Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031099 (periodontitis)
 12,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Porphyromonas gingivalis has been implicated as a contributing etiological agent of adult periodontitis and generalized forms of early-onset periodontitis. Proteases of P. gingivalis may contribute to its pathogenicity by destroying connective tissue as well as inactivating key plasma proteins that might mediate protective host functions. In order to explore this problem, antiserum raised against membrane vesicles of P. gingivalis W83 was used to screen a genomic library of strain W83 constructed by using the lambda DASH vector system. A recombinant phage (lambda 34) expressing a P. gingivalis protease from the library was identified and characterized. Casein substrate zymography of lambda 34 lysates revealed a protease with an apparent molecular mass of 97 kDa. The gene encoding this protease was designated prtH. It was localized to a 3.7-kb HindIII-BamHI fragment and specified an enzyme which hydrolyzed the human C3 complement protein under defined conditions. The nucleotide sequence of this 3.7-kb fragment was determined, and one 2.9-kb open reading frame (992 amino acids) corresponding to a 110-kDa protein was detected, suggesting it might be a precursor of the 97-kDa active protease. prtH is not similar to any previously cloned protease gene from P. gingivalis.
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PMID:Cloning and characterization of a new protease gene (prtH) from Porphyromonas gingivalis. 792 85

Crosstalk between complement and Toll-like receptors (TLRs) coordinates innate immunity. We report a previously unknown immune subversion mechanism involving microbial exploitation of communication between complement and TLRs. Porphyromonas gingivalis, a major oral and systemic pathogen with complement C5 convertase-like activity, synergizes with C5a (fragment of complement protein C5) to increase cyclic adenosine monophosphate (cAMP) concentrations, resulting in suppression of macrophage immune function and enhanced pathogen survival in vitro and in vivo. This synergy required TLR2 signaling, a pertussis toxin- and thapsigargin-sensitive C5a receptor pathway, with protein kinase A and glycogen synthase kinase-3beta as downstream effectors. Antagonistic blockade of the C5a receptor abrogated this evasive strategy and may thus have important therapeutic implications for periodontitis and atherosclerosis, diseases in which P. gingivalis is implicated. This first demonstration of complement-TLR crosstalk for immunosuppressive cAMP signaling indicates that pathogens may not simply undermine complement or TLRs (or both) as separate entities, but may also exploit their crosstalk pathways.
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PMID:Microbial hijacking of complement-toll-like receptor crosstalk. 2015 52