Permissive expansion and homing of adoptively transferred T cells in tumor-bearing hosts.

Activated T cells expressing endogenous or transduced TCRs are two cell types currently used in clinical adoptive T-cell therapy. The ability of these cells to recognize their antigen, expand and traffic to the tumor site are the initial steps necessary for successful therapy. In this study, we used in vivo bioluminescent imaging (BLI) of Renilla luciferase (RLuc) expressing T cells to evaluate the ability of adoptively transferred T cells to survive, expand and home to tumor site in vivo.

Visualizing the dynamic of adoptively transferred T cells during the rejection of large established tumors.

Adoptive T-cell therapy (ATCT) can result in tumor rejection, yet the behavior and fate of the introduced T cells remain unclear. We developed a novel bioluminescence mouse model, which enabled highly sensitive detection of T-cell signals at the single-cell level. Transferred T cells preferentially accumulated within antigen-positive tumors, relative to the unaffected areas in each mouse, and remarkably, expanded within both lymphopenic and P14 mice.

In vivo imaging of an inducible oncogenic tumor antigen visualizes tumor progression and predicts CTL tolerance.

Visualizing oncogene/tumor Ag expression by noninvasive imaging is of great interest for understanding processes of tumor development and therapy. We established transgenic (Tg) mice conditionally expressing a fusion protein of the SV40 large T Ag and luciferase (TagLuc) that allows monitoring of oncogene/tumor Ag expression by bioluminescent imaging upon Cre recombinase-mediated activation. Independent of Cre-mediated recombination, the TagLuc gene was expressed at low levels in different tissues, probably due to the leakiness of the stop cassette.