QUANTIFICATION OF RECOMBINANT HUMAN INTERLEUKIN-1-ALPHA BY A SPECIFIC2-CELL IMMUNOBIOASSAY

The detection of picogram quantities of recombinant human IL-1 alpha i n human and rat serum was accomplished by a sensitive and specific two cell immunobioassay. The specificity is provided by an IL-1 alpha spe cific mouse IgM monoclonal antibody which is non-neutralizing thus all owing for the addition of the EL-4 NOB-1 cell line directly to the IL- 1 alpha monoclonal antibody complex. The above cell line is then conve rted to an IL-2 producer line in response to the captured IL-1 alpha. Supernatant from the EL-4 NOB-1 cells is then added to the IL-2 depend ent CTLL-2 line and cell proliferation measured by thymidine incorpora tion. This assay has the advantage of specificity provided by the anti body capture step, sensitivity provided by the EL-4 NOB-1 line (1-50 p g/ml) and finally ease of maintenance of the responder cell line which requires no feeder cells or mitogens. Data are reported on the sensit ivity, precision, reproducibility and specificity of the assay, the st ability of rhIL-1 alpha in serum and the recovery of rhIL-1 alpha from serum. We also report on the use of this procedure to assay samples f rom rats given ascending doses of rhIL-1 alpha.