Induction of major histocompatibility complex class II glycoproteins by interferon-gamma: attenuation of the effects of restraint stress.

The effect of restraint on the activation of macrophages was evaluated based on the induction of I-A expression following injection of viable Mycobacterium bovis (strain BCG) or treatment in vitro with recombinant interferon-gamma (rIFN-gamma). We found that restraint suppressed the induction of I-A expression when applied just prior to or at the same time as the injection of the microorganisms but had no effect if applied after the injection of the Mycobacteria. The effect of stress was attenuated by increasing the number of microorganisms or by incubating macrophages from stressed mice with higher doses of rIFN-gamma. The suppressive effect of restraint does not appear to be associated with uptake, processing or presentation of antigen but rather to an alteration in the response of the macrophages to rIFN-gamma.