Phagocytic recognition mechanisms in human granulocytes and Acanthamoeba castellanii using type 1 fimbriated Escherichia coli as phagocytic prey

Abstract

The phagocytic capacity of Acanthamoeba castellanii was compared with that of human polymorphonuclear leukocytes (PMNL) using non-fimbriated and fimbriated Escherichia coli with different physicochemical properties as phagocytic preys. The E. coli strain PN7 with mannose-sensitive (MS-)fimbriae adhered both to Acanthamoeba and to PMNL. The adherence to leukocytes but not to the amoebas, was completely inhibited by mannose. E. coli strain ABU2 with MS-fimbriae adhered in a mannose-sensitive manner to the PMNL. To Acanthamoeba the adhesion was only partly inhibited by mannose. The ability to ingest the adhered bacteria differed between the two phagocytes. Thus the PMNL ingested hydrophobic, weakly negative charged rough-like bacteria while hydrophilic smooth-like bacteria resisted ingestion. In contrast, the amoeba ingested both strains irrespective of the physicochemical surface properties. © 1987.