Tumor-specific Tumor-infiltrating Lymphocytes Research Articles

Epithelial ovarian cancer is infiltrated by activated effector T cells co-expressing CD39, PD-1, TIM-3, CD137 and interacting with cancer cells and myeloid cells.

Despite predicted efficacy, immunotherapy in epithelial ovarian cancer (EOC) has limited clinical benefit and the prognosis of patients remains poor. There is thus a strong need for better identifying local immune dynamics and immune-suppressive pathways limiting T-cell mediated anti-tumor immunity. In this observational study we analyzed by immunohistochemistry, gene expression profiling and flow cytometry the antigenic landscape and immune composition of 48 EOC specimens, with a focus on tumor-infiltrating lymphocytes (TILs). Activated T cells showing features of partial exhaustion with a CD137+CD39+PD-1+TIM-3+CD45RA-CD62L-CD95+ surface profile were exclusively present in EOC specimens but not in corresponding peripheral blood or ascitic fluid, indicating that the tumor microenvironment might sustain this peculiar phenotype. Interestingly, while neoplastic cells expressed several tumor-associated antigens possibly able to stimulate tumor-specific TILs, macrophages provided both co-stimulatory and inhibitory signals and were more abundant in TILs-enriched specimens harboring the CD137+CD39+PD-1+TIM-3+CD45RA-CD62L-CD95+ signature. These data demonstrate that EOC is enriched in CD137+CD39+PD-1+TIM-3+CD45RA-CD62L-CD95+ T lymphocytes, a phenotype possibly modulated by antigen recognition on neoplastic cells and by a combination of inhibitory and co-stimulatory signals largely provided by infiltrating myeloid cells. Furthermore, we have identified immunosuppressive pathways potentially hampering local immunity which might be targeted by immunotherapeutic approaches.

Structure-based prediction of neoantigens paired with T cell receptors on pre-existing CD8+ tumor-infiltrating lymphocytes.

e14583 Background: Tumor neoantigens have ability to expand tumor-specific T cell immunity, which could be boosted by anti-PD-1 immunotherapy. Therapeutically relevant neoantigens should be presented on patient HLAs and recognized by tumor-reactive T cells. Despite tumor-infiltrating lymphocytes (TILs) have enriched tumor-reactive T cell populations, most tumor-specific TILs exhibit exhausted phenotype and have limitations to in vitro screening. Here, we developed in silico structure-based prediction of neoantigen discovery pipeline by pairing with T cell receptors (TCRs) on pre-existing CD8+ exhausted tumor-infiltrating lymphocytes. Methods: Tumor resections from patients with liver, stomach, colorectal, and lung cancers are subject to whole exome and transcriptome. In addition, TILs from the patients are subject to scRNA/TCRseq to select TCRs of exhausted T cells, which are mostly thought to have tumor-reactivity. Neoantigen epitopes are prioritized from our in silico pipeline including HLA binding and TCR-peptide-HLA structure-based pairing score. To evaluate the immunogenicity of selected neoantigens, the neoantigens are tested for in vitro IFNg ELISPOT assay using peripheral blood mononuclear cells (PBMCs) from the same patients, which sensitively detects antigen-experienced T cells. Results: For 5 patients with T cell-reactive neoantigens, among 23 neoantigens selected by our in silico pipeline and tested in vitro, 10 neoantigens showed positive pre-existing T cell responses by matched patients. Then, we analyzed gene expression profiles of TILs paired in silico with in vitro T cell response-positive or negative neoantigens (pTILs and nTILs, respectively) combined with TILs from 23 solid cancer patients. Interestingly, pTILs were mostly mapped to the clusters which highly expressed markers of exhaustion and cytotoxicity, while nTILs showed random distribution across all the clusters. Conclusions: Neoantigen prediction using structure-based pairing of neoantigens and phenotype-selected TILs showed promising potential to better select therapeutically-relevant cancer vaccines. This data supports further investigation of our in silico pipeline into more patient samples and preclinical studies in mouse tumor models.

Combined IL-2, agonistic CD3 and 4-1BB stimulation preserve clonotype hierarchy in propagated non-small cell lung cancer tumor-infiltrating lymphocytes

BackgroundAdoptive cell transfer (ACT) of tumor-infiltrating lymphocytes (TIL) yielded clinical benefit in patients with checkpoint blockade immunotherapy-refractory non-small cell lung cancer (NSCLC) prompting a renewed interest in TIL-ACT. This preclinical...

Selective delivery of low-affinity IL-2 to PD-1+ T cells rejuvenates antitumor immunity with reduced toxicity.

