scholarly journals 420 PROSTVAC in combination with nivolumab enhanced immune cell infiltration in prostate cancer

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A450-A450
Author(s):  
Shania Bailey ◽  
Wiem Lassoued ◽  
Antonios Papanicolau-Sengos ◽  
Jennifer Marte ◽  
Nikki Williams ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Cell ◽  
Cell Infiltration ◽  
Immune Microenvironment ◽  
Invasive Margin ◽  
Control Tumor Growth ◽  
Tumor Immune Microenvironment ◽  
Control Tumor

BackgroundProstate cancer (PC) is the most common non-cutaneous diagnosed cancer among men in USA.1 Although clinical outcomes are favorable for patients with localized disease, 20–30% of patients will develop metastatic prostate cancer (mPC) and have poor prognosis. Immunotherapy, as a single agent, provides benefit to a small subset of PC patients, which is thought to be partially due to its known cold tumor immune microenvironment (TIME). Combination studies are needed to enhance benefit.2 Prostvac is a therapeutic cancer vaccine engineered to activate an immune response against prostate-specific Antigen (PSA).3 Prostvac alone could induce systemic immune response by increasing immune-cell infiltrates in and around the tumor.4 In this study, we are exploring the effect of Prostvac in combination with nivolumab in TIME in prostate cancer.MethodsWe treated locally advanced prostate cancer patients (n=6) undergoing radical prostatectomy (RP) with neoadjuvant Prostvac in combination with nivolumab, an immune checkpoint PD-1 inhibitor. Dynamic changes in TIME before and after treatment were studied using multiplex immunofluorescence (Opal Method). Formalin fixed paraffin-embedded sections from matched pre-treated prostate biopsies and post-treated RP samples were stained with a validated T cell panel (DAPI, CD4, CD8, FOXP3, Ki67, Pan CK and PD-L1). To analyze the data, TIME was segmented into 3 compartments: intratumoral, invasive margin and benign.ResultsCombination immunotherapy significantly increased CD4+ T cell density in the invasive margin (mean 211.5 cells/mm2 vs 592.2 cells/mm2, p<0.05), with similar trend in the intratumoral and the benign compartments. CD8+ T cell density increased after treatment in the invasive margin (mean 47.25 cells/mm2 vs 157cells/mm2) and the benign compartment. 5/6 and 4/6 patients showed more than 2-fold increase of CD4 and CD8 T cells in the TIME, respectively, in at least one of the three compartments. Increased proliferative indices in CD4+ and CD8+ T cells were also seen after treatment. Tregs were present in low frequencies in TIME (maximum of 12 cells/mm2) with no significant changes. Moreover, a significant drop in tumor cell Ki67 after treatment (mean 252.8 cells/mm2 vs 100.5 cells/332, p<0.05) suggests that the combination may control tumor growth.ConclusionsThe combination of Neoadjuvant Prostvac and nivolumab was associated with increased immune cell infiltration in a cohort of early prostate cancer patients. A broader examination of the TIME and the role immune cells undertake to control tumor growth is on-going.Trial RegistrationNCT02933255ReferencesSiegel RL, Miller KD, Jemal A. Cancer statistics, 2020. CA Cancer J Clin (Internet) 2020;70:7–3Zhao SG, Lehrer J, Chang SL, et al. The immune landscape of prostate cancer and nomination of PD-L2 as a potential therapeutic target. J Natl Cancer Inst 2018;111:301–10.Madan RA, Arlen PM, Mohebtash M, et al. Prostvac-VF: a vectorbased vaccine targeting PSA in prostate cancer. Expert Opin Investig Drugs 2009;18:1001–11Abdul Sater H, Marté JL, Donahue RN, et al. Neoadjuvant PROSTVAC prior to radical prostatectomy enhances T-cell infiltration into the tumor immune microenvironment in men with prostate cancer. J Immunother Cancer 2020;8(1):655–64Ethics ApprovalThis study was performed in compliance with ethical standard and was approved by the NIH IRB, 17C-0007. All patients participating in this study gave an informed consent before taking part.

