Recently we demonstrated that endothelins secreted from human keratinocytes act as intrinsic mitogens and melanogens for human melanocytes in UVB-induced melanosis. We show here that UVA-induced melanosis is associated with other keratinocyte-derived growth factors, secretion of which is specifically stimulated after exposure of human keratinocytes to UVA. Medium conditioned by UVA-exposed huma...

Pre-incubation of human neutrophils with pertussis toxin significantly inhibited the neutrophil-directed biologic actions of granulocyte-macrophage colony-stimulating factor (GM-CSF) in three separate assays: the induction of c-fos mRNA, the enhancement of both platelet-activating factor-induced mobilization of intracellular calcium, and stimulation of leukotriene synthesis by the calcium ionop...

Genetic antigens of human immunoglobulin G (Gm factors) were measured in members of the families of selected patients with primary immunodeficiency. The sera of seven out of 27 heterozygous relatives had either deficient concentrations of one Gm allotype or an unbalanced ratio of Gm(f)/Gm(a). Since these markers for allelic IgG1 genes are found in almost equal amounts in normal heterozygous per...

The effects of recombinant human erythropoietin (Ep). granulocyte/macrophage (GM) and granulocyte (G) cobny-stimulating factors (CSF). and interleukin-3 (lL-3) on erythroid burst and GM colony growth have been studied in fetal bovine serum (FBS)-supplemented and FBS-deprived culture. Sources of progenitor cells were nonadherent or nonadherent T-lymphocyte-depleted marrow or periphoral blood cel...

We investigated the role of normal human marrow cells with Fc receptors for IgG (Fc gamma+) on autologous granulocyte-macrophage colony (GM-CFC) formation. It was found that Fc gamma+ normal human marrow cells, both with (E+) or without receptors for sheep erythrocytes suppressed GM-CFC at as low a concentration as 0.25 X 10(5) cells/ml of culture. A similar effect was observed with E- Fc gamma...

Eosinophils, cells that are associated with asthma (1, 2), helminthic infections (3), and other clinical disorders, are thought to reside in the peripheral blood for <12 h and in connective tissues for several days (4). The in vitro survival of human peripheral blood eosinophils is limited to <2 d. Because the eosinophilia that normally accompanies helminthic infections is suppressed in athymic...

GM-CSF signals through JAK2 and STAT5 and stimulates the expression of STAT5 target genes, such as pim-1 and CIS. Analyzed by EMSA, GM-CSF stimulation led to much stronger STAT5 DNA-binding to pim-1 or CIS GAS elements in primary human monocytes compared with mature macrophages. Similarly, GM-CSF-induced expression of pim-1 and CIS mRNAs was much stronger in monocytes. These differencies were n...

We have examined the effects of verapamil on the cytotoxicity of etoposide, vincristine, and Adriamycin in human leukemia K562 cells as well as in normal human bone marrow granulocyte-macrophage progenitors (CFU-GM). Etoposide was 10-fold more potent against K562 cells than against normal human bone marrow CFU-GM. Similarly, vincristine cytotoxicity was about 10-fold greater against K562 cells ...

The alveolar macrophage (AM), as a representative human tissue macrophage, was used in an in vitro system to examine the anti-human immunodeficiency virus type-1 (HIV-1) activity of zidovudine (AZT) and granulocyte-macrophage colony-stimulating factor (GM-CSF). AMs were infected with the IIIB strain of HIV-1 and exposed to AZT (1 mumol/L), GM-CSF (30 U/mL), a combination of AZT (1 mumol/L)/GM-C...

The response rate to cetuximab, a chimeric (mouse-human) monoclonal antibody directed against epidermal growth factor receptor (EGFR), in colorectal cancer is low (10–15%), with significant inter-individual variability. Mechanisms proposed thus far to explain resistance to this therapy—such as the emergence of EGFR and KRAS mutations and aberrant ERBB2 signaling—do not account for the total int...