Mucosal immune responses in the lung during respiratory infection: The organization and regulation of iBALT structure

The local immune defenses of respiratory system play a crucial role in safeguarding against pathogens and eliminating infected cells. In this article, we review the current knowledge regarding the establishment and regulation of local immune responses within the lungs, with a particular focus on the formation of inducible bronchus-associated lymphoid tissue (iBALT), which has demonstrated a capacity to mount protective immune responses against several pathogens, including influenza virus, severe acute respiratory syndrome coronavirus (SARS-CoV)/SARS-CoV-2, and Mycobacterium tuberculosis (Mtb). Furthermore, we explore the development and regulation of long-term immune memory within the lungs, which may be facilitated by iBALT. This review aims to provide a summary of potential targets within iBALT for pathogen defense and vaccine design.