scholarly journals Association of CLDN6 and CLDN10 With Immune Microenvironment in Ovarian Cancer: A Study of the Claudin Family

2021 ◽  
Vol 12 ◽  
Author(s):  
Peipei Gao ◽  
Ting Peng ◽  
Canhui Cao ◽  
Shitong Lin ◽  
Ping Wu ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
T Cell ◽  
Immune Cell ◽  
Gene Set Enrichment Analysis ◽  
Cell Infiltration ◽  
Immune Cell Infiltration ◽  
Immune Microenvironment ◽  
Gene Markers ◽  
Expression Levels ◽  
Tumor Immune Microenvironment

BackgroundThe claudin family is a group of transmembrane proteins related to tight junctions. While their involvement in cancer has been studied extensively, their relationship with the tumor immune microenvironment remains poorly understood. In this research, we focused on genes related to the prognosis of ovarian cancer and explored their relationship with the tumor immune microenvironment.MethodsThe cBioPortal for Cancer Genomics database was used to obtain the genetic variation pattern of the claudin family in ovarian cancer. The ONCOMINE and Gene Expression Profiling Interactive Analysis (GEPIA) databases were used to explore the mRNA expression of claudins in cancers. The prognostic potential of these genes was examined via the Kaplan-Meier plotter. The enrichment of immunological signatures was determined by gene set enrichment analysis (GSEA). The correlations between claudins and the tumor immune microenvironment in ovarian cancer were investigated via the Tumor Immune Estimation Resource (TIMER).ResultsClaudin genes were altered in 363 (62%) of queried patients/samples. Abnormal expression levels of claudins were observed in various cancers. Among them, CLDN3, CLDN4, CLDN6, CLDN10, CLDN15, and CLDN16 were significantly correlated with overall survival in patients with ovarian cancer. GSEA revealed that CLDN6 and CLDN10 were significantly enriched in immunological signatures of B cell, CD4 T cell, and CD8 T cell. Furthermore, CLDN6 and CLDN10 were negatively correlated and positively correlated, respectively, with immune cell infiltration in ovarian cancer. The expression levels of CLDN6 and CLDN10 were also negatively correlated and positively correlated, respectively, with various gene markers of immune cells in ovarian cancer. Thus, CLDN6 and CLDN10 may participate in immune cell infiltration in ovarian cancer, and these mechanisms may be the reason for poor prognosis.ConclusionOur study showed that CLDN6 and CLDN10 were prognostic biomarkers correlated with the immune microenvironment in ovarian cancer. These results reveal new roles for CLDN6 and CLDN10 as potential therapeutic targets in the treatment of ovarian cancer.

scholarly journals Characterization of the m6A-Associated Tumor Immune Microenvironment in Prostate Cancer to Aid Immunotherapy

2021 ◽  
Vol 12 ◽  
Author(s):  
Zezhen Liu ◽  
Jiehui Zhong ◽  
Jie Zeng ◽  
Xiaolu Duan ◽  
Jianming Lu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Poor Prognosis ◽  
Response Rate ◽  
Checkpoint Inhibitors ◽  
Cell Infiltration ◽  
Intratumor Heterogeneity ◽  
Immune Microenvironment ◽  
Th2 Cell ◽  
Tumor Immune Microenvironment

