TABLE 3.

Lymphocyte proliferation to free peptides by PBMCs obtained preimmunization, 1 week after the last EIAV lipopeptide immunization, and 1 and 3 weeks after virus challenge in the EIAV lipopeptide immunized group

Time	Horse	Mean response (cpm)a
		Gag 221-245	Gag 250-269	Gag 13-32	Pol 326-347	Pol 704-719	Pol 704-Env 195	EnvPV 195-206	Ana-P16a	PWM	Medium alone
Pre-immunization	H637	1,463	2,276	489	7,154	3740	ND	2,764	2,602	60,650	1,626
	H640	429	663	156	312	2,184	ND	1,599	507	58,695	390
	H641	224	784	364	252	245	ND	98	175	63,182	70
	H646	1,479	789	592	296	1,578	ND	1,676	592	65,667	986
	H651	285	110	613	131	1,182	ND	263	175	54,458	219
Post-immunization	H637	3,658	11,083	1,310	7,426	7,207	6,770	983	710	24,133	546
	H640	25,465	1,978	3,175	3,263	2,104	4,712	340	340	26,397	126
	H641	8,400	7,207	2,047	2,153	1,998	1,736	97	87	20,205	97
	H646	2,391	3,959	941	1,999	902	1,764	510	745	24,696	392
	H651	2,988	2,699	2,699	1,735	868	2,313	1,157	771	29,306	964
1 wk after viral	H637	11,316	21,771	5,675	15,493	4,885	14,809	1,381	531	34,373	118
challenge	H640	34,707	7,216	5,151	11,022	4,395	9,100	73	118	27,882	91
	H641	13,339	25,704	2,033	5,994	5,566	6,136	202	55	25,355	92
	H646	10,852	8,214	2,738	5,254	3,848	6,142	1,184	3,034	48,470	740
	H651	11,998	8,275	4,816	4,959	3,905	5,472	86	247	27,465	95
3 wk after viral	H637	15,609	19,584	339	13,794	8,083	8,881	605	1,236	29,500	242
challenge	H640	27,293	13,409	983	11,697	6,055	13,060	634	380	37,089	317
	H641	12,245	9,248	1,581	11,461	2,917	1,269	797	540	41,917	135
	H646	3004	12,017	2,170	7,010	3,839	9,847	1,836	3,004	34,715	1,669
	H651	4,894	9,853	1,288	7,342	3,091	6,054	1,352	1,610	38,318	644

^aThe values are mean counts per minute of four replicates of PBMC stimulated with either 10 μg/ml of peptide or 2.5 μg/ml PWM. The last column contains the mean counts per minute for medium alone. Peptide responses in boldface were significant positive responses, defined as a mean counts per minute minus mean counts per minute with medium alone of ≥1,000 and also an SI ≥3 (neither calculation is shown in the table). ND, not done.