Development of diagnostic reagents to differentiate between Mycobacterium bovis BCG vaccination and M. bovis infection in cattle

Clin Diagn Lab Immunol. 1999 Sep;6(5):675-82.

Abstract

In Great Britain a recent independent scientific review for the government has concluded that the development of a cattle vaccine against Mycobacterium bovis holds the best long-term prospect for tuberculosis control in British herds. A sine qua non for vaccination is the development of a complementary diagnostic test to differentiate between vaccinated animals and those infected with M. bovis so that test-and-slaughter-based control strategies can continue alongside vaccination. In order to assess the feasibility of developing a differential diagnostic test for a live vaccine, we chose M. bovis BCG Pasteur as a model system. Recombinant forms of antigens which are expressed in M. bovis but not, or only at low levels, in BCG Pasteur (ESAT-6, MPB64, MPB70, and MPB83) were produced. These reagents were tested either alone or in combination by using peripheral blood mononuclear cells from M. bovis-infected, BCG-vaccinated, and Mycobacterium avium-sensitized calves. All four antigens induced in vitro proliferation and gamma interferon responses only in M. bovis-infected animals. A cocktail composed of ESAT-6, MPB64, and MPB83 identified infected animals but not those vaccinated with BCG. In addition, promiscuous T-cell epitopes of ESAT-6, MPB64, and MPB83 were formulated into a peptide cocktail. In T-cell assays with this peptide cocktail, infected animals were identified with frequencies similar to those obtained in assays with the protein cocktail, while BCG-vaccinated or M. avium-sensitized animals did not respond. In summary, our results suggest that peptide and protein cocktails can be designed to discriminate between M. bovis infection and BCG vaccination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Bacterial / chemistry
  • Antigens, Bacterial / immunology
  • BCG Vaccine / chemistry
  • BCG Vaccine / immunology*
  • Biomarkers
  • Cattle
  • Diagnosis, Differential
  • Interferon-gamma / immunology
  • Interleukin-2 / analysis
  • Interleukin-2 / immunology
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / microbiology
  • Lymphocyte Activation / drug effects
  • Lymphocyte Activation / immunology
  • Molecular Sequence Data
  • Mycobacterium Infections / diagnosis*
  • Mycobacterium Infections / immunology
  • Mycobacterium avium / immunology
  • Mycobacterium bovis / immunology
  • Mycobacterium bovis / isolation & purification*
  • Peptide Fragments / chemistry
  • Peptide Fragments / immunology
  • Peptide Fragments / pharmacology
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / immunology
  • Recombinant Proteins / pharmacology
  • Tuberculin Test
  • Tuberculosis, Bovine / diagnosis*
  • Tuberculosis, Bovine / immunology
  • Tuberculosis, Bovine / prevention & control*

Substances

  • Antigens, Bacterial
  • BCG Vaccine
  • Biomarkers
  • Interleukin-2
  • Peptide Fragments
  • Recombinant Proteins
  • Interferon-gamma