Mycobacterium tuberculosis Rv1419 encodes a secreted 13 kDa lectin with immunological reactivity during human tuberculosis

Eur J Immunol. 2010 Mar;40(3):744-53. doi: 10.1002/eji.200939747.

Abstract

In this study, we have identified a secreted 13 kDa lectin from Mtb (Mtb, Mycobacterium tuberculosis; sMTL-13) by homology search of a non-redundant lectin database. Bioinformatic analysis revealed that sMTL-13 belongs to the ricin-type beta-trefoil family of proteins containing a Sec-type signal peptide present in Mtb complex species, but not in non-tuberculous mycobacteria. Following heterologous expression of sMTL-13 and generation of an mAb (clone 276.B7/IgG1kappa), we confirmed that this lectin is present in culture filtrate proteins from Mtb H37Rv, but not in non-tuberculous mycobacteria-derived culture filtrate proteins. In addition, sMTL-13 leads to an increased IFN-gamma production by PBMC from active tuberculosis (ATB) patients. Furthermore, sera from ATB patients displayed high titers of IgG Ab against sMTL-13, a response found to be decreased following successful anti-tuberculosis therapy. Together, our findings reveal a secreted 13 kDa ricin-like lectin from Mtb, which is immunologically recognized during ATB and could serve as a biomarker of disease treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies, Bacterial / genetics
  • Antibodies, Bacterial / immunology
  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology*
  • Antigens, Bacterial / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology*
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Blotting, Western
  • Humans
  • Immunoglobulin G / immunology
  • Immunohistochemistry
  • Lectins / genetics
  • Lectins / immunology*
  • Lectins / metabolism
  • Molecular Sequence Data
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / immunology*
  • Mycobacterium tuberculosis / metabolism
  • Tuberculosis, Pulmonary / genetics
  • Tuberculosis, Pulmonary / immunology*
  • Tuberculosis, Pulmonary / metabolism

Substances

  • Antibodies, Bacterial
  • Antigens, Bacterial
  • Bacterial Proteins
  • Immunoglobulin G
  • Lectins