Mycobacterium tuberculosis AtsG (Rv0296c), GlmU (Rv1018c) and SahH (Rv3248c) Proteins Function as the Human IL-8-Binding Effectors and Contribute to Pathogen Entry into Human Neutrophils

PLoS One. 2016 Feb 1;11(2):e0148030. doi: 10.1371/journal.pone.0148030. eCollection 2016.

Abstract

Mycobacterium tuberculosis is an extremely successful intracellular pathogen that has evolved a broad spectrum of pathogenic mechanisms that enable its manipulation of host defense elements and its survival in the hostile environment inside phagocytes. Cellular influx into the site of mycobacterial entry is mediated by a variety of chemokines, including interleukin-8 (IL-8), and the innate cytokine network is critical for the development of an adaptive immune response and infection control. Using affinity chromatography, liquid chromatography electrospray ionization tandem mass spectrometry and surface plasmon resonance techniques, we identified M. tuberculosis AtsG arylsulphatase, bifunctional glucosamine-1-phosphate acetyltransferase and N-acetylglucosamine-1-phosphate uridyl transferase (GlmU) and S-adenosyl-L-homocysteine hydrolase (SahH) as the pathogen proteins that bind to human IL-8. The interactions of all of the identified proteins (AtsG, GlmU and SahH) with IL-8 were characterized by high binding affinity with KD values of 6.83x10-6 M, 5.24x10-6 M and 7.14x10-10 M, respectively. Furthermore, the construction of Mtb mutant strains overproducing AtsG, GlmU or SahH allowed determination of the contribution of these proteins to mycobacterial entry into human neutrophils. The significantly increased number of intracellularly located bacilli of the overproducing M. tuberculosis mutant strains compared with those of "wild-type" M. tuberculosis and the binding interaction of AtsG, GlmU and SahH proteins with human IL-8 may indicate that these proteins participate in the modulation of the early events of infection with tubercle bacilli and could affect pathogen attachment to target cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Adhesion / genetics
  • Bacterial Adhesion / immunology
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology
  • Bacterial Proteins / metabolism*
  • Disease Models, Animal
  • Female
  • Humans
  • Immune Sera / immunology
  • Interleukin-8 / metabolism*
  • Mice
  • Mutation
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / immunology
  • Mycobacterium tuberculosis / metabolism*
  • Neutrophils / microbiology*
  • Protein Binding
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Tuberculosis / immunology
  • Tuberculosis / microbiology

Substances

  • Bacterial Proteins
  • Immune Sera
  • Interleukin-8
  • Recombinant Proteins

Grants and funding

This work was supported by the National Science Centre (UMO-2011/01/M/NZ6/01764), Poland for JD. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.