Induction of Broad Cytotoxic T Cells by Protective DNA Vaccination Against Marburg and Ebola

Abstract

Marburg and Ebola hemorrhagic fevers have been described as the most virulent viral diseases known to man due to associative lethality rates of up to 90%. Death can occur within days to weeks of exposure and there is currently no licensed vaccine or therapeutic. Recent evidence suggests an important role for antiviral T cells in conferring protection, but little detailed analysis of this response as driven by a protective vaccine has been reported. We developed a synthetic polyvalent-filovirus DNA vaccine against Marburg marburgvirus (MARV), Zaire ebolavirus (ZEBOV), and Sudan ebolavirus (SUDV). Preclinical efficacy studies were performed in guinea pigs and mice using rodent-adapted viruses, whereas murine T-cell responses were extensively analyzed using a novel modified assay described herein. Vaccination was highly potent, elicited robust neutralizing antibodies, and completely protected against MARV and ZEBOV challenge. Comprehensive T-cell analysis revealed cytotoxic T lymphocytes (CTLs) of great magnitude, epitopic breadth, and Th1-type marker expression. This model provides an important preclinical tool for studying protective immune correlates that could be applied to existing platforms. Data herein support further evaluation of this enhanced gene-based approach in nonhuman primate studies for in depth analyses of T-cell epitopes in understanding protective efficacy.

Multivalent TB vaccines targeting the esx gene family generate potent and broad cell-mediated immune responses superior to BCG

“…We have recently reported that highly optimized DNA vaccination with adaptive electroporation (EP) can elicit a strong Th1 and CD8 T cells, cellular immunity necessary to prevent diseae after exposure with Mtb, 28,[35][36][37][38][39] thus suggesting it as a promising platform for the development of a TB vaccine. Although a few studies have shown that EP can enhance immune responses to a DNA TB vaccine, [40][41][42] no current studies have tested this improved optimized DNA platform in the TB animal model.…”

“…28 Negative control mice received 3 equivalent doses of pVAX, and positive control mice were vaccinated subcutaneously with a single dose of 10 6 CFU BCG Statens Serum Institut (SSI) as previously described. 9 The BCG SSI was provided by Aeras.…”

“…28 Briefly, splenocytes were added to a 96-well plate (1 × 10 6 /well) and were stimulated with their respective esx pooled peptides for 5-6 h at 37C/5% CO 2 in the presence of Protein Transport Inhibitor Cocktail (Brefeldin A and Monensin) (ebioscience) according to the manufacturers instructions. The Cell Stimulation Cocktail (plus protein transport inhibitors) (phorbol 12-myristate 13-acetate (PMA), ionomycin, brefeldin A and monensin) (ebioscience) was used as a positive control and R10 media as a negative control.…”

“…28 For mice vaccinated only with BCG SSI, spleens were harvested 6 wk after vaccination. Briefly, spleens were collected in RPMI 1640 medium (supplemented with 10% FBS, 1X AntibioticAntimycotic, and 1X β-ME) and splenocytes were isolated by mechanical disruption of the spleen using a Stomacher machine (Seward Laboratory Systems).…”

Effectiveness evaluation of dendritic cell immunotherapy for osteosarcoma on survival rate and in vitro immune response

“…These are generated through a conjugation between DCs and tumor antigens for the purpose of activating the specific anti-tumor immune response. In addition, the potentiation of immune cell activity by co-incubation of DCs with other immune cells facilitates tumor toxicity (Shedlock et al, 2013;Simor et al, 2013;Shi et al, 2014).…”