Effect of HBV antigens and their immune complexes on the PHA induced lymphocyte proliferation. Modulatory influence on interleukin-2 activity.

Studies were undertaken to evaluate immunomodulating properties of Hepatitis B virus (HBV) preparations: HBsAg, HBeAg and their complexes: HBsAg-IgG and HBeAg-IgG, on PHA-induced lymphocyte proliferation. Cells were obtained from blood of healthy individuals, serologically negative for HBV markers. HBV preparations were purified from sera of children with HBV-mediated glomerulonephritis. Suppression of lymphocyte proliferation observed in the presence of HBsAg and HBsAg-IgG complexes was irreversible. However, the suppressive effect of HBeAg and HBeAg-IgG was abolished when these preparations were removed from the culture. Addition of exogenous interleukin-2/IL-2/reversed only the suppressive effect of HBeAg-IgG which was constantly present in the culture. The inhibition of lymphocyte proliferation correlated well with the decreased level of IL-2 activity in cultures with HBV-preparations. Experiments performed using ultracentrifugation indicated that HBV preparations, especially HBsAg and HBsAg-IgG, may bind to IL-2 and inactivate it in supernatants. The experiments indicate that HBV antigens, as well as other viral products, can inhibit lymphocyte proliferative response to the mitogen. Furthermore, we suggest that this inhibition may occur via suppression of IL-2 synthesis.