Lipopolysaccharide-mediated enhancement of zymosan phagocytosis by RAW 264.7 macrophages is independent of opsonins, laminarin, mannan, and complement receptor 3
| Autor: | Lynette B. Sigola, Jacqueline Vapenik, Ana-Lucía Fuentes, Leonard M. Millis |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Lipopolysaccharides
Phagocytosis Macrophage-1 Antigen Receptors Cell Surface Cell Line Microbiology Mice chemistry.chemical_compound Laminarin Immune system Polysaccharides Animals Macrophage Lectins C-Type Antibodies Blocking Opsonin Mannan Innate immune system Chemistry Macrophages Zymosan hemic and immune systems Opsonin Proteins Mannose-Binding Lectins Biochemistry Surgery Mannose Receptor |
| Zdroj: | Journal of Surgical Research. 189:304-312 |
| ISSN: | 0022-4804 |
| DOI: | 10.1016/j.jss.2014.03.024 |
| Popis: | Background Fungal and bacterial coinfections are common in surgical settings; however, little is known about the effects of polymicrobial interactions on the cellular mechanisms involved in innate immune recognition and phagocytosis. Materials and methods Zymosan particles, cell wall derivatives of the yeast Saccharomyces cerevisiae , are used to model fungal interactions with host immune cells since they display carbohydrates, including beta-glucan, that are characteristic of fungal pathogens. Using in vitro cell culture, RAW 264.7 macrophages were challenged with zymosan, and phagocytosis determined via light microscopy. The effects of different concentrations of lipopolysaccharide (LPS) on zymosan phagocytosis were assessed. In addition, the transfer of supernatant from LPS-treated cells to naive cells, the effects of soluble carbohydrates laminarin, mannan, or galactomannan, and the impact of complement receptor 3 (CR3) inhibition on phagocytosis were also determined. Results LPS enhanced phagocytosis of zymosan in a dose-dependent manner. Transfer of supernatants from LPS-primed cells to naive cells had no effect on phagocytosis. Laminarin inhibited zymosan phagocytosis in naive cells but not in LPS-primed cells. Neither mannan, galactomannan, nor CR3 inhibition had a significant effect on ingestion of unopsonized zymosan in naive or LPS-treated cells. Conclusions Zymosan recognition by naive cells is inhibited by laminarin, but not mannan, galactomannan, or CR3 inhibition. LPS enhancement of phagocytosis is laminarin insensitive and not mediated by supernatant factors or zymosan engagement by the mannose or CR3 receptors. Our data suggest alternative mechanisms of zymosan recognition in the presence and absence of LPS. |
| Databáze: | OpenAIRE |
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