Nasal humoral immunity: the first line of protection against respiratory pathogens.

The nasal cavity is the first site of infection for respiratory pathogens, and control of pathogens at this site is critical for limiting disease progression. Mucosal immunity in the respiratory tract has historically been studied in the lungs despite lung infections typically arising as a result of lack of pathogen control in the upper respiratory tract. However, the generation of vaccines to prevent infection and block transmission requires an understanding of how immune responses are generated and maintained within the nasal cavity. Recently, a concerted research effort to understand immune responses in the nasal cavity and upper respiratory tract has revealed new insight into how local immune responses are generated and help to control respiratory pathogens. Here, we discuss these recent advances and outstanding questions in our understanding of humoral immunity within the nasal cavity and upper respiratory tract.