Cattle T Cell Phenotyping by an 8-Colour, 10-Parameter Panel

This multiplex staining panel was developed to differentiate cattle T cells into conventional (CD4 and CD8) and unconventional (γδ-TCR) subsets as well as their stage of differentiation and activation. The combination of CD45RO and CD62L allows the identification of naïve (TNaïve), central memory (TCM), effector memory (TEM) and terminal effector (TTE) T cells. Activated cattle T cells (TAV) can be identified by the cell surface expression of CD25. This panel was developed using cryopreserved cattle peripheral blood mononuclear cells (PBMCs) and tested on fresh as well as stimulated PBMCs. Therefore, this 8-colour, 10-parameter flow cytometry panel simultaneously identifies cattle TNaïve, TAV, TCM, TEM, TTE and γδ-TCR cells. This panel will improve our ability to examine T cell response to pathogens and vaccines in cattle including the potential to identify previously undescribed subpopulations. Furthermore, this panel can be readily optimised for other bovid species as many of these reagents are likely to cross react. ### Competing Interest Statement The authors have declared no competing interest.