Pentraxin 3 (PTX3), a member of the long pentraxin family, is a multifunctional soluble pattern recognition receptor critical in innate immunity. Unlike short pentraxins (e.g., CRP), PTX3 is produced locally by immune and stromal cells (e.g., macrophages, endothelial cells) in response to inflammatory signals (e.g., TNF-α, IL-1β) or microbial components. It binds pathogens, extracellular matrix components, and apoptotic cells, modulating complement activation, phagocytosis, and tissue repair. Dysregulated PTX3 expression is implicated in chronic inflammation, autoimmune diseases (e.g., rheumatoid arthritis), cancer, and severe infections (e.g., COVID-19).
PTX3-targeting antibodies have emerged as research tools and potential therapeutics. Neutralizing antibodies block PTX3’s interaction with pathogens or complement factors, potentially mitigating excessive inflammation or infection spread. Conversely, agonist antibodies may enhance PTX3’s protective roles in tissue remodeling. Diagnostic antibodies detect PTX3 levels in serum or tissues as a biomarker for sepsis, cardiovascular diseases, or cancer prognosis. Challenges include balancing PTX3’s dual pro- and anti-inflammatory roles and ensuring tissue-specific targeting. Recent studies explore PTX3 antibodies in preclinical models of fibrosis, viral infections, and tumor immunomodulation, highlighting their translational potential in precision medicine.