IL-10, T lymphocyte inhibitor of human blood cell production of IL-1 and tumor necrosis factor.

We have identified and purified a factor that inhibits the production of IL-1 beta and TNF by stimulated human mononuclear cells. The activity is produced by the T cell lines Hut-78 and Mo constitutively under serum-free conditions. Crude conditioned media have titers of up to 100 U/ml (one unit defined as the reciprocal of the dilution producing 50% inhibition).

Differentiation of the IL-3-dependent NFS-60 cell line and adaption to growth in macrophage colony-stimulating factor.

Macrophage CSF (M-CSF) induces responsive bone marrow precursors into rapid growth and differentiation to mature macrophages. Available cell lines that depend on M-CSF for growth are well differentiated and rather adherent. We investigated the effects of M-CSF on immature myeloid cell lines as models of the marrow precursors.

Stimulation of macrophage antibody-dependent killing of tumor targets by recombinant lymphokine factors and M-CSF.

Macrophage colony-stimulating factor (M-CSF) was investigated as a stimulator of ADCC to the murine R1.1 thymoma target by murine peritoneal exudate macrophages which were elicited by proteose peptone. Both an 125IUdR release and a viable cell count assay were used.

Role of interleukin 2, interleukin 4, and alpha, beta, and gamma interferon in stimulating macrophage antibody-dependent tumoricidal activity.

Pretreatment of murine peritoneal exudate macrophages with 1-5 U/ml rIFN-gamma or rIL-2, or higher concentrations of IFN-alpha or IFN-beta greatly stimulated ADCC to Rl lymphoma targets. The assay was direct counting of viable target cells after 9 and 24 h using an E/T ratio of 5:1. 2d of pretreatment was optimal for enhancing ADCC.

Stimulation of macrophage tumoricidal activity by the growth and differentiation factor CSF-1.

The effect of the macrophage growth and differentiation factor CSF-1 on the tumoricidal capacity of murine peritoneal exudate macrophages was investigated. Pretreatment of peptone-elicited macrophages 1 day with 300-1200 U/ml CSF-1 induced moderate killing and greatly stimulated lymphokine (LK)-induced killing of [3H]thymidine-labeled TU5 sarcoma cells to levels above that seen with fresh macrophages. Further addition of CSF-1 at Day 1 at the time of the tumor lysis assay promoted moderate increases in spontaneous and LK-induced activity.

Independent regulation of B-cell inducing factor and IL-2 production by T lymphocytes, and direct and indirect promotion of immunoglobulin secretion by glucocorticosteroid.

The conditions for induction of B-cell inducing factor (BIF) by human peripheral blood T cells was investigated. BIF was assayed by induction of immunoglobulin secreting cells (ISC) in peripheral blood B (non-T) cells stimulated with Staphylococcus aureus bacteria strain Cowan I (Sac), and in the IgM cell line SKW6.4.

Biological properties and molecular biology of the human macrophage growth factor, CSF-1.

CSF-1 is a growth and differentiation factor for the production of mononuclear phagocytes from undifferentiated bone marrow progenitors. In addition to previously described effects on mature cells, we show here that CSF-1 stimulates the production by monocytes of interferon, tumor necrosis factor, and myeloid CSF that produces mainly mixed neutrophil-macrophage colonies in bone marrow culture. Pretreatment with CSF-1 also promotes resistance to viral infection and tumor cytotoxicity in murine peritoneal macrophages.

Rescue of IgM, IgG, and IgA production in common varied immunodeficiency by T cell-independent stimulation with Epstein-Barr virus.

We previously defined three categories of B-cell defects in common varied immunodeficiency (CVI): failure to produce IgG and IgA in response to T cell-dependent (TD) stimulation by Staphylococcus bacteria (Sac) plus pokeweed mitogen or B-cell inducing factor (BIF), failure to produce any immunoglobulin, and failure of Sac-induced proliferation and differentiation. The present study includes the responses of 22 CVI patients to T cell-independent (TI) stimulation by Epstein-Barr virus (EBV). In the majority of patients, EBV-stimulated B cells showed normal proliferation and IgM production.

Human B cell-inducing factor(s) for production of IgM, IgG and IgA: independence from IL 2.

Human peripheral blood B cells are stimulated into proliferation by killed Staphylococcus aureus bacteria strain Cowan I (Sac). T lymphocytes in the presence of a T cell mitogen induce high numbers of immunoglobulin-secreting cells (ISC) in these Sac-stimulated B cells. The T cells can be largely replaced by a lymphokine factor.

Cooperation of IgG monoclonal antibodies in macrophage antibody-dependent cellular cytotoxicity (ADCC) to tumor targets.

