Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The two major gram-positive bacterial (GPB) ligands are peptidoglycan (PGN) and lipoteichoic acid (LTA). These polymeric LTA and highly organized PGN contain repeating carbohydrate moieties, which are potential targets for pattern recognition molecules. The major pattern recognition proteins and receptors, which bind GPB, either have a lectin, PGN recognition, collagen or leucine-rich repeat (LRR) domain. The soluble innate immune proteins (IIPs) that bind to PGN and LTA include pulmonary collectins surfactant-associated proteins (SP-) A and D, lectin-like pentraxins C-reactive protein (CRP) and serum amyloid P component (SAP), and sCD14. Membrane-anchored lectin or lectin-like group members include macrophage mannose receptor (MR), complement receptor 3 (CR3, or Mac-1, or integrin CD11b/CD18), scavenger receptor A (SRCL-1), lectin-like oxidized LDL receptor 1 (LOX-1), and GPI-anchored CD14. Although Toll-like receptor (TLR) 2 and 4, and CD14 contain extracellular LRR domains, only TLRs have a cytoplasmic domain for signal transduction. Three of the four recently discovered human PGN recognition proteins (PGRP) have a transmembrane domain, and hence, considered as true receptors for GPB. Since lysozyme is the only known pulmonary enzyme that can lyse bacterial cell wall PGN, other innate immune molecules appear to be responsible for signalling and enhancing the clearance of GPB infection from the lung. Interestingly, pulmonary collectins bind not only to GPB ligands but also to the receptors, CD14 and TLR, and antigen processing cells such as dentritic cells. These complex interactions appear to play major roles in linking innate and adaptive immunity, and maintaining a pathogen-free lung with minimal, or no inflammation.
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PMID:Pulmonary innate immune proteins and receptors that interact with gram-positive bacterial ligands. 1239 17

The innate immune system recognizes microorganisms through a series of pattern recognition receptors that are highly conserved in evolution. Peptidoglycan (PGN) is a unique and essential component of the cell wall of virtually all bacteria and is not present in eukaryotes, and thus is an excellent target for the innate immune system. Indeed, higher eukaryotes, including mammals, have several PGN recognition molecules, including CD14, Toll-like receptor 2, a family of peptidoglycan recognition proteins, Nod1 and Nod2, and PGN-lytic enzymes (lysozyme and amidases). These molecules induce host responses to microorganisms or have direct antimicrobial effects.
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PMID:Recognition of bacterial peptidoglycan by the innate immune system. 1452 44

Several studies have implicated a role of peptidoglycan (PepG) as a pathogenicity factor in sepsis and organ injury, in part by initiating the release of inflammatory mediators. We wanted to elucidate the structural requirements of PepG to trigger inflammatory responses and organ injury. Injection of native PepG into anesthetized rats caused moderate but significant increases in the levels of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and bilirubin (markers of hepatic injury and/or dysfunction) and creatinine and urea (markers of renal dysfunction) in serum, whereas PepG pretreated with muramidase to digest the glycan backbone failed to do this. In an ex vivo model of human blood, PepG containing different amino acids induced similar levels of the cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), IL-8, and IL-10, as determined by plasma analyses (enzyme-linked immunosorbent assay). Hydrolysis of the Staphylococcus aureus cross-bridge with lysostaphin resulted in moderately reduced release of TNF-alpha, IL-6, IL-8, and IL-10, whereas muramidase digestion nearly abolished the ability to induce cytokine release and IL-6 mRNA accumulation in CD14(+) monocytes compared to intact PepG. However, additional experiments showed that muramidase-treated PepG synergized with lipopolysaccharide to induce TNF-alpha and IL-10 release in whole blood, despite its lack of inflammatory activity when administered alone. Based on these studies, we hypothesize that the structural integrity of the glycan chain of the PepG molecule is very important for the pathogenic effects of PepG. The amino acid composition of PepG, however, does not seem to be essential for the inflammatory properties of the molecule.
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PMID:Organ injury and cytokine release caused by peptidoglycan are dependent on the structural integrity of the glycan chain. 1497 33

