Incorporating Centrally Tolerized Mice as a Design Principle to Circumvent Reporter Immunogenicity in Cancer Research Models

The study of tumor progression and metastasis in a physiologic setting commonly involves implantation of tumor cells into immunocompetent mice. For this purpose, tumor cells are labeled routinely with bioluminescent and/or fluorescent proteins prior to transplantation, despite the fact that these foreign proteins generate adaptive immune responses. We have described previously how incorporating centrally tolerized mouse strains into tumor and metastasis modeling can be used as a study design principle to properly control for artifactual immune responses against such reporters. In this issue of Cancer Research, Khan and colleagues applied a tolerized mouse strain-the Tol mouse-to overcome limitations associated with the use of xenoantigenic fluorescent and bioluminescent reporters in immunocompetent settings. The authors showed how antigenic responses against such proteins can confound interpretation of study results when measuring the efficacy of immunotherapy regimens. This study readily demonstrates the utility of employing centrally tolerized transgenic models to improve preclinical investigations of cancer metastasis and therapeutic resistance. See related article by Khan et al., p. 2165.