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Vaccine administration and PBMC collection were performed after written informed consent in accordance with the Declaration of Helsinki

Vaccine administration and PBMC collection were performed after written informed consent in accordance with the Declaration of Helsinki. proteome using a matrix of overlapping peptide pools demonstrated that TAK-003 elicits a broad response directed across the DENV-2 proteome, with focused reactivity against NS1 and NS3. We conclude that, as measured by an IFN- ELISPOT assay, a single dose of TAK-003 generates potent T cell-mediated immunity which is durable in magnitude and breadth through 4 months post-vaccination. (2). DENV is a single-stranded positive sense RNA virus that belongs to the family Flaviviridae, genus experimental models and adoptive transfer animal models (5, 10, 22C24), although these models have not translated to human disease, and definitive evidence of ADE in humans has been elusive. In light of gaps in knowledge about the relationship between humoral CP-724714 immunity and outcome of DENV infection, there is the need to investigate the contribution of other immune response parameters, particularly cell mediated immunity (CMI)especially T cell-mediated immunityto the outcome of DENV infection (25C27). Recent studies suggest that the expression of certain HLA allelesand the nature/magnitude of the T cell responses they facilitatecorrespond to susceptibility or resistance to disease, and potential DENV vaccine efficacy (28, 29). Human T cell responses to DENV were first characterized over 30 years ago, and many ITGA9 of the general principles originally described have remained consistent (25, 27). Infection with one DENV induces both CD4+ and CD8+ memory T cells specific for DENV epitopes, with a small number of epitopes dominating the response in each individual (28, 29). Epitopes are located throughout the DENV polyprotein, although several regions, especially non-structural protein 3 (NS3) and the capsid protein, appear to have a concentration of immunodominant epitopes targeted by CD8+ T cells and CD4+ T cells, respectively (30C32). The amino acid homology across the four DENV serotypes varies for each epitope; however, most epitopes are well-conserved among strains within the same serotype and differ at relatively few positions (1C3 of 9 residues) from the corresponding epitopes of other DENV serotypes (and other flaviviruses) (33, 34). As is observed in DENV-elicited humoral immunity, the overall T cell response induced by a primary DENV infection is strongest to the serotype to which the subject was exposed, but variable degrees of cross-reactivity are usually observed to one or more of the other serotypes (35, 36). TAK-003 is a tetravalent, recombinant DENV vaccine candidate based on the attenuated PDK-53 DENV-2 virus strain that is currently undergoing phase III testing with a two-dose vaccine schedule (37). The PDK-53 strain was initially derived from the WT DENV-2 16,681 isolate, and attenuated by serial passage in primary dog kidney (PDK) cells. Key attenuation mutations have been identified in the 5 UTR, NS1, and NS3 regions of the viral genome (38). This DENV-2 backbone virus was previously shown to be safe, immunogenic, and capable of stimulating durable cellular and humoral immunity (39C43). To create a vaccine capable of eliciting an immune response against all four DENV serotypes, recombinant viruses were created using the PDK-53 DENV-2 genetic backbone and the prM and E genes from DENV-1,-3, and-4 (44). The tetravalent TAK-003 formulation was also shown to be safe, immunogenic, and protective against lethal DENV challenge in both rodent models and non-human primates (37, 44, 45). In clinical trials, TAK-003 is CP-724714 well-tolerated and capable of generating significant humoral immunity against all four DENV serotypes in both children and adults, regardless of previous CP-724714 dengue serostatus (46C51). Previous analysis of the T cell cytokine production profile generated by TAK-003 administration in flavivirus-na?ve recipients demonstrated that this product generates a pool of NS1, NS3, and NS5 reactive CD8+ T cells capable of producing IFN-, TNF-, and to a lesser extent IL-2 upon restimulation (52). However, the CP-724714 magnitude, stability, and antigen specificity of cell-mediated immunity generated in response to a TAK-003 vaccination has not previously been described in detail. In this study, we demonstrate that a single dose of TAK-003 elicits a potent T cell response CP-724714 as assessed by IFN- ELISPOT 28- and 120-days post vaccination. Reactivity against the structural genes of DENV-1,-2,-3, and-4 contained within the vaccine formulation was.