have no effect or an enhancing effect on CFU-c growth; (b) all 3 mitogens generate CFU-c suppressor T cells on day 1 of culture; (c) the inhibitory activity is detectable until day 4 of culture, though overall reduced, and is completely lost on day; 7 (d) the trend for supernatants of mitogen-treated T cells is quite similar with a tendency to complete loss of the inhibitory effect on day 7. We interpret these data as indicating that T cells release a soluble inhibitor of CFU-c growth within a few hours from polyclonal activation, the production of which is either controlled or lost with time in culture.

Topics: Anemia, Aplastic; Bone Marrow Cells; Cell Survival; Cells, Cultured; Colony-Forming Units Assay; Concanavalin A; Hematopoiesis; Humans; Lymphocyte Activation; Mitogens; Phytohemagglutinins; T-Lymphocytes; T-Lymphocytes, Regulatory

A patient with constitutional Fanconi-like aplastic anemia who developed a preleukemic state was transplanted with bone marrow from his HLA-identical MLC-negative brother. Before transplantation his mononuclear leukocytes were found to have a defective stimulating and responder capacity in mixed leukocyte culture with cells of an unrelated individual. After removal of T cells the stimulating capacity was completely restored. MLC testing with separated cell fractions seems important to establish HLA-D identity with a possible donor, especially when MLC tests with unseparated cells are negative.

Topics: Adult; Anemia, Aplastic; Bone Marrow Transplantation; Cell Separation; Concanavalin A; Humans; Lectins; Leukocytes; Lymphocyte Culture Test, Mixed; Male; Preleukemia; T-Lymphocytes

Topics: Adult; Anemia, Aplastic; Cell Membrane; Cell Nucleus; Concanavalin A; Erythroblasts; Erythrocytes; Female; Humans; Immunoglobulin G; Phytohemagglutinins; T-Lymphocytes, Regulatory; Tuberculin

The ability of peripheral blood mononuclear cells from patients with idiopathic aplastic anaemia to provide colony-stimulating activity (CSA) was compared to that of normal controls. CSA was prepared by incubating peripheral blood mononuclear cells with phytohaemagglutinin. The supernatant derived from the latter is known as activated lymphocyte-conditioned medium (ALCM). The CSA of ALCM in eight patients was compared to that of normals in 12 experiments. In all but one instance there was decreased CSA by patient ALCM. Possible implications of these findings are discussed.

Topics: Adult; Anemia, Aplastic; Cells, Cultured; Child; Colony-Forming Units Assay; Concanavalin A; Culture Media; Female; Granulocytes; Humans; Lymphocyte Activation; Macrophages; Male; Mitogens; Phytohemagglutinins; Pokeweed Mitogens