The lung is a complex organ consisting of many different cell types, including various epithelial, immune and mesenchymal cells which interact intricately to drive lung development, maintain its normal functioning, and mediate repair and regeneration after injury (Sikkema et al., 2023, Zepp and Morrisey, 2019). During development, immune-epithelial interactions contribute to lung maturation and the formation of a healthy respiratory system (Barnes et al., 2023). In adulthood, immune-epithelial crosstalk is necessary to maintain homeostatic conditions in the lungs by promoting tolerance and limiting unnecessary immune responses. Similarly, there is a complex network of cell-cell communications in the airway and alveolar epithelium with innate and adaptive immune cells to repair and regenerate the lungs in response to infections and injury (Hewitt and Lloyd, 2021, Planer and Morrisey, 2023). Disruption of this delicate balance can lead to epithelial damage and progression to disease states including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary disease (IPF), allergic responses and asthma.
In this review, we summarise our current knowledge of immune-epithelial interactions during human lung development, homeostasis and repair. We highlight the importance of these interactions in COPD and IPF, and summarise current gaps and challenges that need to be addressed for improved clinical interventions.
