Interactions between mycoplasma lipoproteins and the host immune system

Chambaud, Isabelle; Wróblewski, Henri; Blanchard, Alain

doi:10.1016/s0966-842x(99)01641-8

Cited by 164 publications

(157 citation statements)

References 65 publications

Supporting

Mentioning

152

Contrasting

Unclassified

Order By: Relevance

“…Among these, lipoprotein has long been regarded as a potent inflammatory factor. In general, all membrane-anchored lipoproteins contain a lipidated N-terminal cysteinyl residue often accompanied by N-acylation (30). The significance of the lipidation on the N-terminal cysteine has been indicated by several studies.…”

Section: Discussionmentioning

confidence: 99%

Two Lipoproteins Extracted fromEscherichia coliK-12 LCD25 Lipopolysaccharide Are the Major Components Responsible for Toll-Like Receptor 2-Mediated Signaling

Lee

Tobias

2002

The Journal of Immunology

113

View full text Add to dashboard Cite

Toll-like receptor 2 (TLR2)-mediated cell activation induced by commercial preparations of LPS was recently shown to arise from impurities whose identities are not known. In this work, we determined the molecules responsible for TLR2-mediated cell activation in LPS derived from Escherichia coli K-12 strain LCD25. When LCD25 LPS was phenol extracted, two proteins capable of TLR2-mediated cell activation were purified and identified as E. coli lipoproteins. We cloned, expressed, and purified these two lipoproteins, Lip19 and Lip12. Lip19 or Lip12 activated TNF-α production from RAW264.7 and THP-1 cells in a TLR2-dependent manner. However, neither Lip19 nor Lip12 activated HUVECs, which lack endogenous TLR2. Additionally, IκB kinase β and c-Jun N-terminal kinase 1 activation in THP-1 cells induced by Lip19 or Lip12 was observed. TLR2 activation by Lip19 and Lip12 in HEK293 cells was blocked by inhibitory anti-TLR2 mAbs. The unlipidated mutants, Lip19-C19S and Lip12-C21S, in which the NH2-terminal cysteine was substituted by serine, lost their ability to activate TLR2-transfected HEK 293 cells. Taken together, these results demonstrate that two lipoproteins constitute the major contaminants responsible for TLR2-mediated cell activation in E. coli LCD25 LPS.

show abstract

Section: Discussionmentioning

confidence: 99%

Two Lipoproteins Extracted fromEscherichia coliK-12 LCD25 Lipopolysaccharide Are the Major Components Responsible for Toll-Like Receptor 2-Mediated Signaling

Lee

Tobias

2002

The Journal of Immunology

113

View full text Add to dashboard Cite

show abstract

“…More recently, they have also been implicated in the progression of AIDS, chronic fatigue syndrome, acute respiratory distress syndrome, and others 39 . However, these arguments have not succeeded in sensitizing scientists in regard to a pathogenetic relation, because most of these arguments are based on case reports whose positivity for mycoplasmas results from serological data, culture, or PCR 40,41 .…”

Section: Discussionmentioning

confidence: 99%

“…When the cells are coinfected with a virus, an increase in the pathogenicity of both infectious agents occurs 60,61 . Mycoplasmas have anchoring lipoproteins on the external surface of their plasma membrane, which may be an explanation for why they are not recognized by the defense immune system of the host 62 .…”

Section: Discussionmentioning

confidence: 99%

Coinfection with Mycoplasma Pneumoniae and Chlamydia Pneumoniae in ruptured plaques associated with acute myocardial infarction

Higuchi¹,

Reis²,

Sambiase³

et al. 2003

Arq. Bras. Cardiol.

View full text Add to dashboard Cite

OBJECTIVE: To study atheromas, Mycoplasma pneumoniae (M. pneumoniae), and Chlamydia pneumoniae (C. pneumoniae). METHODS: C. pneumoniae was studied with immunohistochemistry and M. pneumoniae with in situ hybridization (ISH), in segments of coronary arteries (SCA) as follows: group A - thrombosed ruptured plaques (TRP) of 23 patients who died due to acute myocardial infarction (AMI); group B - 23 nonruptured plaques (NRP) of group A patients; group C - NRP of 11 coronary patients who did not die due to AMI; and group D - 11 SCA from patients with dilated cardiomyopathy or Chagas' disease without atherosclerosis. RESULTS: The mean number of C. pneumoniae+ cells/400x in groups A, B, C, and D was, respectively, 3.3±3.6; 1.0±1.3; 1.2±2.4; and 0.4±0.3; and the percentage of M. pneumoniae area was, respectively, 3.9±3.5; 1.5± 1.6; 0.9±0.9; and 0.4±0.2. More M. pneumoniae and C. pneumoniae were found in of group A than in group B (P<0.01). Good correlation was seen between the area of the vessel and the M. pneumoniae area in the plaque (r = 0.46; P=0.001) and between C. pneumoniae+ cells and CD4+ T lymphocytes (r = 0.42; P<0.01). The number of C. pneumoniae+ cells correlated with CD20+ B cells (r=0.48; P<0.01). CONCLUSION: M. pneumoniae and C. pneumoniae are more frequently found in TRP correlate with the intensity of the inflammation and diameter of the vessel (positive remodeling)

