Pattern recognition receptors TLR4 and CD14 mediate response to respiratory syncytial virus

The innate immune system contributes to the earliest phase of the host defe nse against foreign organisms and has both soluble and cellular pattern rec ognition receptors for microbial products. Two important members of this re ceptor group, CD14 and the Toll-like receptor (TLR) pattern recognition rec eptors, are essential for the innate immune response to components of Gramn egative and Cram-positive bacteria, mycobacteria, spirochetes and yeast. We now find that these receptors function in an antiviral response as well,Th e innate immune response to the fusion protein of an important respiratory pathogen of humans, respiratory syncytial virus (RSV), was mediated by TLR4 and CD14. RSV persisted longer in the lungs of infected TLR l-deficient mi ce compared to normal mice,Thus, a common receptor activation pathway can i nitiate innate immune responses to both bacterial and viral pathogens.