Enhanced T cell receptor gene therapy for cancer.
BACKGROUND
Adoptive therapy with T cell receptor- (TCR-) redirected T cells has shown efficacy in mouse tumor models and first responses in cancer patients. One prerequisite to elicit effective anti-tumor reactivity is the transfer of high-avidity T cells. Their generation, however, faces several technical difficulties. Target antigens are often expressed at low levels and their recognition requires the use of high-affine receptors. Yet, mainly low-affinity TCRs have been isolated from tumor-infiltrating lymphocytes. Furthermore, upon transfer into a T cell the introduced receptor has to compete with the endogenous TCR.


METHODS
This review discusses how the functional avidity of TCR-modified T cells can be enhanced by i) increasing the amount of introduced TCR heterodimers on the cell surface; and ii) generating receptors with high affinity. Risks of TCR gene therapy and possible safety mechanisms are discussed.


RESULTS
The reader will gain an overview of the technical developments in TCR and T cell engineering.


CONCLUSIONS
Despite technical obstacles, many advances have been made in the generation of high-avidity T cells expressing enhanced TCRs. Mouse studies and clinical trials will evaluate the effect of these improvements.
Kieback
Elisa
E
Max Delbrück Center for Molecular Medicine, Robert-Rössle-Strasse 10, D-13092 Berlin, Germany.
Uckert
Wolfgang
W
D000818:Animals; D015316:Genetic Therapy / Q000009:adverse effects; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000009:adverse effects; D051379:Mice; D009369:Neoplasms / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000637:transplantation*; D016896:Treatment Outcome
D011948:Receptors, Antigen, T-Cell