Diversity of in vitro cytokine responses by human macrophages to infection by mycobacterium tuberculosis strains.
Macrophages are an important component in the first line of defence of the innate immune system. They are capable of producing cytokines in response to bacterial challenge, as well as in response to cytokine stimuli from other cells in the immune system. The microbicidal response of human monocyte-derived macrophages in vitro, induced by exogenously added cytokines, is highly variable. We found that tumour necrosis factor-alpha (TNF-alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) could have either stimulatory or inhibitory effects on intracellular BCG killing, depending on the macrophage donor. Macrophages infected in vitro by various clinical isolates of Mycobacterium tuberculosis or the laboratory strain H37Rv, produced varying levels of both TNF-alpha and IFN-gamma. Certain M. tuberculosis strains tended to be associated with high cytokine production in each of three independent experiments, indicating that strains may differ in the host response elicited to infection.
Department of Medical Biochemistry, University of Stellenbosch Medical School, Tygerberg 7505, South Africa. egvh@maties.sun.ac.za
E G
EG
Hoal-van Helden
L A
LA
Stanton
R
R
Warren
M
M
Richardson
P D
PD
van Helden
D000293:Adolescent; D000328:Adult; D000368:Aged; D016207:Cytokines / Q000096:biosynthesis* / Q000097:blood; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis; D006801:Humans; D007239:Infections; D008264:Macrophages / Q000378:metabolism* / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D013045:Species Specificity; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha; D016178:Granulocyte-Macrophage Colony-Stimulating Factor