IL-3

Interleukin-3 (IL-3) functions primarily as a hematopoietic growth factor, promoting proliferation and differentiation of multipotent progenitor cells into myeloid lineages^[1]. Mechanistically, IL-3 signals through the IL-3 receptor (IL-3R), activating JAK2/STAT5 and PI3K/AKT pathways, thereby regulating cell survival and expansion^[1][2]. In disease models, IL-3 is implicated in allergic inflammation, asthma, and hematologic malignancies, where elevated IL-3 levels correlate with enhanced eosinophil and basophil activity^[2][3]. Compared with related cytokines such as IL-5 and GM-CSF, IL-3 exhibits broader lineage specificity and induces distinct transcriptional programs in target cells^[2][4]. Agonists of IL-3R have been used experimentally to expand hematopoietic stem cells ex vivo, whereas neutralizing antibodies and small molecule inhibitors targeting IL-3 or its receptor attenuate pathologic inflammation and leukemic proliferation^[3][5]. Functionally, IL-3 modulation in preclinical studies demonstrates the capacity to influence immune cell composition, providing a controlled model for evaluating therapeutic interventions in allergic and myeloproliferative disorders^[3][5].