TABLE 2.

CD8⁺ T lymphocytes protect against lethal Ebola virus challenge

Cells or serum transferred	Amt transferred	No. of survivors/total after challenge with:
		300 LD50s	3,000 LD50s
Unfractionated T cells	8 × 106  cells	20/20	10/10
	1 × 106  cells	16/20	8/10
	1 × 105  cells	3/20	1/10
	1 × 104  cells	1/20	0/10
CD8-enriched T cellsa	1 × 106  cells	17/20	9/10
CD4-enriched T cellsb	1 × 106  cells	0/20	NDe
MLR control T cellsc	8 × 106  cells	1/20	0/10
Naive control T cellsd	8 × 106  cells	0/20	0/10
Ebola virus NP serum	1 ml	0/20	ND
Lassa virus N serum	1 ml	0/20	ND

^aCombined results from different experiments, in which the CD8-enriched cultures were 94 to 96% CD8⁺ cells and <3% CD4⁺ cells. 

^bCombined results from different experiments, in which the CD4-enriched cultures contained 95 to 98% CD4⁺ cells and 2 to 3% CD8⁺ cells. 

^cMLR, mixed lymphocyte reaction. Control cells specific for allogeneic BALB/c cells and approximately 80% CD8⁺. 

^dNaive control cells from unvaccinated C57BL/6 mice that were stimulated in vitro with the Ebola virus NP peptide. 

^eND, not determined.