Predicting and analyzing interactions between Mycobacterium tuberculosis and its human host

PLoS One. 2013 Jul 2;8(7):e67472. doi: 10.1371/journal.pone.0067472. Print 2013.

Abstract

The outcome of infection by Mycobacterium tuberculosis (Mtb) depends greatly on how the host responds to the bacteria and how the bacteria manipulates the host, which is facilitated by protein-protein interactions. Thus, to understand this process, there is a need for elucidating protein interactions between human and Mtb, which may enable us to characterize specific molecular mechanisms allowing the bacteria to persist and survive under different environmental conditions. In this work, we used the interologs method based on experimentally verified intra-species and inter-species interactions to predict human-Mtb functional interactions. These interactions were further filtered using known human-Mtb interactions and genes that are differentially expressed during infection, producing 190 interactions. Further analysis of the subcellular location of proteins involved in these human-Mtb interactions confirms feasibility of these interactions. We also conducted functional analysis of human and Mtb proteins involved in these interactions, checking whether these proteins play a role in infection and/or disease, and enriching Mtb proteins in a previously predicted list of drug targets. We found that the biological processes of the human interacting proteins suggested their involvement in apoptosis and production of nitric oxide, whereas those of the Mtb interacting proteins were relevant to the intracellular environment of Mtb in the host. Mapping these proteins onto KEGG pathways highlighted proteins belonging to the tuberculosis pathway and also suggested that Mtb proteins might use the host to acquire nutrients, which is in agreement with the intracellular lifestyle of Mtb. This indicates that these interactions can shed light on the interplay between Mtb and its human host and thus, contribute to the process of designing novel drugs with new biological mechanisms of action.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Bacterial Proteins
  • Host-Pathogen Interactions*
  • Humans
  • Macrophages / metabolism
  • Macrophages / microbiology
  • Metabolic Networks and Pathways / genetics*
  • Molecular Sequence Annotation
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / metabolism*
  • Nitric Oxide / biosynthesis
  • Protein Interaction Mapping*
  • Protein Interaction Maps
  • Tuberculosis, Pulmonary / metabolism*
  • Tuberculosis, Pulmonary / microbiology

Substances

  • Bacterial Proteins
  • Nitric Oxide

Grants and funding

This work has been supported by the National Research Foundation (NRF) and the Claude Leon Foundation Postdoctoral Fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.