TABLE 1.

Virus-specific cytotoxic activity in the spleens of mice deficient in type I, type II, or both type I and II IFN receptors, or in spleens 129/SvEv of control mice, following infection with 10⁶ PFU of LCMV-Docile^a

Day of infection	Dilution	% CTL activity specific to the indicated viral epitope
		129/SvEv mice		IFN-α/βR−/− mice		IFN-γR−/− mice		IFN-α/β-γR−/− mice
		GP1	NP	GP1	NP	GP1	NP	GP1	NP
6	1	71	54	81	61	55	47	82	43
	3	52	35	66	41	32	32	64	22
	9	28	16	39	19	14	12	33	8
9	1	31	17	69	98	28	7	46	15
	3	15	6	42	53	27	7	35	8
	9	7	2	22	3	21	6	10	4
15	1	2	5	12	15	1	1	27	13
	3	2	3	6	7	1	2	14	2
	9	2	2	2	3	2	1	6	2
30	1	2	3	4	3	5	4	4	5
	3	2	2	2	2	2	2	3	2
	9	2	2	2	2	1	1	2	2

^aSplenocytes isolated on days 6, 9, 15, and 30 after infection were stimulated in vitro with GP1_33–41 or NP_396–404 peptide-pulsed splenocytes as described in Materials and Methods. The cytolytic activity of restimulated splenocytes cultured at a density of 4 × 10⁶ cells/well was measured in a ⁵¹Cr release assay, using MC57G cells pulsed with 10 μg of GP1_33–41 NP_396–404 peptide per ml. Restimulated splenocytes were resuspended in 1 ml of medium per culture well, and serial threefold dilutions of effector cells were performed. Lysis of untreated target cells was ≤5% at the highest effector cell/target cell ratio. Results are representative of those from three separate experiments.