%0 Journal Article %T Tumor Evasion from T Cell Surveillance %A Katrin T pfer %A Stefanie Kempe %A Nadja M¨šller %A Marc Schmitz %A Michael Bachmann %A Marc Cartellieri %A Gabriele Schackert %A Achim Temme %J Journal of Biomedicine and Biotechnology %D 2011 %I Hindawi Publishing Corporation %R 10.1155/2011/918471 %X An intact immune system is essential to prevent the development and progression of neoplastic cells in a process termed immune surveillance. During this process the innate and the adaptive immune systems closely cooperate and especially T cells play an important role to detect and eliminate tumor cells. Due to the mechanism of central tolerance the frequency of T cells displaying appropriate arranged tumor-peptide-specific-T-cell receptors is very low and their activation by professional antigen-presenting cells, such as dendritic cells, is frequently hampered by insufficient costimulation resulting in peripheral tolerance. In addition, inhibitory immune circuits can impair an efficient antitumoral response of reactive T cells. It also has been demonstrated that large tumor burden can promote a state of immunosuppression that in turn can facilitate neoplastic progression. Moreover, tumor cells, which mostly are genetically instable, can gain rescue mechanisms which further impair immune surveillance by T cells. Herein, we summarize the data on how tumor cells evade T-cell immune surveillance with the focus on solid tumors and describe approaches to improve anticancer capacity of T cells. %U http://www.hindawi.com/journals/biomed/2011/918471/