The aim of this study was to elucidate the correlation between m6A modification and the tumor immune microenvironment (TIME) in prostate cancer (PCa) and to identify the m6A regulation patterns suitable for immune checkpoint inhibitors (ICIs) therapy. We evaluated the m6A regulation patterns of PCa based on 24 m6A regulators and correlated these modification patterns with TIME characteristics. Three distinct m6A regulation patterns were determined in PCa. The m6A regulators cluster with the best prognosis had significantly increased METTL14 and ZC3H13 expression and was characterized by low mutation rate, tumor heterogeneity, and neoantigens. The m6A regulators cluster with a poor prognosis had markedly high KIAA1429 and HNRNPA2B1 expression and was characterized by high intratumor heterogeneity and Th2 cell infiltration, while low Th17 cell infiltration and Macrophages M1/M2. The m6Ascore was constructed to quantify the m6A modification pattern of individual PCa patients based on m6A-associated genes. We found that the low-m6Ascore group with poor prognosis had a higher immunotherapeutic response rate than the high-m6Ascore group. The low-m6Ascore group was more likely to benefit from ICIs therapy. This study was determined that immunotherapy is more effective in low-m6Ascore PCa patients with poor prognosis.

scholarly journals DNA Methylation based glioblastoma subclassification is related to tumoral T cell infiltration and patient survival

2020 ◽  
Author(s):  
Joost Dejaegher ◽  
Lien Solie ◽  
Zoé Hunin ◽  
Raf Sciot ◽  
David Capper ◽  
...  
Keyword(s):  
Dna Methylation ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Cell ◽  
Methylation Pattern ◽  
Response To Therapy ◽  
Cell Infiltration ◽  
Mesenchymal Tumors ◽  
T Cell Infiltration

Abstract Background Histologically classified Glioblastomas (GBM) can have different clinical behavior and response to therapy, for which molecular subclassifications have been proposed. We evaluated the relationship of epigenetic GBM subgroups with immune cell infiltrations, systemic immune changes during radiochemotherapy and clinical outcome. Methods 450K genome-wide DNA methylation was assessed on tumor tissue from 93 patients with newly diagnosed GBM, treated with standard radiochemotherapy and experimental immunotherapy. Tumor infiltration of T cells, myeloid cells and PD-1 expression were evaluated. Circulating immune cell populations and selected cytokines were assessed on blood samples taken before and after radiochemotherapy. Results Forty-two tumors had a mesenchymal, 27 a RTK II, 17 a RTK I and 7 an IDH DNA methylation pattern Mesenchymal tumors had the highest amount of tumor-infiltrating CD3+ and CD8+ T cells and IDH tumors the lowest. There were no significant differences for CD68+ cells, FoxP3+ cells and PD-1 expression between groups. Systemically, there was a relative increase of CD8+ T cells and CD8+ PD-1 expression and a relative decrease of CD4+ T cells after radiochemotherapy in all subgroups except IDH tumors. Overall survival was the longest in the IDH group (median 36 months), intermediate in RTK II tumors (27 months) and significantly lower in mesenchymal and RTK I groups (15.5 and 16 months respectively). Conclusions Methylation based stratification of GBM is related to T cell infiltration and survival, with IDH and mesenchymal tumors representing both ends of a spectrum. DNA methylation profiles could be useful in stratifying patients for immunotherapy trials.

706 BT7480, a fully synthetic tumor-targeted immune cell agonist (TICA™) induces tumor localized CD137 agonism and modulation of tumor immune microenvironment

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A748-A748
Author(s):  
Punit Upadhyaya ◽  
Kristen Hurov ◽  
Jessica Kublin ◽  
Jun Ma ◽  
Elizabeth Repash ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Cell ◽  
Immune Microenvironment ◽  
Plasma Exposure ◽  
Tumor Models ◽  
Human Pbmc ◽  
Tumor Immune Microenvironment ◽  
Animal Care ◽  
Anti Tumor Activity

