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D Metcalf

Publications and source records attributed to D Metcalf.

At least 397 records · Page 22Linked to original sources
PubMed1976

Characteristics of B-lymphocyte colony growth in vitro.

A cloning system in semisolid agar has been developed which supports colony formation by mouse B-lymphocytes. Colonies appear to be clones and colony cells synthesize immunoglobulin. Approximately one cell in 50 in the spleen or lymph nodes is capable of forming a colony and colony-forming cells appear to have the properties of B-lymphocytes. Colony formation is dependent on mercaptoethanol but the possible additional involvement of a specific B-lymphocyte regulatory factor has not been excluded.

Animals↗
PubMed1976

Inhibition by mouse serum of hemopoietic colony formation in vitro.

The inhibitory activity of BALB/c serum for granulocytic and macrophage colony formation by mouse marrow cells in vitro was separable by flotation centrifugation into the very light density (VLD) fraction. On gel filtration the inhibitory material had an apparent molecular weight of 250,000 and on electrophoresis was localized as a single peak near the albumin region. These inhibitory preparations exhibited lack of specificity and inhibited colony formation by normal B-lymphocytes, lymphoid leukemic, plasma cytoma and mastocytoma cells. Preincubation of C57BL marrow cells at 37 degrees C with high concentrations of VLD fractions was cytotoxic and completely suppressed colony formation. Incubation at 0 degrees C or at 37 degrees C with low VLD concentrations caused a pattern of colony formation similar to that observed in cultures of marrow cells from mice with high serum inhibitory activity (CBA, BALC/c). The lack of specificity of serum inhibitors casts doubt on the role of these inhibitors as specific in vivo regulators of granulopoiesis and monocyte-macrophage formation.

Animals↗
PubMed1976

Development of B-lymphocyte colony-forming cells in foetal mouse tissues.

In CBA and (CBA X C57B1)F1 mice, cells forming B-lymphocyte colonies in agar culture were first detected in the 17-day foetal liver and the following day in the spleen, bone marrow and peripheral blood. Colony-forming cells were not detected in the yolk sac or foetal thymus. Adult levels of colony-forming cells were achieved within 3 days of birth. In organ cultures of 15-day foetal liver or spleen, B-lymphocyte colony-forming cells developed during a 5-day incubation period, indicating that both organs can function as bursal analogues. Foetal liver colony-forming cells were of small size and generated colonies of cells with a pattern of membrane immunoglobulin similar to colony cells generated by cells from adult animals.

Animals↗
PubMed1975

Growth of B-lymphocyte colonies in vitro.

In semisolid agar cultures containing mercaptoethanol, cells from the spleen, lymph nodes, marrow, peritoneal cavity, thoracic duct, and blood of normal mice generated clusters and colonies of up to 3,000 cells. Colony numbers and growth were markedly enhanced by the addition of sheep red cells. The frequency of colony-forming cells in the spleen or lymph nodes was 0.5-2.0%, and cluster forming cells were approximately five times more numerous. The mononuclear cells comprising these colonies had the electronmicroscopic morphology of immature lymphoid and plasma cells. The majority of the cells possessed Fc receptors, 61-69% reacted with anti-mu-serum and 4-11% with anti-gamma2-serum. Analysis of single cells from individual colonies indicated a higher frequency of the cells with membrane immunoglobulin and a clonal pattern of anti-mu or anti-gamma-reactivity. The clonal nature of colonies was supported by an analysis of NIP-binding cells in colonies grown from CBA spleen cells enriched for NIP-binding cells. Mass-harvested colony cells synthesized immunoglobulin in short-term liquid cultures. It is concluded that the colonies are clones of functionally active B-lymphoid cells.

Animals↗
PubMed1975

[Characterization of megakaryocyte colonies in vitro].

Agar cultures of mouse bone marrow cells can be stimulated by medium conditioned by activated mouse lymphoid cells to produce pure or mixed colonies containing up to 80 megakaryocytes. These have been characterized on the basis of their morphology, polyploid mitoses and DNA content and high cytoplasmic content of acetylcholinesterase.

Acetylcholinesterase↗
PubMed1975

Heterogeneity of in vitro colony- and cluster-forming cells in the mouse marrow: segregation by velocity sedimentation.

C57BL bone marrow cells were separated on the basis of their sedimentation velocity at unit gravity and cell fractions cultured in agar using three types of colony stimulating factor (CSF). Colony-forming cells separated as a single peak (s equal 4.4 mm/hr) in cultures stimulated by mouse lung conditioned medium (CSFMLCM) or endotoxin serum (CSFES). Cluster-forming cells were separable into two peaks and the majority were larger than colony-forming cells (s equal 5.7 mm/hr). Partial segregation of colony-forming cells was observed according to the morphological types of colonies generated, large cells tending to generate macrophage colonies and small cells, granulocytic colonies. Large colony-forming cells were more responsive to stimulation by CSF than small cells. Human urine (CSFHU) appeared unable to proliferation of most small colony-forming cells. Colony-forming cells appear to be a highly heterogeneous population with intrinsic differences in responsiveness to CSF and with differing capacities to generate colonies whose cells differentiate to granulocytes of macrophages.

Animals↗
PubMed1975

Preparation and neutralization characteristics of an anti-CSF antibody.

