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L.A. Rodriguez
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O08 - Preclinical Therapeutic Models I (ID 92)
- Event: WCLC 2013
- Type: Oral Abstract Session
- Track: Biology
- Presentations: 2
- Moderators:C. Mascaux, R. Natale
- Coordinates: 10/28/2013, 16:15 - 17:45, Bayside Auditorium A, Level 1
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O08.02 - Critical Role of CD28 Costimulation in Tumor-Targeted T-cell Therapy Clinical Trial for Pleural Malignancies (ID 2995)
16:25 - 16:35 | Author(s): L.A. Rodriguez
- Abstract
- Presentation
Background
Successful translation of adoptive T-cell therapy for solid cancers is predicated on the ability to generate a potent antitumor immune response and establish T-cell persistence. Thoracic malignancies typically lack expression of costimulatory ligands but do express negative regulators of T- cell function—factors that may impede T-cell therapy. We hypothesized that cancer antigen–targeted T cells engineered with activating CD28 costimulatory signaling would eradicate tumor and establish long-term functional persistence.Methods
Mesothelin-specific chimeric antigen receptors (CARs) were engineered without (Mz) or with (M28z) a CD28 costimulatory domain. CAR-transduced human T cells were evaluated in vitro for cytotoxicity ([51]Cr-release assay), cytokine release (Luminex cytokine-release assay), and proliferation (cell-counting assay). In vivo assessment included monitoring of tumor progression by bioluminescence imaging (BLI), flow cytometric analysis of splenic/peripheral blood T-cell phenotypes, and Kaplan-Meier analysis of median survival, in NOD-scid IL-2Rγ-null mice bearing orthotopically implanted mesothelin-expressing mesothelioma cells (MSTO-211H: CD80/86-, TGF-β+, PD-L1+) and treated with human T cells transduced to express either Mz, M28z, or a control vector.Results
In vitro, M28z CAR–transduced T cells exhibited equivalent cytotoxicity but enhanced Th1 cytokine secretion and antigen-specific proliferation, compared with Mz transduced T cells. In vivo, mice treated with a single low dose of M28z CAR–transduced T cells achieved tumor eradication and prolonged survival (median survival not reached; p=0.01), compared with mice treated with an equal dose of Mz-transduced (median survival, 63 days; tumor eradication in 20% of mice) or control CAR–transduced (median survival, 36 days) T cells (Figure 1A, 1B). Furthermore, CD28 costimulation enhanced CD62L[-]CD45RA[-] effector memory T-cell persistence (Figure 1C), leading to a robust T-cell proliferative response and superior control of tumor burden on tumor rechallenge 87 days after T-cell administration (Figure 1D, 1E). Figure 1Conclusion
CD28 costimulation plays an important role in achieving long-term antitumor efficacy and functional persistence in mesothelin-targeted T-cell therapy. These data provide the scientific rationale for our upcoming clinical trial for pleural malignancies.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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O08.03 - T-cell Imaging to Noninvasively Monitor Adoptive T-cell Therapy for Thoracic Malignancies (ID 2994)
16:35 - 16:45 | Author(s): L.A. Rodriguez
- Abstract
- Presentation
Background
Noninvasive T-cell imaging technology allows monitoring of adoptive T-cell responses without the need for invasive biopsies. Herein, we report dynamic imaging of tumor-targeted T cells in preclinical models by use of luminescent-enhanced firefly luciferase vector, and we further demonstrate the successful use of a clinical-grade herpes simplex virus type 1 thymidine kinase (HSV1-tk)–incorporated vector for monitoring of T-cell trafficking, antigen-specific proliferation, and biodistribution.Methods
T cells transduced with mesothelin-targeted chimeric antigen receptors (M28z) were either cotransduced with an enhanced firefly luciferase vector (effLuc-M28z) or singly transduced with HSV1-tk-M28z (TK-M28z). To simultaneously visualize tumor during T-cell PET imaging, cancer-cell imaging was performed using MSTO-GFP/ffLuc+ (MSTO-211H cells transduced to express mesothelin and the green fluorescent protein/firefly luciferase fusion protein). In vitro, uptake of [18]F-FEAU radiotracer by T cells was measured by [3]H channel counting. In vivo studies used either SCID-beige or NSG mice bearing pleural or flank tumors. Bioluminescence imaging (BLI) quantification was determined by the mean number of photons per second in the region of interest. PET imaging with [18]F-FEAU was performed in a 3-dimensional microPET scanner. T-cell imaging results were validated by flow cytometric and immunohistochemical analysis of harvested tissue.Results
Quantification studies showed a linear relationship between photon emission and T-cell number both in vitro and in vivo. In vivo, evaluation of T-cell biodistribution kinetics, by intravenous administration of effLuc-M28z T cells into mice bearing flank tumors, demonstrated initial accumulation of T cells in the lungs, liver, and spleen and progressive accumulation in the tumor (Figure 1A). Pleurally administered effLuc-M28z+ T cells displayed an increasing BLI signal (5-fold; p<0.01) in response to antigen 72 hours after administration, compared with pleurally administered effLuc+ T cells alone (control) (Figure 1B). T-cell accumulation in pleural tumor and extrathoracic sites (spleen) was confirmed by flow cytometric analysis of tissues harvested at serial time points (Figure 1C). These results were reproduced with clinical-grade vector TK-M28z+ T cells administered intrapleurally in mice bearing pleural tumor. Serial [18]F-FEAU PET imaging showed antigen-specific T-cell accumulation with decreasing tumor burden, as seen by corresponding tumor BLI (Figure 1D). Figure 1Conclusion
We provide an optimized method for monitoring of T-cell trafficking, localization and proliferation in thoracic malignancies. Our findings—derived using a clinical-grade imaging construct and substrate—provide convincing evidence for the use of noninvasive T-cell monitoring in our upcoming adoptive T-cell therapy clinical trial.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
