BACKGROUND AND OBJECTIVE: Pulmonary emphysema is associated with frequent respiratory infections but little is known about the reasons for this susceptibility to bacterial infection. We previously demonstrated an impaired inflammatory response to Streptococcus pneumoniae in an experimental emphysema mouse model at 24 h, or longer following bacterial inoculation. Toll-like receptors (TLR) have been recognized as regulators in the inflammatory response. We examined the expression of TLR on alveolar macrophages in experimental emphysema mice and evaluated the immediate inflammatory response of the emphysematous lung to streptococcal infection. METHODS: Elastase was administered once into mice trachea to induce pulmonary emphysema. Three weeks later, expression of TLR-2 and TLR-4 in the BAL cells was examined by immunostaining. Following the intratracheal inoculation of Streptococcus pneumoniae, pro-inflammatory cytokine concentrations were measured in the BAL fluids of the control and emphysema mice. RESULTS: The expression of TLR-2 and TLR-4 was significantly elevated in the alveolar macrophages of emphysema mice. Six hours after infection, neutrophils in the BAL fluid of emphysema mice were significantly increased, and the levels of tumour necrosis factor-alpha, IL-1beta and IL-6 were significantly elevated, compared with the control mice. At 3 h post inoculation, macrophage inflammatory protein-2 levels were significantly elevated. CONCLUSIONS: The immediate inflammatory response in the emphysematous lung is significantly enhanced in response to streptococcal infection. This may be partly attributed to the increased expression of TLR in the alveolar macrophages of emphysema mice.
BACKGROUND AND OBJECTIVE:Pulmonary emphysema is associated with frequent respiratory infections but little is known about the reasons for this susceptibility to bacterial infection. We previously demonstrated an impaired inflammatory response to Streptococcus pneumoniae in an experimental emphysemamouse model at 24 h, or longer following bacterial inoculation. Toll-like receptors (TLR) have been recognized as regulators in the inflammatory response. We examined the expression of TLR on alveolar macrophages in experimental emphysemamice and evaluated the immediate inflammatory response of the emphysematous lung to streptococcal infection. METHODS: Elastase was administered once into mice trachea to induce pulmonary emphysema. Three weeks later, expression of TLR-2 and TLR-4 in the BAL cells was examined by immunostaining. Following the intratracheal inoculation of Streptococcus pneumoniae, pro-inflammatory cytokine concentrations were measured in the BAL fluids of the control and emphysemamice. RESULTS: The expression of TLR-2 and TLR-4 was significantly elevated in the alveolar macrophages of emphysemamice. Six hours after infection, neutrophils in the BAL fluid of emphysemamice were significantly increased, and the levels of tumour necrosis factor-alpha, IL-1beta and IL-6 were significantly elevated, compared with the control mice. At 3 h post inoculation, macrophage inflammatory protein-2 levels were significantly elevated. CONCLUSIONS: The immediate inflammatory response in the emphysematous lung is significantly enhanced in response to streptococcal infection. This may be partly attributed to the increased expression of TLR in the alveolar macrophages of emphysemamice.
Authors: Valerie R Stolberg; Alexandra L McCubbrey; Christine M Freeman; Jeanette P Brown; Sean W Crudgington; Sophina H Taitano; Bridget L Saxton; Peter Mancuso; Jeffrey L Curtis Journal: J Immunol Date: 2015-05-18 Impact factor: 5.422
Authors: Maria Aparecida Esteves Rabelo; Leda Marília Fonseca Lucinda; Maycon Moura Reboredo; Lídia Maria Carneiro da Fonseca; Fernando Fonseca Reis; Thaís Fernanda Fazza; Danielle Ribeiro Brega; Flavia de Paoli; Adenilson de Souza da Fonseca; Bruno Valle Pinheiro Journal: Inflammation Date: 2018-02 Impact factor: 4.092