( nded greatly in numbers in the laborato...)Innovative movies show real-time immune-cell activity within tumors

The hope in these trials is that these enhanced T cell populations will specifically target and destroy the patient's cancer. To date, despite a few remarkable successes, these trials have proven frustratingly uneven. Greater insights into the mechanisms of interaction between T cells and tumor cells could provide vital new information to advance these efforts.

"Through adoptive transfer," Weninger explains, "we were able to compare two situations, one in which the T cells recognize something on the tumor and one in which they don't. When the T cells recognized the antigen, they interacted directly with the tumor cells. After tumor cell destruction, they became actively migratory, hunting for more tumor cells. In the absence of antigen, the T cells did not interact with tumor cells, and could not sustain an active migratory behavior within tumors."

"There are several significant conclusions from these experiments," Weninger says. "First, it is now possible to visualize the behavior of the individual cellular components of the tumor microenvironment in real-time. Second, we have demonstrated that T cells physically interact with tumor cells, which had not been shown before. Finally, it's the presence of antigen that determines how T cells migrate and interact with the tumor cells.

"These experiments set the basis for unraveling the molecular requirements for T cell migration and T cell-tumor cell interactions. We should then be able to use results from this research to further improve immunotherapeutic strategies against cancer in patients."