The effect of interferon-gamma and lipopolysaccharide on the growth of Francisella tularensis LVS in murine macrophage-like cell line J774.

Background: Francisella tularensis, a causative agent of human tularemia, displaying the ability to proliferate inside the human cells.

Aims: To evaluate the growth potential of F. tularensis LVS strain in macrophage-like cell line J774 modulated by recombinant interferon gamma and E. coli derived lipopolysaccharide.

Results: Stimulation of J774 cells either by interferon-gamma or lipopolysaccharide alone, or especially in combination before infection F. tularensis, revealed protective effects. Higher concentrations of stimulating agents were needed to inhibit ongoing F. tularensis infection.

Conclusions: Stimulation of J774 cell line by combination of interferon-gamma with lipopolysaccharide inhibits the intracellular growth of F. tularensis.