Deinococcus Mn²⁺-peptide complex: A novel approach to alphavirus vaccine development

Area of Science:

• Virology
• Vaccinology
• Radiation Biology

Background:

• Chikungunya virus (CHIKV) and Venezuelan equine encephalitis virus (VEEV) are significant global health concerns with no current FDA-approved vaccines.
• CHIKV outbreaks are frequent in Asia, Europe, and the Americas, while VEEV poses bioweapon risks.
• Classical gamma-irradiation for vaccine inactivation can damage viral surface proteins, reducing immunogenicity.

Purpose of the Study:

• To develop novel inactivated vaccines for VEEV and CHIKV using a gamma-radiation approach combined with a synthetic Mn-decapeptide-phosphate complex (MnDpPi).
• To evaluate the safety and efficacy of MnDpPi-enhanced gamma-inactivated VEEV and CHIKV vaccines in preclinical models.
• To demonstrate the potential of this method for rapid and cost-effective vaccine development against various pathogens.

Main Methods:

• Utilized gamma-radiation in conjunction with MnDpPi, a complex mimicking antioxidants from Deinococcus radiodurans, for virus inactivation.
• Applied supra-lethal doses of gamma-rays (50,000Gy) to VEEV and CHIKV in the presence of MnDpPi.
• Assessed viral inactivation, safety in neonatal mice, epitope preservation, and protective efficacy upon immunization in mouse models.

Main Results:

• Gamma-irradiation of VEEV and CHIKV with MnDpPi preserved substantial viral epitopes, even at high radiation doses.
• The inactivated viruses were confirmed to be completely inactivated and safe for in vivo use.
• Immunization with VEEV inactivated in the presence of MnDpPi demonstrated significantly improved protective efficacy in mice.

Conclusions:

• The MnDpPi-based gamma-inactivation method offers a promising strategy for developing safe and effective vaccines against VEEV and CHIKV.
• This approach overcomes limitations of traditional gamma-irradiation by protecting viral epitopes from oxidative damage.
• The technique is adaptable for rapid and cost-effective vaccine production against a wide range of pathogens.