Differential effects of beta-lactams on human IFN-gamma activity.

Objectives: To investigate whether a range of beta-lactam antibiotics conjugate to and hence reduce the activity of IFN-gamma, as has been shown for penicillin G. A selection of penicillins, cephalosporins, a monobactam (aztreonam), a beta-lactamase inhibitor (clavulanic acid), a carbapenem (meropenem) and the non-beta-lactam penicillin derivative d-penicillamine were tested for their effect on IFN-gamma activity.

Methods: Following exposure to a range of concentrations of these compounds, for varying lengths of time, IFN-gamma activity was assayed by induction of CD54 on the surface of the lung epithelial cell line A549, utilizing an ELISA.

Nitric oxide regulation of human peripheral blood mononuclear cells: critical time dependence and selectivity for cytokine versus chemokine expression.

NO is antiproliferative for T cells and other immune cells, but there is debate over whether it influences cytokine expression and if so whether it shows cytokine selectivity. Furthermore, the NO effect may depend on exposure time. To address these issues, we precultured human PBMC with the NO donors S-nitrosoglutathione (a natural storage form of NO) or S-nitroso-N-acetyl-D-penicillamine for up to 48 h before cell activation and then monitored proliferation and cytokine and chemokine expression.