Six IgG monoclonal antibodies representing the four murine IgG isotypes were active individually in ADCC to T-lymphoma targets mediated by murine macrophages and human blood K cells. The monoclonals were directed against four antigens (Thy-1.2, H-2k, Ly 2.

Cell-mediated lysis of tumor targets directed by murine monoclonal antibodies of IgM and all IgG isotypes.

Seven murine monoclonal antibodies to antigens expressed on T lymphoma targets were tested for directing antibody-dependent cellular cytotoxicity (ADCC). Peptone-induced peritoneal exudate macrophages, the LPS-stimulated RAW264.10 cell line, and human blood nonadherent mononuclear leukocytes were used as effector cells.

Colony-stimulating factors and regulation of macrophage tumoricidal and microbicidal activities.

Conditioned medium from antigen- or mitogen-stimulated spleen cells, lymphokines, contained factors that induced formation of granulocyte and macrophage colonies in cultures of bone marrow cells (CSF). Lymphokines also contained factors that induced macrophage non-specific tumoricidal activity against fibrosarcoma 1023, antibody-dependent tumoricidal activity against lymphoma 18-8, and antimicrobial activities against amastigotes of the protozoan parasite, Leishmania tropica. The factors that regulated macrophage effector functions, however, were different from those that induced colony formation, and could be distinguished from CSF by Sephadex gel chromatography or heat sensitivity.

Differences in antibody-dependent cellular cytotoxicity and activated killing of tumor cells by macrophage cell lines.

A series of murine macrophage cell lines was assayed for killing of B and T lymphocytic and myeloid tumor targets by radiolabel release at effector:target ratios of 20:1. One group of lines was inactive in all assays. Another group of lines showed moderate spontaneous cytotoxicity to lymphoid tumors that was greatly enhanced by inclusion of antibody, lipopolysaccharide, or phorbol myristate acetate in the 22-hr assays.

Cell interactions influencing murine marrow megakaryocytes: nature of the potentiator cell in bone marrow.

Auxiliary bone marrow cells are required for optimal murine megakaryocyte colony formation in addition to progenitor cells and a colony stimulating activity (CSA) present in WEHI-3 cell conditioned medium. These auxiliary cells are adherent, with a sedimentation rate of 5.8 mm hr-1 and buoyant density of 1.

All classes of murine IgG antibody mediate macrophage phagocytosis and lysis of erythrocytes.

Antibody-dependent phagocytosis and lysis of sheep RBC by mouse peritoneal exudate cells were studied using IgG subclass fractions of sera prepared by protein A-Sepharose chromatography. Three IgG1, 3 IgG2a, 4 IgG2b, and 1 IgG3 hybridoma antibodies to RBC were also used. The results showed that some monoclonal IgG2a and IgG2b antibodies were more active than IgG1 or IgG3 preparations when normalized to hemagglutinating activity, but all IgG sources mediated both effector mechanisms.

Corticosteroids block newly induced but not constitutive functions of macrophage cell lines: myeloid colony-stimulating activity production, latex phagocytosis, and antibody-dependent lysis of RBC and tumor targets.

Hydrocortisone at 10(-4) M added to macrophage cell lines had no effect on the following activities: J774.1 antibody-dependent phagocytosis and lysis of sheep RBC, RAW 264 antibody-dependent lysis of tumor targets, latex bead phagocytosis by PU5-1.8 cells, and constitutive production of myeloid colony-stimulating activity (CSA) by WEHI-3 cells.

Induction of myeloid colony-stimulating activity in murine monocyte tumor cell lines by macrophage activators and in a T-cell line by concanavalin A.

Certain fibrosarcoma lines in culture and the WEHI-3 myelomonocytic leukemia cell line have previously been shown to secrete myeloid colony-stimulating activity (CSA) spontaneously. We describe here other hematopoietic tumor cell lines in which CSA is either produced constitutively or inducible by immunostimulators. CSA production in macrophage and monocyte tumor lines is induced by lipopolysaccharide, zymosan, Mycobacterium strain Bacillus Calmette-Guérin, tuberculin purified protein-derivative preparation from mycobacteria, and dextran sulfate.

Immunologic functions and in vitro activation of cultured macrophage tumor lines.

Five murine monocyte of macrophage tumor lines adapted to culture were characterized for differentiated properties. They ingested zymosan and latex beads, bore receptors for immunoglobulin and complement, synthesized lysozyme (most of which was secreted), and produced granulocyte colony-stimulating activity, either spontaneously or inducibly. Some of the lines also mediated phagocytosis and exocytosis of red blood cells (RBC) and lysis of tumor targets, dependent on the presence of specific antitarget sera.