Determination of soluble tumor necrosis factor receptor 2 produced by alternative splicing

Soluble cytokine receptors have proven to be very useful biomarkers in a large variety of diseases, including cancer, infections, and chronic inflammatory diseases. These soluble receptors are produced by proteolytic cleavage or alternative splicing. Several cytokine receptors including tumor necrosis factor receptor 2 (TNFR2) can be generated by both mechanisms. However, the conventional ELISA systems do not differentiate between these two types of soluble receptors. We describe a sandwich ELISA to specifically quantify soluble TNFR2 protein generated by alternative splicing. This method requires the use of a capturing monoclonal antibody (mAb) specific of an epitope present in the soluble TNFR2 generated by alternatively splicing but absent in the proteolytically generated isoform. Here we present a detailed protocol for the production and validation of such a mAb. This method has the potential to be applied for measuring other soluble cell surface molecules generated by alternative splicing.