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

FEBS Letters

Scapigliati, G.¹  Boraschi, D.¹  Tagliabue, A.¹  Ghiara, P.¹  Bartalini, M.¹ 

[1] Laboratory of Immunopharmacology, Sclavo Research Centre, Siena, Italy

关键词: Interleukin 1 receptor;    Interleukin 1α;    Interleukin 1β;    (RAJI B lymphoma;    EL4-6.1 thymoma);   

DOI  :  10.1016/0014-5793(89)80169-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The interleukin 1 receptors (IL-1R) on the human B lymphoma RAJI and on the murine thymoma EL4-6.1 have been characterized. Equilibrium binding analysis using both ¹²⁵I-labeled IL-1α and IL-1β showed that RAJI cells have a higher number of binding sites/cell for IL-1β (2400, K _d 2.2 nM) than for IL-1α (316, K _d 0.13 nM). On the other hand, EL4-6.1 cells have more receptors/cell for IL-1α (22 656, K _d 1 nM) than for IL-1β (2988, K _d 0.36 nM). Dexamethasone (DXM) induced on RAJI cells a time-dependent increase in binding sites for both IL-1β and IL-1α without affecting their binding affinities. However, while receptor-bound ¹²⁵I-IL-1α was displaced with equal efficiency by both IL-1 forms, only unlabeled IL-1β could effectively displace ¹²⁵I-IL-1β. Cross-linking experiments indicated that RAJI cells have a predominant IL-1R of about 68 kDa, while EL4-6.1 cells have an IL-1-binding polypeptide of 80 kDa. These results suggest that B and T cells possess structurally different IL-1R with distinct binding properties for IL-1α and IL-1β.

【 授权许可】

Unknown