Figure 2.

FIV-specific suppressor activity in normal cats. Mitogen-activated lymphoblasts were prepared from the blood (a) and lymph nodes (b) of two normal, specific pathogen-freecats which had never been exposed to either infectious FIV or FIV antigens, and were cocultured with FIV_PET-infected MYA-1 cells at ratios of 4:1 (---), 2:1 (– – –), and 1:1 (· · ·). Control cultures contained FIV_PET-infected MYA-1 cells alone (——). Replication of FIV was indicated by the detection of viral p24 in the culture supernatant by ELISA. The results shown represent the mean OD values at 650 nm for the two cats ± 2 SD, error bars are not discernible where the SD is small.