Enhanced protective immunity to CSFV E2 subunit vaccine by using IFN-γ as immunoadjuvant in weaning piglets

Area of Science:

• Veterinary Immunology
• Vaccinology
• Virology

Background:

• Classical swine fever virus (CSFV) E2 glycoprotein is a key target for vaccine development.
• Current CSFV E2 subunit vaccines offer incomplete protection in pigs.
• Interferon-gamma (IFN-γ) is a known immune adjuvant with potential to enhance vaccine efficacy.

Purpose of the Study:

• To evaluate the efficacy of porcine interferon-gamma (IFN-γ) as an adjuvant for a CSFV E2 subunit vaccine in pigs.
• To determine if IFN-γ enhances the immunogenicity and protective immunity induced by the CSFV E2 subunit vaccine.

Main Methods:

• Pigs were immunized with either the CSFV E2 subunit vaccine alone or in combination with porcine IFN-γ.
• Humoral immune responses (antibody titers) and cellular immune responses (IFN-γ expression) were measured.
• Vaccine efficacy was assessed by challenging pigs with the CSFV C-strain.

Main Results:

• Porcine IFN-γ did not significantly increase CSFV-specific antibody or neutralizing antibody titers.
• Co-administration of E2 and IFN-γ significantly enhanced CSFV-specific IFN-γ expression, indicating improved cellular immunity.
• The E2 + IFN-γ subunit vaccine conferred complete protection against CSFV challenge, while the E2 vaccine alone provided incomplete protection.

Conclusions:

• Porcine IFN-γ acts as an effective adjuvant, enhancing cellular immune responses to the CSFV E2 subunit vaccine.
• The E2 + IFN-γ subunit vaccine demonstrates potential as a promising marker vaccine for classical swine fever control and eradication.