PD-1 signaling on T cells is the major pathway that limits T cell immunity, but the efficacy of anti–PD-1 therapy has been limited to a small proportion of patients with advanced cancers. We fortuitously observed that anti–PD-1 therapy depends on IL-2 signaling, which raises the possibility that a lack of IL-2 limits anti–PD-1–induced effector T cell expansion. To selectively deliver IL-2 to PD-1+CD8+ tumor-infiltrating lymphocytes (TILs), we engineered a low-affinity IL-2 paired with anti–PD-1 (PD-1–laIL-2), which reduced affinity to peripheral Treg cells but enhanced avidity to PD-1+CD8+ TILs. PD-1–laIL-2 exerted better tumor control and lower toxicity than single or mixed treatments. Mechanistically, PD-1–laIL-2 could effectively expand dysfunctional and tumor-specific CD8+ T cells. Furthermore, we discovered that presumably dysfunctional PD-1+TIM3+ TILs are the dominant tumor-specific T cells responding to PD-1–laIL-2. Collectively, these results highlight that PD-1–laIL-2 can target and reactivate tumor-specific TILs for tumor regression as a unique strategy with stronger efficacy and lower toxicity.

Tumor-Infiltrating Lymphocytes (TILs) as a Biomarker of Abscopal Effect of Cryoablation in Breast Cancer: A Pilot Study

BackgroundMorphological evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer is gaining momentum as an immunological biomarker. This experiment evaluates the role of TILs in distant tumors as a measure of abscopal effect from cryoablation of breast cancer.MethodsBALB/c mice underwent bilateral orthotopic transplant with 4T1-12B (triple-negative) cells. At 2 weeks, left tumors were treated by either resection (standard of care group) or cryoablation (intervention group) followed by resection of the distant right tumors 1 week posttreatment. TIL scores were calculated from hematoxylin and eosin-stained sections and phenotyped for cytotoxic T-lymphocyte (CTL) markers by immunofluorescence. Primarily resected tumors served as baseline (Tbaseline), whereas resected distant right-sided served as the readout for abscopal effect (AbsRes or AbsCryo). Mice were monitored for tumor recurrence and metastasis.ResultsThe AbsCryo had a significant mean (SD) increase in stromal (2.8 [1.1]%; p = 0.015) and invasive margin TILs (50 [12]%; p = 0.02) compared with TBaseline (1.0 [0]% and 31 [4.9]%, respectively). CTL phenotyping revealed a significant increase in mean (SD) CD8+ T cells (15.7 [12.1]; p = 0.02) and granzyme B (4.8 [3.6]; p = 0.048) for the AbsCryo compared with TBaseline (5.2 [4.7] and 2.4 [0.9], respectively). Posttreatment, the cryoablation group had no recurrence or metastasis, whereas the resected group showed local recurrence and lung metastasis in 40% of the mice. Postprocedure increase in TIL score of distant tumors was associated with decrease in tumor relapse (p = 0.02).ConclusionsCryoablation induced a robust tumor-specific TIL response compared with resection, suggesting an abscopal effect leading to the prevention of cancer recurrence and metastasis.

Systematic analysis of CD39, CD103, CD137, and PD-1 as biomarkers for naturally occurring tumor antigen-specific TILs.

The detection of tumor-specific T cells in solid tumors is integral to interrogate endogenous antitumor responses and to advance downstream therapeutic applications. Multiple biomarkers are reported to identify endogenous tumor-specific tumor-infiltrating lymphocytes (TILs), namely CD137, PD-1, CD103, and CD39; however, a direct comparison of these molecules has yet to be performed. We evaluated these biomarkers in primary human ovarian tumor samples using single-cell mass cytometry to compare their relative phenotypic profiles, and examined their response to autologous tumor cells ex vivo. PD-1+ , CD103+ , and CD39+ TILs all contain a CD137+ cell subset, while CD137+ TILs highly co-express the aforementioned markers. CD137+ TILs exhibit the highest expression of cytotoxic effector molecules compared to PD-1+ , CD103+ , or CD39+ TILs. Removal of CD137+ cells from PD-1+ , CD103+ , or CD39+ TILs diminish their IFN-γsecretion in response to autologous tumor cell stimulation, while CD137+ TILs maintain high HLA-dependent IFN-γ secretion. CD137+ TILs exhibited an exhausted phenotype but with CD28 co-expression, suggesting possible receptiveness to reinvigoration via immune checkpoint blockade. Together, our findings demonstrate that the antitumor abilities of PD-1+ , CD103+ , and CD39+ TILs are mainly derived from a subset of CD137-expressing TILs, implicating CD137 as a more selective biomarker for naturally occurring tumor-specific TILs.

