Immune responses induced by heterologous boosting of recombinant bacillus Calmette-Guerin with Ag85B-ESAT6 fusion protein in levamisole-based adjuvant

Immunol Invest. 2012;41(4):412-28. doi: 10.3109/08820139.2012.658940. Epub 2012 Feb 23.

Abstract

In the present study, we evaluated the effectiveness of a levamisole-based adjuvant (ADL) to enhance the ability of the Ag85B-ESAT6 fusion protein to boost immune responses after primary vaccination with recombinant bacillus Calmette-Guerin (rBCG) in Balb/c mice. The results were compared with that of the control adjuvant formulation of dimethyl dioctadecylammonium bromide (DDA) and monophosphoryl lipid A (MPL), which has previously been shown to induce T-helper type 1 (Th1)-biased responses. Enzyme-linked immunospot (ELISPOT) assay with Ag85B and ESAT6 derived peptides corresponding to CD4+ and CD8+ T cell restricted epitopes and cell surface immunostaining indicated that Ag85B-ESAT6/ADL predominantly triggered activation of CD4+ T cells. Functional CD8+ T cells with interferon (IFN)-γ production or cytotoxicity were undetectable all vaccinated mice. The ADL adjuvant modified T-helper (Th) subtypes by up-regulating multiple signature cytokines. Furthermore, profiles of the immunoglobulin G (IgG) subtypes indicated ADL enhanced the secretion of Th1-associated IgG2a antibodies and decreased the yield of Th2-associated IgG1 subtype. These observations suggest that the ADL adjuvant formulated with a protein booster may induce Th1-biased cellular and humoral immune responses to primary vaccination with a live attenuated bacterial TB vaccine.

MeSH terms

  • Acyltransferases / genetics
  • Acyltransferases / immunology*
  • Adjuvants, Immunologic / pharmacology*
  • Animals
  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology*
  • Antigens, CD / metabolism
  • Antigens, Differentiation, T-Lymphocyte / metabolism
  • BCG Vaccine / immunology*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology*
  • Cytokines / biosynthesis
  • Escherichia coli / metabolism
  • Female
  • Immunization, Secondary
  • Immunoglobulin G / immunology
  • Interferon-gamma / biosynthesis
  • Lectins, C-Type / metabolism
  • Levamisole / pharmacology*
  • Lymphocyte Activation / immunology
  • Mice
  • Mice, Inbred BALB C
  • Recombinant Fusion Proteins / immunology
  • Spleen / cytology
  • Spleen / immunology
  • T-Lymphocytes, Cytotoxic / immunology
  • Tuberculosis / prevention & control

Substances

  • Adjuvants, Immunologic
  • Antigens, Bacterial
  • Antigens, CD
  • Antigens, Differentiation, T-Lymphocyte
  • BCG Vaccine
  • Bacterial Proteins
  • CD69 antigen
  • Cytokines
  • ESAT-6 protein, Mycobacterium tuberculosis
  • Immunoglobulin G
  • Lectins, C-Type
  • Recombinant Fusion Proteins
  • Levamisole
  • Interferon-gamma
  • Acyltransferases
  • antigen 85A, Mycobacterium tuberculosis