RESUMO
Infections of the lung cause observable sickness thought to be secondary to inflammation. Signs of sickness are crucial to alert others via behavioral-immune responses to limit contact with contagious individuals. Gram-negative bacteria produce exopolysaccharide (EPS) that provides microbial protection; however, the impact of EPS on sickness remains uncertain. Using genome-engineered Pseudomonas aeruginosa (P. aeruginosa) strains, we compared EPS-producers versus non-producers and a virulent Escherichia coli (E. coli) lung infection model in male and female mice. EPS-negative P. aeruginosa and virulent E. coli infection caused severe sickness, behavioral alterations, inflammation, and hypothermia mediated by TLR4 detection of the exposed lipopolysaccharide (LPS) in lung TRPV1+ sensory neurons. However, inflammation did not account for sickness. Stimulation of lung nociceptors induced acute stress responses in the paraventricular hypothalamic nuclei by activating corticotropin-releasing hormone neurons responsible for sickness behavior and hypothermia. Thus, EPS-producing biofilm pathogens evade initiating a lung-brain sensory neuronal response that results in sickness.
Assuntos
Infecções por Escherichia coli , Escherichia coli , Pulmão , Polissacarídeos Bacterianos , Infecções por Pseudomonas , Pseudomonas aeruginosa , Animais , Feminino , Masculino , Camundongos , Biofilmes , Escherichia coli/fisiologia , Hipotermia/metabolismo , Hipotermia/patologia , Inflamação/metabolismo , Inflamação/patologia , Pulmão/microbiologia , Pulmão/patologia , Pneumonia/microbiologia , Pneumonia/patologia , Pseudomonas aeruginosa/fisiologia , Células Receptoras Sensoriais , Polissacarídeos Bacterianos/metabolismo , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Infecções por Pseudomonas/metabolismo , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/patologia , Nociceptores/metabolismoRESUMO
Neutrophils are heterogeneous, but the mechanisms underlying their ability to polarize remain unclear. In this issue of Immunity, Gour et al. demonstrate that the GPCR Mrgpra1 and the neuropeptide NPFF, molecules involved in pain and itch, direct neutrophil polarization that impacts host defense and pneumonia susceptibility.