Research Report 2010 - MDC

Graduate and undergraduatestudentsWisam AlsamahKathleen AndersDana BriesemeisterChristian Buschow*Xiaojing ChenDana HoserAna JukicaAnna KruschinskiCynthia PerezJelena PopovicMichael RotheChristian SchönKarin SchmidtChristian SchönTechnical AssistantsKathrin BorgwaldAngelika GärtnerMarkus HenselSabrina HornStefanie KupschTanja SpecowiakMartin Textor*Christel WestenSecretariatKarin KaramatskosSylvia Klahn*part of the period reportedof HER-2 expression on the tumor cells. Finally, thesereceptor transduced NK cells, but not their mock transducedcounterpart, efficiently eradicated tumor cells inRAG2 knockout mice as visualized by in vivo imaging.Taken together, these results indicate that the expressionof this activating receptor overrides inhibitory signalsin primary human NK cells and directs them specificallytoward HER-2 expressing tumor cells both in vitroand in vivo.A safeguard eliminates T cell receptor genemodifiedautoreactive T cells after adoptivetransferBy transfer of T cell receptor (TCR) genes, antigen specificityof T cells can be redirected to target any antigen.Adoptive transfer of TCR-redirected T cells into patientshas shown promising results. However, thisimmunotherapy bears the risk of autoreactive sideeffects if the TCR recognizes antigens on self-tissue.Here, we introduce a safeguard based on a TCR-intrinsicdepletion mechanism to eliminate autoreactive TCRredirectedT cells in vivo. By the introduction of a 10-aatag of the human c-myc protein into murine (OT-I, P14)and human (gp100) TCR sequences, we were able todeplete T cells that were transduced with these myctaggedTCRs with a tag-specific antibody in vitro. T cellstransduced with the modified TCR maintained equalproperties compared with cells transduced with thewild-type receptor concerning antigen binding andeffector function. More importantly, therapeutic in vivodepletion of adoptively transferred T cells rescued miceshowing severe signs of autoimmune insulitis fromlethal diabetes. This safeguard allows termination ofadoptive therapy in case of severe side effects.Selected PublicationsKieback, E., Charo, J., Sommermeyer, D., Blankenstein, Th. And Uckert, W.(2008). A safeguard eliminates T cell receptor gene-modified autoreactiveT cells after adoptive transfer. Proc. Natl. Acad. Sci. USA 105: 623-628.Li, L.-P., Willimsky, G., Seitz, S., Xu, Y., Li, Y., Schwarz, L., Schlag, P. andBlankenstein, Th. (2008). SV40 large T antigen-transformed human primarynormal and cancerous mammary epithelial cells are phenotypicallysimilar but can be distinguished in 3D culture with selection medium.Int. J. Cancer 123: 1516-1525.Willimsky, G., Czeh, M., Loddenkemper, C., Gellermann, J., Schmidt, K.,Wust, P., Stein, H. and Blankenstein, Th. (2008). Immunogenicity of premalignantlesions is the primary cause of general cytotoxic T lymphocyteunresponsiveness. J. Exp. Med. 205: 1687-1700.Kruschinski, A., Moosmann, A., Poschke, I., Norell, H., Chmielewski, M.,Seliger, B., Kiessling, R., Blankenstein, Th., Abken, H. and Charo, J. (2008).Engineering antigen-specific primary human NK cells against HER-2 positivecarcinomas. Proc. Natl. Acad. Sci. USA 105: 17481-17486.Kammertoens, T. and Blankenstein, T. (2009) Making and circumventingtolerance to cancer. Eur. J. Immunology, in press.Cancer Research 123