Abstract 2978: Unique 3D organoids autologous TIL coculture platform enables high throughput immune-oncology drug response studies

Abstract Background: Cancer progression and response to therapy are governed by complex cellular interactions in the tumor microenvironment (TME). A better understanding of TME and the immune microenvironment requires robust experimental systems modeling patient specific immune interactions. Conventional 2D cultures lack in recapitulating 3D morphological structures and complex immune biology of native human tumors. A vastly heterogenous TME impacts patient treatment response. There is a dearth of 2D or 3D in vitro models that mimic in vivo diversity of TME, including infiltrating immune populations. 3D organoid cultures typically contain neoplastic epithelium and fail to retain syngeneic tumor-infiltrating lymphocytes (TILs) interactions vital for exhibiting a clinically significant drug response. Here we describe patient-derived xenograft (PDX) derived 3D organoid (PDXO) cultures with autologous TILs to avoid alloreactivity and simulate tumor specific immune response. The described model allows the evaluation of TIL infiltration and high throughput screening of immune-modulatory therapies. Methods: Patient-derived xenografts from mice were enzymatically digested to establish PDXO. PDXO were characterized for expression of cancer specific cell-surface markers. TILs were expanded in culture from PBMCs from matching patients and characterized using flow cytometry. Organoids and TILs from the same patient were fluorescently labeled and cocultured for four days, and tumor infiltration and drug cytotoxicity with and without immune-therapeutics was evaluated. CellInsight CX7 high content imaging platform was used to track TILs, and cancer cells, and TIL infiltration was confirmed via immunofluorescence. Luminex technology was used to quantify changes in the cytokine profile upon drug treatment. Results: PDXO were established to mimic in vivo tumor biology. Tumor-specific TILs were expanded and characterized for expression of memory, inhibitory, proliferation, and regulatory T cell markers. TIL infiltration in organoids was observed from day one in culture and maintained over four days. Immunofluorescence for T cell marker CD3 (cluster of differentiation 3) within PDXO confirmed TIL infiltration. Infiltrating TILs and tumor cell killing evaluation using fluorescent dyes via high throughput imaging platform showed disease and patient-specific response. PDXO treatment with immune-modulatory therapeutics led to changes in the secreted levels of cytokines IL2 (interleukin 2), IFNγ (interferon gamma), and TNFα (tumor necrotic factor alpha). Conclusion: Our patient autologous TILs - PDXO culture platform can be used for high throughput drug screening to model immune-therapeutic response with the tumor specific immune microenvironment. Citation Format: Garima Kaushik, Padma Kamineny, Amy Wesa. Unique 3D organoids autologous TIL coculture platform enables high throughput immune-oncology drug response studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2978.

Abstract 2178: Expansion of tumor-specific tumor-infiltrating lymphocytes (TIL) from head and neck tumors

Abstract Background: Until recently, treatment options for patients with head and neck cancer include a combination of surgery, chemotherapy and radiation. Although the combined use of these treatment options modestly improves survival, combination therapy increases toxicity. Overall survival of these treatment regimens for patients with advanced head and neck cancer is just over 10 months. Even with the newly approved and vastly more tolerable use of anti-PD-1 immunotherapy, survival is only extended by 3-5 months. In comparison, adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) has improved the median overall survival in patients with metastatic melanoma to 52 months. The goal of this study was to test the feasibility of expanding tumor-reactive TIL from head and neck tumors for the development of a clinical trial. Methods: Primary tumors were resected from 20 head and neck cancer patients. Tumors were minced into small fragments (1-3 mm3) and plated in high dose IL-2. After 4 weeks, expanded TIL were phenotyped by flow cytometry and tested for tumor reactivity by IFN-gamma production after co-culture of TIL with autologous tumor digest. IFN-gamma levels were determined by ELISA. Reactive TIL were expanded using a rapid expansion protocol (REP). Results: The mean expansion of TIL per fragment was 1.96 × 106. From 20 primary tumors, seven were contaminated and discarded. TIL were successfully expanded from 11/13 (85%) evaluable tumors. The phenotype of expanded TIL consisted of CD3− CD56+ NK cells and CD3+ T cells. Tumor-specific reactivity was analyzed for seven samples. TIL expanded from three (43%) tumors were predominantly CD8+ and were reactive against autologous tumor as determined by IFN-gamma ELISA. Expansion of TIL during REP resulted in an average 600-fold increase in cell numbers (range of 61 - 1,774 fold) and led to the depletion of NK cells and an increase of CD3+ T cells. Conclusions: In this study, we have demonstrated the feasibility of growing tumor-reactive TIL from head and neck tumors. This study raises the potential for the implementation of ACT with TIL for the treatment of head and neck cancer patients. Citation Format: Luz Nagle, Amy Mackay Weber, MacLean Hall, Matthew Beatty, J. Trad Wadsworth, Caitlin McMullen, Krupal Patel, Kathryn Vorwald, Christine Chung, Shari Pilon-Thomas. Expansion of tumor-specific tumor-infiltrating lymphocytes (TIL) from head and neck tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2178.

