Identification and localization of minimal MHC-restricted CD8+ T cell epitopes within the Plasmodium falciparum AMA1 protein

Table 4 ELISpot IFN-γ activity of AMA1 15-mer peptides after depletion of CD4+ and CD8+ T cells

Vol.	Pool	Peptide number*	Sequence	Control depletion sfc/m	CD4 depletion sfc/m (%)	CD8 depletion sfc/m (%)
001	Ap1			155	222 (+43%)	55 (-65%)
		1	LLSAFEFTYMINFGR	85	58 (-32%)	37 (-56%)
		5	KEYEYPLHQEHTYQQ	72	168 (+133%)	17 (-76%)
		16	TSNNEVVVKEEYDE	103	252 (+148%)	13 (-88%)
002	Ap1			187	148 (-21%)	5 (-97%)
		3	INEHREHPKEYEYPL	185	152 (-18%)	11 (-94%)
005	Ap1			267	173 (-35%)	11 (-96%)
		3	INEHREHPKEYEYPL	233	145 (-37%)	0 (-100%)
	Ap4			273	117 (-57%)	0 (-100%)
		7	LMSPMTLDEMRHFYK	204	137 (-32%)	1 (-100%)
012	Ap10			48	37 (-23%)	0 (-100%)
		16	TSNNEVVVKEEYDE	79	90 (+14%)	0 (-100%)

The percent change in ELISpot activity is shown after depletion of CD4+ or CD8+ T cells. Depletion of CD8+ T cells reduced ELISpot activity by 56-100%, whereas CD4+ T cell depletion reduced activity by no more than 57%. Although this suggested that the primary epitopes within these peptide pools and 15-mers are CD8+ T cell epitopes, some peptides may also contain CD4+ T cell epitopes. v001 and v012 showed an increase in ELISpot activity after CD4+ T cell depletion that may indicate the removal of regulatory T cells that had been suppressing CD8+ T cell activity.
* See last column of Table 3.

ISSN: 1475-2875