• Skip to main content
  • Skip to primary sidebar
Transfusion News
  • About Us
  • Topics
    • Adverse Events (non-infectious)
    • Blood Donation
    • Cell Therapy
    • Coagulation & Plasma Transfusion
    • Platelet Transfusion
    • Policy and Guidelines
    • Quality Control and Regulatory
    • RBC Transfusion
    • Serology/Genotyping
    • Special Transfusion Situations
    • Transfusion Transmitted Infections
  • Continuing Education
  • Archives
  • Podcasts
  • Question of the Day
  • Search
  • Subscribe to Email Alerts
  • Follow us on
  • Search
  • Subscribe to Email Alerts

Red Blood Cells May Act as Immune Sentinels

November 1, 2021

Anucleated red blood cells (RBCs) are essential for delivery of oxygen throughout the body but have been considered immunologically inert.  New evidence recently published in Science Translational Medicine, however, suggests that RBCs promote immune activation by binding to unmethylated, cell free CpG nucleic acid fragments and promoting cytokine production.  Toll-like receptors play a key role in inflammation by identifying nucleic acid fragments.  Lam and colleagues show that mammalian RBCs express the toll-like receptor 9 (TLR9) on their surface and that TLR9 surface expression is increased during sepsis.  Furthermore, TLR9 expressed on RBCs binds pathogenic CpG nucleic acids resulting in altered RBC cytoskeletal proteins and Band 3 distribution.  Lam et al also show that CpG binding by RBCs leads to attenuation of the RBC self-preservation marker CD47, resulting in accelerated erythrophagocytosis and activation of the innate immune system (by increased expression of interferon and interlukin-6).  Consistent with these laboratory findings, they show that patients with severe and/or anemic COVID-19 have increased levels of nucleic acids bound to RBCs compared to patients with less severe disease.  Further comprehensive studies are required to better understand how RBCs modulate innate inflammatory responses.

Reference:

Lam LKM, Murphy S, Kokkinaki D, Venosa A, et al.  DNA binding to TLR9 expressed by red blood cells promotes innate immune activation and anemia.  Science Translational Medicine 2021; 13(16)

Filed Under

  • News
  • Special Transfusion Situations

Recommended

  • Donor-specific HLA antibodies can be reduced in kidney transplant patients with multiple plasmapheresis procedures

  • Novel Surgical Schedules Developed to Optimize Preoperative Blood Ordering

  • Restrictive Transfusions Threshold Safe for Cardiac Surgery Patients

Show Comments

Comments on this article are closed.

Get the latest news. Subscribe to our mailing list. Sign Up

Primary Sidebar

Latest News

  • New Erythropoietin Gene Variants Linked to Hereditary Erythrocytosis

  • Multifaceted Threats to the Blood Supply from Climate Change

  • Distinct Roles for Differently Aged Platelets

  • Anemia Treatment Bundle Improves Hemoglobin Recovery after Critical Illness

    Question of the Day

    Copyright © 2025 John Wiley & Sons, Inc. All Rights Reserved.
    Privacy Policy

    Association for the Advancement of Blood and Biotherapies Wiley