Mycobacterial ESAT-6 protein enhances mouse IFN-gamma responses to Mycoplasma hyopneumoniae P71 protein

J Interferon Cytokine Res. 2002 Jul;22(7):807-13. doi: 10.1089/107999002320271404.


Type 1 immune responses play an important role in the resolution of diseases with infectious or oncogenic etiologies. Vaccines for production animals frequently target humoral immune responses and are often ineffective in protecting against disease. In order to shift the immune response more toward cellular immunity (i.e., type 1 response), we tested the ability of a mycobacterial protein, early secretory antigenic target (ESAT-6), to enhance interferon-gamma (IFN-gamma) secretion during the recall response with a second antigen. The Mycoplasma hyopneumoniae membrane protein P71 was used as a test antigen in murine vaccination studies. The ESAT-6 open reading frame (ORF) was fused to DNA encoding P71 to produce a recombinant protein that was used to immunize BALB/c mice. Control mice immunized with P71 alone demonstrated a splenic response characterized by release of interleukin-10 (IL-10) and a balanced antigen-specific IgG1/IgG2a antibody response. The presence of ESAT-6 as a fusion partner with P71 during immunization, however, resulted in an enhanced P71-specific IFN-gamma response, decreased release of IL-10, and significantly greater (p < 0.05) IgG2a antibody levels in comparison to immunizing with P71 alone. These results demonstrate that ESAT-6 can modify the profile of an immunologic response to an accompanying immunogen.

Publication types

  • Comparative Study

MeSH terms

  • Adjuvants, Immunologic
  • Animals
  • Antibodies, Bacterial / biosynthesis
  • Antibodies, Bacterial / blood
  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology
  • Antigens, Bacterial / pharmacology*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology*
  • Female
  • Immunization
  • Immunoglobulin G / biosynthesis
  • Immunoglobulin G / blood
  • Interferon-gamma / biosynthesis
  • Interferon-gamma / metabolism*
  • Interleukin-10 / biosynthesis
  • Interleukin-10 / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / immunology*
  • Mycoplasma / genetics
  • Mycoplasma / immunology*
  • Open Reading Frames / genetics
  • Recombinant Fusion Proteins / immunology
  • Specific Pathogen-Free Organisms
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocyte Subsets / metabolism*
  • Th1 Cells / immunology
  • Th1 Cells / metabolism


  • Adjuvants, Immunologic
  • Antibodies, Bacterial
  • Antigens, Bacterial
  • Bacterial Proteins
  • ESAT-6 protein, Mycobacterium tuberculosis
  • Immunoglobulin G
  • Membrane Proteins
  • Recombinant Fusion Proteins
  • p71 membrane protein, Mycoplasma hyopneumoniae
  • Interleukin-10
  • Interferon-gamma