Mixed Th1 and Th2 Mycobacterium tuberculosis-specific CD4 T cell responses in patients with active pulmonary tuberculosis from Tanzania

PLoS Negl Trop Dis. 2017 Jul 31;11(7):e0005817. doi: 10.1371/journal.pntd.0005817. eCollection 2017 Jul.

Abstract

Mycobacterium tuberculosis (Mtb) and helminth infections elicit antagonistic immune effector functions and are co-endemic in several regions of the world. We therefore hypothesized that helminth infection may influence Mtb-specific T-cell immune responses. We evaluated the cytokine profile of Mtb-specific T cells in 72 individuals with pulmonary TB disease recruited from two Sub-Saharan regions with high and moderate helminth burden i.e. 55 from Tanzania (TZ) and 17 from South Africa (SA), respectively. We showed that Mtb-specific CD4 T-cell functional profile of TB patients from Tanzania are primarily composed of polyfunctional Th1 and Th2 cells, associated with increased expression of Gata-3 and reduced expression of T-bet in memory CD4 T cells. In contrast, the cytokine profile of Mtb-specific CD4 T cells of TB patients from SA was dominated by single IFN-γ and dual IFN-γ/TNF-α and associated with TB-induced systemic inflammation and elevated serum levels of type I IFNs. Of note, the proportion of patients with Mtb-specific CD8 T cells was significantly reduced in Mtb/helminth co-infected patients from TZ. It is likely that the underlying helminth infection and possibly genetic and other unknown environmental factors may have caused the induction of mixed Th1/Th2 Mtb-specific CD4 T cell responses in patients from TZ. Taken together, these results indicate that the generation of Mtb-specific CD4 and CD8 T cell responses may be substantially influenced by environmental factors in vivo. These observations may have major impact in the identification of immune biomarkers of disease status and correlates of protection.

MeSH terms

  • Adult
  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • Coinfection / immunology
  • Female
  • Helminthiasis / immunology*
  • Helminths / isolation & purification
  • Humans
  • Interferon-gamma / blood
  • Male
  • Mycobacterium tuberculosis
  • South Africa
  • Tanzania
  • Th1-Th2 Balance*
  • Tuberculosis, Pulmonary / immunology*
  • Tumor Necrosis Factor-alpha / blood

Substances

  • Tumor Necrosis Factor-alpha
  • Interferon-gamma

Grants and funding

The research leading to these results has received funding from the [European Community's] Seventh Framework Programme ([FP7/2007-2013]) under EC-GA n° [241642]. This work was also supported by Swiss National Science Foundation Grants 320030_173071 and by the Strategic Health Innovation Partnerships (SHIP) Unit of the South African Medical Research Council with funds received from the South African Department of Science and Technology. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.