C1q enhances the phagocytosis of Cryptococcus neoformans blastospores by human monocytes.


Journal Article

We investigated whether C1q, a subunit of the first component of C, could modulate human peripheral blood monocyte-mediated phagocytosis of Cryptococcus neoformans (CN). Adherence of monocytes to C1q-coated surfaces induced a significant enhancement of ingestion of CN blastospores that had been opsonized with specific anticapsular IgG (IgG-CN). Additionally, C1q enhanced the monocyte-mediated phagocytosis of CN opsonized with C (CN-absorbed, nonimmune, normal human serum; C-CN). Ingestion of IgG- and C-CN by control and C1q-stimulated monocytes was maximal by 1 h of incubation. The monocyte-mediated enhancement of phagocytosis caused by C1q was paralleled by a proportionate increase in fungicidal activity, an effect which was maximal by 3 h of incubation. Human serum albumin-adherent, control monocytes exhibited only a low level of killing after 3 h of incubation. C1q enhancement was blocked by preincubation of the surfaces with a goat, polyclonal F(ab')2 anti-C1q. This study describes a new cellular function for the cell surface C1q receptor: the enhancement of phagocytosis of a pathogenic organism by monocytes.

Full Text

Cited Authors

  • Bobak, DA; Washburn, RG; Frank, MM

Published Date

  • July 15, 1988

Published In

Volume / Issue

  • 141 / 2

Start / End Page

  • 592 - 597

PubMed ID

  • 3290342

Pubmed Central ID

  • 3290342

International Standard Serial Number (ISSN)

  • 0022-1767


  • eng

Conference Location

  • United States