IL-15

Interleukin-5 (IL-5) is a key cytokine that orchestrates the differentiation, survival, and activation of eosinophils[1][2]. Mechanistically, IL-5 signals through the IL-5 receptor (IL-5R), a heterodimer composed of a unique α subunit and a shared βc subunit, triggering JAK/STAT, PI3K, and MAPK pathways to modulate immune responses[3][4]. In disease models, IL-5 drives eosinophilic inflammation in asthma, hypereosinophilic syndrome, and other allergic conditions, serving as a validated biomarker and therapeutic target[5][6]. Compared with related cytokine isoforms such as IL-3 and GM-CSF, IL-5 exhibits selective potency toward eosinophils, with minimal effects on neutrophils or basophils[3][7]. Pharmacologic inhibition of IL-5 using monoclonal antibodies or receptor antagonists effectively reduces eosinophil counts and mitigates tissue inflammation in preclinical and clinical studies[5][6]. For experimental applications, IL-5 agonists are utilized to expand eosinophil populations in vitro and in vivo, facilitating mechanistic studies of allergic inflammation and immune regulation[2][8]. Collectively, IL-5 serves as a central mediator in eosinophil biology, linking receptor-specific signaling to disease pathogenesis and therapeutic intervention strategies[1][5][6].
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