Oncolytic virus promotes tumor-reactive infiltrating lymphocytes for adoptive cell therapy.

Adoptive cell therapy (ACT) using tumor-specific tumor-infiltrating lymphocytes (TILs) has demonstrated success in patients where tumor-antigen specific TILs can be harvested from the tumor, expanded, and re-infused in combination with a preparatory regimen and IL2. One major issue for non-immunogenic tumors has been that the isolated TILs lack tumor specificity and thus possess limited in vivo therapeutic function. An oncolytic virus (OV) mediates an immunogenic cell death for cancer cells, leading to elicitation and dramatic enhancement of tumor-specific TILs. We hypothesized that the tumor-specific TILs elicited and promoted by an OV would be a great source for ACT for solid cancer. In this study, we show that a local injection of oncolytic poxvirus in MC38 tumor with low immunogenicity in C57BL/6 mice, led to elicitation and accumulation of tumor-specific TILs in the tumor tissue. Our analyses indicated that IL2-armed OV-elicited TILs contain lower quantities of exhausted PD-1hiTim-3+ CD8+ T cells and regulatory T cells. The isolated TILs from IL2-expressing OV-treated tumor tissue retained high tumor specificity after expansion ex vivo. These TILs resulted in significant tumor regression and improved survival after adoptive transfer in mice with established MC38 tumor. Our study showcases the feasibility of using an OV to induce tumor-reactive TILs that can be expanded for ACT.

In vitro 4-1BB stimulation promotes expansion of CD8+ tumor-infiltrating lymphocytes from various sarcoma subtypes.

Tumor-specific tumor-infiltrating lymphocytes (TILs) can be in vitro expanded and have the ability to induce complete and durable tumor regression in some patients with melanoma following adoptive cell therapy (ACT). In this preclinical study, we investigated the feasibility of expanding TIL from sarcomas, as well as performing functional in vitro analyses on these. TILs were expanded in vitro by the use of IL2 stimulation with or without the addition of 4-1BB and CD3 antibodies. Phenotypical and functional analyses were mainly performed by flow cytometry. TILs were expanded from 25 of 28 (89%) tumor samples from patients with 9 different sarcoma subtypes. TILs were predominantly αβ T-cells of effector memory subtype with CD4+ dominance. In particular, CD8+ TIL highly expressed LAG3 and to a lesser degree PD-1 and BTLA. In total, 10 of 20 TIL cultures demonstrated in vitro recognition of autologous tumor. In some cases, the fraction of tumor-reactive T cells was more than 20%. 4-1BB stimulation augmented expansion kinetics and favored CD8+ occurrence. In conclusion, TIL expansion from sarcoma is feasible and expanded TILs highly express LAG3 and comprise multifunctional tumor-reactive T-cells.

Multi-dimensional analysis of tumor-specific and bystander CD8+ tumor infiltrating lymphocytes with TetTCR-SeqHD

Abstract Objective Antigen specific CD8+ T cells were isolated from primary tumor tissue and analyzed for on the single cell level to determine tumor-specific signatures for further study. Methods Primary tumor, metastatic lesions, adjacent healthy tissue and peripheral blood were from collected from patients at Dell Seton Medical Center at the University of Texas. Matched tumor and healthy samples underwent exome and RNA sequencing to allow prediction of tumor-specific epitopes. We then synthesized DNA-barcoded tetramers for all predicted tumor associated-epitopes and an HLA-matched library of exogenous epitopes. Tetramer stained CD8+ T cells were then sorted and analyzed by TetTCR-SeqHD, a technology that we recently developed to link TCR antigen specificity, TCR sequence, gene expression, and phenotype of single T cells. Results We analyzed ~2900 tumor infiltrating lymphocytes (TILs) and T cells from adjacent healthy tissue and observed enrichment for cytotoxic effector and tissue resident memory cells within the tumor versus the healthy tissues. We also note an enrichment of bystander cells, specifically those reactive to Epstein Barr Virus epitopes, within the cytotoxic cluster. Finally, we analyze the distribution and differential expression between tumor-specific lymphocytes and bystander T cells, noting reduced expression of CD57 and CD49d in the tumor-specific TILs, as previously described. Conclusions We validate the use of TetTCR-SeqHD for gaining insight into phenotypic and gene expression differences between bystander and tumor-specific TILs. We identified markers for future exploration and demonstrate key differences between shared clonal populations within healthy and cancerous tissues.