BackgroundAfter disappointing first clinical experiences with agonistic anti-CD137 (4-1BB) antibodies, a new generation of both systemic and targeted CD137 agonists is entering clinical development.1–3 These strategies rely on biologic agents with suboptimal properties for CD137 agonism due to their relatively large sizes and long circulating half-lives. These properties may limit their tissue penetration and cause sustained agonism resulting in overstimulation and activation-induced cell death of lymphocytes due to continuous exposure.Fully synthetic constrained bicyclic peptides (Bicycles™) with antibody-like affinities and target selectivity are uniquely suited to circumvent the above barriers to optimal targeted CD137 agonistic therapeutics. BT7480 is a tumor-targeted immune cell agonist (TICA) designed to deliver a highly potent CD137 agonist to Nectin-4 overexpressing tumor tissue with a flexible dosing schedule maximizing anti-tumor activity while circumventing the need for continuous systemic exposure.MethodsBT7480 functional activity in vitro was analyzed by measuring IL-2 and IFN gamma production from primary human PBMC/tumor cell co-cultures. BT7480 in vivo activity was determined in huCD137-syngeneic tumor models using tumor immune cell and transcriptional profiling by FACS, IHC, and Nanostring as well as tumor growth kinetics as read-outs.ResultsBT7480 binds potently and simultaneously to Nectin-4 and CD137 as assessed biochemically and caused Nectin-4-dependent CD137 agonism in primary human PBMC co-cultured with tumor cells. Treatment of Nectin-4 expressing tumors in immunocompetent mice with BT7480 leads to profound reprogramming of the tumor immune microenvironment including increased T cell infiltration and upregulation of a cytotoxic cell gene signature. BT7480 treatment induces complete tumor regressions and subsequent resistance to tumor re-challenge. TICA-dependent anti-tumor activity and established immunologic memory are dependent on cytotoxic T cells. Importantly, BT7480 in vivo activity is not dependent on continuous plasma exposure since once weekly dosing of BT7480 provides a maximum anti-tumor activity despite minimal BT7480 plasma exposure after day 2.BT7480 demonstrates linear pharmacokinetics in non-human primates and appears well tolerated at exposures in excess of the predicted efficacious exposure in humans.ConclusionsBT7480 is a highly potent Nectin-4 expression dependent CD137 agonist with optimal target binding, pharmacologic, and pharmacokinetic properties that enable intermittent dosing for curative effect through modulation of tumor immune microenvironment in syngeneic mouse tumor models. BT7480 is currently being evaluated in IND-enabling safety studies.Ethics ApprovalThe care and use of animals were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) of WuXi AppTec and conducted in accordance with the regulations of the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC).ReferencesHinner, et al. Tumor-localized costimulatory t-cell engagement by the 4-1BB/HER2 Bispecific antibody-anticalin fusion PRS-343. Clin. Cancer Res 2019 Oct 1;25(19):5878–5889.Claus, et al. Tumor-targeted 4-1BB agonists for combination with T cell bispecific antibodies as off-the-shelf therapy. Sci. Transl. Med 2019 Jun 12;11(496):eaav5989.Eskiocak, et al. Differentiated agonistic antibody targeting CD137 eradicates large tumors without hepatotoxicity. JCI Insight 2020 Mar 12;5(5):e133647.

The tumor immune microenvironment of germline BRCA1/2 and sporadic prostate cancer.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 152-152
Author(s):  
Anna S. Trigos ◽  
Anupama Pasam ◽  
Patricia Diana Banks ◽  
Roslyn Wallace ◽  
Simon P. Keam ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cells ◽  
Immune System ◽  
Cd8 T Cells ◽  
Dna Repair Genes ◽  
Cd4 Cells ◽  
Immune Microenvironment ◽  
Cd8 Cells ◽  
Tumor Immune Microenvironment ◽  
Repair Genes

