Leukocyte Dectin-1 Expression Is Differentially Regulated in Fungal Versus Polymicrobial Sepsis
OBJECTIVE:: To examine peripheral leukocyte Dectin-1 regulation in clinically relevant models of fungal and polymicrobial sepsis. DESIGN:: Prospective animal study. SETTING:: University medical school research laboratory. SUBJECTS:: Age, weight, and sex matched ICR/HSD mice. INTERVENTIONS:: Mice were infected with Candida albicans (1 × 10, intravenously) or were subjected to cecal ligation and puncture to induce polymicrobial sepsis. MEASUREMENTS:: Blood, spleen, and peritoneal exudate were harvested and leukocytes were isolated. Leukocytes were evaluated for membrane-associated Dectin-1 expression and cell phenotype by flow cytometry. MAIN RESULTS:: In C. albicans infection, Dectin-1-positive blood and splenic leukocytes were increased from 23.5% to 58.9% over the course of infection. The increased percentage of Dectin-1-expressing cells was primarily attributable to neutrophilia. However, the amount of Dectin-1 expressed by blood and splenic neutrophils in C. albicans-infected mice was decreased by a range of 49.0% to 53.3%. C. albicans infection also resulted in an infiltration of Dectin-1-positive macrophages and neutrophils into the kidney. In contrast, polymicrobial sepsis decreased blood leukocyte Dectin-1-expressing cells by up to 51.4%. This reduction was due to a decrease in Dectin-1-positive neutrophils in the periphery. However, the percentage of Dectin-1-expressing cells in the peritoneal cavity increased by 774% with cecal ligation and puncture. Treatment of isolated neutrophils with three soluble glucans, mannan, lipopolysaccharide, or a variety of cytokines revealed that glucans, alone or in combination, were the only treatment that resulted in a decrease in Dectin-1-positive neutrophils. CONCLUSIONS:: We conclude that peripheral leukocyte Dectin-1 expression is differentially regulated in fungal vs. polymicrobial sepsis. These data demonstrate that leukocyte Dectin-1 levels are modulated in response to infections of fungal and nonfungal origin.
Ozment-Skelton, Tammy A.; Defluiter, Elizabeth A.; Ha, Tuanzhu; Li, Chuanfu; Graves, Bridget M.; Ferguson, Donald A.; Schweitzer, John B.; Preizsner, Johanna; Brown, Gordon D.; Gordon, Siamon; Kalbfleisch, John H.; and Williams, David. 2009. Leukocyte Dectin-1 Expression Is Differentially Regulated in Fungal Versus Polymicrobial Sepsis. Critical Care Medicine. Vol.37(3). 1038-1045. https://doi.org/10.1097/CCM.0b013e3181968fa0 PMID: 19237915 ISSN: 0090-3493