Dataset Information

CXCR1-mediated neutrophil degranulation and fungal killing promote Candida clearance and host survival.

ABSTRACT: Systemic Candida albicans infection causes high morbidity and mortality and is now the leading cause of nosocomial bloodstream infection in the United States. Neutropenia is a major risk factor for poor outcome in infected patients; however, the molecular factors that mediate neutrophil trafficking and effector function during infection are poorly defined. Using a mouse model of systemic candidiasis, we found that the neutrophil-selective CXC chemokine receptor Cxcr1 and its ligand, Cxcl5, are highly induced in the Candida-infected kidney, the target organ in the model. To investigate the role of Cxcr1 in antifungal host defense in vivo, we generated Cxcr1(-/-) mice and analyzed their immune response to Candida. Mice lacking Cxcr1 exhibited decreased survival with enhanced Candida growth in the kidney and renal failure. Increased susceptibility of Cxcr1(-/-) mice to systemic candidiasis was not due to impaired neutrophil trafficking from the blood into the infected kidney but was the result of defective killing of the fungus by neutrophils that exhibited a cell-intrinsic decrease in degranulation. In humans, the mutant CXCR1 allele CXCR1-T276 results in impaired neutrophil degranulation and fungal killing and was associated with increased risk of disseminated candidiasis in infected patients. Together, our data demonstrate a biological function for mouse Cxcr1 in vivo and indicate that CXCR1-dependent neutrophil effector function is a critical innate protective mechanism of fungal clearance and host survival in systemic candidiasis.

SUBMITTER: Swamydas M

PROVIDER: S-EPMC4938152 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

CXCR1-mediated neutrophil degranulation and fungal killing promote Candida clearance and host survival.

Swamydas Muthulekha M Gao Ji-Liang JL Break Timothy J TJ Johnson Melissa D MD Jaeger Martin M Rodriguez Carlos A CA Lim Jean K JK Green Nathaniel M NM Collar Amanda L AL Fischer Brett G BG Lee Chyi-Chia Richard CC Perfect John R JR Alexander Barbara D BD Kullberg Bart-Jan BJ Netea Mihai G MG Murphy Philip M PM Lionakis Michail S MS

Science translational medicine 20160101 322

Systemic Candida albicans infection causes high morbidity and mortality and is now the leading cause of nosocomial bloodstream infection in the United States. Neutropenia is a major risk factor for poor outcome in infected patients; however, the molecular factors that mediate neutrophil trafficking and effector function during infection are poorly defined. Using a mouse model of systemic candidiasis, we found that the neutrophil-selective CXC chemokine receptor Cxcr1 and its ligand, Cxcl5, are h ...[more]

PMID: 26791948

Similar Datasets

Project description:Myocardial infarction (MI) is one of the most common cardiac emergencies with high morbidity and is a leading cause of death worldwide. Since MI could develop into a life-threatening emergency and could also seriously affect the life quality of patients, continuous efforts have been made to create an effective strategy to prevent the occurrence of MI and reduce MI-related mortality. Numerous studies have confirmed that neutrophils play important roles in inflammation and innate immunity, which provide the first line of defense against microorganisms by producing inflammatory cytokines and chemokines, releasing reactive oxygen species, and degranulating components of neutrophil cytoplasmic granules to kill pathogens. Recently, researchers reported that neutrophils are closely related to the severity and prognosis of patients with MI, and neutrophil to lymphocyte ratio in post-MI patients had predictive value for major adverse cardiac events. Neutrophils have been increasingly recognized to exert important functions in MI. Especially, granule proteins released by neutrophil degranulation after neutrophil activation have been suggested to involve in the process of MI. This article reviewed the current research progress of neutrophil granules in MI and discusses neutrophil degranulation associated diagnosis and treatment strategies. Video abstract Neutrophils played a crucial role throughout the process of MI, and neutrophil degranulation was the crucial step for the regulative function of neutrophils. Both neutrophils infiltrating and neutrophil degranulation take part in the injury and repair process immediately after the onset of MI. Since different granule subsets (e g. MPO, NE, NGAL, MMP-8, MMP-9, cathelicidin, arginase and azurocidin) released from neutrophil degranulation show different effects through diverse mechanisms in MI. In this review, we reviewed the current research progress of neutrophil granules in MI and discusses neutrophil degranulation associated diagnosis and treatment strategies. Myeloperoxidase (MPO); Neutrophil elastase (NE); Neutrophil gelatinase-associated lipocalin (NGAL); Matrix metalloproteinase 8 (MMP-8); Matrix metalloproteinase 9 (MMP-9).

Project description:Candida albicans remains the predominant cause of fungal infections, where adhered microbial cells form biofilms - densely packed communities. The central feature of C. albicans biofilms is the production of an extracellular matrix (ECM) consisting of polymers and extracellular nucleic acids (eDNA, eRNA), which significantly impedes the infiltration of host cells. Neutrophils, as crucial players in the innate host defense, employ several mechanisms to eradicate the fungal infection, including NETosis, endocytosis, or the release of granules containing, among others, antimicrobial peptides (AMPs). The main representative of these is the positively charged peptide LL-37 formed from an inactive precursor (hCAP18). In addition to its antimicrobial functions, this peptide possesses a propensity to interact with negatively charged molecules, including nucleic acids. Our in vitro studies have demonstrated that LL-37 contacting with C. albicans nucleic acids, isolated from biofilm, are complexed by the peptide and its shorter derivatives, as confirmed by electrophoretic mobility shift assays. We indicated that the generation of the complexes induces discernible alterations in the neutrophil response to fungal nucleic acids compared to the effects of unconjugated molecules. Our analyses involving fluorescence microscopy, flow cytometry, and Western blotting revealed that stimulation of neutrophils with DNA:LL-37 or RNA:LL-37 complexes hamper the activation of pro-apoptotic caspases 3 and 7 and fosters increased activation of anti-apoptotic pathways mediated by the Mcl-1 protein. Furthermore, the formation of complexes elicits a dual effect on neutrophil immune response. Firstly, they facilitate increased nucleic acid uptake, as evidenced by microscopic observations, and enhance the pro-inflammatory response, promoting IL-8 production. Secondly, the complexes detection suppresses the production of reactive oxygen species and attenuates NETosis activation. In conclusion, these findings may imply that the neutrophil immune response shifts toward mobilizing the immune system as a whole, rather than inactivating the pathogen locally. Our findings shed new light on the intricate interplay between the constituents of the C. albicans biofilm and the host's immune response and indicate possible reasons for the elimination of NETosis from the arsenal of the neutrophil response during contact with the fungal biofilm.

Dataset Information

CXCR1-mediated neutrophil degranulation and fungal killing promote Candida clearance and host survival.

Publications

CXCR1-mediated neutrophil degranulation and fungal killing promote Candida clearance and host survival.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets