Recombinant tumour necrosis factor-alpha decreases whereas recombinant interleukin-6 increases growth of a virulent strain of Mycobacterium avium in human macrophages.
The ability of a virulent strain of Mycobacterium avium to infect and replicate within human monocyte-derived macrophages of normal donors was assessed. Moreover, the ability of selected cytokines to modulate the intracellular growth of M. avium was investigated. Our virulent strain of M. avium grew progressively in human macrophages. Treatment of macrophage monolayers with interferon-gamma (IFN-gamma) did not lead to any significant change in the infection pattern. Conversely, treatment with tumour necrosis factor-alpha (TNF-alpha) led to a significant reduction in the growth of M. avium in the macrophages. In contrast, treatment of macrophages with interleukin-6 (IL-6) enhanced their susceptibility to M. avium significantly. This finding was substantiated by other results which showed that IL-6 increased the growth of M. avium in tissue culture medium. These results suggest that cytokines may influence the M. avium-macrophage interaction, in a positive or negative manner.
Denis
M
M
Bioscience 1, ICI Pharmaceuticals, Macclesfield, Cheshire, U.K.
Gregg
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D002478:Cells, Cultured; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D015850:Interleukin-6 / Q000276:immunology*; D008264:Macrophages / Q000382:microbiology*; D009162:Mycobacterium avium / Q000254:growth & development*; D011994:Recombinant Proteins / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*; D014774:Virulence
D015850:Interleukin-6; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma