Innate and adaptive immune responses in respiratory virus infection: implications for the clinic.

Stambas, John; Lu, Chunni; Tripp, Ralph A

INTRODUCTION The innate immune response is the first line of defense against pathogens and consists of physical, chemical and cellular defenses. The adaptive immune response is the second line of defense and is specific to the pathogen. Innate immunity occurs immediately while adaptive immunity develops upon pathogen exposure, and is long-lasting, highly specific, and sustained by memory T cells. Respiratory virus infection typically induces effective immunity but over-exuberant responses are associated with pathophysiology. Cytokines expressed in response to viral infection can enhance biological responses, activate, and trigger signaling pathways leading to adaptive immunity that involves B cell-mediated humoral and T cell-mediated cellular immune responses. Vaccines induce immunity, specifically B cell and T cell responses. Vaccination targeting respiratory viruses like influenza is generally efficacious, but for many viruses, our understanding of vaccination strategies and immunity is incomplete or in its infancy. Studies that examine innate and adaptive immune responses to respiratory virus infection will aid vaccine development and may reduce the burden of respiratory viral disease. AREAS COVERED A literature search was performed using PubMed, a search engine maintained by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine (NLM) bibliographic database. The areas of search covered: innate, adaptive, respiratory virus, vaccine development, B cell, and T cell. EXPERT OPINION Immunity rests on two pillars, i.e. the innate and adaptive immune system, which function together on different tasks to maintain homeostasis. A better understanding of immunity is necessary for disease prevention and intervention.