Determining cross-reactivity between human and mouse tissue using mono-specific antibodies

Abstract: ABSTRACT The Swedish Human Proteome Resource (HPR) is a project about mapping of human genes and proteins. It aims to describe the function and distribution of all human genes and corresponding proteins, using in-house produced antibodies and tissue microarrays (TMA) for enzyme based immunohistochemistry. The mono-specific antibodies are used for immunostaining of human tissue. Specific predicted antigens named Protein Epitope Signature Tag (PrEST) are needed to produce mono-specific antibodies. PrEST are produced using recombinant technology from predicted genes and used as immunogens to produce (mono-specific) antibodies in rabbits. In this study, 84 mono-specific antibodies with known specificity to human proteins were used for immunohistochemical analysis of mouse tissues to determine the cross reactivity between mouse and human. For 6 of the 84 antibodies the results differed between mouse and human tissue. A comparison between the PrEST used with the mouse proteome using database search programs showed homologies that were less than 100% in these six cases. Thus, future studies on cross reactivity will focus on how to increase the accuracy in its prediction at the in silico stage of the experiment.