[Modulation by quinolones of the in vitro proliferative response of splenic cells of the mouse and IL 1 production].

Besides their antibacterial activity, antibiotics can modulate immune response. In this work, we studied the effects of 6 quinolones (nalidixic and pipemidic acid, pefloxacin, norfloxacin, ofloxacin, ciprofloxacin) on Con A or LPS induced mitogenic response in mice. Data presented here show that pefloxacin and ofloxacin enhanced Con A (1 microgram/ml) induced proliferative response when used at low concentrations (0.1 microgram/ml and 1 microgram/ml). In the same conditions LPS induced response was not modified. When used at high concentrations (greater than 25 micrograms/ml), inhibition of both LPS and Con A induced responses was observed. Con A induced response needs interaction between macrophages and T lymphocytes. So, we investigated whether quinolones could act on interleukin 1 (IL 1) production by macrophages. Our results showed that pefloxacin and ofloxacin, used at low concentrations, enhanced LPS induced IL 1 production by macrophages.