The metabolic fate of 14C-labeled immunoadjuvant peptidoglycan monomerII. In vitro studies

Ladešić, Branko; Tomašić, Jelka; Kveder, S.; Hršak, Ivo

doi:10.1016/0304-4165(81)90042-8

Cited by 35 publications

(22 citation statements)

References 9 publications

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“…Lysozyme splits the peptidoglycan at a different site (3) and was much less effective in enhancing the anti-Po I MAb binding. Amidase activity was shown to be present in sera from different animal species (13,22) as we have found for the ASF activity. The ASF activity was destroyed by mercaptoethanol and by heating, and was influenced by chelating agents, as found by others for the serum amidase (16).…”

Section: Discussionsupporting

confidence: 76%

“…We reasoned that the ASF activity could be due to serum enzymes, for instance lysozyme and/or the N-acetylmuramyl-L-alanine amidase described in 1981 by Lade56 et al (13). The amidase is a sialic acid-containing glycoprotein (16) which has the ability to degrade the peptidoglycan by cleavage of the bond between the muramic acid and the peptide side chain attached to it (16,22).…”

Section: Discussionmentioning

confidence: 99%

“…The serum amidase may support the killing of bacteria (1 6) and may function in the clearing of bacterial products in vivo (13,21). Studies of the role of this enzyme should benefit from the use of a purified amidase.…”

Section: Discussionmentioning

confidence: 99%

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Enhancement by a serum factor of the immunoaccessibility of an enterobacterial porin protein domain

Henriksen¹,

Mæland²

1991

APMIS

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Enhancement by a serum factor of the immunoaccessibility of an enterobacterial porin protein domain. APMIS 99: 703-710, 1991. Monoclonal antibody (MAb) generated against the domain Po I on the outer membrane (OM) porin (Po) protein of an Escherichia coli 055 strain showed weak binding by the OM in ELISA. Human serum and sera from different animal species enhanced the MAb binding in ELISA when the antibody was incubated together with serum or the OM was pretreated with serum. Human serum also enhanced the MAb binding when coats were prepared by using OMS from various cross-reacting bacteria. The ability of human serum to amplify the MAb binding by OMS was similar to that of lysostaphin. Amplification by serum was not observed when MAbs against three other enterobacterial OM proteins were tested. The amplifying serum factor was destroyed by heating (l0OOC) and by mercaptoethanol. It appeared in fractions which corresponded to an apparent molecular weight of 75.000-80.000 after gel permeation, and, after ion-exchange chromatography, in fractions which contained a protein of 60 kD when analysed by SDS-PAGE. These data support the notion that the serum-induced enhancement of the anti-Po I MAb binding was due to a previously described serum amidase (N-acetylmuramyl-L-alanine amidase) which has peptidoglycan-degrading activity. The effects of the amplifying serum factor may influence the antibody levels which are measured when OMS from Gram-negative bacteria are used as antigen in a serodiagnostic test.

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Section: Discussionsupporting

confidence: 76%

Section: Discussionmentioning

confidence: 99%

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Enhancement by a serum factor of the immunoaccessibility of an enterobacterial porin protein domain

Henriksen¹,

Mæland²

1991

APMIS

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“…The majority of this material, however, localizes in the mononuclear, phagocytic system and is only slowly eliminated over time (12,17,35,36). Mammalian enzymes, including lysozyme (16) and muramyl-L-alanine amidase, have limited activity on many gram-positive bacterial cell walls (25). However, it has been recently demonstrated using gas chromatography-tandem mass spectrometry (GC-MS 2 ) that Mur is not present in normal rat spleen (23).…”

mentioning

confidence: 99%

Muramic Acid Is Not Generally Present in the Human Spleen as Determined by Gas Chromatography-Tandem Mass Spectrometry

2002

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It has been hypothesized that bacterial debris may accumulate in tissues of the reticuloendothelial system (RES) serving as an inflammatory stimulus for human disease. In support of this hypothesis, muramic acid (Mur), a component of bacterial peptidoglycan (PG), has previously been reported to be present in culturenegative human spleen. High-performance liquid chromatography (HPLC) was employed in these analyses, and a peak was detected at the retention time of Mur. However, HPLC is best used as a screening technique, and it is vital that these tentative observations be reexamined by the state-of-the-art approach (gas chromatography-tandem mass spectrometry [GC-MS 2 ]). Indeed, in the present work using GC-MS 2 , Mur was not detected in six out of seven human spleens previously examined by HPLC. However, Mur was categorically detected at minute concentrations, 50 ppb, in one spleen. In conclusion, since Mur is not generally found in culture-negative human spleen, in future studies, these tissues can serve as negative controls. The study of Mur levels in inflammation (e.g., reactive arthritis) could prove important in testing the hypothesis that bacterial debris persisting in tissues could serve as a depot inciting diseases of unknown etiology.

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“…In these animal studies, muramic acid was not detected in normal tissues. Persistence of bacterial debris occurs despite partial degradation by mammalian enzymes, including lysozyme (19) and muramyl-L-alanine amidase (28). Solubilized cell wall fragments have also been shown to be excreted in the urine (45).…”

mentioning

confidence: 99%

Failure To Detect Muramic Acid in Normal Rat Tissues but Detection in Cerebrospinal Fluids from Patients with Pneumococcal Meningitis

et al. 2000

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Muramic acid serves as a marker for the presence of bacterial cell wall debris in mammalian tissues. There have been a number of controversial and sometimes conflicting results on assessing the levels of muramic acid in health and disease. The present report is the first to use the state-of-the art technique, gas chromatographytandem mass spectrometry, to identify and quantify the levels of muramic acid in tissues. Muramic acid was not found in normal rat brain or spleen. However, when tissues were spiked with muramic acid, it was readily identified. The detection limit was <1 ng of muramic acid/100 mg (wet weight) of tissue. The levels of muramic acid reported in diseased human spleen and spleen of arthritic rats, previously injected with bacterial cell walls, were 100-to 1,000-fold higher. In the present study, muramic acid was also readily detected in the cerebrospinal fluid of patients with pneumococcal meningitis (6.8 to 3,900 ng of muramic acid/ml of cerebrospinal fluid). In summary, there can be an enormous difference in the levels of muramic acid found in different mammalian tissues and body fluids in health and disease. This report could have great impact in future studies assessing the role of bacterial cell wall remnants in the pathogenesis of certain human inflammatory diseases.

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The metabolic fate of 14C-labeled immunoadjuvant peptidoglycan monomerII. In vitro studies

Cited by 35 publications

References 9 publications

Enhancement by a serum factor of the immunoaccessibility of an enterobacterial porin protein domain

Enhancement by a serum factor of the immunoaccessibility of an enterobacterial porin protein domain

Muramic Acid Is Not Generally Present in the Human Spleen as Determined by Gas Chromatography-Tandem Mass Spectrometry

Failure To Detect Muramic Acid in Normal Rat Tissues but Detection in Cerebrospinal Fluids from Patients with Pneumococcal Meningitis

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