Phosphoantigen/IL2 expansion and differentiation of Vγ2Vδ2 T cells increase resistance to tuberculosis in nonhuman primates

PLoS Pathog. 2013 Aug;9(8):e1003501. doi: 10.1371/journal.ppat.1003501. Epub 2013 Aug 15.

Abstract

Dominant Vγ2Vδ2 T-cell subset exist only in primates, and recognize phosphoantigen from selected pathogens including M. tuberculosis(Mtb). In vivo function of Vγ2Vδ2 T cells in tuberculosis remains unknown. We conducted mechanistic studies to determine whether earlier expansion/differentiation of Vγ2Vδ2 T cells during Mtb infection could increase immune resistance to tuberculosis in macaques. Phosphoantigen/IL-2 administration specifically induced major expansion and pulmonary trafficking/accumulation of phosphoantigen-specific Vγ2Vδ2 T cells, significantly reduced Mtb burdens and attenuated tuberculosis lesions in lung tissues compared to saline/BSA or IL-2 controls. Expanded Vγ2Vδ2 T cells differentiated into multifunctional effector subpopulations capable of producing anti-TB cytokines IFNγ, perforin and granulysin, and co-producing perforin/granulysin in lung tissue. Mechanistically, perforin/granulysin-producing Vγ2Vδ2 T cells limited intracellular Mtb growth, and macaque granulysin had Mtb-bactericidal effect, and inhibited intracellular Mtb in presence of perforin. Furthermore, phosphoantigen/IL2-expanded Vγ2Vδ2 T effector cells produced IL-12, and their expansion/differentiation led to enhanced pulmonary responses of peptide-specific CD4+/CD8+ Th1-like cells. These results provide first in vivo evidence implicating that early expansion/differentiation of Vγ2Vδ2 T effector cells during Mtb infection increases resistance to tuberculosis. Thus, data support a rationale for conducting further studies of the γδ T-cell-targeted treatment of established TB, which might ultimately help explore single or adjunctive phosphoantigen expansion of Vγ2Vδ2 T-cell subset as intervention of MDR-tuberculosis or HIV-related tuberculosis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bronchoalveolar Lavage
  • Cell Differentiation / drug effects
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Interleukin-2 / administration & dosage*
  • Interleukin-2 / pharmacology
  • Lung / immunology*
  • Lung / metabolism
  • Lung / microbiology
  • Macaca fascicularis / metabolism
  • Macaca fascicularis / microbiology*
  • Mycobacterium tuberculosis / physiology*
  • Phosphoproteins / metabolism*
  • Receptors, Antigen, T-Cell, gamma-delta / metabolism*
  • T-Lymphocytes / cytology*
  • T-Lymphocytes / immunology
  • T-Lymphocytes / microbiology
  • Tuberculosis / immunology
  • Tuberculosis / microbiology
  • Tuberculosis / prevention & control*

Substances

  • Interleukin-2
  • Phosphoproteins
  • Receptors, Antigen, T-Cell, gamma-delta