Nine of ten rabbits immunized with a partially purified L-cell CSF had demonstrable titers of anti-CSF activity. In vitro the antibody was markedly inhibitory to both post-endotoxin mouse sera and several mouse tissue extracts. CSF containing conditioned media prepared from a number of sources showed variable inhibition suggesting that murine CSF's may be characterized by marked antigenic differences. Human sources of CSF were also inhibited thus indicating a degree of cross-reactivity between murine and human factors. These studies may provide the initial steps toward definition of the role of CSF in vivo.

Animals↗
PubMed1975

Growth of mouse megakaryocyte colonies in vitro.

Mouse bone marrow and spleen cells formed pure or mixed colonies of up to 80 megakaryocytes in agar cultures after stimulation by medium conditioned by activated mouse lymphoid cells. Megakaryocytes were identified on the basis of their morphology, polyploid mitoses and DNA content, and high cytoplasmic content of acetylcholinesterase. Megakaryocyte colony-forming cells were relatively small with a peak sedimentation velocity of 4.2 mm/hr. Spleen, lymph node, and thymus cells produced the factor stimulating megakaryocyte proliferation after culture in medium containing 2-mercaptoethanol, with or without added mitogens or allogeneic spleen cells. Peak activity in conditioning medium was associated with the small lymphocyte fractions in mouse spleen.

Animals↗
PubMed1975

Growth and responsiveness of human granulocytic leukemic cells in vitro.

Cells from patients with acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) can be grown and their properties analyzed in agar gel cultures. Levels of the glycoprotein regulator colony stimulating factor (CSF) were found to be elevated in 19-66% of plasmas tested from patients with various types of granulocytic leukemia, and the growth of AML and CML cells in vitro was observed to be dependent on, and responsive to, stimulation by CSF-containing material. In both diseases, the leukemic cells appear to be in a responsive state with respect to normal growth regulators, and potentially alterations in regulator levels may therefore be able to achieve sustained arrest of the growth of leukemic populations.

Bone Marrow↗
PubMed1975

Serum potentiation of granulocyte and macrophage colony formation in vitro.

Addition of serum or plasma from many species increased the number and size of neutrophilic granulocyte and macrophage colonies formed in vitro by mouse bone marrow cells after stimulation by a variety of preparations containing colony stimulating factor (CSF). The active factor in serum was heat-labile, non-dialyzable and eluted from G-100 columns in the serum albumin region. Serum non-selectively affected all cells potentially capable of forming granulocytic and macrophage colonies but did not potentiate the formation of eosinophilic or megakaryocytic colonies. The potentiating activity of mouse serum was increased by prior injection of the mice with endotoxin but was not affected by prior whole-body irradiation. Colony potentiating activity in plasma from patients with myeloid of lymphoid leukemia did not differ from that of normal human plasma.

Animals↗
PubMed1975

Colony stimulating factor and the regulation of granulopoiesis and macrophage production.

The growth and differentiation of colonies of granulocytes and/or macrophages in semisolid cultures of hemopoietic cells requires the presence of "colony stimulating" factors (CS factors). Colony stimulating factors are found in serum, urine and certain tissues, and in media "conditioned" by certain cells in culture. A procedure has been developed for purification of CS factor from human urine. The 100,000-fold purified product is active on mouse bone marrow cells at less than or equal to 10(-11) M but is only partially purified. Polydispersity of activity has made further purification difficult and may necessitate use of biologically selective techniques such as immunosorbent chromatography. Knowledge of the properties of human urinary CS factor has been derived from the in vitro assay of biological activity following various treatments. It appears to be a sialic acid-containing glycoprotein of molecular weight 45,000-60,000 daltons that migrates electrophoretically between alpha1 globulin and albumin. Highly purified CS factor preparations can be iodinated with five atoms of iodine per molecule of protein without loss of biological activity. Neutralizing antibody to human urinary CS factor neutralizes CS factor from other human and monkey sources. Higher concentrations of antiserum are required for neutralization of murine CS factor. Human urinary CS factor has similar properties to human and murine CS factors that stimulate the early appearance of macrophages in murine colonies. It is physically distinct from CS factors that stimulate the formation of pure granulocytic colonies by murine or human hemopoietic cells. Purified CS factor of the human urinary type is being used to investigate the nature of the interaction of CS factor with target cells and its physiological role in vivo.

Animals↗
PubMed1975

Receptors for C3 and IgG on macrophage, neutrophil and eosinophil colony cells grown in vitro.

Macrophage, neutrophil, and eosinophil colony cells from bone marrow culture in semisolid agar medium were studied for membrane C3 and IgG receptors. The capacity of these cells to bind either erythrocytes-19S antibody-complement (EAC) or erythrocyte-7S antibody (EA7S) complexes was measured using the rosette method. Whereas macrophage and neutrophil colony cells showed receptors for both C3 and IgG, eosinophil colony cells appear to bear only IgG receptors. Studies correlating colony age and the presence of receptors showed that 60 to 70% of the cells from 3-day-old macrophage colonies were reactive for EAC and EA7S contrasting with 80 to 90% of the cells from 6- to 12-day-old colonies. Neutrophils behaved somewhat differently: EAC and EA7S reactive cells were seen in colonies after 4 or 5 days in culture and comprised only 50 to 60% of the colony population. Eosinophilic colonies showed 50 to 60% EA7S reactive cells after 6 to 7 days in culture, but no EAC reactive cells were found among these colonies at any time. The characteristics and properties of the receptors detected on colony cells were similar to those on macrophages and neutrophils from normal peritoneal fluid or bone marrow. Most macrophage colony cells were actively phagocytic whereas neutrophils and eosinophilic colony cells failed to show phagocytosis under the same conditions.

Animals↗