Interleukin-1 down-regulates gene and surface expression of interleukin-1 receptor type I by destabilizing its mRNA whereas interleukin-2 increases its expression

• Published in: Immunology 1992-03, Vol.75 (3), p.427-434
• Main Authors: YE, K, KOCH, K.-C, CLARK, B. D, DINARELLO, C. A
• Format: Article
• Language: English
• Subjects: Analysis of the immune response. Humoral and cellular immunity; Animals; Biological and medical sciences; Cells, Cultured; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Gene Expression Regulation - immunology; Half-Life; Humans; Immunobiology; Interleukin-1 - immunology; Interleukin-2 - immunology; Lymphokines, interleukins ( function, expression); Mice; Protein Kinase C - immunology; Receptors, Immunologic - analysis; Receptors, Immunologic - genetics; Receptors, Interleukin-1; Regulatory factors and their cellular receptors; RNA, Messenger - analysis
• ISSN: 0019-2805; 1365-2567

The interleukin-1 receptor type I (IL-1RtI) plays an important role in the biological effects of IL-1, but regulation of its surface and gene expression remains unknown. We found that occupancy of 2-15% of the IL-1 surface receptor results in dramatic down-regulation of IL-1RtI both at the mRNA and cell surface level in murine D10S cells, a subline of T-helper type 2 cells. At these low occupancy levels (3 x 10(-12) to 3 x 10(-13) M), the reduction in IL-1RtI surface expression appears at 24 hr and continues to 48 and 72 hr. At the mRNA level, low occupancy of the IL-1R results in decreased IL-1RtI mRNA stability; steady state half-life of the IL-1RtI mRNA is reduced from 6 to 1 hr after exposure to 3 x 10(-12) M IL-1. This down-regulation of IL-1RtI by IL-1 is blocked by cycloheximide, suggesting de novo protein synthesis is necessary for decreased RNA stability. Low concentrations of human IL-1 beta, murine and rabbit IL-1 alpha or beta similarly down-regulated IL-1RtI, whereas low concentrations of human IL-1 alpha failed to reduce the receptor surface expression, despite inducing a full proliferative response. We also observed that the effect of IL-1 on this down-regulation was not through protein kinase C (PKC), since PMA rapidly increased IL-1RtI mRNA levels within 30 min and persisted for 24 hr. IL-2 up-regulated IL-1RtI in D10S cells at both mRNA and protein levels. These results demonstrate that low occupancy of IL-1 receptors induces down-regulation of IL-1RtI surface as well as mRNA expression. The regulation of IL-1RtI gene expression may be one of the mechanisms by which IL-1-mediated events are controlled.