Azithromycin targets the CD27 pathway to modulate CD27hi T-lymphocyte expansion and type-1 effector phenotype

Area of Science:

• Immunology
• Pharmacology
• Cell Biology

Background:

• Azithromycin (AZM) is a widely used macrolide antibiotic for infections and inflammatory conditions.
• Its precise immunomodulatory mechanisms, particularly on T-lymphocytes, remain incompletely understood.
• The CD27 pathway is implicated in T-lymphocyte-mediated inflammatory and autoimmune diseases.

Purpose of the Study:

• To investigate the impact of azithromycin on CD27 expression and regulation in T-lymphocytes.
• To explore the functional consequences of AZM-induced CD27 changes on CD4+ and CD8+ T-cell phenotypes.

Main Methods:

• Utilized cellular immunology techniques on peripheral blood mononuclear cells from healthy donors.
• Assessed surface CD27 expression, soluble CD27 levels, T-cell expansion, proliferation, and cell division.
• Analyzed mTOR activity and inflammatory cytokine (IFN-γ) production.

Main Results:

• Azithromycin downregulated surface CD27 and induced soluble CD27 release.
• AZM-exposed CD27high T-cells showed defective expansion, proliferation, and cell division, linked to lower mTOR activity.
• AZM treatment depleted CXCR3+CD27high effector T-cells (Th1 and Tc1) and inhibited IFN-γ production.

Conclusions:

• Azithromycin modulates T-lymphocyte function by altering the CD27 pathway.
• Findings offer mechanistic insights into AZM's immunomodulatory effects.
• Suggests potential clinical benefits of AZM in inflammatory/autoimmune diseases dominated by Th1/Tc1 responses.