Immature Neutrophils Play a Role in Reducing Inflammation by Producing IL-10 During Infections

Recent research from the University of Tsukuba highlights an important function of immature neutrophils, a subset of white blood cells typically involved in host defense. Under normal conditions, mature neutrophils dominate the bloodstream, responding to pathogens by inducing inflammation. However, during infections, tissue injuries, or physical stress, the proportion of immature neutrophils rises. Until now, the significance of this increase was unclear.

A study published in Nature Communications sheds light on this phenomenon, revealing that a specific immune pathway activates innate lymphoid cells to produce interferon-γ (IFN-γ). This cytokine triggers immature neutrophils, which originate in the bone marrow, to migrate into the bloodstream and reach inflamed tissues. These neutrophils express a scaffold protein called Ahnak, which plays a crucial role in their response. When stimulated by IFN-γ, Ahnak causes the immature neutrophils to downregulate the chemokine receptor CXCR4, enabling their exit from the bone marrow.

Significantly, the study found that immature neutrophils produce interleukin-10 (IL-10), an anti-inflammatory cytokine that helps in suppressing excessive inflammation and preventing tissue damage. Researchers observed that in humans, these IL-10-producing immature neutrophils express Ahnak, and their levels increase in the blood of patients with COVID-19, indicating a potentially protective role.

This discovery suggests that while mature neutrophils promote inflammation as part of the immune response, immature neutrophils serve a complementary function by modulating inflammation through IL-10 production. These insights could pave the way for new therapeutic strategies aimed at controlling inflammation and minimizing tissue damage in various diseases.

Understanding the balance between different neutrophil types could be key in developing treatments for inflammatory conditions and infections, ultimately improving patient outcomes.

Source: medicalxpress.com | Published August 26, 2025