human MHC class II molecule DR and is effective in mice, also augmented CD8 + T cell effector functions by inducing CD4 + T helper cells [30] [31] [32] [33] [34] [35] . Both CD4 + and CD8 + epitopes were targeted in order to drive a protective immune response [34, 35] . Adjuvanting antigens contributes to the success of vaccination. An example herein is that 3-deacylated monophosphoryl lipid A(GLA-SE), a detoxified derivative of the lipopolysaccharide (LPS) from Salmonella minnesota R595 was a potent adjuvant. This GLA-SE is a novel adjuvant which was formulated in an emulsion [21] [22] [23] [24] . This is a Toll-like receptor 4 (TLR4) agonist that is a potent activator of Th1 responses [21] [22] [23] [24] . It has been used as an adjuvant in human vaccine trials for several infectious disease and malignancy indications. It has been very effective as an adjuvant providing CD4 + T cell help for immunizations against other protozoan infections such as leishmaniasis [21] [22] [23] [24] . In our study, a robust response was observed when GLA-SE was included in preparation for immunization of mice. Pam 2 Cys (S-[2,3-bis(palmitoyloxy)propyl] cysteine) is a lipid component of macrophage-activating lipopeptide. Pam 2 Cys binds to and activates dendritic cells by engagement of Toll-like receptor 2 (TLR-2) [24] . Tolllike receptors (TLRs) function as pattern-recognition receptors in mammals [36] . We have found that both TLR2 and TLR4 receptors participate in human host defense against T. gondii infection through their activation by GPIs and GIPLs(Melo, Hargrave, Miller, Blackwell, Gazinelli, McLeod et al, in preparation, 2010). TLR2 and TLR4 likely work together with other MyD88-dependent receptors, including other TLRs, to elicit an effective host response against T. gondii infection [36] . In our study, there was a slightly more robust response observed when Pam 2 Cys was co-administered for some peptides, but not all of them.