Interleukin 1 receptor-driven neutrophil recruitment accounts to MyD88-dependent pulmonary clearance of legionella pneumophila infection in vivo.

Legionella pneumophila, the etiological agent of Legionnaires' disease, triggers activation of multiple innate immune pathways that lead to the restriction of bacterial replication in vivo. Despite the critical role for MyD88 in infection clearance, the receptors and mechanisms responsible for MyD88-mediated pulmonary bacterial clearance are still unclear. Here, we used flagellin mutants of L. pneumophila, which bypass the NAIP5/NLRC4-mediated restriction of bacterial replication, to assess the receptors involved in MyD88-mediated pulmonary bacterial clearance. By systematically comparing pulmonary clearance of L. pneumophila in C57BL/6 MyD88(-/-), TLR2(-/-), TLR3(-/-), TLR4(-/-), TLR9(-/-), IL-1R(-/-), and IL-18(-/-) mice, we found that, while the knockout of a single Toll-like receptor or interleukin 18 resulted only in minor impairment of bacterial clearance, deficiency in the interleukin 1 (IL-1) receptor led to a significant impairment. IL-1/MyD88-mediated pulmonary bacterial clearance occurs via processes involving the recruitment of neutrophils. Collectively, our data contribute to the understanding of the effector mechanisms involved in MyD88-mediated pulmonary bacterial clearance.

Mascarenhas DP ，Pereira MS ，Manin GZ ，Hori JI ，Zamboni DS ... -  《-》

MyD88-dependent responses involving toll-like receptor 2 are important for protection and clearance of Legionella pneumophila in a mouse model of Legionnaires' disease.

Archer KA ，Roy CR 《-》

Myeloid differentiation primary response gene (88)- and toll-like receptor 2-deficient mice are susceptible to infection with aerosolized Legionella pneumophila.

Hawn TR ，Smith KD ，Aderem A ，Skerrett SJ ... -  《JOURNAL OF INFECTIOUS DISEASES》

Role of Toll-like receptor 2 in recognition of Legionella pneumophila in a murine pneumonia model.

Fuse ET ，Tateda K ，Kikuchi Y ，Matsumoto T ，Gondaira F ，Azuma A ，Kudoh S ，Standiford TJ ，Yamaguchi K ... -  《JOURNAL OF MEDICAL MICROBIOLOGY》

Cooperation between multiple microbial pattern recognition systems is important for host protection against the intracellular pathogen Legionella pneumophila.

Archer KA ，Ader F ，Kobayashi KS ，Flavell RA ，Roy CR ... -  《-》