An intact signal peptide on dengue virus E protein enhances immunogenicity for CD8+ T cells and antibody when expressed from modified vaccinia Ankara

Abstract

Dengue is a global public health concern and this is aggravated by a lack of vaccines or antiviral therapies. Despite the well-known role of CD8(+) T cells in the immunopathogenesis of Dengue virus (DENV), only recent studies have highlighted the importance of this arm of the immune response in protection against the disease. Thus, the majority of DENV vaccine candidates are designed to achieve protective titers of neutralizing antibodies, with less regard for cellular responses. Here, we used a mouse model to investigate CD8(+) T cell and humoral responses to a set of potential DENV vaccines based on recombinant modified vaccinia virus Ankara (rMVA). To enable this study, we identified two CD8(+) T cell epitopes in the DENV-3 E protein in C57BL/6 mice. Using these we found that all the rMVA vaccines elicited DENV-specific CD8(+) T cells that were cytotoxic in vivo and polyfunctional in vitro. Moreover, vaccines expressing the E protein with an intact signal peptide sequence elicited more DENV-specific CD8(+) T cells than those expressing E proteins in the cytoplasm. Significantly, it was these same ER-targeted E protein vaccines that elicited antibody responses. Our results support the further development of rMVA vaccines expressing DENV E proteins and add to the tools available for dengue vaccine development.

A new immunization and treatment strategy for mouse mammary tumor virus (MMTV) associated cancers

“…This also includes modulation of the host immune response, as in the case of Human Cytomegalovirus (HCMV), where the signal peptide (through regulation of cell surface expression of two NK cell ligands) differentially affected two distinct NK cell evasion pathways [38]. A recent publication [39], reported that an intact signal peptide on dengue virus E protein (ER-targeted E protein) enhanced the immunogenicity for CD8 + T cells and generated superior antibody responses when expressed from the immunogenic recombinant vaccine vector Vaccinia Ankara.…”

The Evolution of Poxvirus Vaccines

“…HBs clinical [321] 30 CTL and 16 HTL epitopes preclinical [322] Hepatitis C NS3, NS4 and NS5B (genotype 1b) preclinical and clinical [323,324] E1 and E2 (genotype 1b) preclinical [325] C, E1 and E2, p7, NS2, NS3, NS4A, NS4B, NS5A and NS5B (genotype 1a) preclinical [326] Chikungunya C, E3, E2, 6K and E1 preclinical [327] E3 and E2 preclinical [328] E3-E2, 6K-E1 or E3-E2-6K-E1 preclinical [329] Dengue Envelope (Dengue type 2 virus) preclinical [330] Envelope (Dengue type 3 virus) preclinical [331] Ebola GP (Zaire and Sudan strains) preclinical [332] CCHF GP preclinical [333] SARS Spike protein preclinical [334][335][336][337] Spike or nucleocapsid proteins preclinical [338] Nucleocapsid preclinical [339] MERS Spike protein preclinical [340] RSV F or G glycoprotein preclinical [342][343][344] Rift valley fever Gn/Gc GP preclinical [345,346] Rabies Glycoprotein preclinical [347] JEV Membrane (prM) and envelope (E) proteins (Korean strain) preclinical [348][349][350] B cell, CTL and Th multiple linear epitopes (SA14 strain) preclinical [351] Measles HA preclinical [352] F and HA preclinical [94,353] CMV Soluble GP B (gB) preclinical [354] UL55 (surface glycoprotein), UL83 (tegument protein) and UL123/e4 (nuclear protein) preclinical [355] pp65 (tegument protein) and CMV immediate early gene IE1 preclinical [356] pp65-2, gB and IE1 (Rhesus CMV) preclinical…”

Computational analysis of perturbations in the post-fusion Dengue virus envelope protein highlights known epitopes and conserved residues in the Zika virus

“…Barring Ser7, all residues are completely conserved in ZIKV/DENV1-4 ( Figure 2 ). A N-terminal peptide (DENV3,4-12 VGVGNRDFV) that enhances immunogenicity for CD8+ T cells when expressed from modified vaccinia Ankara includes Phe11, Ser7 and Arg9 39 . Arg9 and Glu13 are also epitopes of other antibodies 35 .…”

“…and post-fusion 12 DENV2-E protein. These residues are overwhelmingly conserved in ZIKV and all DENV serotypes ( Figure 2 ), and are known epitopes 23 , 35 , 39 – 43 . While perturbation was found to be a good predictor of an epitope, not all epitopes are perturbed.…”

“…Firstly, a quantitative analysis of spatial and electrostatic perturbation in the pre 37 and post-fusion 12 DENV-2 E proteins was done using MEPP 38 . This revealed that highly perturbed residues are overwhelmingly conserved, and also epitopes of known neutralizing antibodies 23 , 35 , 39 – 43 . Characterization of α -helices in E-proteins using techniques (PAGAL 44 , 45 ) previously applied to the Ebola virus 46 ) revealed that α 1 in ZIKV-E and DENV-E proteins is not conserved in the sequence space.…”