Download Abstracts
Total Page：16
File Type：pdf, Size：1020Kb
ABSTRACTS International Society for Biological Therapy of Cancer 23rd Annual Meeting Abstracts (Primary Authors are Italicized) at present little is known regarding the immunobiology of BTSCs, including their intrinsic ability to be recognized by cytolytic T lymphocytes (CTLs) based on antigen presentation and antigen ADOPTIVE TRANSFER processing, their sensitivity to CTL-mediated effector mechanisms such as perforin/granzyme lytic pathways, or their employment of potential Selective Expansion of Human T Regulatory Cell Subsets and escape mechanisms that render CTLs anergic or apoptotic. We have expanded the CD133+ cancer stem cell population from T-cell Depletion: Role of Rapamycin (Sirolimus) primary human brain tumors and have demonstrated that these cells do 1,2 2 1 Christoph Bergmann , Laura Strauss , Stephan Lang , exhibit stem cell-like properties: they (1) grow in neurosphere-like 1,2 2 1 Magis Mandapathil , Theresa L. Whiteside . Department of Otorhino- clusters; (2) self-renew in vitro to reform secondary neurospheres; 2 laryngology, University of Duisburg-Essen, Essen, Germany; Department of (3) express stem cell markers; (4) differentiate to express lineage specific Pathology, University of Pittsburgh Cancer Institute, Pittsburgh, PA. markers; and (5) form tumors in nonobese diabetic-severely compro- Objective: The immunosuppressive drug rapamycin promotes the mised immunodeficient mice. We are currently evaluating the utility of expansion of regulatory T-cell subsets, CD4+CD25high Foxp3+ and T cells for BTSC elimination. Using target populations that are either interleukin (IL)-10+ Tr1 cells. The mechanisms still remain unknown. loaded with a cytomegalovirus (CMV) pp65 immunodominant peptide Here, we studied expansion, survival and apoptotic pathways of human or engineered to express CMV pp65, we show that BTSCs are killed by regulatory T cells (nTreg) and Tr1 cells in response to rapamycin. CMV-specific T cells as efficiently as matched differentiated tumor lines Methods: CD4+CD25+ and CD4+CD25 À T cells were sorted from in vitro; and CMV-specific CTL are capable of ablating the in vivo peripheral blood mononuclear cells of normal controls (n = 15) using tumor initiation of ex vivo expanded pp65+ BTSC tumor spheres. AutoMACS. CD4+CD25+ T cells were expanded in the presence of Furthermore, we demonstrate that chimeric immunoreceptor redirected anti-CD3/CD28 Abs and 1000 IU/mL IL-2 for 3 weeks (nTreg). Sorted IL13Ra2-specific CTL, presently being evaluated in an FDA-approved CD4+CD25 À T cells were co-cultured with autologous immature pilot phase I trial, can kill IL13Ra2-expressing BTSCs in vitro, and dendritic cells and tumor cells of HNSCC cell line in presence of low reduce the engrafted potential of this population in an orthotopic murine doses of IL-2, IL-10, and IL-15 for 10 days (Tr1 cells). Rapamycin tumor model. Current models now predict that curative therapies for (1 nM) was added to half of the cultures. After harvest, phenotype many cancers will require the elimination of the stem/progenitor expression of survival proteins or rapamycin-induced apoptosis (Annex- population, and our studies lay the foundation for an immunotherapy inV) was determined. Regulatory function was tested in co-cultures with approach to achieve this goal. autologous CFSE-labeled CD4+CD25 À or CD8+CD25 À T responders. Results: Expansion of CD4+CD25high Foxp3+ nTreg cells was significantly promoted after expansion of CD4+CD25+ T cells in Adoptive Transfer of ‘‘Young’’ MART1/Melan-A CTL presence of rapamycin (P<0.001) and cells showed high suppressor Generated With Artificial APC and IL-2/IL-15: Emergence and activity (>82%). Furthermore, rapamycin promoted up-regulation of Persistence of a Memory/Effector Phenotype antiapoptotic and down-regulation of proapoptotic proteins on nTreg, opposed to inverse effect on naive T cells. In vitro induction of Tr1 cells Marcus O. Butler, Philip A. Friedlander, Mary Mooney, with suppressor activity in CD4+CD25 À T cells was significantly Alla Berezovskaya, Linda Drury, Marisa Flavin, Andrew Murray, augmented in presence of rapamycin, as was level of expressions of Osamu Imataki, Makito Tanaka, Heather Daley, Myriam Armant, apoptotic proteins and cytotoxins on these cells. Both nTreg and Tr1 Grace Kao, Frank Stephen Hodi, Lee M. Nadler, Naoto Hirano. Dana- cells were resistant to rapamycin-mediated apoptosis. Farber Cancer Institute, Harvard Medical School, Boston, MA. Conclusions: Rapamycin models the sensitivity of effector and suppres- We are conducting a ‘‘first-in-human’’ study of adoptively transferred sor T cells to apoptosis favoring the survival of Treg subsets, nTreg and MART1/Melan-A–specific cytotoxic T lymphocytes (CTL) lines in Tr1 cells. Thus, this