HtpG-A Major Virulence Factor and a Promising Vaccine Antigen against Mycobacterium tuberculosis

Biomolecules. 2024 Apr 11;14(4):471. doi: 10.3390/biom14040471.

Abstract

Tuberculosis (TB) is the leading global cause of death f rom an infectious bacterial agent. Therefore, limiting its epidemic spread is a pressing global health priority. The chaperone-like protein HtpG of M. tuberculosis (Mtb) is a large dimeric and multi-domain protein with a key role in Mtb pathogenesis and promising antigenic properties. This dual role, likely associated with the ability of Heat Shock proteins to act both intra- and extra-cellularly, makes HtpG highly exploitable both for drug and vaccine development. This review aims to gather the latest updates in HtpG structure and biological function, with HtpG operating in conjunction with a large number of chaperone molecules of Mtb. Altogether, these molecules help Mtb recovery after exposure to host-like stress by assisting the whole path of protein folding rescue, from the solubilisation of aggregated proteins to their refolding. Also, we highlight the role of structural biology in the development of safer and more effective subunit antigens. The larger availability of structural information on Mtb antigens and a better understanding of the host immune response to TB infection will aid the acceleration of TB vaccine development.

Keywords: chaperone; folding; protein structure; tuberculosis; vaccine.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Bacterial* / chemistry
  • Antigens, Bacterial* / immunology
  • Bacterial Proteins* / chemistry
  • Bacterial Proteins* / immunology
  • Humans
  • Molecular Chaperones / chemistry
  • Molecular Chaperones / immunology
  • Molecular Chaperones / metabolism
  • Mycobacterium tuberculosis* / immunology
  • Tuberculosis / immunology
  • Tuberculosis / microbiology
  • Tuberculosis / prevention & control
  • Tuberculosis Vaccines* / immunology
  • Virulence Factors* / chemistry
  • Virulence Factors* / immunology

Substances

  • Antigens, Bacterial
  • Virulence Factors
  • Tuberculosis Vaccines
  • Bacterial Proteins
  • Molecular Chaperones

Grants and funding

A.R. acknowledges funding from PRIN 2022 PNRR “NextGen-erationEU”, project Prot. P2022JE8FN—FIGHT_TB “FIndinG High-grade anTigens towards an innovative TB vaccines” —D.D. MUR Prot. n. 0001363 of 1 September 2023. V.N. and R.B. were funded by the project INF-ACT “One Health Basic and Translational Research Actions addressing Unmet Needs on Emerging Infectious Diseases PE00000007”, PNRR Mission 4, EU “NextGen-erationEU”—D.D. MUR Prot. n. 0001554 of 11 October 2022.