Complement receptor 3 (CR3) mediates both opsonic and nonopsonic phagocytosis of bacteria. Leukocyte adhesion deficiency (LAD) allows for the study of CR3-dependent phagocyte-bacterial ingestion, since LAD phagocytes do not express this receptor. Phagocytes from an infant with LAD were unable to ingest 50% of the Pseudomonas aeruginosa strains studied, which indicates a requirement for CR3. However, the remaining strains were phagocytosed in the absence of CR3, and ingestion was blocked by monoclonal antibodies directed at CD14. This CR3/CD14 receptor bias was further confirmed by using thioglycollate-elicited murine peritoneal macrophages, which have nonfunctional CR3 before activation. Results indicate that either CR3 or CD14 is involved independently in nonopsonic phagocytosis of different P. aeruginosa strains. Clearance of P. aeruginosa from the endobronchial space may be facilitated by nonopsonic phagocytosis, since low levels of opsonins are present. The impact of lung infection with P. aeruginosa may be determined, in part, by the phagocytic receptor that mediates ingestion.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1086/319685 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Spatial Discrimination Limit Analysis of Macrophage Phagocytosis Between Target Antigens and Non-Target Objects Using Microcapillary Manipulation Assay.
Micromachines (Basel)
November 2024
Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.
Article Synopsis
- The study investigates the role of the FcGR-IgG bond in macrophage phagocytosis and its potential for selective antigen discrimination, especially in mixed particle environments.
- Experimentation revealed that while an IgG-coated surface aids in the initial phagocytic process, non-coated particles can still be ingested if they are associated with opsonized ones.
- The findings suggest that while the zipper mechanism is important for starting phagocytosis, once it begins, it allows for unintended targets to be engulfed, which could have implications for both immune response research and medical applications.
Bacterial Opsonization Changes Adhesion Interactions between Endothelial Cells and Neutrophils in a Model of Experimental Septicemia.
Bull Exp Biol Med
June 2024
Research Laboratory of Scanning Probe Microscopy, Scientific Education Center Physics of Solid-State Nanostructures, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.
The influence of non-opsonized and opsonized S. aureus 2879M and E. coli 321 strains on the total strength of interaction between the endothelial cell and neutrophil during the docking process was studied using in vitro model of experimental septicemia.
View Article and Find Full Text PDFPKC-α is involved in the signaling of phagocytosis induced by two snake venom secretory PLAS in macrophages.
Toxicon
August 2024
Laboratório de Farmacologia - Instituto Butantan, São Paulo, Brazil. Electronic address:
Phagocytosis, an essential process for host defense, requires the coordination of a variety of signaling reactions. MT-II, an enzymatically inactive Lys49 phospholipase A (PLA) homolog, and MT-III, a catalytically-active Asp49 PLA, are known to activate phagocytosis in macrophages. In this study, the signaling pathways mediating phagocytosis, focusing on protein kinases, were investigated.
View Article and Find Full Text PDFThe potential of bacterial anti-phagocytic proteins in suppressing the clearance of extracellular vesicles mediated by host phagocytosis.
Front Immunol
June 2024
School of Life Sciences, Tianjin University, Tianjin, China.
Extracellular vesicles (EVs), characterized by low immunogenicity, high biocompatibility and targeting specificity along with excellent blood-brain barrier permeability, are increasingly recognized as promising drug delivery vehicles for treating a variety of diseases, such as cancer, inflammation and viral infection. However, recent findings demonstrate that the intracellular delivery efficiency of EVs fall short of expectations due to phagocytic clearance mediated by the host mononuclear phagocyte system through Fcγ receptors, complement receptors as well as non-opsonic phagocytic receptors. In this text, we investigate a range of bacterial virulence proteins that antagonize host phagocytic machinery, aiming to explore their potential in engineering EVs to counteract phagocytosis.
View Article and Find Full Text PDFMonocytes, particularly nonclassical ones, lose their opsonic and nonopsonic phagocytosis capacity during pediatric cerebral malaria.
Front Immunol
June 2024
UMR152 PHARMADEV, IRD, UPS, Toulouse University, Toulouse, France.
Introduction: Innate immunity is crucial to reducing parasite burden and contributing to survival in severe malaria. Monocytes are key actors in the innate response and, like macrophages, are plastic cells whose function and phenotype are regulated by the signals from the microenvironment. In the context of cerebral malaria (CM), monocyte response constitutes an important issue to understand.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!