Abstract B154: Differential effects of corticosteroids and anti-TNF on tumor-specific immune responses— Implications for the management of irAEs

Abstract Background: Up to 60% of patients treated with cancer immunotherapy develop severe or life threatening immune-related adverse events (irAEs). Immunosuppression with high doses of corticosteroids or, in refractory cases, with tumor necrosis factor (TNF) antagonists, are the mainstay of treatment for irAEs. It is currently unknown what is the impact of corticosteroids and anti-TNF on the activity of antitumor T-cells. Methods: The influence of clinically relevant doses of dexamethasone (corresponding to an oral dose of 10 to 125 mg prednisolone) and infliximab (anti-TNF) on the activation and killing capacity of tumor-infiltrating lymphocytes (TILs) was tested in vitro. Results: Overall, dexamethasone at low or intermediate/high dose impaired the activation (respectively -46% and -62% in n=8) and tumor-killing ability (respectively -48% and -53% in n=6) of tumor-specific TILs. In contrast, a standard clinical dose of infliximab only had a minor effect on T-cell activation and tumor killing (respectively -20% in n=8 and -10% in n=6). A brief resting following exposure to dexamethasone was sufficient to rescue the in vitro activity of TILs. Conclusions: Clinically relevant doses of infliximab only influenced to a lesser extent the activity of tumor-specific TILs in vitro, whereas even low doses of corticosteroids markedly impaired the antitumor activity of TILs. These data support steroid-sparing strategies and early initiation of anti-TNF for the treatment of irAEs in immuno-oncology. Citation Format: Marco Donia, Troels H. Borch, Haja D. Radic, Christopher Chamberlain, Aishwarya Gokuldass, Inge Marie Stentoft Svane, Arianna Draghi. Differential effects of corticosteroids and anti-TNF on tumor-specific immune responses— Implications for the management of irAEs [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B154.

Differential effects of corticosteroids and anti-TNF on tumor-specific immune responses: implications for the management of irAEs.

Up to 60% of patients treated with cancer immunotherapy develop severe or life threatening immune-related adverse events (irAEs). Immunosuppression with high dose corticosteroids, or tumor necrosis factor (TNF) antagonists in refractory cases, is the mainstay of treatment for irAEs. It is currently unknown what impact corticosteroids and anti-TNF have on the activity of antitumor T cells. In our study, the influence of clinically relevant doses of dexamethasone (corresponding to an oral dose of 10-125 mg prednisolone) and infliximab (anti-TNF) on the activation and killing ability of tumor-infiltrating lymphocytes (TILs) was tested in vitro. Overall, dexamethasone at low or intermediate/high doses impaired the activation (-46 and -62%, respectively) and tumor-killing ability (-48 and -53%, respectively) of tumor-specific TILs. In contrast, a standard clinical dose of infliximab only had a minor effect on T cell activation (-20%) and tumor killing (-10%). A 72-hr resting period after withdrawal of dexamethasone was sufficient to rescue the in vitro activity of TILs, while a short withdrawal did not result in a full rescue. In conclusion, clinically relevant doses of infliximab only had a minor influence on the activity of tumor-specific TILs in vitro, whereas even low doses of corticosteroids markedly impaired the antitumor activity of TILs. However, the activity of TILs could be restored after withdrawal of steroids. These data indirectly support steroid-sparing strategies and early initiation of anti-TNF therapy for the treatment of irAEs in immuno-oncology.

52P - Differential effects of corticosteroids and anti-TNF on tumor-specific immune responses: Implications for the management of irAEs

Up to 60% of patients treated with cancer immunotherapy develop severe or life threatening immune-related adverse events (irAEs). Immunosuppression with high dose corticosteroids, or tumor necrosis factor (TNF) antagonists in refractory cases, is the mainstay of treatment for irAEs. It is currently unknown what impact corticosteroids and anti-TNF have on the activity of antitumor T cells. In our study, the influence of clinically relevant doses of dexamethasone (corresponding to an oral dose of 10-125 mg prednisolone) and infliximab (anti-TNF) on the activation and killing ability of tumor-infiltrating lymphocytes (TILs) was tested in vitro. Overall, dexamethasone at low or intermediate/high doses impaired the activation (-46 and -62%, respectively) and tumor-killing ability (-48 and -53%, respectively) of tumor-specific TILs. In contrast, a standard clinical dose of infliximab only had a minor effect on T cell activation (-20%) and tumor killing (-10%). A 72-hr resting period after withdrawal of dexamethasone was sufficient to rescue the in vitro activity of TILs, while a short withdrawal did not result in a full rescue. In conclusion, clinically relevant doses of infliximab only had a minor influence on the activity of tumor-specific TILs in vitro, whereas even low doses of corticosteroids markedly impaired the antitumor activity of TILs. However, the activity of TILs could be restored after withdrawal of steroids. These data indirectly support steroid-sparing strategies and early initiation of anti-TNF therapy for the treatment of irAEs in immuno-oncology.

