[Condition and mechanism of host antiinfect capacity induced by bypass-activated complement: experimental study]

To verify host antiinfect capacity induced by bypass-activated complement.

A monolayer culture of human PMNs and rats kupffer cells (KCs) were added with zymosan-activated human serum (ZAHS) and 3 parameters were measured. ZAHS had been neutralized in tube with antiserum against human C3 and C5.

In 0.07-0.09 ml ZAHS and 1-3 h, intracellular bactericidal activity (ICBA) showed a peak but significant top value at 2nd hour. The value dropped markedly with time and significantly in 4-6 h. Superoxide ions (O2-) dynamics was similar to ICBA. Acid phosphatase (ACP) curve distinguished from the former's with monotonous decrease (1-6 h) and more deep. With 0.11 ml ZAHS after 4 h, about 80% of KCs were fallen off. Three parameters of PMNs were decreased and reached the lowest point in the 6th hour after the adding 0.05-0.09 ml of ZAHS. After blocking test with antihuman C3 and C5 serum, the values of ICBA, O2- and ACP surpassed those in the experimental group.

The possible mechanism of the origination of the harmful effects of ZAHS is suggested. Before KCs and PMNs undertake phagocytosis, they release the bactericidal and inflamagenic (O2- and ACP) so the intracellular bactericidal activity of KCs and PMNs are decreased. The accumulation of KCs and PMNs in tissues can damage themselves and the adjacent tissues barrier, which will lead to the occurrence of infection.