| First Author | Ribes S | Year | 2010 |
| Journal | Infect Immun | Volume | 78 |
| Issue | 2 | Pages | 865-71 |
| PubMed ID | 19933834 | Mgi Jnum | J:157788 |
| Mgi Id | MGI:4436971 | Doi | 10.1128/IAI.01110-09 |
| Citation | Ribes S, et al. (2010) Toll-like receptor stimulation enhances phagocytosis and intracellular killing of nonencapsulated and encapsulated Streptococcus pneumoniae by murine microglia. Infect Immun 78(2):865-71 |
| abstractText | Toll-like receptors (TLRs) are crucial pattern recognition receptors in innate immunity that are expressed in microglia, the resident macrophages of the brain. TLR2, -4, and -9 are important in the responses against Streptococcus pneumoniae, the most common agent causing bacterial meningitis beyond the neonatal period. Murine microglial cultures were stimulated with agonists for TLR1/2 (Pam(3)CSK(4)), TLR4 (lipopolysaccharide), and TLR9 (CpG oligodeoxynucleotide) for 24 h and then exposed to either the encapsulated D39 (serotype 2) or the nonencapsulated R6 strain of S. pneumoniae. After stimulation, the levels of interleukin-6 and CCL5 (RANTES [regulated upon activation normal T-cell expressed and secreted]) were increased, confirming microglial activation. The TLR1/2, -4, and -9 agonist-stimulated microglia ingested significantly more bacteria than unstimulated cells (P < 0.05). The presence of cytochalasin D, an inhibitor of actin polymerizaton, blocked >90% of phagocytosis. Along with an increased phagocytic activity, the intracellular bacterial killing was also increased in TLR-stimulated cells compared to unstimulated cells. Together, our data suggest that microglial stimulation by these TLRs may increase the resistance of the brain against pneumococcal infections. |
