Influence of agents with immunomodulating activity on phagocytosis and bactericidal function of human polymorphonuclear cells.

Six immunomodulators were tested for the influence on phagocytosis and intracellular bactericidal activity of human polymorphonuclear cells (PMN). Frentizole, lamprene, intal and levamisole but not dapsone enhanced phagocytosis in the presence of serum. Without serum, frentizole strongly enhanced phagocytosis, whereas lamprene, levamisole and dapsone had weaker enhancing activity. Rifampin suppressed phagocytosis of Staphylococcus aureus whether the serum was present or not. The influence on phagocytosis was time and dose dependent. All drugs but dapsone markedly enhanced intracellular bactericidal activity of PMN in a dose dependent fashion. Dapsone enhanced bactericidal activity without the serum and suppressed it in its presence. It may be concluded that immunomodulators are a heterogeneous group of substances and their influence on phagocytosis and cellular bactericidal activity varies. Enhancing activity of some immunomodulators implies that they may be used in conditions with impaired phagocytosis.