Cancer vaccine using low affinity epitopes proves successful in mice


Antitumor immunotherapy is a challenging endeavor since most human tumor–associated antigens are nonmutated self-proteins expressed on normal tissues. The ideal vaccination approach requires self-tolerance while eliciting an effective antitumor response. In an effort to design the ideal vaccine, David-Alexandre Gross and colleagues from Institut Gustave Roussy, France, examined epitopes (parts of antigen molecules) derived from murine telomerase reverse transcriptase (mTERT) – an enzyme expressed in more than 80% of human tumors – as potential anticancer vaccines. In the February 2 issue of the Journal of Clinical Investigation they report that epitopes with a low affinity for HLA class I molecules, molecules which bind and present antigens to T cells for killing – could be modified to generate an immune response against the tumor without stimulating an immune response against self. Mice vaccinated with the modified low-affinity epitopes maintained tumor immunity, while mice vaccinated with high-affinity epitopes died after challenge with tumor cells. These studies highlight the importance of rational epitope selection for effective cancer vaccines.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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