A Multistage Antigen Complex Epera013 Promotes Efficient and Comprehensive Immune Responses in BALB/c Mice

Area of Science:

• Immunology
• Vaccinology
• Microbiology

Background:

• Tuberculosis (TB) remains a significant global health threat, with adult TB often stemming from latent Mycobacterium tuberculosis (MTB) reactivation.
• Current BCG vaccination strategies are insufficient for controlling the TB pandemic, highlighting the need for improved vaccines.
• Developing new TB vaccines with enhanced safety and long-lasting efficacy is critical for disease prevention and control.

Purpose of the Study:

• To evaluate the immunogenicity and protective efficacy of novel subunit vaccines against MTB infection.
• To compare the immune responses elicited by a recombinant fusion protein (Epera013f) and a protein mixture (Epera013m) against the existing BCG vaccine.
• To assess the potential of Epera013f as a promising candidate for future TB vaccine development.

Main Methods:

• Construction of a single recombinant fusion protein (Epera013f) and a protein mixture (Epera013m) using five immunodominant antigens.
• Formulation of Epera013m and Epera013f with an aluminum adjuvant and administration to BALB/c mice.
• Analysis of humoral and cellular immune responses, and Mycobacterium tuberculosis growth inhibition capacity post-immunization.

Main Results:

• Both Epera013f and Epera013m induced significant immune responses and protective efficacy against H37Rv infection, outperforming BCG.
• Epera013f demonstrated a more comprehensive and balanced immune status, encompassing Th1, Th2, and innate immune responses, compared to Epera013m and BCG.
• The multistage antigen complex Epera013f exhibited substantial immunogenicity and ex vivo protective efficacy against MTB infection.

Conclusions:

• The novel subunit vaccines Epera013f and Epera013m show considerable potential for TB prevention.
• Epera013f elicits a broader and more balanced immune response, suggesting its superiority over Epera013m and BCG.
• Epera013f is a promising candidate for further development as a next-generation TB vaccine.