Toll-like receptor 2 (TLR2) plays a major role in innate resistance in the lung against murine Mycoplasma.
Mycoplasma lipoproteins are recognized by Toll-like receptors (TLR), but TLRs' role in responses to infection are unknown. Mycoplasma pulmonis is a naturally occurring respiratory pathogen in mice. In the current study, we used TLR-transfected HEK cells and TLR2(-/-) bone marrow-derived dendritic cells to demonstrate TLR2-mediated events are important in the initial host-mycoplasma interactions promoting cytokine responses. As we found alveolar macrophages expressed TLR1, TLR2 and TLR6 mRNAs, a role for TLR2 in innate immune clearance in lungs was examined. Three days post-infection, TLR2(-/-) mice had higher M. pulmonis numbers in lungs, but not in nasal passages. However, TLR2(-/-) mice had higher lung cytokine levels, indicating TLR2-independent mechanisms are also involved in host responses. Thus, TLR2 plays a critical role in the ability of innate immunity to determine M. pulmonis numbers in the lung, and it is likely that early after respiratory infection that TLR2 recognition of M. pulmonis triggers initial cytokine responses of host cells.
Love
Wees
W
Department of Molecular Biology and Immunology, University of North Texas Health Science Center in Fort Worth, Fort Worth, Texas, USA.
Dobbs
Nicole
N
Tabor
Leslie
L
Simecka
Jerry W
JW
D000818:Animals; D018893:Bronchoalveolar Lavage; D005786:Gene Expression Regulation; D007113:Immunity, Innate / Q000276:immunology*; D015850:Interleukin-6 / Q000378:metabolism; D008168:Lung / Q000276:immunology* / Q000382:microbiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D050296:Microbial Viability; D009174:Mycoplasma / Q000166:cytology / Q000276:immunology*; D009175:Mycoplasma Infections / Q000276:immunology* / Q000382:microbiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051194:Toll-Like Receptor 1 / Q000235:genetics / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D051216:Toll-Like Receptor 6 / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D015850:Interleukin-6; D012333:RNA, Messenger; C493486:Tlr2 protein, mouse; C495369:Tlr6 protein, mouse; D051194:Toll-Like Receptor 1; D051195:Toll-Like Receptor 2; D051216:Toll-Like Receptor 6; D014409:Tumor Necrosis Factor-alpha