IL13RA1

IL13RA1 Full Name

interleukin 13 receptor, alpha 1

IL13RA1 Introduction

Interleukin 13 receptor, alpha 1 (IL13RA1), is a transmembrane glycoprotein that serves as a crucial component of the receptors for two key type 2 cytokines, interleukin-13 (IL-13) and interleukin-4 (IL-4). The human IL13RA1 gene is located on the X chromosome (Xq24). Structurally, it is a member of the type I cytokine receptor family, containing extracellular cytokine-binding motifs, a transmembrane domain, and a relatively short cytoplasmic tail. IL13RA1 is constitutively expressed on a wide variety of cell types, most prominently on hematopoietic cells (e.g., B cells, monocytes, basophils) and non-hematopoietic structural cells (e.g., epithelial cells, endothelial cells, fibroblasts, and smooth muscle cells), which are primary targets for IL-13-mediated effects.

Figure 1.Cartoon representation of the molecular structure of interleukin 13 receptor.

IL13RA1 is indispensable for mediating the biological functions of IL-13. It primarily functions by pairing with IL4 receptor alpha (IL4RA) to form the Type II IL-4/13 receptor complex. Binding of IL-13 to IL13RA1 within this complex initiates downstream signaling. This receptor system is a central driver of type 2 immune responses, which are essential for host defense against helminth parasites. Furthermore, IL13RA1 can also pair with IL13RA2 to form an alternative, high-affinity decoy or signaling complex, depending on the cellular context. The activation of the canonical Type II receptor on structural cells orchestrates key physiological changes, including mucus hypersecretion, airway hyperreactivity, and tissue fibrosis.

Clinical Significance
Under normal physiological conditions, IL13RA1 contributes to a wide range of biological processes by mediating the effects of IL-13 and IL-4. Its ubiquitous expression across tissues—including the colon, liver, spleen, thymus, heart, lung, brain, skin, and kidney (with notable absence in skeletal muscle)—reflects its diverse roles. In the immune system, IL13RA1 regulates the function of monocytes/macrophages, suppressing their cytotoxic activity and pro-inflammatory cytokine production while upregulating anti-inflammatory mediators such as IL-1RA (interleukin-1 receptor antagonist). It also plays a role in maintaining epidermal barrier function, myocardial homeostasis, and glucose metabolism, with soluble IL13RA1 (sIL13RA1) identified as a circulating regulator of glucose levels. Additionally, IL13RA1 is involved in regulating the generation and differentiation of age-associated/autoimmune B cells (ABCs), which are critical for immune homeostasis and autoimmunity regulation. Together, these functions position IL13RA1 as a key mediator of tissue integrity, immune balance, and metabolic regulation.

Alternate Names for IL13RA1

IL13RA1; interleukin 13 receptor, alpha 1; NR4; CD213A1; IL-13Ra; interleukin-13 receptor subunit alpha-1; CT19; IL-13RA1; IL-13R-alpha-1; CD213a1 antigen