Bioinformatics analysis and immunogenicity assessment of the novel
multi-stage DNA vaccine W541 against Mycobacterium tuberculosis
Abstract
Background: Vaccination is one of the effective measures to prevent
latent tuberculosis infection (LTBI) from developing into active
tuberculosis (TB). Applying bioinformatics methods to pre-evaluate the
biological characteristics and immunogenicity of vaccines can improve
the efficiency of vaccine development. Objectives: To evaluate the
immunogenicity of tuberculosis vaccine W541 and explore the application
of bioinformatics technology in tuberculosis vaccine research. Methods:
This study concatenated the immunodominant sequences of Ag85A, Ag85B,
Rv3407, and Rv1733c to construct the W541 DNA vaccine. Then,
bioinformatics methods were used to analyze the physicochemical
properties, antigenicity, allergenicity, toxicity, and population
coverage of the vaccine, identify its epitopes, and perform molecular
docking with MHC alleles and Toll-like receptor 4 (TLR4) of the host.
Finally, the immunogenicity of the vaccine was evaluated through animal
experiments. Results: the W541 vaccine protein is a soluble cytoplasmic
protein with a half-life of 1.1 hours in vivo and an instability index
of 45.37. It has good antigenicity and wide population coverage without
allergenicity and toxicity. It contains 138 HTL epitopes, 73 CTL
epitopes, 8 linear and 14 discontinuous epitopes of B cells, and a
strong affinity for TLR4. Immune simulations showed it could effectively
stimulate innate and adaptive immune responses. Animal experiments have
confirmed that the W541 DNA vaccine could effectively activate the Th1-
and Th17-type immune responses, producing high levels of IFN-γ and
IL-17A, but could not significantly increase antibody levels.
Conclusion: the W541 DNA vaccine can induce strong cellular immune
responses. However, further optimization of the vaccine design is needed
to make the expressed protein more stable in vivo. Bioinformatics
analysis could reveal vaccines’ physicochemical and immunological
information, which is critical for guiding vaccine design and
development.