Soluble type-I interleukin-1 receptor blocks chicken IL-1 activity

• Published in: Developmental and comparative immunology Vol. 25; no. 4; pp. 345 - 352
• Main Authors: Klasing, K.C., Peng, R.K.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.05.2001
• Subjects: Animals; Base Sequence; Chicken; Chickens; Cloning, Molecular; Cytokines; HD11 cells; Inflammatory response; interleukin 1 receptors; Interleukin-1 - antagonists & inhibitors; Interleukin-1 receptor; Lipopolysaccharides - pharmacology; Lymphocytes - drug effects; Lymphocytes - metabolism; Macrophages - drug effects; Male; Molecular Sequence Data; Monocytes; Monocytes - drug effects; Monocytes - metabolism; Pichia - genetics; Pichia pastoris; Rabbits; Receptors, Interleukin-1 - genetics; Receptors, Interleukin-1 - physiology; Recombinant Fusion Proteins - pharmacology; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; Solubility; Thymocytes; Type-I; Vaccination; Type-I; Cytokines; Inflammatory response; Interleukin-1 receptor; sIL-1R I, soluble IL-1R I; HD11 cells; CM, conditioned medium containing IL-1; SI, stimulation index; Monocytes; Anti-IL-1R I, rabbit antisera against IL-1R I; Thymocytes; IL, interleukin; IL-1R I, IL-1 type-I receptor; LPS, lipopolysaccharide; Chicken
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/S0145-305X(00)00064-1

The ligand-binding domain of the chicken type-I interleukin-1 (IL-1) receptor (soluble IL-1R I; sIL-1R I) was cloned into a Pichia pastoris expression system and the resulting sIL-1R I binding protein was used to produce antisera in rabbits (anti-IL-1R I). Two experiments were conducted to determine the capacity of sIL-1R I or anti-IL-1R I to block the IL-1 bioactivity (thymocyte co-stimulation) in conditioned media (CM) from HD11 chicken macrophages stimulated with lipopolysaccharide. In the first experiment, pre-incubation of CM with unpurified sIL-1R I significantly decreased its thymocyte co-stimulation activity by 57%. Further purification of sIL-1R I from other proteins secreted or shed from P. pastoris expression system by size exclusion filtration or ammonium sulfate (60%) precipitation did not influence its capacity to neutralize IL-1 bioactivity. These partially purified sIL-1R I preparations significantly decreased thymocyte co-stimulation activity in CM by 70.7 and 77.3%, respectively. In the second experiment, pre-incubation of thymocytes with antisera against the sIL-1R I decreased IL-1 activity in CM by 70% relative to control thymocyte cultures that received no antibody and by 59% relative to thymocyte cultures incubated with pre-immune sera. Presumably anti-sIL-1R I diminished the IL-1 bioactivity in CM by blocking IL-1 binding to its type-I receptor on thymocytes. Thus, 30% of the IL-1-like activity released by LPS-stimulated HD11 macrophages is probably due to at least one other cytokine. Our data are consistent with the type-I receptor being the primary IL-1 receptor on chicken thymocytes that is capable of providing a signal for proliferation.