Fatty acid-binding protein 5 limits the generation of Foxp3+ regulatory T cells through regulating plasmacytoid dendritic cell function in the tumor microenvironment

Int J Cancer. 2022 Jan 1;150(1):152-163. doi: 10.1002/ijc.33777. Epub 2021 Sep 20.

Abstract

Plasmacytoid dendritic cells (pDCs) promote viral elimination by producing large amounts of Type I interferon. Recent studies have shown that pDCs regulate the pathogenesis of diverse inflammatory diseases, such as cancer. Fatty acid-binding protein 5 (FABP5) is a cellular chaperone of long-chain fatty acids that induce biological responses. Although the effects of FABP-mediated lipid metabolism are well studied in various immune cells, its role in pDCs remains unclear. This study, which compares wild-type and Fabp5-/- mice, provides the first evidence that FABP5-mediated lipid metabolism regulates the commitment of pDCs to inflammatory vs tolerogenic gene expression patterns in the tumor microenvironment and in response to toll-like receptor stimulation. Additionally, we demonstrated that FABP5 deficiency in pDCs affects the surrounding cellular environment, and that FABP5 expression in pDCs supports the appropriate generation of regulatory T cells (Tregs). Collectively, our findings reveal that pDC FABP5 acts as an important regulator of tumor immunity by controlling lipid metabolism.

Keywords: FABP; Treg; pDC; translational research; tumor microenvironment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dendritic Cells / immunology*
  • Fatty Acid-Binding Proteins / physiology*
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / metabolism*
  • Interferon Type I / metabolism*
  • Lipid Metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neoplasm Proteins / physiology*
  • T-Lymphocytes, Regulatory / immunology*
  • Toll-Like Receptors / metabolism
  • Tumor Microenvironment*

Substances

  • Fabp5 protein, mouse
  • Fatty Acid-Binding Proteins
  • Forkhead Transcription Factors
  • Foxp3 protein, mouse
  • Interferon Type I
  • Neoplasm Proteins
  • Toll-Like Receptors