Table I. Amino acid sequences and allelic identity of peptides used to study in vitro antagonism.

For the ELISPOT assays, two MSP1 derived peptides, M7* (3D7) and M8* (Wellcome) were synthesized. These peptides are identical to those used by Lee et al. (M7, M8) and were described as non-conserved sequenced paired APL antagonists (38). These epitopes were present in two of the 20mer peptides previously used in the MSP1 vaccine clinical trials (24): M92 (containing M7*) and M53 (containing M8* with one αα change, Y-V indicated in bold). Additionally two more peptides from this trial M85 and M48 were used. These were similarly dimorphic and contained African epitopes shown to be immunogenic (39) but have not previously been tested for antagonism. For both pairs, the 3D7 or Wellcome peptides were made up individually and in a combined pool, with each peptide at a concentration of 10μg/mL. Final concentration in the ELISPOT assay was 5μg/mL.

Peptide Name	Strain	Sequence
M7*	3D7	D Y L I N L K A K I N D C
M8*	Wellcome	L F V I H L E A K V L N V
M92	3D7	L V N K I D D Y L I N L K A K I N D C N
M53	Wellcome	N D K I D L F V I H L E A K V L N Y T Y
M85	3D7	F A Q E G I S Y Y E K V L A K Y K D D L
M48	Wellcome	A N D V L G Y Y K I L S E K Y K S D L D