The damage-associated molecular-pattern S100A9 is found at inflammatory sites in infections and various autoimmune diseases. It is released at very high concentrations in the extracellular milieu by activated neutrophils and monocytes in response to various agents. This proinflammatory protein is found in infected mucosae and tissue abscesses where it acts notably as a potent neutrophil activator. In this study, we examined the role of S100A9 in the control of infections. S100A9 was found to increase human neutrophil bactericidal activity toward Escherichia coli. Although S100A9 induced the accumulation of reactive oxygen species over time through the activation of NADPH oxidase, its antimicrobial activity was mediated mainly by enhancing the efficiency of neutrophil phagocytosis. Interestingly, S100A9 did not act by increasing cell surface expression of CD16, CD32, or CD64 in neutrophils, indicating that its biological effect in FcR-mediated phagocytosis is independent of upregulation of FcγR levels. However, S100A9-induced phagocytic activity required the phosphorylation of Erk1/2, Akt, and Syk. Taken together, our results demonstrate that S100A9 stimulates neutrophil microbicidal activity by promoting phagocytosis.
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http://dx.doi.org/10.4049/jimmunol.1002956 | DOI Listing |
J Mater Chem B
January 2025
State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
Achieving microecological balance is a complex environmental challenge. This is because the equilibrium of microecological systems necessitates both the eradication of harmful microorganisms and preservation of the beneficial ones. Conventional materials predominantly target the elimination of pathogenic microorganisms and often neglect the protection of advantageous microbial species.
View Article and Find Full Text PDFFront Vet Sci
January 2025
Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
Aim: This study aimed to investigate the antibacterial efficacy of probiotic-derived cell-free supernatants (CFS) encapsulated within nanostructured lipid carriers (NLCs) against multidrug-resistant and . Additionally, it aimed to identify specific bioactive compounds that contribute to the reported antibacterial properties by characterizing the metabolite substances present in the CFS using a metabolomic analysis technique.
Methods: Eight strains of lactic acid bacteria including (L22F and L25F), (P72N, BF9, BF 14, BYF 20 and BYF 26) and (BF 12) were selected as probiotic candidates.
Int J Nanomedicine
January 2025
Key Laboratory of Livestock Infectious Diseases, Ministry of Education, and Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, People's Republic of China.
Background: Antibiotic resistance of many bacteria, including Methicillin-resistant (MRSA), has become a major threat to global health. Zinc Oxide Quantum dots (ZnO-QDs) show good antibacterial activity, but most of them are insoluble in water, limiting their application range, and there is a lack of research on drug resistance inducement.
Methods: The water-soluble zinc oxide quantum dots modified by APTES (ZnO@APTES QDs) were prepared by a microwave assisted synthesis.
Infect Drug Resist
January 2025
Department of Tuberculosis, Beijing Chest Hospital, Capital Medical University, Beijing, People's Republic of China.
Background: Contezolid (CZD) is an analog of Linezolid (LZD) that has demonstrated potent in vitro and in vivo activity against tuberculosis (TB) while presenting a safer side-effect profile. In this study, we evaluated the early bactericidal activity (EBA) of CZD compared to LZD, with LZD serving as a control.
Methods: Naive, smear-positive pulmonary TB patients were enrolled and randomly assigned to receive either a 14-day monotherapy regimen of 600 mg LZD once daily (QD) or 800 mg CZD twice daily (BID).
Small
January 2025
Sports Medicine Center, West China Hospital, Sichuan University, Chengdu, 610041, China.
Due to the inherent aseptic and enclosed characteristics of joint cavity, septic arthritis (SA) almost inevitably leads to intractable infections and rapidly progressing complex pathological environments. Presently, SA faces not only the deficient effectiveness of the gold-standard systemic antibiotic therapy but also the scarcity of effective localized targeted approaches and standardized animal models. Herein, an ingenious multifunctional nanosystem is designed, which involves the methylation of hyaluronic acid (HA), copolymerization with DEGDA, loading with vancomycin (VAN), and then coating with fused macrophage-platelet membrane (denoted as FM@HA@VAN).
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