The mucosal immune system of the respiratory tract

Most viruses use host mucosal surfaces as their initial portals of infection. The respiratory tract has the body's second-largest mucosal surface area after the digestive tract. An understanding of the unique nature of the mucosal immune system of respiratory organs is therefore extremely important for the development of new-generation vaccines and novel methods of preventing and treating respiratory infectious diseases, including viral infections.

Graphical abstractDownload full-size imageHighlights► The mucosal immune system (MIS) consists of inductive and effector sites. ► MIS can induce antigen-specific immune responses at both local and distal sites. ► Microfold cells (M cells) are professional antigen-sampling cells. ► NALT and iBALT organogenesis differs from that of other secondary lymphoid tissues. ► Understanding the MIS is important for the development of effective vaccines.