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

Area of Science:

• Immunology and Cell Biology
• Molecular Biology and Biochemistry

Background:

• Interleukin-1 (IL-1) is a key cytokine involved in immune responses.
• Understanding IL-1 receptor interactions is crucial for modulating immune signaling.
• Chicken macrophages release IL-1-like activity upon lipopolysaccharide stimulation.

Purpose of the Study:

• To investigate the role of the chicken type-I IL-1 receptor (sIL-1R(I)) in neutralizing IL-1 bioactivity.
• To assess the efficacy of soluble IL-1R(I) and anti-IL-1R(I) antibodies in blocking IL-1 effects.
• To determine the primary IL-1 receptor mediating proliferation in chicken thymocytes.

Main Methods:

• Cloning of the chicken type-I IL-1 receptor ligand-binding domain into Pichia pastoris.
• Production of antisera against the soluble IL-1R(I) in rabbits.
• Assaying IL-1 bioactivity via thymocyte co-stimulation in conditioned media (CM).
• Pre-incubation experiments using sIL-1R(I) or anti-IL-1R(I) with CM or thymocytes.

Main Results:

• Unpurified and partially purified sIL-1R(I) significantly reduced IL-1 bioactivity in CM by 57-77%.
• Antisera against sIL-1R(I) decreased IL-1 activity in CM by 70% compared to controls.
• Data suggest that approximately 30% of IL-1-like activity may be mediated by other cytokines.

Conclusions:

• The type-I IL-1 receptor is the primary receptor on chicken thymocytes mediating IL-1-induced proliferation.
• Soluble IL-1R(I) and specific antibodies are effective in neutralizing IL-1 bioactivity.
• These findings provide insights into IL-1 signaling pathways in avian immunology.