Zymosan is a well-known reagent for the examination of inflammatory response and is prepared from yeast, Saccharomyces cerevisiae. In the activation process, Toll-like receptor (TLR) 2 and TLR6 act as functional receptors for NF-kappaB activation. Although zymosan is primarily composed of beta-glucans, little is known about the active component of zymosan-mediated biological activities. The active moiety of zymosan was fractionated by its solubility in water, and its biological activity on macrophages and TLRs-transfectants examined. The macrophage cell line, RAW264.7, was treated with zymosan-derived preparations, and tumor necrosis factor alpha (TNF-alpha) produced in the culture supernatant was measured by ELISA. Increased TNF-alpha production was observed by stimulation with water-soluble (ZWS) or water-insoluble fraction (ZWIS). ZWS showed higher activity in TNF-alpha production. NF-kappaB activation via TLR2, TLR1/ TLR2, TLR2/TLR6, and TLR4/MD-2/CD14 also was enhanced by stimulation with ZWS and ZWIS. In particular, ZWS showed higher activity via TLR1/TLR2, TLR2/TLR6, and TLR4/MD-2/CD14 than other preparations. ZWS activity was decreased by treatment with polymyxin B, but not with lysozyme and zymolyase. Furthermore, ZWS contained significant more endotoxin than any other preparations. Therefore, we suggest that the active moiety of ZWS for the NF-kappaB activation has an endotoxin-like substance, that is abundantly observed in Gram-negative bacteria. These results imply that the inflammatory activity of zymosan is induced not only by beta-glucans, but also by other endotoxin-like water-soluble substances.
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PMID:Activation of toll-like receptor-mediated NF-kappa beta by zymosan-derived water-soluble fraction: possible contribution of endotoxin-like substances. 1611 11

The innate immune system recognizes micro-organisms through a series of pattern recognition receptors that are highly conserved in evolution. Peptidoglycan (PGN) is a unique and essential component of the cell wall of virtually all bacteria, is not present in eukaryotes, and is an excellent target for the innate immune system. Indeed, higher eukaryotes, including mammals, have several PGN recognition molecules, including CD14, Toll-like receptor 2 (TLR2), nucleotide oligomerization domain (Nod)-containing proteins, a family of peptidoglycan recognition proteins (PGRPs), and PGN-lytic enzymes (lysozyme and amidase). These molecules induce host responses to micro-organisms, degrade PGN, or have direct antimicrobial effects.
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PMID:Peptidoglycan recognition in innate immunity. 1626 4

We describe a case of true histiocytic sarcoma (HS) with features of HS in clinical manifestation, histological presentation, and immunohistochemical panels. The flow cytometry studies were used for the diagnosis. The tumor presents in the small intestine with involvement of regional mesenteric lymph nodes of a 68-year-old female. Histological examination reveals that tumor cells are large and pleomorphic. They have vesicular chromatin and abundant eosinophilic cytoplasm. Immunohistochemical studies show the tumor cells to be positive for CD45 (LCA), CD45RO, CD4, CD68, and lysozyme; and negative for all other T-, B-, macrophage, follicular dendritic- and hematopoietic-cell markers. Proliferation rate is 5% by MIB stain. Flow cytometry studies reveal large atypical cells positive for CD4, CD14, and CD45. There are 29 cases of HS reported in the literature since 2001. All of these cases are summarized. The diagnostic methods and the possible prognostic factors are discussed. We believe that the correct diagnosis of HS is important for clinical treatment and prognostic prediction, although it is very rare.
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PMID:Histiocytic sarcoma in the small intestine: a case report with flow cytometry study and review of the literature. 1854 86

We present a case of a histiocytic sarcoma incidentally detected in peripheral lung tissue resected for a spontaneous pneumothorax. Furthermore, we discuss the practical approach to pulmonary Langerhans cell histiocytosis, the main differential diagnosis of this lesion in the lung, based on morphological and immunohistochemical features. A 23-year-old male patient presented with recurrent pneumothoraces. The pulmonary tissue showed a single round granuloma-like lesion measuring 4 mm in diameter in close neighbourhood to a bronchial wall. The granuloma consisted of histiocytic cells with enlarged pale nuclei, plasma cells, lymphocytes and scanty eosinophilic granulocytes giving the impression of a granuloma of pulmonary Langerhans cell histiocytosis on haematoxylin and eosin (H&E) stains. Immunohistochemically, the histiocytic cells were negative for CD1a and S-100. They were positive for CD68, HLA-DR, CD14, CD4, CD11c, CD45LCA and lysozyme. MIB1 (Ki67) showed a nuclear staining of approximately 10% of the histiocytic cells. In summary, these findings were in keeping with a histiocytic sarcoma, a rare haematopoetic neoplasm. By demonstrating this particular case, we emphasise the importance of proving the diagnosis of pulmonary Langerhans cell histiocytosis by means of immunohistochemistry. In case of a negative CD1a reaction in a histiocytic lesion, further immunohistochemical studies have to be performed in order not to misdiagnose a malignant haematopoetic lesion.
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PMID:Pulmonary histiocytic sarcoma mimicking pulmonary Langerhans cell histiocytosis in a young adult presenting with spontaneous pneumothorax: a potential diagnostic pitfall. 1956 69

