Nasal mucosal administration of chitin microparticles boosts innate immunity against influenza A virus in the local pulmonary tissue

Influenza virus infection remains a major health concern due to morbidity and mortality associated with epidemics and occasional pandemics. The absence of acquired immunity to antigenically distinct, emerging virus strains stresses the need for a generic drug that protects independent of vaccination. Here, we demonstrate that prophylactic administration of chitin microparticles (CMP) via the intranasal route significantly reduced lung viral titres and clinical signs. Pre-treatment boosted the innate immune response to subsequent infection by recruiting innate cells, such as neutrophils, and increasing inflammatory cytokines. Although an increase in virus-specific T cells was observed, the memory phase was diminished. Our data demonstrate that in the absence of prior exposure to influenza virus. CMP reduce clinical signs by boosting innate immunity. (C) 2010 Elsevier Ltd. All rights reserved.