Pulmonary and blood dendritic cells from sarcoidosis patients more potently induce IFNγ-producing Th1 cells compared with monocytes

J Leukoc Biol. 2022 Apr;111(4):857-866. doi: 10.1002/JLB.5A0321-162R. Epub 2021 Aug 25.


Sarcoidosis is a systemic inflammatory disease mainly affecting the lungs. The hallmark of sarcoidosis are granulomas that are surrounded by activated T cells, likely targeting the disease-inducing antigen. IFNγ-producing Th1 and Th17.1 T cells are elevated in sarcoidosis and associate with disease progression. Monocytes and dendritic cells (DCs) are antigen-presenting cells (APCs) and required for T cell activation. Several subsets of monocytes and DCs with different functions were identified in sarcoidosis. However, to what extent different monocyte and DC subsets can support activation and skewing of T cells in sarcoidosis is still unclear. In this study, we performed a transcriptional and functional side-by-side comparison of sorted monocytes and DCs from matched blood and bronchoalveolar lavage (BAL) fluid of sarcoidosis patients. Transcriptomic analysis of all subsets showed upregulation of genes related to T cell activation and antigen presentation in DCs compared with monocytes. Allogeneic T cell proliferation was higher after coculture with monocytes and DCs from blood compared with BAL and DCs induced more T cell proliferation compared with monocytes. After coculture, proliferating T cells showed high expression of the transcription factor Tbet and IFNγ production. We also identified Tbet and RORγt coexpressing T cells that mainly produced IFNγ. Our data show that DCs rather than monocytes from sarcoidosis patients have the ability to activate and polarize T cells towards Th1 and Th17.1 cells. This study provides a useful in vitro tool to better understand the contribution of monocytes and DCs to T cell activation and immunopathology in sarcoidosis.

Keywords: IFNγ; T cells; Th1; dendritic cell; monocyte; sarcoidosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dendritic Cells
  • Humans
  • Interferon-gamma / metabolism
  • Lung / pathology
  • Monocytes
  • Sarcoidosis* / pathology
  • Th1 Cells*
  • Th17 Cells


  • Interferon-gamma