Mechanisms of the innate immunity in the respiratory system

The respiratory system is permanently exposed to the influence of numerous harmful environmental factors: various microbial pathogens, allergens and air pollution, with non-volatile toxic chemicals of tobacco smoke. Therefore, there have been developed several mechanisms protecting from these factors. These mechanisms can be classified as innate, non-specific, or acquired, much more specific, which are associated with regular immune response. In this review authors shortly describe the innate, nonspecific mechanisms, which compose the first line of antimicrobial defense in our respiratory system. The mechanisms of innate immunity include passive protection, provided by the mucus-mediated mechanical barrier Moreover, by means of active defense, several potent immunoregulatory factors and various substances displaying antibacterial, antifungal and antiviral activity are also engaged.