A highly sensitive, modified assay for Interleukin-1 / 中国免疫学杂志

ABSTRACT

In this paper, we describe a highly sensitive, modified assay which takes advantage of the capacity of a mouse thymoma cell line EL4 subclone to produce high concentration of IL-2 upon stimulation by interleukin I (IL-1).The assay was generally performed in 2 stages which included IL-1-dependent IL-2 production and IL-2 biological activity assay, and took about 40 hours to complete. The sensitivity of this assay was got to be 10~(-2) ～10~(-4)U/ml (2.5～25?10~(-4)pg/ml, about 10~2～10~3 times more sensitive than that of the mouse thymocyte co-stimulated assay) by selecting the optimal serum concentration, EL 4 cell density, IL-1-induced time and EL4 supernatant dilution. The rapid one step assay was performed by co-culturing the EL4 cells with CTLL-2 cells. This rapid assay could be completed within 30 hours with sensitivity of 10~(-1)U/ml. The assay was not affected by high concentrations of rHuTNF- ?, rHuTNF- ? or rHuIL-6,and was only slightly affected by high concentrations of rHuIL-2, ConA, PHA,LPS and SEB, and much affected by A23187.