THE ROLE OF COMPLEMENT AND ANTIBODY IN OPSONIZATION AND INTRACELLULAR KILLING OF CANDIDA-ALBICANS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 57  (2) , 307-314
Abstract
The relationship between ingestion (measured by the phagocytic index method), iodination (measured by the neutrophil iodination micromethod) and intracellular killing (measured by the methylene blue test) of C. albicans by human polymorphonuclear leukocytes was explored. The effects of complement and antibody on ingestion and intracellular killing of C. albicans were determined. Optimal phagocytosis of C. albicans was observed in fresh untreated human serum. Phagocytosis was present but reduced in serum depleted of antibody (by absorption) or complement (by heating at 56.degree. C for 30 min). In the complete absence of serum or in FCS [fetal calf serum], the levels were reduced still further. The percentage killed of ingested C. albicans remained constant irrespective of the number of organisms ingested. Thus, the greater the number ingested, the greater the number killed. Maximal intracellular killing expressed as a percentage of ingested Candida occurred in fresh untreated serum. Intracellular killing did occur in heat-inactivated serum and absorbed serum, although the levels were significantly reduced. C. albicans opsonized in fresh normal PHS [pooled human serum] are probably phagocytosed and killed more efficiently than those opsonized with only complement or antibody.