Courtesy Jean-Robert Brisson NRC Inst. Biological Sciences
CD8+ T-cell tolerance of tumors can block an aggressive immune response against cancer and may diminish the efficacy of therapeutic vaccines. But Yiping Yang, a Duke University immunologist, says he and his colleagues have found a way to overcome T-cell tolerance using the immune system's innate response to pathogens. Membrane-bound Toll-like receptors (TLRs) detect repetitive epitopes commonly found in pathogens. Activating these receptors can influence adaptive responses, including T cell-mediated immunity.
The team reactivated tolerant T cells in mice by providing continuous TLR signals from viral vectors containing tumor antigens, and then inoculated mice with lymphoma cells. Ninety percent of the viral vector-treated mice survived after 15 weeks, compared to only 10% of those that had received just dendritic cell vaccine. But, Yvonne Paterson, professor of microbiology at the University of Pennsylvania, says that live vectors might trigger unfavorable immune responses.
Yang states ...
