An age-structured model of dendritic cell trafficking in the lung

As the sentinels of the immune system, dendritic cells (DC) play a critical role in initiating and maintaining appropriate T cell responses through capture and presentation of antigen, costimulation, and mediator release. Although much is known about certain aspects of DC function, the exact relationship between lung epithelial DC precursor populations in the blood and their functional role in antigen presentation are not clearly understood. I created an age-structured mathematical model for DC trafficking into the lung to address this question. While capturing experimentally observed system dynamics, I found that blood DC are preferentially recruited over blood monocytes. For short-lived antigens, the model results suggest that lung epithelial DC derived from blood DC exhibit a 625% increase in antigen density compared with those derived from blood monocytes. Finally, these results motivate future experimental studies to clarify aspects of DC trafficking in the lung.