Impaired IFN-α-mediated signal in dendritic cells differentiates active from latent tuberculosis

PLoS One. 2018 Jan 10;13(1):e0189477. doi: 10.1371/journal.pone.0189477. eCollection 2018.

Abstract

Individuals exposed to Mycobacterium tuberculosis (Mtb) may be infected and remain for the entire life in this condition defined as latent tuberculosis infection (LTBI) or develop active tuberculosis (TB). Among the multiple factors governing the outcome of the infection, dendritic cells (DCs) play a major role in dictating antibacterial immunity. However, current knowledge on the role of the diverse components of human DCs in shaping specific T-cell response during Mtb infection is limited. In this study, we performed a comparative evaluation of peripheral blood circulating DC subsets as well as of monocyte-derived Interferon-α DCs (IFN-DCs) from patients with active TB, subjects with LTBI and healthy donors (HD). The proportion of circulating myeloid BDCA3+ DCs (mDC2) and plasmacytoid CD123+ DCs (pDCs) declined significantly in active TB patients compared to HD, whereas the same subsets displayed a remarkable activation in LTBI subjects. Simultaneously, the differentiation of IFN-DCs from active TB patients resulted profoundly impaired compared to those from LTBI and HD individuals. Importantly, the altered developmental trait of IFN-DCs from active TB patients was associated with down-modulation of IFN-linked genes, marked changes in molecular signaling conveying antigen (Ag) presentation and full inability to induce Ag-specific T cell response. Thus, these data reveal an important role of IFN-α in determining the induction of Mtb-specific immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antigens, CD / immunology
  • Dendritic Cells / immunology*
  • Down-Regulation
  • Female
  • Humans
  • Interferon-alpha / immunology*
  • Latent Tuberculosis / immunology
  • Latent Tuberculosis / pathology*
  • Male
  • Middle Aged
  • Mycobacterium tuberculosis / immunology

Substances

  • Antigens, CD
  • Interferon-alpha

Grants and funding

This work was supported by the Italian Association for Research against Cancer (AIRC) grant #11610 to LG and by grants from the Italian Ministry of Health “Ricerca Corrente” and from the European Union, HEALTH-F3-2009-241642 and EC FP7 NEWTBVAC (contract no. HEALTH.F3.2009 241745) to DG. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.