14PD - Expansion of tumor specific tumor-infiltrating lymphocytes (TIL) from sarcoma and the potential benefit of anti-CD137 stimulation: A prerequisite for adoptive cell transfer (ACT) immunotherapy

14PD - Expansion of tumor specific tumor-infiltrating lymphocytes (TIL) from sarcoma and the potential benefit of anti-CD137 stimulation: A prerequisite for adoptive cell transfer (ACT) immunotherapy

Selection of Shared and Neoantigen-Reactive T Cells for Adoptive Cell Therapy Based on CD137 Separation.

Adoptive cell therapy (ACT) of autologous tumor infiltrating lymphocytes (TIL) is an effective immunotherapy for patients with solid tumors, yielding objective response rates of around 40% in refractory patients with metastatic melanoma. Most clinical centers utilize bulk, randomly isolated TIL from the tumor tissue for ex vivo expansion and infusion. Only a minor fraction of the administered T cells recognizes tumor antigens, such as shared and mutation-derived neoantigens, and consequently eliminates the tumor. Thus, there are many ongoing effects to identify and select tumor-specific TIL for therapy; however, those approaches are very costly and require months, which is unreasonable for most metastatic patients. CD137 (4-1BB) has been identified as a co-stimulatory marker, which is induced upon the specific interaction of T cells with their target cell. Therefore, CD137 can be a useful biomarker and an important tool for the selection of tumor-reactive T cells. Here, we developed and validated a simple and time efficient method for the selection of CD137-expressing T cells for therapy based on magnetic bead separation. CD137 selection was performed with clinical grade compliant reagents, and TIL were expanded in a large-scale manner to meet cell numbers required for the patient setting in a GMP facility. For the first time, the methodology was designed to comply with both clinical needs and limitations, and its feasibility was assessed. CD137-selected TIL demonstrated significantly increased antitumor reactivity and were enriched for T cells recognizing neoantigens as well as shared tumor antigens. CD137-based selection enabled the enrichment of tumor-reactive T cells without the necessity of knowing the epitope specificity or the antigen type. The direct implementation of the CD137 separation method to the cell production of TIL may provide a simple way to improve the clinical efficiency of TIL ACT.

Expansion of Tumor-Infiltrating CD8+ T cells Expressing PD-1 Improves the Efficacy of Adoptive T-cell Therapy.

Recent studies have found that tumor-infiltrating lymphocytes (TIL) expressing PD-1 can recognize autologous tumor cells, suggesting that cells derived from PD-1+ TILs can be used in adoptive T-cell therapy (ACT). However, no study thus far has evaluated the antitumor activity of PD-1-selected TILs in vivo In two mouse models of solid tumors, we show that PD-1 allows identification and isolation of tumor-specific TILs without previous knowledge of their antigen specificities. Importantly, despite the high proportion of tumor-reactive T cells present in bulk CD8 TILs before expansion, only T-cell products derived from sorted PD-1+, but not from PD-1- or bulk CD8 TILs, specifically recognized tumor cells. The fold expansion of PD-1+ CD8 TILs was 10 times lower than that of PD-1- cells, suggesting that outgrowth of PD-1- cells was the limiting factor in the tumor specificity of cells derived from bulk CD8 TILs. The highly differentiated state of PD-1+ cells was likely the main cause hampering ex vivo expansion of this subset. Moreover, PD-1 precisely identified marrow-infiltrating, myeloma-specific T cells in a mouse model of multiple myeloma. In vivo, only cells expanded from PD-1+ CD8 TILs contained tumor progression, and their efficacy was enhanced by PDL-1 blockade. Overall, our data provide a rationale for the use of PD-1-selected TILs in ACT. Cancer Res; 77(13); 3672-84. ©2017 AACR.

