Flow cytometry analysis of CD11c-positive peripheral blood mononuclear cells in horses

Horses have played a prominent role in shaping our modern world, with important effects on health. Unfortunately, better characterization of the horse immune system is still needed. In this report, using flow cytometry techniques, four monoclonal antibodies against horse CD11c integrin were characterized and described for their ability to provide a positive recognition signal in peripheral blood mononuclear cells. Further immune cell phenotype experiments were performed using MHC-II, CD14, TLR4 and the specific anti-horse CD11c monoclonal antibody (1C4). With this staining panel, it was possible to detect a cell population defined by CD11c⁺MHC-II⁺TLR4⁺CD14^low, which could be considered as putative dendritic cells. This manuscript shows that a new monoclonal antibody (1C4) can be used for the characterization of dendritic cells and their different lineages, opening the possibility of better understanding the mechanisms of immunity in horses.