show abstract

“…Evidence that proteins remain detergentassociated on phase partitioning with Triton X-114 was not included as this may not adequately discriminate Lpp from peripheral membrane proteins or proteins tethered to membranes by other mechanisms. Furthermore, although Lpps are apparently highly abundant in Mollicutes (Razin et al, 1998 ;Chambaud et al, 1999), these Lpps were excluded from the present analysis as it has been previously noted that they may have distinctive signal peptide features in terms of both length (Edman et al, 1999) and their lipobox cleavage sites (Cleavinger et al, 1994(Cleavinger et al, , 1995. In this respect it is also notable that the putative Lgt sequences in the Mycoplasma genomes have distinctive sequence features (our unpublished observations).…”

Section: Construction Of a Dataset Of Experimentally Verified Gram-mentioning

confidence: 99%

“…Indeed, putative Lpps may represent at least 0n5-8n0 % of the bacterial proteome (Chambaud et al, 1999 ;Tjalsma et al, 1999a ;Haake, 2000). However, it remains possible that a significant proportion of these putative Lpps are ' false-positives ', misidentified due to the coincident presence of a cysteine within the signal sequences of exported proteins or proteins targeted for insertion into plasma membranes.…”

Section: -[Livmfwstag](2)-[livmfystagcq]-mentioning

confidence: 99%

Pattern searches for the identification of putative lipoprotein genes in Gram-positive bacterial genomes

2002

View full text Add to dashboard Cite

INTRODUCTIONThe bacterial cell envelope is of major significance as the focal point for interaction between the bacterium and its environment, notably the host in the case of bacterial pathogens. Bacterial cell envelope proteins thus carry out numerous important functions including roles in adhesion, nutrient acquisition and a variety of interactions with host defences. In Gram-positive bacteria the matrix of peptidoglycan and other wall polymers surrounding the cell is not an efficient barrier to the passage of small macromolecules, due both to its inherent structural permeability and to its turnover during normal cell growth. Indeed, peptidoglycan may be sufficiently permeable as to allow the passage of globular proteins of up to "50 kDa in size (Demchick & Koch, 1996 ;Dijkstra & Keck, 1996). Consequently, in the absence of a retentive outer membrane, Grampositive bacteria have evolved distinct mechanisms for retaining proteins within their cell envelopes, including covalent linkage to the peptidoglycan and non-covalent binding to teichoic acids and other cell envelope polymers (Navarre & Schneewind, 1999 ;Cossart & Jonquieres, 2000 ;Janulczyk & Rasmussen, 2001). Also significant among these mechanisms is membraneanchoring of bacterial lipoproteins (Lpps) by covalent N-terminal lipidation (Braun & Wu, 1994 ; Sutcliffe & Russell, 1995). Lpps in Gram-positive bacteria perform important roles as substrate-binding proteins (SBPs) in ABC transporter systems ; in antibiotic resistance ; in cell signalling ; in protein export and folding ; in sporulation and germination ; in conjugation and various other functions (Sutcliffe & Russell, 1995 valent to those carried out by periplasmic proteins of Gram-negative bacteria.The archetypal bacterial Lpp is the murein lipoprotein of Escherichia coli characterized by Braun and coworkers (reviewed in Braun & Wu, 1994). Structural studies revealed that a diacylglycerol moiety is thioether linked to an N-terminal cysteine of this Lpp and that this lipid group serves to orientate the protein by anchoring it to the inner leaflet of the outer membrane. Chemically identical lipid modifications have since been proposed, primarily on the basis of protein sequence analysis (see below), for a great many proteins in both Gram-positive and Gram-negative bacteria, although relatively few have received extensive biochemical characterization.Biosynthesis of bacterial lipoprotein of the ' Braun ' type proceeds via a well conserved pathway that is apparently unique to prokaryotes (Fig. 1). Following signal-peptidedirected export of the prolipoprotein (proLpp), the enzyme prolipoprotein diacylglycerol transferase (Lgt) uses phospholipid substrates and catalyses the addition of a diacylglycerol lipid unit onto the thiol of a crucial conserved cysteine which is located within a ' lipobox ' motif at the cleavage region of the proLpp signal peptide (Sankaran et al., 1995 ; Qi et al., 1995). Subsequently, the signal peptide is removed by a specific lipoprotein signal peptidase II (Lsp) enzyme which ...

show abstract

Interactions between mycoplasma lipoproteins and the host immune system

Cited by 164 publications

References 65 publications

Two Lipoproteins Extracted fromEscherichia coliK-12 LCD25 Lipopolysaccharide Are the Major Components Responsible for Toll-Like Receptor 2-Mediated Signaling

Two Lipoproteins Extracted fromEscherichia coliK-12 LCD25 Lipopolysaccharide Are the Major Components Responsible for Toll-Like Receptor 2-Mediated Signaling

Coinfection with Mycoplasma Pneumoniae and Chlamydia Pneumoniae in ruptured plaques associated with acute myocardial infarction

Pattern searches for the identification of putative lipoprotein genes in Gram-positive bacterial genomes

Contact Info

Product

Resources

About