152 Background: Prostate cancer (PC) is considered an immunologically ‘cold’ tumor and therefore patients are generally not considered good candidates for immunotherapy. Tumors arising in germline (g) BRCA1/2 mutation carriers are associated with higher genomic instability and levels of immune infiltration in breast and ovarian cancer. We investigated how germline mutations in DNA repair genes affect the tumor immune microenvironment (TME) of PC. Methods: Archival primary tumor samples from 26 patients with g BRCA2 mutations, 5 with g BRCA1, 5 with mutations in other DNA repair genes ( ATM, CHEK2, FANCI, PALB2 or BRCA2+ MSH2), and 26 sporadic patients were analyzed. OPAL multiplex immunohistochemistry was used to detect 7 markers (CD3, CD4, CD8, FOXP3, PDL1, AMACR, DAPI) to identify immune subsets and provide the X,Y coordinates of single cells. We developed novel computational distance-based methods to characterize the spatial distribution of cells. Gene expression was evaluated with the Nanostring panel of 770 immune genes. Results: g BRCA1/2 carriers showed lower levels of T cells (9.73% of the tumor stroma) compared to sporadic tumors (14.8%). In in both cothors the T cell population was dominated by CD4+ cells (69.5%), with CD8+ cells representing only 25.6%. Sporadic PCs displayed aggregation of T cells into large clusters in the stroma dominated by CD4+ cells and few CD8+ cells, while 77% of high-grade g BRCA2 patients were enriched in high levels of free, non-aggregated CD8+ T-cells in the tumor area. HLA-A expression was 2.37 times higher in g BRCA2 patients ( p = 3.4x10−8), who also showed higher expression of genes associated with a present but suppressed immune system ( p = 1.4x10−4). gBRCA2 patients with larger T-cell aggregates had an overall poorer prognosis compared to patients without (time to metastasis 55.1 vs. 85.3 months, survival time 67.3 vs. 85.0 months). Conclusions: g BRCA2 carriers displayed higher levels of HLA-A, more free CD8+ T cells infiltrating tumor regions and higher inflammatory signatures, suggesting an immune system that could potentially be harnessed. The degree of clustering of T cells (free vs. aggregated) within the TME may provide valuable prognostic information that warrants further validation.

scholarly journals 700 EphA2/CD137 Bicycle tumor-targeted immune cell agonists (TICAsTM) induce tumor regressions, immunogenic memory, and reprogramming of the tumor immune microenvironment

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A742-A742
Author(s):  
Kristen Hurov ◽  
Johanna lahdenranta ◽  
Gemma Mudd ◽  
Punit Upadhyaya ◽  
Elizabeth Repash ◽  
...  
Keyword(s):  
T Cell ◽  
Tumor Cell ◽  
Immune Cell ◽  
Immune Microenvironment ◽  
New Class ◽  
Tumor Immune Microenvironment ◽  
Nf Kappab ◽  
Animal Care ◽  
Anti Tumor Activity