drug is applicable decedent studies of these cells and metastatic melanoma. Autologous CD8+ T cells are stimulated weekly may be beneficial in immunotherapy in T-cell mediated diseases. with peptide-pulsed human cell-based artificial antigen presenting cell (APC) and expanded with low-dose interleukin (IL)-2 and IL-15. After 3 weeks, polyclonal MART1 CTLs are reinfused without chemotherapy, IL-2, or vaccination. Two reinfusions are scheduled per subject where Targeted Elimination of Brain Tumor Stem Cells With T-cell the second graft is produced from CD8+ T cells harvested 14 days after Therapies the first reinfusion. To date, Z4 Â 109 CTL with potent effector function Christine E. Brown1, Renate Starr1, Catalina Martinez1, and central effector memory phenotype were successfully generated for Stanley R. Riddell2, Behnam Badie3, Michael C. Jensen1. 1Division of all enrolled subjects. Five CTL infusions were administered to 3 subjects Cancer Immunotherapeutics and Tumor Immunology; 2Division of Allergy at 2 Â 108/m2 (39% MART1 multimer positivity, median). Clinically, all and Infectious Diseases, Fred Hutchinson Cancer Research Center, infusions were well tolerated. Multimer staining showed that, immedi- Seattle, WA; 3Department of Neurosurgery, City of Hope, Duarte, CA. ately postinfusion, the percentage of CD8+ T cells specific for MART1 Human brain tumors have been shown to consist of a subset of cells, temporarily increased in all subjects. In subject 2, a sustained 2.2-fold which exhibit stem cell-like properties and can drive tumor formation. increase in MART1 T cells was observed 21 and 39 days after the second Brain tumor stem/progenitor cells (BTSCs) are a formidable cellular Infusion. Interestingly, in this subject, immunophenotyping of periph- target for current therapeutic regimens, and have been shown to be eral MART1 CTL converted from a naive to a mixture of naive/memory chemoresistant and radioresistant due to the high expression of phenotypes. We identified 10 individual MART1 T-cell clonotypes from multidrug resistant pumps, antiapoptotic genes, and preferential peripheral CD45RA– memory T cells on day 21. Clonotypic TCR Vb activation of the DNA damage response pathway. We hypothesize that CDR3 analysis revealed that 7 out of 10 of these clonotypes existed in the glioma cancer stem cell population represents a clinical entity that CTL grafts. Furthermore, 4 clonotypes persisted in the peripheral is attractive for cellular immunotherapeutic intervention. However, CD45RA– memory fraction on day 39. This data suggests that J Immunother Volume 31, Number 9, November–December 2008 921 Abstracts J Immunother Volume 31, Number 9, November–December 2008 adoptively transferred ‘‘young’’ MART1 CTL are endowed with the capacity to persist in vivo without additional immunomodulation. In Intralesional Placement of Lymphokine-activated Killer (LAK) subject 3, who showed a mixed clinical response, 5 individual MART1 Cells After Resection of Primary Glioblastoma (GBM) T-cell clonotypes were isolated from lung metastases. Four out of 5 Robert O. Dillman, Christopher Duma, Robin Ellis, Andrew N. Cornforth, clones were included in the CTL grafts. This finding supports the Patric M. Schiltz, Shari Sharp, Carol DePriest. Hoag Cancer Center, possibility that infused CTL can traffic and localize to sites of disease. Newport Beach, CA. Intriguingly, in both subjects, we were able to identify MART1 CTL Background: Median survival for resectable glioblastoma (GBM) clonotypes that were not detectable in the CTL grafts but possibly patients is only 12 to 15 months, even with the addition of intraoperative emerged after CTL infusion, indicating that adoptive transfer of BCNU chemotherapy wafers or adjuvant temozolomide; so an addi- MART1-specific CTL may provoke a de novo antitumor response. tional effective adjuvant treatment would be desirable. We previously Taken together, these results suggest that ‘‘young’’ MART1 CTL observed minimal toxicity and an encouraging 9-month median survival generated ex vivo with a cell-based artificial APC in the presence of IL-2 and 34% 1-year survival from the date of treatment with intralesional and IL-15 may persist in vivo and induce de novo anti-tumor responses. autologous lymphokine-activated killer (LAK) cells in 40 patients with After completion of initial safety studies, we will introduce other recurrent GBM (J Immunother. 2004;27:398–404,). The purpose of the immunomodulators such as lymphodepletion, IL-2 administration, and/ current study was to obtain safety and efficacy data for the use of LAK or checkpoint blockade with anti-CTLA4 monoclonal antibody to our cells placed intralesionally in patients with surgically proven GBM as artificial APC-based adoptive T-cell therapy. part of primary therapy rather than after disease