Design and Characterization of a Multistage Peptide-Based Vaccine Platform to Target Mycobacterium tuberculosis...

Area of Science:

• Immunology
• Vaccinology
• Molecular Biology

Background:

• Tuberculosis (TB) vaccine development faces challenges due to Mycobacterium tuberculosis (Mtb) complex immunopathology, impacting efficacy against active and latent stages.
• Multistage vaccines, incorporating antigens from both pathogen phases, are a promising strategy, supported by the current TB vaccine clinical pipeline.

Purpose of the Study:

• To design and characterize a novel multistage peptide-based vaccine platform for tuberculosis.
• To evaluate the immunogenicity and efficacy of a palmitoylated multiepitope conjugate (Pal-CGHP) compared to a peptide pool (PM1).

Main Methods:

• Selected CD4+ and CD8+ T cell epitopes (CFP10, GlfT2, HBHA, PPE15) for a multistage vaccine platform.
• Synthesized a multiepitope conjugate (Ac-CGHP) using thiol-maleimide chemoselective ligation.
• Assessed cellular uptake and immunogenicity of Pal-CGHP in human and murine antigen-presenting cells and in BALB/c mice.

Main Results:

• The peptide pool (PM1) triggered a T cell response in Mtb-sensitized PBMCs.
• The palmitoylated conjugate (Pal-CGHP) demonstrated enhanced cellular uptake and improved immunogenicity.
• Pal-CGHP induced significantly higher T cell proliferation and production of IFNγ and TNFα compared to PM1 in mice.

Conclusions:

• The designed peptide-based vaccine platform shows potential for inducing robust T cell responses against Mtb.
• Pal-CGHP represents a promising candidate for a novel, effective tuberculosis vaccine targeting both active and latent stages.
• The study highlights the structure-activity relationship and benefits of palmitoylation for enhanced vaccine efficacy.