Janus kinase-2 inhibition induces durable tolerance to alloantigen by human dendritic cell-stimulated T cells yet preserves immunity to recall antigen Academic Article uri icon


MeSH Major

  • Dendritic Cells
  • Immune Tolerance
  • Janus Kinase 2
  • T-Lymphocytes


  • Janus kinase-2 (JAK2) conveys receptor-binding signals by several inflammatory cytokines, including IL-6, via phosphorylation of signal transducer and activator of transcription 3 (STAT3). We demonstrate that selective JAK2 inhibition by TG101348 during initial encounters between human T cells and allogeneic monocyte-derived dendritic cells induces durable, profound, and specific T-cell tolerance upon reexposure to the same alloantigens. Subsequent responses by nonalloreactive T cells to stimulation de novo by a pathogenic nominal antigen remain intact. TG101348 also suppresses primed T-cell responses when present only during alloantigen restimulation. TG101348 ablates IL-6/JAK2-mediated phosphorylation of STAT3, but has no off-target effects on IL-2 or IL-15/JAK3/pSTAT5-dependent signaling, which sustain the responses of regulatory T cells (Tregs) and other effector T cells. JAK2 inhibition preserves Treg numbers and thereby enhances the ratio of CD4(+) Tregs to CD8(+)CD25(+) effector T cells in favor of Tregs. JAK2 inhibition also reduces the production of IL-6 and TNF-α in allogeneic MLRs, impairing the activation of central and effector memory T cells as well as the expansion of responder Th1 and Th17 cells. While we have reported the limitations of isolated IL-6R-α inhibition on dendritic cell-stimulated alloreactivity, we demonstrate here that JAK2 represents a relevant biologic target for controlling GVHD or allograft rejection without broader immune impairment.

publication date

  • November 10, 2011



  • Academic Article



  • eng

PubMed Central ID

  • PMC3217413

Digital Object Identifier (DOI)

  • 10.1182/blood-2011-06-363408

PubMed ID

  • 21917753

Additional Document Info

start page

  • 5330

end page

  • 9


  • 118


  • 19