MP48-20 EXPANSION OF TUMOR INFILTRATING LYMPHOCYTES (TIL) FROM PRIMARY BLADDER TUMORS

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology II1 Apr 2017MP48-20 EXPANSION OF TUMOR INFILTRATING LYMPHOCYTES (TIL) FROM PRIMARY BLADDER TUMORS Michael Poch, Maclean Hall, Krithika Kodumudi Kodumudi, Cortlin Croft, Mayer Fishman, John Mullinax, Amod Sarniak, James Mule, and Shari Pilon-Thomas Michael PochMichael Poch More articles by this author , Maclean HallMaclean Hall More articles by this author , Krithika Kodumudi KodumudiKrithika Kodumudi Kodumudi More articles by this author , Cortlin CroftCortlin Croft More articles by this author , Mayer FishmanMayer Fishman More articles by this author , John MullinaxJohn Mullinax More articles by this author , Amod SarniakAmod Sarniak More articles by this author , James MuleJames Mule More articles by this author , and Shari Pilon-ThomasShari Pilon-Thomas More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1501AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Patients with advanced bladder cancer have limited therapeutic options resulting in a median overall survival (OS) between 12 and 15 months. At our institution, adoptive cell therapy (ACT) using tumor infiltrating lymphocytes (TIL) has resulted in a durable median OS of 52 months in patients with metastatic melanoma. Immune-mediated anti-tumor responses have been previously shown in bladder cancer, therefore we investigated the phenotype and function of TIL expanded from bladder tumors to establish feasibility of ACT for the treatment of bladder cancer. METHODS Tumor specimens, including primary bladder tumors and lymph node metastases, were collected from 29 bladder cancer patients having standard of care tumor resection, who also had consented to an IRB-approved protocol for TIL generation. The tissue was minced into fragments, placed in individual wells of a 24-well plate, and propagated in high dose IL-2 for four weeks. TIL were considered expanded if they propagated to fill =2 wells. The remaining tumor material was digested into a single cell suspension and frozen. TIL were phenotyped by flow cytometry and assessed for autologous tumor reactivity through co-culture with tumor digest and IFN-gamma ELISA. RESULTS Twenty-seven of 29 tumors were harvested from radical cystectomy patients. Urothelial cell bladder tumors were cultured from 23 patients, of whom 19 (83%) demonstrated TIL expansion. Among these were 9/12 with preceding chemotherapy and 10/11 which had been chemotherapy naive. Expanded TIL were predominantly CD3+ (median 63%, range 10-87%) with a median of 30% CD8+ T cells (range 5-70%). Eight of 15 tested samples (53%) contained TIL that secreted IFN-gamma in response to autologous tumor. Microbial contamination was observed in six specimens. All lymphatic (5/5 samples) tissue collected demonstrated TIL expansion. CONCLUSIONS The study establishes the practical first step towards an autologous TIL therapy process for therapeutic testing in patients with bladder cancer. Human bladder cancer tissue can be used to expand tumor-specific TIL in vitro. TIL were also able to be expanded from patients that received chemotherapy prior to tumor resection. Future efforts will explore the ability to further expand bladder TIL cultures to clinically meaningful numbers to develop novel ACT strategies for patients with this diagnosis. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e645 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Michael Poch More articles by this author Maclean Hall More articles by this author Krithika Kodumudi Kodumudi More articles by this author Cortlin Croft More articles by this author Mayer Fishman More articles by this author John Mullinax More articles by this author Amod Sarniak More articles by this author James Mule More articles by this author Shari Pilon-Thomas More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Expansion of tumor infiltrating lymphocytes (TIL) from bladder cancer.

142 Background: Patients with advanced bladder cancer have limited therapeutic options resulting in a median overall survival (OS) between 12 and 15 months. At our institution, adoptive cell therapy (ACT) using tumor infiltrating lymphocytes (TIL) has resulted in a durable median OS of 52 months in patients with metastatic melanoma. Immune-mediated anti-tumor responses have been previously shown in bladder cancer, therefore we investigated the phenotype and function of TIL expanded from bladder tumors to establish feasibility of ACT for the treatment of bladder cancer. Methods: Tumor specimens, including primary bladder tumors and lymph node metastases, were collected from 29 bladder cancer patients having standard of care tumor resection, who also had consented to an IRB-approved protocol for TIL generation. The tissue was minced into fragments, placed in individual wells of a 24-well plate, and propagated in high dose IL-2 for four weeks. TIL were considered expanded if they propagated to fill ≥2 wells. The remaining tumor material was digested into a single cell suspension and frozen. TIL were phenotyped by flow cytometry and assessed for autologous tumor reactivity through co-culture with tumor digest and IFN-gamma ELISA. Results: Transitional cell bladder tumors were cultured from 23 patients, of whom 19 (83%) demonstrated TIL expansion. Microbial contamination precluded TIL growth in six specimens. TIL were cultured from 9/12 (75%) patients with preceding chemotherapy and 10/11 (91%) who were chemotherapy naive. Expanded TIL were predominantly CD3+(median 63%, range 10-87%) with a median of 30% CD8+ T cells (range 5-70%). Eight of 15 tested samples (53%) contained TIL that secreted IFN-gamma in response to autologous tumor. Conclusions: The study establishes the practical first step towards an autologous TIL therapy process for therapeutic testing in patients with bladder cancer. Human bladder cancer tissue can be used to expand tumor-specific TIL in vitro. TIL were also expanded from patients that received chemotherapy prior to tumor resection. Future efforts will explore the ability to further expand bladder TIL cultures to clinically meaningful numbers to develop novel ACT strategies for patients with this diagnosis.

