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Nihon Rinsho. Japanese Journal of... Nov 1999
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Journal of Materials Chemistry. B Jan 2023Drug resistance caused by facultative intracellular bacteria such as Salmonella typhimurium () is still a tough challenge. Bacteria phagocytosed by macrophages have...
Drug resistance caused by facultative intracellular bacteria such as Salmonella typhimurium () is still a tough challenge. Bacteria phagocytosed by macrophages have evolved a variety of mechanisms to defend against host attack, and the poor entry of antibiotics into infected macrophages is conducive to the survival of intracellular bacteria. In this report, we prepared a quasi-opsonized chloramphenicol (Chl)-loaded micellar system (B-mLBP-M/Chl) assembled by a bacterial lipase-sensitive polymer with a conjugate of lipopolysaccharide-binding protein (LBP) analog and biotin (B) as a ligand, which could eliminate drug-resistant with quasi-opsonization 3 steps: (i) target and release antibiotics on bacteria lipase, (ii) opsonize to be digested by the macrophage, and (iii) activate the macrophage for fighting. The B-mLBP-M/Chl could target bacterial LPS through mLBP by simulating the N-terminal sequence of native LBP, exhibiting a high ability to target the localized infection site in mice. It could also activate the phagocytosis of macrophages coupled biotin, cooperating with antibiotics and effectively improving the survival of mice with little pathological damage to tissues. Moreover, compared with native opsonin, B-mLBP does not cause an excessive inflammatory response and could recover homeostasis after exerting the quasi-opsonization by regulating the levels of pro-inflammatory cytokines and anti-inflammatory cytokines. With a universal target site for Gram-negative bacteria and macrophage activation, this B-mLBP-M/Chl could be applied to other bacterial infections in the future. In particular, this analog may also serve as a useful template to design safe artificial opsonin, which could be a ligand for drug delivery systems or prodrugs.
Topics: Animals; Mice; Opsonin Proteins; Micelles; Biotin; Ligands; Macrophages; Cytokines; Bacterial Infections; Anti-Bacterial Agents
PubMed: 36594907
DOI: 10.1039/d2tb01802k -
Nihon Rinsho. Japanese Journal of... Jul 2005
Review
Topics: Burns; Complement Activation; Complement System Proteins; Humans; Hypoproteinemia; Immunity, Innate; Immunologic Deficiency Syndromes; Immunologic Tests; Liver Cirrhosis; Luminescent Measurements; Neoplasms; Opsonin Proteins; Phagocytes; Reference Values
PubMed: 16111200
DOI: No ID Found -
Clinical Immunology (Orlando, Fla.) Sep 2012
Topics: Animals; Bacterial Vaccines; Complement Activation; Complement C2; Female; Humans; Male; Opsonin Proteins
PubMed: 22863655
DOI: 10.1016/j.clim.2012.07.005 -
The New England Journal of Medicine Feb 1970
Topics: Adult; Complement System Proteins; History, 19th Century; History, 20th Century; Humans; Infections; Male; Opsonin Proteins; Phagocytosis
PubMed: 4903824
DOI: 10.1056/NEJM197002122820712 -
Marine Drugs Feb 2022Crustin are a family of antimicrobial peptides that play an important role in protecting against pathogens infection in the innate immune system of crustaceans....
Crustin are a family of antimicrobial peptides that play an important role in protecting against pathogens infection in the innate immune system of crustaceans. Previously, we identified several novel types of crustins, including type VI and type VII crustins. However, their immune functions were still unclear. In the present study, the immune function of type VII crustin LvCrustinVII were investigated in . was wildly expressed in all tested tissues, with relatively high expression levels in hepatopancreas, epidermis and lymphoid organ. Upon infection, was significantly upregulated in hepatopancreas. Recombinant LvCrustinVII (rLvCrustinVII) showed strong inhibitory activities against Gram-negative bacteria and , while weak activities against the Gram-positive bacteria . Binding assay showed that rLvCrustinVII could bind strongly to and , as well as the cell wall components Glu, LPS and PGN. In the presence of Ca, rLvCrustinVII could agglutinate and enhance hemocyte phagocytosis. The present data partially illustrate the immune function of , which enrich our understanding on the functional mechanisms of crustins and provide useful information for application of this kind of antimicrobial peptides.
