FIG. 6.

Adoptive transfer of immune lymphocytes into RacL11-infected, irradiated recipient CBA mice. Immune lymphocytes for transfer were isolated from the spleens of donor mice inoculated 2 weeks previously with 2 × 10⁶ PFU of KyA. Donor lymphocytes were restimulated in vitro for 5 days in the presence of 3 × 10⁵ KyA-infected, mitomycin C-treated L-M fibroblast stimulators. On the day of transfer, recipient mice were given 500 cGy of total-body γ irradiation and were infected i.n. with 1.5 × 10⁶ PFU of RacL11. Immune donor lymphocytes were either left untreated, depleted in vitro of CD4⁺ or CD8⁺ T cells, or depleted of both CD4⁺ and CD8⁺ T cells immediately prior to transfer. Following in vitro depletion, the remaining cells were transferred in a volume of 0.25 ml to recipient mice via tail vein injection. Control mice received 2 × 10⁷ nonimmune (Non-Imm) splenocytes. The amount of infectious EHV-1 was determined by standard plaque titration on RK monolayers as described in Materials and Methods. Each dot represents the log PFU per lung determined from a single mouse. The horizontal bars represent the mean log PFU per experimental group.