Interferon-sensitized hematopoietic progenitors dynamically alter organismal immunity

Area of Science:

• Immunology
• Hematology
• Inflammation Research

Background:

• Tissue-restricted inflammation can influence systemic immunity through poorly understood mechanisms.
• Understanding how localized inflammation conditions the broader immune system is critical for managing diverse diseases.

Purpose of the Study:

• To elucidate the mechanisms by which localized skin inflammation impacts systemic host responses.
• To investigate the role of type I interferon (IFN) in modulating hematopoietic stem/progenitor cells (HSPCs) following inflammation.

Main Methods:

• Utilized a compartmentalized model of skin inflammation in mice.
• Analyzed type I IFN-mediated activation of HSPCs and its effects on systemic immunity.
• Investigated chromatin accessibility changes and functional states of HSPCs post-inflammation.

Main Results:

• Skin inflammation induced type I IFN signaling, activating HSPCs and altering systemic immunity.
• Post-inflamed mice showed protection from atherosclerosis but worsened outcomes in influenza infection.
• IFN-mediated HSPC modulation was dependent on IFNAR signaling and transferable, indicating immune suppression.

Conclusions:

• Transient inflammation, specifically type I IFN signaling, has profound and enduring effects on HSPC function and systemic immunity.
• IFN-modulated HSPCs exhibit long-term epigenetic changes and an altered functional state.
• This study provides insights into immune memory and the impact of peripheral signals on hematopoietic stem cells.