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

Table 6 ELISpot IFN-γ activity of the original peptide pool and the derived 8-10-mer epitopes

Epitope number	Sequence	HLA supertype	sfc/m	Pool	sfc/m	Vol.
E1	FEFTYMINF	B44	121^4m	Ap1	133^4m	001
E2	SDVYRPINEH	B44	114^4m	Ap1	133^4m	001
E3	HPKEYEYPL	B08	69^4m	Ap1	96^4m	002
E4	YEYPLHQEH	B44	222^4m	Ap1	133^4m	001
E5	YLKDGGFAF	B08	9^10d	Ap4	46^10d	005
E6	TLDEMRHFYK	A01	51^4m	Ap4	114^4m	002
E7	MRHFYKDNKY	A01	15^10d	Ap4	46^10d	005
E8	NEFPAIDLF	B44	224^4m	Ap7	200^4m	001
-	-	-	49^7m	Ap7	80^7m	012
E9	KLVFELSA	A02	169^4m	Ap7	200^4m	001
E10	RYKSHGKGY	A01	11^7m	Ap8	108^7m	012
E11	ETQKCEIFNV	A02	21^10m	Ap8	57^10m	008
E12	TQKCEIFNV	A02	172^4m	Ap8	104^4m	001
E13	EIFNVKPTCL	A02	37^10m	Ap8	57^10m	008
E14	NEVVVKEEY	B44	344^4m	Ap10	155^4m	001
-	-	-	104^7m	Ap10	151^7m	012

Synthetic peptide 8-10-mers were tested in ELISpot assay using PBMC collected 10 days (v005), 4 months (v001, v002), 7 months (v012) or 10 months (v008) following immunization (PBMC collected at 1 month were no longer available). Activity was measured as sfc/m. Nine of the 14 epitopes (E1, E2, E3, E4, E6, E8, E9, E12 and E14) were confirmed as positive using the parent peptide pool as controls, in most cases recalling responses equivalent to those recalled by the parent peptide pool (epitope number and sequences in bold). Four of the epitopes (E5, E7, E11, E13) did not meet the 40 sfc/m cut-off but these results were not considered meaningful as the responses of the parent peptide pools were only marginally positive. The parent peptide pool for E10 recalled 108 sfc/m while the responses to the peptide were much lower (11 sfc/m), suggesting that E10 may not be correctly identified. Assays where the parent peptide pool did not exceed the cut-off of 40 sfc/m were not included in the table (see Methods).

ISSN: 1475-2875