Topics: Agglutination; Animals; Antimicrobial Cationic Peptides; Arthropod Proteins; Bacteria; Epidermis; Hemocytes; Hepatopancreas; Opsonin Proteins; Penaeidae; Phagocytosis; Recombinant Proteins
PubMed: 35323456
DOI: 10.3390/md20030157 -
Canadian Journal of Microbiology Jul 1993Legionella pneumophila adhered to and multiplied intracellularly in the human histiocytic lymphoma U-937 cell line. The infectious process was evaluated by viable...
Legionella pneumophila adhered to and multiplied intracellularly in the human histiocytic lymphoma U-937 cell line. The infectious process was evaluated by viable bacterial cell colony counts and documented by transmission and scanning electron microscopy. In the absence of opsonins, wash-resistant bacterial adherence to host cells occurred within 1 h and attachment of 1 or 2 organisms per U-937 host cell involved close surface interactions at the prokaryotic and eukaryotic membranes. Intracellular multiplication of bacteria was maximal by 24 h after inoculation of cell monolayers. Release of L. pneumophila from these cells appeared as a lytic process that resulted in an increase in the numbers of microorganisms in the extracellular fluids and a concomitant decline in the number of intracellular bacteria. The course of cellular infection was completed by 72 h. The cellular and ultrastructural events of L. pneumophila adherence and uptake by U-937 cells in the absence of antibody or complement have been defined. In addition, this work further establishes the U-937 cell as a suitable model for investigating Legionella--host cell interactions.
Topics: Bacterial Adhesion; Colony Count, Microbial; Humans; Legionella pneumophila; Lymphoma, Large B-Cell, Diffuse; Opsonin Proteins; Tumor Cells, Cultured
PubMed: 8364804
DOI: 10.1139/m93-103 -
Ceskoslovenska Pediatrie May 1970
Review
Topics: Animals; Antibodies; Antigen-Antibody Reactions; Complement System Proteins; Escherichia coli Infections; Immunity; In Vitro Techniques; Infections; Methods; Opsonin Proteins; Phagocytosis; Swine
PubMed: 4910259
DOI: No ID Found -
Postepy Higieny I Medycyny... 1987
Review
Topics: Adjuvants, Immunologic; Burns; Fibronectins; Humans; Opsonin Proteins
PubMed: 3299342
DOI: No ID Found -
Frontiers in Immunology 2021Mammalian phagocytes can phagocytose (i.e. eat) other mammalian cells in the body if they display certain signals, and this phagocytosis plays fundamental roles in... (Review)
Review
Mammalian phagocytes can phagocytose (i.e. eat) other mammalian cells in the body if they display certain signals, and this phagocytosis plays fundamental roles in development, cell turnover, tissue homeostasis and disease prevention. To phagocytose the correct cells, phagocytes must discriminate which cells to eat using a 'phagocytic code' - a set of over 50 known phagocytic signals determining whether a cell is eaten or not - comprising find-me signals, eat-me signals, don't-eat-me signals and opsonins. Most opsonins require binding to eat-me signals - for example, the opsonins galectin-3, calreticulin and C1q bind asialoglycan eat-me signals on target cells - to induce phagocytosis. Some proteins act as 'self-opsonins', while others are 'negative opsonins' or 'phagocyte suppressants', inhibiting phagocytosis. We review known phagocytic signals here, both established and novel, and how they integrate to regulate phagocytosis of several mammalian targets - including excess cells in development, senescent and aged cells, infected cells, cancer cells, dead or dying cells, cell debris and neuronal synapses. Understanding the phagocytic code, and how it goes wrong, may enable novel therapies for multiple pathologies with too much or too little phagocytosis, such as: infectious disease, cancer, neurodegeneration, psychiatric disease, cardiovascular disease, ageing and auto-immune disease.
Topics: Animals; Calreticulin; Cellular Senescence; Humans; Intercellular Adhesion Molecule-3; Opsonin Proteins; Phagocytosis; Phosphatidylserines; Polysaccharides; Signal Transduction; Synapses
PubMed: 34177884
DOI: 10.3389/fimmu.2021.629979