title: Increased intracellular killing of bacteria in vitro by monocytes of patients with metastatic melanoma before and during treatment with interferon-gamma and interferon-alpha.
abstract: The effect of recombinant human interferon-gamma (rHuIFN-gamma) and interferon-alpha (rHuIFN-alpha) as in vivo stimuli for the activation of human monocytes was investigated on the basis of the bactericidal activity of peripheral blood monocytes in 11 patients with metastatic melanoma before and during treatment with interferons. Patients received increasing doses of rHuIFN-gamma and a fixed dose of rHuIFN-alpha, both administered subcutaneously three times a week. The rates of intracellular killing of Listeria monocytogenes and Salmonella typhimurium after in vitro phagocytosis by monocytes collected from melanoma patients before interferon treatment were increased (P less than 0.01) by a factor of 1.7 and 1.4, respectively, relative to the rate constants in blood monocytes of healthy donors. During treatment with the interferons, the rates of intracellular killing of the bacteria by patients' monocytes did not further increase. The findings underscore the immunogenicity of malignant melanoma and put into question the macrophage activating activity of IFN-gamma with respect to the bactericidal activity of monocytes.
authors.affiliation: Department of Clinical Oncology, Leiden University Hospital, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Osanto
authors.forename: M T
authors.initials: MT
authors.lastname: van den Barselaar
authors.forename: J T
authors.initials: JT
authors.lastname: van Dissel
mesh_terms: D000328:Adult; D000368:Aged; D001770:Blood Bactericidal Activity / Q000276:immunology*; D005260:Female; D006801:Humans; D007370:Interferon Type I / Q000627:therapeutic use*; D007371:Interferon-gamma / Q000627:therapeutic use*; D008089:Listeria monocytogenes / Q000276:immunology; D008297:Male; D008545:Melanoma / Q000276:immunology / Q000556:secondary* / Q000628:therapy; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology*; D011994:Recombinant Proteins; D012486:Salmonella typhimurium / Q000276:immunology
chemical_list: D007370:Interferon Type I; D011994:Recombinant Proteins; D007371:Interferon-gamma