Differential binding of IL‐ 1α and IL‐ 1β to receptors on B and T cells

Abstract

The interleukin 1 receptors (IL-IR) on the human B lymphoma RAJI and on the murine thymoma EL4-6.1 have been characterized. Equilibrium binding analysis using both 12SI-labeled IL-I~ and IL-lfl showed that RAJI cells have a higher number of binding sites/ceil for IL-lfl (2400, Kd 2.

IL-1B and IL-6 gene polymorphisms encode significant risk for the development of recurrent aphthous stomatitis (RAS)

“…Two receptors, IL-1R1 and IL-1R2, with different affinities for IL-1␣ and IL-1␤ have been described. 24,25 Not all tissues express these receptors equally. The distribution of these receptors in oral tissues is not known but differences in receptor affinity and distribution could be important in explaining the association of IL-1B, but not IL-1A polymorphisms, with RAS.…”

The superficial layer of human articular cartilage is more susceptible to interleukin‐1–induced damage than the deeper layers

“…IL-1 a and IL-Ip, the 2 agonist isoforms of 1L-1 (17-21), bind to specific cell-membrane receptors and set in motion complex signal transduction pathways which are not yet fully understood (22). The human recombinant form of IL-1 receptor antagonist protein also binds to the same receptors, but since it fails to initiate signal transduction or elicit biological responses, it blocks cellular ARTICULAR SURFACE SUSCEPTIBILITY TO IL-1 479 responses to IL-1 (23) and acts as a pure antagonist (24)(25)(26)(27)(28).Two structurally related cell membrane receptors for IL-1 have been identified, the 80-kd type I receptor and the 68-kd type I1 receptor (29)(30)(31)(32). The type I receptor occurs on all cells that are responsive to IL-I, including human chondrocytes (16,33), while the type I1 receptor occurs on B cells, monocytes, neutrophils, and bone marrow cells (34).…”

“…Two structurally related cell membrane receptors for IL-1 have been identified, the 80-kd type I receptor and the 68-kd type I1 receptor (29)(30)(31)(32). The type I receptor occurs on all cells that are responsive to IL-I, including human chondrocytes (16,33), while the type I1 receptor occurs on B cells, monocytes, neutrophils, and bone marrow cells (34).…”

“…The coexpression of type I and type I1 receptors for IL-1 has also recently been reported in human synoviocytes (36). The smaller type I1 receptor has a shorter cytoplasmic domain (31,34,37,38). Apparently, it is not a signalling receptor, but acts as a "decoy target" at the cell surface or extracellularly in soluble form, trapping IL-I and thereby diminishing the effective signalling of IL-1 via its type I receptor (39).…”

Modulation of the effects of interleukin‐1 on glycosaminoglycan synthesis by the urine‐derived interleukin‐1 inhibitor, but not by interleukin‐6

“…The fact that by binding to the receptor, the IL-1 inhibitor is capable of blocking IL-1 activity on the aforementioned target cells suggests that the IL-1 receptor pathway is involved, rather than the phosphatidylcholine pathway. In addition, it was found recently that B and T cells have structurally distinct IL-1 receptors, and that these cells possess different binding properties for IL-la and IL-1p (27). The activity of the IL-1 inhibitor suggests either that the receptor in human synovial cells and human articular cartilage belongs to the T cell-type receptor, since binding inhibition has been demonstrated on EL4-6.1 T cells, or that despite their structural heterogeneity, B and T cells bind the same inhibitor; this latter hypothesis is being investigated.…”