Calfee, Halter & Griswold LLP
Mutant cell lines unresponsive to interleukin 1
 Mutant cell lines which have lost their ability to respond to IL-1 are provided. In one embodiment, the mutant cell line lacks or is essentially free of IL-1 receptor associate kinase (IRAK), an IL-1 signaling pathway component. The present invention also provides a method for making mutant cell lines that are unresponsive to IL-1, TNF, or to both cytokines. The method comprises the steps of: transfecting cells with a Herpes Simplex Virus thymidine kinase (HSV-TK) gene and a second gene for positive selection, each of said genes being operatively linked to an IL-1 inducible promoter or a TNF inducible promoter; selecting for transfected cells that express HSV thymidine kinase and the product of the positive selection gene in response to IL-1 or TNF; determining a gancyclovir concentration which kills the selected cells in the presence of IL-1 or TNF and which does not kill the selected cells in the absence of IL-1 or TNF; mutagenizing the selected cells using a chemical mutagenizing agent; and treating the mutagenized cells with the determined concentration of gancyclovir and IL-1 or TNF. The present invention also relates to a method of identifying domains or amino acids in IRAK that are essential for IRAK to function in the IL-1 signaling pathway. 
Cleveland Clinic Foundation
C
C07K
inventional
George R. Xiaoxia
Stark Li