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M T Aye

Publications and source records attributed to M T Aye.

34 records · Page 2Linked to original sources
PubMed1990

Detection of surface and cytoplasmic CD4 on blood monocytes from normal and HIV-1 infected individuals.

CD4 on blood monocytes is generally regarded as being found on a subset of blood monocytes. However, our results show that all monocytes are CD4+ but the number of molecules per cell is lower than T cells. We have performed immunofluorescent (flow cytometry, microscopy) analysis of monocytes from normal donors and HIV-1-infected patients using anti-CD4 (Leu-3a) and the monocyte-specific marker anti-CD14 (Leu-M3) monoclonal antibodies. Specifically: (1) 91% of monocytes from normal individuals show dual positivity for CD14 and CD4 (n = 14) as measured by flow cytometry; (2) 76% of monocytes expressed surface bound CD4 and CD14 when an enhanced two colour immunofluorescence microscopic technique was employed; (3) all CD14+ monocytes stained with an intensity of 3+(-)4+ for cytoplasmic CD4. Few monocytes were CD14- and CD4+. Cell surface CD4 expression was blocked with unconjugated anti-CD4 prior to staining; (4) the staining intensity for cytoplasmic CD4 in T cells was negligible; (5) CD4 expression on monocytes obtained from patients was as observed with normal individuals. The conclusion drawn is that all monocytes are CD4+ and the CD4 expression in monocytes is mainly cytoplasmic. Thus, all monocytes are potentially infectable with HIV-1.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Registry of unrelated bone marrow donors.

Reports of successful transplantation of bone marrow obtained from unrelated donors who were histocompatibility leukocyte antigen (HLA) identical prompted the Canadian Red Cross Blood Transfusion Service in Ottawa to assess the possibility of developing a bone marrow donor registry in Canada. We sent a pamphlet that explained the program to 1568 people who had undergone apheresis and asked them to reply, stating their interest. At the same time the pamphlets and a poster were placed in the blood donor clinic. We received 1232 replies (78.6%) from the apheresis donors, 838 (68.0%) of which indicated a willingness to attend information sessions. Of the 7158 people who gave blood during the 3-month study period, 225 (3.1%) were interested. At the time this paper was written 47 information sessions had been held, and 721 people had attended, 624 (86.5%) of whom had signed a consent form. This indicates a clear interest in a bone marrow donation program. We believe that the ethical issues are overcome by requesting the donation before identification of any patient. From our experience a national registry of unrelated donors seems feasible, and steps are being taken to implement such a program.

Blood Component Removal↗
PubMed1986

Characterization of reticulofibroblastoid colonies (CFU-RF) derived from bone marrow and long-term marrow culture monolayers.

The maintenance of hemopoietic precursors in long-term liquid bone marrow cultures (LTBMC) is associated with the presence of an adherent stromal layer composed of heterogeneous cell populations. We have used a culture assay to promote the growth of one of its cellular components and characterize its properties. Freshly obtained bone marrow cells and cells derived from the adherent layer of LTBMC were grown in methylcellulose-clotted plasma in the presence of phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM), hydrocortisone (HC), and citrated normal human plasma. Both sources contained cells (CFU-RF) that gave rise to colonies of cells with a reticulofibroblastoid appearance. In the presence of HC, most colonies contained lipid-laden cells. Colonies could be further propagated as adherent layers when transferred into liquid cultures. These cells produced laminin, fibronectin, and collagen types I, III, IV, and V. They were negative for Von Willebrand factor VIII. The ability to synthesize laminin and collagen type IV distinguished these cells from a population of previously described bone marrow fibroblasts (CFU-F). The relationship of CFU-RF to hemopoietic precursors was investigated using patients with chronic myeloid leukemia and bone marrow transplant recipients. Cells within CFU-RF-derived colonies were uniformly negative for the Philadelphia chromosome, thus making it unlikely that they belonged to the malignant hemopoietic clone. CFU-RF-derived colonies in bone marrow transplant recipients were found to be exclusively of host origin. Both observations support the view that CFU-RF is not part of the repertoire of hemopoietic stem cells.

Antigens↗
PubMed1983

Opposing effects of 12-O-tetradecanoylphorbol 13-acetate on human myeloid and lymphoid cell proliferation.

The effect of 12-O-tetradecanoylphorbol 13-acetate (TPA) on human hematopoietic cells has been investigated. It was found that 1-10 ng/ml of TPA totally abrogated erythroid and granulocytic colony growth and, simultaneously in the presence of PHA, stimulated T-lymphocyte colony formation. TPA concentrations insufficient to inhibit myeloid colony growth also failed to stimulate lymphocyte colony formation. Optimal culture conditions for the growth of these colonies required the presence of TPA, PHA, and leukocyte-conditioned medium in the cultures. Cells within the colonies were 80-90% E-rosette positive and by monoclonal antibody characterization contained 45-66% OKT3-positive cells. Colony-forming cells were found in both E-rosette-positive and-negative fractions. Although by cell surface marker characterization the cells within the colonies had properties of T-cells, the exact relationship of cells forming colonies under these conditions to those detected in other T-cell colony assays remain to be determined.