Abstract B12: Immune checkpoint blockade to improve T cell infiltration and function in colorectal cancer

Abstract Adoptive transfer of tumor infiltrating lymphocytes (TIL) has emerged as a promising approach to induce effective anti-tumor immunity and tumor regression in various types of cancers. Current studies suggest that the presence of TIL play a role in patient outcomes and can predict tumor stage, node positivity, and in some reports, disease free and overall survival in patients with colorectal cancer. TIL may be inactivated in patients due to factors in the local tumor microenvironment, such as regulatory T cells, myeloid derived suppressor cells and the expression of a number of co-inhibitory immune checkpoints including PD-L1, BTLA, PD-1, CTLA-4, Lag-3 and Tim-3. We first examined the feasibility of expanding TIL from the tumors of three colorectal patients. Tumors were minced into fragments and cultured in media supplemented with 6000 IU IL2 / mL. TIL growth was observed in tumor fragments from each of the three patients with a total of 12 out of 41 fragments demonstrating TIL expansion. TIL grown out of these fragments were predominantly CD3+ with 32% CD4+T cells and 46% CD8+ T cells and 18.5% NK cells. Seven of the 12 fragments tested were tumor specific as demonstrated by IFN-gamma production in response to autologous tumor. CD8+ T cells within the patient TIL expressed PD-1, BTLA, Lag-3 and Tim-3 and a co-stimulatory molecule, 41BB. In addition, we found high levels of PD-L1 expression on tumors of colorectal patients and human colorectal cell lines. Since we observed high levels of immune checkpoints expression in colorectal patients, we wanted to develop a preclinical colorectal model to investigate the effect of immune checkpoint blockade on tumor growth and TIL function. A previous study from our lab has shown that TIL from our preclinical MC38 colorectal murine model express high levels of co-inhibitory checkpoints and that blockade of PD-L1 leads to enhanced infiltration and anti-tumor specificity of TIL. However, given the dynamic nature of immune responses to tumors and expression of multiple immune checkpoints, it may be necessary to block additional checkpoints to improve clinical efficacy. In this study, we examined whether blockade of the immune checkpoint receptor BTLA had an effect on TIL infiltration and tumor growth. Mice bearing MC-38 tumors treated with anti-BTLA antibody demonstrated a delay in tumor growth (150mm2, p<0.01) on day 28 post tumor injection compared to isotype control (300mm2). We observed an increase in CD8+ T cell infiltration (30%, p<0.001) in the tumors of anti-BTLA antibody treated mice compared to mice treated with isotype control (13%). TIL isolated from the anti-BTLA antibody treated mice demonstrated increased IFN-gamma and granzyme B secretion compared to isotype controls (p<0.001). Dual immune checkpoint blockade with anti-PD-L1 and anti-BTLA antibodies had a synergistic effect in delaying tumor growth. We also measured a significant increase in CD8+CD107a+IFN-gamma+ secreting T cells (37%) compared to TIL from mice treated with anti-PD-L1 (27%) or anti-BTLA antibody alone (25%) (p<0.002). These findings suggest that targeting immune checkpoint molecules can improve T cell infiltration and anti-tumor immunity in a preclinical model of colorectal cancer. In addition, we demonstrate that tumor-specific TIL can be expanded from the tumors of colorectal patients. This study presents a rationale for the potential synergy between blockade of multiple immune checkpoints and adoptive transfer of TIL for the treatment of colorectal cancer. Citation Format: Krithika N. Kodumudi, James Charles, Carrie Luu, John Mullinax, Julie Li, MacLean Hall, Amy Weber, Amod A. Sarnaik, Shari Pilon-Thomas. Immune checkpoint blockade to improve T cell infiltration and function in colorectal cancer. [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer: From Initiation to Outcomes; 2016 Sep 17-20; Tampa, FL. Philadelphia (PA): AACR; Cancer Res 2017;77(3 Suppl):Abstract nr B12.