Opsonic effect of C-reactive protein on phagocytosis and intracellular killing of virulent and attenuated strains of Candida albicans by human neutrophils.

In the presence of autologous complement, maximal phagocytosis of Candida albicans blastospores of both a virulent and attenuated strain by human neutrophils in a monolayer assay was achieved after 30 min. The proportion of phagocytes containing intracellular blastospores was 33-36% with an average of 1.5 blastospores per phagocyte. In contrast to the attenuated strain of C. albicans, the virulent strain resisted opsonization by C-reactive protein (CRP) and of those blastospores ingested, only 8% were killed. These findings support the concept that CRP may play a protective role in candidosis independent of complement. The fate of strains of different virulence may be a result of differences in CRP receptors or killing mechanisms.