BackgroundDespite compelling preclinical data, agonistic anti-CD137 antibodies have been hampered by failure to delineate hepatotoxicity from efficacy in clinical studies.1 2 A new generation of both systemic and targeted CD137 agonists that are now entering clinical development rely on biologic agents with suboptimal properties for CD137 agonism due to their relatively large sizes and long circulating half-lives.3–5 These properties may limit their tissue penetration and cause sustained agonism resulting in overstimulation and activation-induced cell death of lymphocytes due to continuous exposure.BCY12491 is a tumor-targeted immune cell agonist (TICATM) that exemplifies a new class of fully synthetic immunomodulators with constrained bicyclic peptides (Bicycles®) targeting a tumor antigen and a co-stimulatory molecule. We developed this new class of synthetic molecules with antibody-like affinities and target selectivity to circumvent the beforementioned barriers to optimal targeted CD137 agonistic therapeutics. BCY12491 (EphA2/CD137 TICA) is designed to deliver a highly potent CD137 agonist to EphA2 overexpressing tumor tissue with an intermittent dosing schedule maximizing anti-tumor activity while circumventing the need for continuous systemic exposure.MethodsBCY12491 bioactivity was assessed in vitro using a CD137 reporter assay and by measuring cytokine production from primary human PBMC/tumor cell co-cultures. BCY12491 in vivo activity was determined in huCD137-syngeneic tumor models by measuring tumor growth kinetics and using tumor immune cell and transcriptional profiling by FACS, IHC, and Nanostring.ResultsBCY12491 engages EphA2 and CD137 with high affinity resulting in picomolar potency in co-culture assays consisting of EphA2-expressing tumor cell lines and CD137-expressing Jurkat NF-kappaB-luciferase reporter cells. Moreover, BCY12491 caused EphA2-dependent CD137 agonism in primary human PBMCs co-cultured with tumor cells with varied levels of EphA2 expression. Treatment of MC38 tumors in immunocompetent mice with BCY12491 leads to a profound reprogramming of the tumor immune microenvironment including increased T cell infiltration and stimulation of NF-kappaB signaling, costimulatory signaling, cytotoxicity and cytokine/chemokine signaling functional pathways. BCY12491 treatment leads to MC38 tumor regressions, complete responses, and immunogenic memory without continuous drug exposure in the periphery. This anti-tumor activity is dependent on CD8+ T cells, but not on NK 1.1+ cells.ConclusionsBCY12491 is a potent EphA2-dependent CD137 agonist with optimal target binding, pharmacologic, and pharmacokinetic properties that enable anti-tumor TME remodeling and complete responses in vivo with intermittent dosing. This work unleashes a new and tractable avenue to testing a novel class of therapeutic CD137 agonists in humans for the treatment of cancer.Ethics ApprovalThe care and use of animals were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) of WuXi AppTec and conducted in accordance with the regulations of the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC).ReferencesSegal NH, Logan TF, Hodi FS, et al. Results from an integrated safety analysis of urelumab, an agonist anti-CD137 monoclonal antibody. Clin Cancer Res 2017;23(8):1929–1936.Chester C, Sanmamed MF, Wang J, Melero I. Immunotherapy targeting 4-1BB: mechanistic rationale, clinical results, and future strategies. Blood 2018;131(1): 49–57.Hinner MJ, Aiba RSB, Jaquin TJ, et al. Tumor-Localized Costimulatory T-Cell Engagement by the 4-1BB/HER2 Bispecific Antibody-Anticalin Fusion PRS-343. Clin Cancer Res. 2019;25(19):5878–5889.Claus C, Ferrara, C, Xu W, et al. Tumor-targeted 4-1BB agonists for combination with T cell bispecific antibodies as off-the-shelf therapy. Sci Transl Med 2019;11(496): eaav5989.Eskiocak U, Guzman W, Wolf B, et al. Differentiated agonistic antibody targeting CD137 eradicates large tumors without hepatotoxicity. JCI Insight 2020;5(5):e133647.

scholarly journals Enhanced CD4+ and CD8+ T cell infiltrate within convex hull defined pancreatic islet borders as autoimmune diabetes progresses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander J. Dwyer ◽  
Jacob M. Ritz ◽  
Jason S. Mitchell ◽  
Tijana Martinov ◽  
Mohannad Alkhatib ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Convex Hull ◽  
Pancreatic Islets ◽  
Immune Cell ◽  
Nod Mice ◽  
Cell Infiltration ◽  
Immune Cell Infiltration ◽  
Analytical Strategy ◽  
Islet Mass

