EFFECTS OF RECOMBINANT INTERFERON-GAMMA AND CHEMOTHERAPY WITH ISONIAZID AND RIFAMPICIN ON INFECTIONS OF MOUSE PERITONEAL-MACROPHAGES WITH LISTERIA-MONOCYTOGENES AND MYCOBACTERIUM-MICROTI INVITRO

  • 1 October 1986
    • journal article
    • research article
    • Vol. 67  (5) , 707-717
Abstract
The effect of recombinant murine interferon-gamma (IFN-.gamma.) on the growth of Listeria monocytogenes for 4 h and Mycobacterium microti for up to 3 days in monolayers of peritoneal macrophages from BALB/c mice was examined by serial viable counts of cell-associated bacteria. Macrophages pretreated with 10 u IFN-.gamma. per ml were bacteriostatic and with 100 u or 1000 u per ml were bactericidal against L. monocytogenes. Addition of IFN-.gamma. 3 days before infection caused monolayers to be bactericidal against M. microti mainly during the first 15 min after infection. This was just evident with 10 u IFN-.gamma. per ml and greater with 100 u or 1000 u per ml. If IFN-.gamma. was added when phagocytosis of M. microti was complete, about 2 h after infection, its action was only bacteriostatic, the viable counts remaining stationary while those of unexposed monolayers increased. IFN-.gamma. 100 u per ml added before infection did not alter the bactericidal activity of rifampicin 10 mg/l, nor did it alter the killing curves for isoniazid I mg/l or for rifampicin 10 mg/l if added after completion of phagocytosis.