Cells, Cultured↗
PubMed1982

Studies on the effect of deoxyadenosine on deoxycoformycin-treated myeloid and lymphoid stem cells.

Adenosine deaminase (ADA) deficiency has been reported in association with severe combined immunodeficiency disease (SCID). The mechanism by which ADA deficiency causes immune dysfunction has been investigated in model systems to which the ADA inhibitor deoxycoformycin (dCf) had been added. Previously, we demonstrated that dCF did not prevent proliferation and differentiation of myeloid and lymphoid stem cells. We have now shown that addition of deoxyadenosine to dCf-containing cultures inhibited proliferation of hemopoietic stem cells. This inhibition was, however, equally effective for both normal myeloid and lymphoid stem cells. These findings suggest that other differences may exist between SCID myeloid and lymphoid stem cells to account for the relative sparing of myelopoiesis in SCID patients.

Adenosine Deaminase Inhibitors↗
PubMed1981

Effect of 2'-deoxycoformycin on erythroid, granulocytic, and T-lymphocyte colony growth.

The finding of elevated intracellular levels of adenosine deaminase (ADA) in some patients with acute lymphoblastic leukemia has led to attempts to control this disease with the adenosine deaminase inhibitor 2'-deoxycoformycin (dCF). Because of clinical reports indicating its relative freedom from myelotoxicity, we have tested the effects of this drug on erythroid, granulocytic, and T-lymphocyte colony formation by normal marrow and peripheral blood cells. While clinically the drug has been found to be active at serum concentrations of approximately 10 microM, we have tested it at concentrations up to and including 1 mM. It was found that both erythroid and granulocytic colony growth was completely unaffected by 1 mM dCF, a concentration at least 2 magnitudes higher than that necessary to totally ablate intracellular ADA levels. T-lymphocyte colony growth was unaffected by 100 microM dCF, but at 1 mM some inhibition was observed. These findings therefore indicate that dCF, while able to cause leukemic cell lysis in vivo, has no inhibitory effect on the proliferative capacity of normal hematopoietic cells.

Adenine↗
PubMed1979

Erythroid and granulocytic colony growth in cultures supplemented with human serum lipoproteins.

The ability of human serum to support erythroid and granulocytic colony formation has been investigated. It was found that normal human serum could replace fetal calf serum in the cultures and was able to support the growth of these hemopoietic colonies. Serum fractions enriched for low density lipoproteins, either by precipitation with Heparin-Mn++ or by ultracentrifugation, was found to contain this growth supporting activity of human serum.

Bone Marrow Cells↗
PubMed1979

Evidence for proliferation of erythroid progenitor cells in the absence of added erythropoietin.

The cellular mechanisms underlying the requirement of leukocyte conditioned medium for human erythroid colony formation has been studied. Using photographic methods it was found that erythroid progenitor cells were able to form small colonies in the absence of added erythropoietin (epo). The addition of epo at this time leads to further growth and hemoglobinization of cells within the colony. Leukocyte conditioned medium was found to be required for this early proliferative stage of erythroid colony formation.

Bone Marrow Cells↗
PubMed1977

Erythroid colony formation in cultures of human marrow: effect of leukocyte conditioned medium.

A method, based on the differing capacities of cells to adhere to a column of polyester fibres, has been described for separating human bone marrow cells into a nonadherent and an adherent fraction. The effect of this cell separation procedure on colony formation by erythroid progenitor cells was investigated. In contrast to the unseparated population, it was found that erythropoietin-dependent erythroid colony formation by nonadherent cells could be considerably enhanced by the addition of leukocyte conditioned medium to the cultures. Similar erythroid enhancing activity was also detected in a partially purified preparation of granulocytic colony stimulating activity obtained from human embryo kidney culture supernatants. Erythroid colony formation in the absence of added erythropoietin, by non-adherent bone marrow cells from patients with polycythemia rubra vera, were also enhanced by the addition of LCM to the cultures. This finding suggests that the enhancing factor in LCM may not be dependent on the presence of erythropoietin in the cultures for its activity. While the cellular mechanisms by which leukocyte conditioned medium enhances erythroid growth remain to be determined, the data presented provides strong evidence for the view that the plating efficiency of erythroid progenitor cells is determined not only be the concentration of erythropoietin, but also by the presence of leukocyte conditioned medium in the cultures.

Bone Marrow Cells↗
PubMed1975

Interacting populations affecting proliferation of leukemic cells in culture.

Peripheral blood cells from three patients with acute leukemic have been studied using a suspension culture method previously described.1 Cytogenetic studies in two of the patients permitted the identification of the proliferating cells in the cultures as being derived from a leukemic population. Cell separation studies using velocity sedimentation supported the concept that growth of the leukemic cells in culture is dependent on an interaction between two populations of leukemic cells.

Autoradiography↗