Interaction ofCandida albicanswith Adherent Human Peripheral Blood Mononuclear Cells IncreasesC. albicansBiofilm Formation and Results in Differential Expression of Pro- and Anti-Inflammatory Cytokines

Abstract

Monocytes and macrophages are the cell types most commonly associated with the innate immune response against Candida albicans infection. Interactions between the host immune system and Candida organisms have been investigated for planktonic Candida cells, but no studies have addressed these interactions in a biofilm environment. In this study, for the first time, we evaluated the ability of C. albicans to form biofilms in the presence or absence of adherent peripheral blood mononuclear cells (PBMCs; enriched for monocytes and macrophages by adherence). Our analyses using scanning electron and confocal scanning laser microscopy showed that the presence of PBMCs enhanced the ability of C. albicans to form biofilms and that the majority of PBMCs were localized to the basal and middle layers of the biofilm. In contrast to the interactions of PBMCs with planktonic C. albicans, where PBMCs phagocytose fungal cells, PBMCs did not appear to phagocytose fungal cells in biofilms. Furthermore, time-lapse laser microscopy revealed dynamic interactions between C. albicans and PBMCs in a biofilm. Additionally, we found that (i) only viable PBMCs influence Candida biofilm formation, (ii) cell surface components of PBMCs did not contribute to the enhancement of C. albicans biofilm, (iii) the biofilm-enhancing effect of PBMCs is mediated by a soluble factor released into the coculture medium of PBMCs with C. albicans, and (iv) supernatant collected from this coculture contained differential levels of pro-and anti-inflammatory cytokines. Our studies provide new insight into the interaction between Candida biofilm and host immune cells and demonstrate that immunocytes may influence the ability of C. albicans to form biofilms.

Late Endosomal Trafficking of Alternative Serotype Adenovirus Vaccine Vectors Augments Antiviral Innate Immunity

“…1A and B). Analysis of adherent PBMC, which include multiple cellular subsets (30), showed that Ad35 and Ad26 similarly colocalized with late endosomes by 2 h postinfection (data not shown). Both Ad35 and Ad26 accumulated in the late endosomal compartment to significantly higher levels than Ad5 at 2 h postinfection as measured by both LAMP1 (3.1-and 6.4-fold greater colocalization, respectively; P ϭ 0.0088 and P ϭ 0.0001, respectively) and M6P (5.8-and 9.8-fold greater colocalization, respectively; P Ͻ 0.0001 for both) colocalization.…”

Development of a Contemporary Animal Model of Candida albicans-Associated Denture Stomatitis Using a Novel Intraoral Denture System

“…C. albicans biofilms exhibit increased resistance to drugs and antifungal host defenses (14,23,29,30). Compared with free-floating C. albicans, biofilms have been shown to preferentially induce production of cytokines involved in driving Th1 or Th17 responses (14,48). In the case of DS, it is possible that a C. albicans biofilm formed on the denture continually inoculates the host mucosa, leading to tissue-associated biofilm formation.…”

“…albicans readily forms biofilms on denture material in vitro and in vivo, which consist of a network of hyphae and yeast encased in a polysaccharide matrix (34,(39)(40)(41). C. albicans biofilms exhibit increased resistance to drugs and antifungal host defenses (14,23,29,30). Compared with free-floating C. albicans, biofilms have been shown to preferentially induce production of cytokines involved in driving Th1 or Th17 responses (14,48).…”

Medical biofilms

“…Similarly, Chandra et al (2007) showed that peripheral blood mononuclear cells (PBMCs) enhanced the ability of the yeast, Candida albicans, to form biofilms and that the majority of PBMCs were localized to the basal and middle layers of the biofilm. They also found that only viable PBMCs enhanced Candida biofilm formation and that PBMCs cell surface components did not contribute to this biofilm enhancement; the biofilm-enhancing effect is mediated by a soluble factor released into the medium, and that the supernatant collected from co-cultures contained differential levels of pro-and anti-inflammatory cytokines.…”