Alteration of polymorphonuclear leukocyte activity by viable Candida albicans

Abstract

The response of human polymorphonuclear leukocytes (PMN) to blastospores and pseudo-hyphae of the opportunistic fungus Candida albicans has been studied in vitro and in vivo. Of the fungicidal mechanisms elucidated thus far, the myeloperoxidase-hydrogen peroxide-halide system appears to be most effective against cells of this fungus. In our studies on the interaction between murine PMN and blastospores, we assayed the release of H2O2 by PMN incubated with viable or killed, unopsonized or opsonized blastospores by using two assay systems, lysis of murine erythrocytes and oxidation of scopoletin. Our results showed that PMN released increasing amounts of H2O2 when incubated with increasing numbers of opsonized or unopsonized killed blastospores, but released decreasing amounts of H2O2 when incubated with increasing numbers of opsonized or unopsonized viable blastospores. The oxidative metabolic burst by PMN in the presence of viable or killed blastospores was also measured by using reduction of nitroblue tetrazolium and chemiluminescence. Viable blastospores stimulated a stronger metabolic burst than killed blastospores, suggesting that PMN respond to live blastospores more vigorously than killed blastospores; however, live blastospores appear to alter or inhibit the release of H2O2 by PMN.

Yeasts, enteric rods and pseudomonads in the subgingival flora of severe adult periodontitis

“…The yeasts, enteric rods, or pseudomonads isolated in the present study are pathogens in various medical infections (9,49,79), and possess an array of virulence factors of possible relevance to periodontal disease (69). For example, C. albicans can invade sulcular epithelium and gingival connective tissues (3,16,20), inhibit PMN functions (29), kill monocytes (15), degrade alpha-2-macroglobulin (58,59), procedure collagenase (33), phospholipases (53), aminopeptidases (46), acid and alkaline phosphatases (13) keratin protease (24), and TgGl, IgAl, and IgA2 immunoglobulin proteases (58,59).…”

Binding and Internalization of Herpes Simplex Virus‐Antibody Complexes by Polymorphonuclear Leukocytes

“…It has been well established that PMN ingest and kill bacteria and fungi [Hilger and Danley, 1980;Klebanoff, 1975;Schuit, 19791. In antiviral defense, PMN are presumed to be active in the clearance of virus-antibody complexes through phagocytosis following recognition by receptors that bind to antibody and complement [Allison, 19741. Opsonins, such as IgG, interact with the material to be phagocytized, adding a host protein coating that facilitates internalization via the PMN Fc receptor [Eden et al, 1973;Phillips-Quagliata et al, 1969;Theofilopoulos et al, 1974;Wiggins and Cochrane, 19811. A variety of techniques have been employed to quantitate phagocytosis by PMN.…”

A C‐terminal EGF‐like domain governs BAD1 localization to the yeast surface and fungal adherence to phagocytes, but is dispensable in immune modulation and pathogenicity of Blastomyces dermatitidis

“…with 3 ml of 10% casein in PBS, PEC were harvested in 3 ml of cold PBS supplemented with 0.05% EDTA. After two washes with Hanks’ balanced salt solution (HBSS; Gibco BRL), PEC were enriched for polymorphonuclear leucocytes (PMNs) and macrophages on a two‐step Histopaque gradient (Sigma) according to the methods of Hilger and Danley (1980). Each cell fraction was stained with Diff Quick (Baxter, Dade Behring), and cell composition was analysed by light microscope.…”