Adherence influences monocyte responsiveness to interleukin-10

Area of Science:

• Immunology
• Cell Biology

Background:

• Interleukin-10 (IL-10) is a key anti-inflammatory cytokine.
• Monocyte function is influenced by their adherence properties.

Purpose of the Study:

• To investigate how monocyte adherence affects IL-10's biological properties.
• To elucidate the role of adherence in modulating IL-10-mediated anti-inflammatory responses.

Main Methods:

• Monocyte-enriched peripheral blood mononuclear cells were cultured under adherent and non-adherent conditions.
• Cells were treated with IL-10, and effects on CD11b expression, Toll-like receptor (TLR) expression and function, cytokine production, phagocytosis, and signaling pathways (STAT3, Tyk2, SOCS3) were assessed.
• Heme oxygenase-1 expression was analyzed.

Main Results:

• Adherence enhanced IL-10-induced decrease in CD11b expression.
• IL-10 upregulated TLR2 and TLR4 mRNA and TLR4 surface expression in adherent cells.
• Absence of adherence abrogated IL-10's inhibitory effects on lipopolysaccharide-induced TNF and G-CSF production, and increased IL-1beta and soluble TNF receptor II release.
• Adherence amplified IL-10's enhancement of phagocytosis.
• IL-10 induced STAT3/Tyk2 phosphorylation and SOCS3 expression, with prolonged activation in adherent monocytes.
• Heme oxygenase-1 was induced by IL-10 in adherent monocytes but not in non-adherent cells.

Conclusions:

• Monocyte adherence significantly modulates the anti-inflammatory properties and functional outcomes of IL-10.
• Adherence enhances IL-10's effects on immune cell function, including receptor expression, cytokine regulation, and phagocytosis.
• These findings highlight the importance of cellular context in understanding cytokine signaling and immune responses.