AbstractThe notion that T cell insulitis increases as type 1 diabetes (T1D) develops is unsurprising, however, the quantitative analysis of CD4+ and CD8+ T cells within the islet mass is complex and limited with standard approaches. Optical microscopy is an important and widely used method to evaluate immune cell infiltration into pancreatic islets of Langerhans for the study of disease progression or therapeutic efficacy in murine T1D. However, the accuracy of this approach is often limited by subjective and potentially biased qualitative assessment of immune cell subsets. In addition, attempts at quantitative measurements require significant time for manual analysis and often involve sophisticated and expensive imaging software. In this study, we developed and illustrate here a streamlined analytical strategy for the rapid, automated and unbiased investigation of islet area and immune cell infiltration within (insulitis) and around (peri-insulitis) pancreatic islets. To this end, we demonstrate swift and accurate detection of islet borders by modeling cross-sectional islet areas with convex polygons (convex hulls) surrounding islet-associated insulin-producing β cell and glucagon-producing α cell fluorescent signals. To accomplish this, we used a macro produced with the freeware software ImageJ equipped with the Fiji Is Just ImageJ (FIJI) image processing package. Our image analysis procedure allows for direct quantification and statistical determination of islet area and infiltration in a reproducible manner, with location-specific data that more accurately reflect islet areas as insulitis proceeds throughout T1D. Using this approach, we quantified the islet area infiltrated with CD4+ and CD8+ T cells allowing statistical comparison between different age groups of non-obese diabetic (NOD) mice progressing towards T1D. We found significantly more CD4+ and CD8+ T cells infiltrating the convex hull-defined islet mass of 13-week-old non-diabetic and 17-week-old diabetic NOD mice compared to 4-week-old NOD mice. We also determined a significant and measurable loss of islet mass in mice that developed T1D. This approach will be helpful for the location-dependent quantitative calculation of islet mass and cellular infiltration during T1D pathogenesis and can be combined with other markers of inflammation or activation in future studies.

scholarly journals 602 STING agonist-based treatment promotes vascular normalization and tertiary lymphoid structure formation in the therapeutic melanoma microenvironment

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A637-A637
Author(s):  
Manoj Chelvanambi ◽  
Ronald Fecek ◽  
Jennifer Taylor ◽  
Walter Storkus
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Cell ◽  
Ex Vivo ◽  
In Vitro Assays ◽  
Type I ◽  
Vascular Normalization ◽  
S 100 ◽  
Transcriptional Changes

BackgroundThe degree of immune infiltration in tumors, especially CD8+ T cells, greatly impacts patient disease course and response to interventional immunotherapy. Hence, enhancement of TIL prevalence is a preferred clinical endpoint, one that may be achieved via administration of agents that normalize the tumor vasculature (VN) leading to improved immune cell recruitment and/or that induce the development of local tertiary lymphoid structures (TLS) within the tumor microenvironment (TME).MethodsLow-dose STING agonist ADU S-100 (5 μg/mouse) was delivered intratumorally to established s.c. B16.F10 melanomas on days 10, 14 and 17 post-tumor inoculation under an IACUC-approved protocol. Treated and control, untreated tumors were isolated at various time points to assess transcriptional changes associated with VN and TLS formation via qPCR, with corollary immune cell composition changes determined using flow cytometry and immunofluorescence microscopy. In vitro assays were performed on CD11c+ BMDCs treated with 2.5 μg/mL ADU S-100 (vs PBS control) and associated transcriptional changes analyzed via qPCR or profiled using DNA microarrays. For TCRβ-CDR3 analyses, CDR3 was sequenced from gDNA isolated from enzymatically digested tumors and splenocytes.ResultsWe report that activation of STING within the TME leads to slowed melanoma growth in association with increased production of angiostatic factors including Tnfsf15 (Vegi), Cxcl10 and Angpt1, and TLS inducing factors including Ccl19, Ccl21, Lta, Ltb and Tnfsf14 (Light). Therapeutic responses from intratumoral STING activation were characterized by increased vascular normalization (VN), enhanced tumor infiltration by CD8+ T cells and CD11c+ DCs and local TLS neo-genesis, all of which were dependent on host expression of STING. Consistent with a central role for DC in TLS formation, ex vivo ADU S-100-activated mCD11c+ DCs also exhibited upregulated expression of TLS promoting factors including lymphotoxin-α (LTA), IL-36, inflammatory chemokines and type I interferons. TLS formation was associated with the development of a therapeutic TIL TCR repertoire enriched in T cell clonotypes uniquely detected within the tumor but not the peripheral circulation in support or local T cell cross-priming within the TME.ConclusionsOur data support the premise that i.t. delivery of STING agonist promotes a pro-inflammatory TME in support of VN and TLS formation, leading to the local expansion of unique TIL repertoire in association with superior anti-melanoma efficacy.

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