[The role of innate immunity in otitis media].

Otitis media (OM) belongs to the most common pediatric diseases and causes more medical contacts, surgical interventions, and drug prescriptions than any other infectious disease. Recent findings have identified a critical role of innate immunity in recovery from OM. The middle ear mucosa identifies invading pathogens by sensing pathogen-associated molecule patterns (PAMPs) via pattern recognition receptors such as the Toll-like receptors (TLRs). They generate immediate antimicrobial responses and cytokine release, leading to an inflammatory reaction as seen in acute or chronic OM. Cross-talk between TLRs can enhance or suppress the healing process in the middle ear. In order to prevent over-activation on the one hand and insufficient immune response on the other, the signaling network between different TLRs must be integrated and controlled by positive and negative feedback loops. This guarantees a proper immune response in the middle ear after infection. In this review, we focus on the involvement of the innate immune system and TLRs in OM, as well on their relevance for new vaccination strategies and immunotherapies.