An innovative approach to vaccination against tumors

Antigen-specific cancer immunotherapy and anti-angiogenesis represent two attractive mechanisms that could be of use in the treatment of cancer. In September 1 Journal of Clinical Investigation, Wen-Fang Cheng and colleagues from Johns Hopkins University School of Medicine show an innovative vaccination approach that combines both mechanisms and suggest this is likely generate a potent antitumor effect.

Cheng et al. engineered a fusion gene encoding a known viral tumor antigen (HPV-16 E7), linked directly to the chaperone protein calreticulin (CRT) and found that this combination can significantly enhance the potency of the E7-expressing DNA vaccine. Mice vaccinated subdermally with CRT/E7 DNA exhibited enhanced E7-specific CD8⁺ T cell responses and complete resistance to tumor cells expressing the viral antigen. But, a simple mixture of the viral sequence and the CRT sequence had minimal effect, suggesting that calreticulin-mediated immune antigen presentation is crucial (J Clin Invest 2001, 108:669-678)....