Characterization of antigen-presenting cells from the porcine respiratory system

Antigen-presenting cells (APCs) are strategically placed in all anatomic sites with high antigen exposure such as the respiratory system. The aim of this study was to evaluate phenotypic and functional properties of APCs from the lung (L-Cs), mediastinal lymph node (LN-Cs) and bronchoalveolar lavage cells (BAL-Cs). The APCs were first analyzed based on forward scatter and side scatter profiles and the selection of MHC-II^highCD172a⁺ cells (referred to as APCs); then the expression of CD1a, CD163, CD206, CD16 and CD11R3 was evaluated in the APCs. The results showed that CD1a, CD163 and CD206 were differentially expressed among L-Cs, LN-Cs and BAL-Cs, suggesting the phenotype MHC-II^highCD172a⁺CD1a^low/-CD163^lowCD206^- for L-Cs and MHC-II^highCD172a⁺CD1a⁺CD163^low/-CD206⁺ for LN-Cs. BAL-Cs were MHC-II^highCD172a⁺CD1a^-CD163^highCD206^+/-. The functional characteristics of L-Cs and LN-Cs were different from those of BAL-Cs, confirming that L-Cs and LN-Cs resemble specialized APCs. In conclusion, we present the characterization of APCs from L-Cs, LN-Cs and BAL-Cs of the porcine respiratory system.