TLR3 and bacterial infectious disease: Viral and bacterial infections exacerbate the immune system and increase morbidity of patients with chronic airways diseases; viral infections trigger an innate immune response through host detection of viral dsRNA via several different mechanisms, including activation of a member of the class of pattern recognition receptors, Toll-like receptor 3; lung inflammation associated with viral infections includes robust increase in cytokines, such as IL-1β, IL-6, IL-8, TNF-α, GM-CSF, IP-10, RANTES, and MIP-1α [18].