Open AccessApparent killing of Mycobacterium tuberculosis by cytokine‐activated human monocytes can be an artefact of a cytotoxic effect on the monocytes
Author(s) -
WARWICKDAVIES J.,
DHILLON J.,
O'BRIEN L.,
ANDREW P. W.,
LOWRIE D. B.
Publication year - 1994
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1994.tb06544.x
Subject(s) - mycobacterium tuberculosis , immunology , monocyte , tuberculosis , cytotoxic t cell , tumor necrosis factor alpha , cytokine , microbiology and biotechnology , interferon gamma , biology , bacteria , interferon , in vitro , medicine , pathology , biochemistry , genetics
SUMMARY A protocol using combined exposure to interferon‐gamma (IFN‐γ), calcitriol and tumour necrosis factor‐alpha (TNF‐α) has been reported to activate human monocytes in vitro to kill Mycobacterium tuberculosis. We have attempted to repeat the findings in two laboratories, with negative results: treated cells were no different from untreated cells in this respect. However, the treated cells were more sensitive to a toxic effect of the bacteria. We suggest that the reported dramatic mycobacterial killing may have been an illusory consequence of the toxicity leading to cell lysis and loss of the liberated bacteria from the assay.