| First Author | Dabbagh K | Year | 2002 |
| Journal | J Immunol | Volume | 168 |
| Issue | 9 | Pages | 4524-30 |
| PubMed ID | 11970998 | Mgi Jnum | J:113992 |
| Mgi Id | MGI:3687944 | Doi | 10.4049/jimmunol.168.9.4524 |
| Citation | Dabbagh K, et al. (2002) Toll-like receptor 4 is required for optimal development of Th2 immune responses: role of dendritic cells. J Immunol 168(9):4524-30 |
| abstractText | LPS potently induces dendritic cell maturation and the production of proinflammatory cytokines, such as IL-12, by activation of Toll-like receptor 4 (TLR4). Since IL-12 is important for the generation and maintenance of Th1 responses and may also inhibit Th2 cell generation from naive CD4 T cell precursors, it has been inferred that TLR4 signaling would have similar effects via the induction of IL-12 secretion. Surprisingly, we found that TLR4-defective mice subjected to sensitization and pulmonary challenge with a protein allergen had reductions in airway inflammation with eosinophils, allergen-specific IgE levels, and Th2 cytokine production, compared with wild-type mice. These reduced responses were attributable, at least in part, to decreased dendritic cell function: Dendritic cells from TLR4-defective mice expressed lower levels of CD86, a costimulatory molecule important for Th2 responses. They also induced less Th2 cytokine production by antigenically naive CD4 T cells in vitro and mediated diminished CD4 T cell Ag-specific pulmonary inflammation in vivo. These results indicate that TLR4 is required for optimal Th2 responses to Ags from nonpathogenic sources and suggest a role for TLR4 ligands, such as LPS derived from commensal bacteria or endogenously derived ligands, in maturation of the innate immune system before pathogen exposure. |
