Effects of immunological adjuvants on the mouse complement system--II. Anti-complementary effects of surface-active compounds.

The anti-complementary effects of the surface-active immunological adjuvants dimethyldioctadecylammonium bromide (DDA) and pluronic polyols L101 and L121 were investigated in the mouse system. All three adjuvants showed complement (C)-inactivating effects. DDA caused a time- and dose-dependent reduction of alternative pathway (AP) and overall C activity, which varied with the serum concentration.

Increased local complement levels upon intraperitoneal injection of mice with Listeria monocytogenes and regulation by polyanions.

Alternative complement pathway activity in mouse peritoneal fluid was determined by a sensitive microtiter assay with rabbit erythrocytes as target cells and cobra venom factor as the inducer of bystander hemolysis. The intra- and interstrain variations in five mouse strains were 30% and, maximally, 64%, respectively. No activity was detected in genetically C5-deficient mice.

Analytic study of the differential anticomplementary effects of dextran sulphate and heparin in the assay for the mouse alternative pathway.

In a recent paper, a linkage between immunological adjuvant activity in mice and in vitro anticomplementary (alternative pathway assay) effects was described for different polyanions. This connection was found only if mouse serum was used as a complement (C) source. In order to investigate the possible role of C in adjuvant activity, the differential effects of polyanions on mouse C were studied in detail.