TABLE 2.

Enhanced survival of mice genetically deficient for both CD4 and CD8 T lymphocytes to scrapie infection

C57BL/6 mouse group	No. of mice	Survival time after inoculation with mouse scrapiea (mean no. of days ± SE)
		i.c.	i.p.
Wild type	8	148 ± 8	189 ± 3
CD4−/−	8	156 ± 8	NDb
CD8−/−	8	154 ± 8	ND
CD4−/− CD8−/−	8	193 ± 5c	242 ± 10c
MHC class I−/−	6	165 ± 5	ND
MHC class II−/−	6	158 ± 7	ND

^aMice were inoculated with 100,000 PFU of scrapie as described in Materials and Methods and sacrificed when moribund. The presence of scrapie was confirmed by pathogenomic findings on brain sections viewed by light microscopy (spondiosis, gliosis, and neuronal dropout) and by demonstration of conversion from PrP^c to PrP^sc by Western blotting (33, 35).

^bND, not done.

^cP < 0.01.