Inhibiting Inflammation with Myeloid Cell-Specific Nanobiologics Promotes Organ Transplant Acceptance

Immunity. 2018 Nov 20;49(5):819-828.e6. doi: 10.1016/j.immuni.2018.09.008. Epub 2018 Nov 6.

Abstract

Inducing graft acceptance without chronic immunosuppression remains an elusive goal in organ transplantation. Using an experimental transplantation mouse model, we demonstrate that local macrophage activation through dectin-1 and toll-like receptor 4 (TLR4) drives trained immunity-associated cytokine production during allograft rejection. We conducted nanoimmunotherapeutic studies and found that a short-term mTOR-specific high-density lipoprotein (HDL) nanobiologic treatment (mTORi-HDL) averted macrophage aerobic glycolysis and the epigenetic modifications underlying inflammatory cytokine production. The resulting regulatory macrophages prevented alloreactive CD8+ T cell-mediated immunity and promoted tolerogenic CD4+ regulatory T (Treg) cell expansion. To enhance therapeutic efficacy, we complemented the mTORi-HDL treatment with a CD40-TRAF6-specific nanobiologic (TRAF6i-HDL) that inhibits co-stimulation. This synergistic nanoimmunotherapy resulted in indefinite allograft survival. Together, we show that HDL-based nanoimmunotherapy can be employed to control macrophage function in vivo. Our strategy, focused on preventing inflammatory innate immune responses, provides a framework for developing targeted therapies that promote immunological tolerance.

Keywords: CD40; TRAF6; immunotherapy; innate immune memory; mTOR; nanoimmunotherapy; trained immunity; transplantation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allografts
  • Animals
  • Biomarkers
  • Graft Survival / immunology*
  • HMGB1 Protein / genetics
  • Immune Tolerance
  • Immunity, Innate
  • Immunologic Memory
  • Immunosuppression*
  • Inflammation / immunology*
  • Macrophages / immunology
  • Macrophages / metabolism
  • Mice
  • Myeloid Cells / immunology*
  • Myeloid Cells / metabolism*
  • Organ Transplantation*
  • TOR Serine-Threonine Kinases / metabolism
  • Vimentin / genetics

Substances

  • Biomarkers
  • HMGB1 Protein
  • Vimentin
  • TOR Serine-Threonine Kinases