Influenza virus tetramer staining of porcine CD4-CD8 αhighT cells. SwIV tetramer staining of CD4-CD8αhigh T cell subsets. Individual samples were stained by an epitope candidate tetramer (GTEKLTITY) and a negative control tetramer (ASYGAGAGY). Singlet lymphocytes are gated in P1 (blue). CD4-CD8αhigh cells are gated in P2 (orange), and CD4-CD8αhigh APC+BV+ tetramer double positive cells are shown in P3 (green) for animal number 4. Percentages of tetramer reactive cells within the CD4-CD8αhigh population are shown for each sample.