TABLE 1.

Roles of TLRs and TLR adaptors in acute lower respiratory tract bacterial infections

TLR or TLR adaptorInfection-causing bacterium (reference[s])Phenotypea
SurvivalNeutrophil influxbBacterial burdencBacterial disseminationd
TLRs
    TLR2Acinetobacter baumannii (43)NDND
Legionella pneumophila (7, 28, 33)
Porphyromonas gingivalis (1)NDNSND
Pseudomonas aeruginosa (73)NDNS↑ (early)ND
Streptococcus pneumoniae (21)
    TLR4Acinetobacter baumannii (43)
Haemophilus influenzae (88)ND
Klebsiella pneumoniae (13)NDND
Pseudomonas aeruginosa (73)ND↓ (late)NSND
Streptococcus pneumoniae (22)ND
    TLR5Legionella pneumophila (32)ND↓ (early)NSND
    TLR9Klebsiella pneumoniae (9)NS
Legionella pneumophila (10)NSND
Streptococcus pneumoniae (4)NS
TLR adaptors
    MyD88Escherichia coli (38, 40)NDND
Haemophilus influenzae (91)NDNDND
Klebsiella pneumoniae (41)NDNDND
Legionella pneumophila (7, 33)
Pseudomonas aeruginosa (73, 78, 80)
Staphylococcus aureus (78)NDNDND
Streptococcus pneumoniae (4)
    TIRAPKlebsiella pneumoniae (41)
Pseudomonas aeruginosa (41)NDND
    TRIFEscherichia coli (38, 40)
  • a Phenotype was determined using gene-deficient or mutant mice after intrapulmonary infection. ↓, decreased; ↑, increased; ND, not determined; NS, no significant difference.

  • b Neutrophil influx was determined using bronchoalveolar lavage fluid and/or lung parenchyma.

  • c Bacterial burden was measured as the number of CFU in the lungs.

  • d Bacterial dissemination was measured as the number of CFU in the blood or spleen.