Caracterização do papel de TLR2 no desenvolvimento da resposta imune após a infecção com Aggregatibacter actinomycetemcomitans / TLR2 signaling is critical for immune protection against Aggregatibacter actinomycetemcomitans infections
AUTOR(ES)
Valéria Gelani
DATA DE PUBLICAÇÃO
2007
RESUMO
Polymorphonuclear leukocytes (PMNs) are the first line of defense against bacterial infections. PMNs express a numerous pattern-recognition receptors (PRR) that facilitate identification of invading microorganisms. Toll-like receptors (TLRs) represent the main class of PRR involved to a recognize pathogenic microorganism. However, the role played by TLR-2 in the recognition and killing of Aggregatibacter actinomycentemcomitans by PMNs is unknown. Thus, we investigated the ability of TLR-2 to mediate neutrophil phagocytosis and bactericidal activity. To determine the role of A. actinomycentemcomitans in triggering neutrophil infiltration, TLR2-/- mice were infected intraperitoneally (2x109 bacteria) and sacrificed after 24 hours. Peritoneal inflammatory cells were isolated and analyzed by optical microscopy. Examination of local inflammatory infiltrates revealed that neutrophil influx into peritoneal cavity of TLR2-/- mice was similar than that observed into their littermate controls wild type C57BL/6 mice (WT). A. actinomycentemcomitans was detected in the spleen of the TLR2-/- mice but not in WT. In the phagocytic assays, TLR2-/- presented minor number of ingested inflammatory cells than WT. Peritoneal cells were stimulated with A. actinomycetemcomitans antigens, and NO and myeloperoxidase was measured after 48 hours; results showed that TLR2-/- cells produce less NO and MPO than WT. In addition, TLR2-/- deficient mice presented higher bone loss following oral infection with A. actinomycetemcomitans when compared with WT and higher tissue destruction.
ASSUNTO(S)
neutrophils neutrófilos receptores do tipo toll periodontal disease tlr2 doença periodontal
Documentos Relacionados
- The role of TLR4 (Toll like receptor 4) in the recognition of Aggregatibacter actinomycetemcomitans
- Infecção bucal e resposta imune humoral a leucotoxina de Aggregatibacter actinomycetemcomitans em camundungo
- TLR4 signaling induces TLR2 expression in endothelial cells via neutrophil NADPH oxidase
- TLR2 and TLR4 mediated host immune responses in major infectious diseases: a review
- Role of TLR2 and TLR4 on human neutrophil functions against Paracoccidioides brasiliensis