Milk is the single source of nutrients for the newborn mammal. The composition of milk of different mammals has been adapted during evolution of the species to fulfill the needs of the offspring. Milk not only provides nutrients, but it also serves as a medium for transfer of host defense components to the offspring. The host defense proteins in the milk of different mammalian species are expected to reveal signatures of evolution. The aim of this study is therefore to study the difference in the host defense proteome of human and bovine milk. We analyzed human and bovine milk using a shot-gun proteomics approach focusing on host defense-related proteins. In total, 268 proteins in human milk and 269 proteins in bovine milk were identified. Of these, 44 from human milk and 51 from bovine milk are related to the host defense system. Of these proteins, 33 were found in both species but with significantly different quantities. High concentrations of proteins involved in the mucosal immune system, immunoglobulin A, CD14, lactoferrin, and lysozyme, were present in human milk. The human newborn is known to be deficient for at least two of these proteins (immunoglobulin A and CD14). On the other hand, antimicrobial proteins (5 cathelicidins and lactoperoxidase) were abundant in bovine milk. The high concentration of lactoperoxidase is probably linked to the high amount of thiocyanate in the plant-based diet of cows. This first detailed analysis of host defense proteins in human and bovine milk is an important step in understanding the function of milk in the development of the immune system of these two mammals.
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PMID:The host defense proteome of human and bovine milk. 2155 75

Chronic lymphocytic leukaemia (CLL) cells convert CD14(+) cells from patients into 'nurse-like' cells (NLCs). CLL cells can also convert CD14(+) peripheral blood mononuclear cells (PBMCs) from healthy donors into cells with morphological similarities to NLCs (CD14(CLL) -cells). However it is unclear whether only CLL cells induce this conversion process. This study showed that CD14(+) PBMCs from healthy donors could also be converted into differentiated cells (CD14(B) -cells) by non-malignant B-cells. In order to identify changes specifically induced by CLL cells, we compared gene expression profiles of NLCs, CD14(CLL) -cells and CD14(B) -cells. CD14(+) cells cultured with CLL cells were more similar to NLCs than those cultured with non-malignant B-cells. The most significant changes induced by CLL cells were deregulation of the antigen presentation pathway and of genes related to immunity. NLCs had reduced levels of lysozyme activity, CD74 and HLA-DR in-vitro while expression of inhibitory FCGR2B was increased. These findings suggest an impaired immunocompetence of NLCs which, if found in-vivo, could contribute to the immunodeficiency in CLL patients.
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PMID:Nurse-like cells show deregulated expression of genes involved in immunocompetence. 2161 84

Cutaneous myeloid sarcoma is often challenging to diagnose based solely upon histopathological features. Although immunohistochemistry can aid in its diagnosis, specific markers have not been clearly identified. We evaluated the utility of immunohistochemical markers in 57 cutaneous myeloid sarcoma cases. In addition to classical markers (CD117, CD163, CD34, myeloperoxidase and lysozyme), we used CD33 and CD14, recently described markers in paraffin-embedded tissue samples, and Kruppel-like factor 4 (KLF-4), a novel monocytic marker. Our results show that lysozyme was expressed in 91%, CD33 in 60%, myeloperoxidase in 54%, CD34 in 39% and CD117 in 36% of cases. An antibody panel that included lysozyme, CD117 and CD33 identified all cases. The monocytic markers CD14, KLF-4 and CD163 were expressed in 60, 58 and 40% of all cases, respectively. CD14 and KLF-4 expression was significantly more common in cases with monocytic differentiation. CD14 is the single most sensitive and specific marker for monocytic differentiation (79 and 80%). Although KLF-4 in isolation is relatively insensitive (50 and 87%), it enhances sensitivity in detecting monocytic cutaneous myeloid sarcoma when combined with CD14. Our results indicate that in addition to classical immunohistochemical markers, targeted use of newer antibodies, including CD33, CD14 and KLF-4 is useful in the diagnosis of cutaneous myeloid sarcoma and in the detection of monocytic differentiation.
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PMID:Use of classic and novel immunohistochemical markers in the diagnosis of cutaneous myeloid sarcoma. 2205 91


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