CD8A and infection: Fig. 6b shows the relationship between antigen dose and hybridoma response. Reactivating K3− clones, treated with phosphonoacetic acid to prevent any post-induction spread of lytic infection, showed significantly better epitope presentation than K3+ (Fig. 6c). The 49100.2 hybridoma can also exert anti-viral effects. Without phosphonoacetic acid treatment, K3− clones showed both better antigen presentation and lower virus titers when 49100.2 cells were added (Fig. 6d). Therefore K3 protected the reactivating cells against CD8+ T cell recognition.