CD8A and infection: Interestingly, on day 4 post infection with PR8 encoding the OT-I cognate ligand, SIINFEKL, OT-I CD8+ T cells in the MedLNs of ICAM-1/2-/- mice proliferated and differentiated vigorously, whereas by day 7, their numbers declined in the ICAM-1/2-/- MedLNs as well as in the ICAM-1/2-/- lungs.