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Supplementary Figure 2: Gating strategy for flow cytometry. Live CD45+ cells were gated after live/dead discrimination and removal of doublets as shown.

The role of B cells in antitumor immunity and their impact on emerging immunotherapies is increasingly gaining attention. B-cell effector functions include not only secretion of antibodies, but also presentation of antigens to T cells. A physiologic B-cell subset with immunostimulatory properties was described in humans, defined by a high expression of CD86 and downregulation of CD21. We used multicolor flow cytometry and IHC to elucidate abundance and spatial distribution of these antigen-presenting B cells (BAPC) in blood (peripheral blood mononuclear cells, PBMC) and tumor samples of 237 patients with cancer. Antigen-specific T-cell responses to cancer testis antigens were determined using tetramer staining and sorted BAPCs in FluoroSpot assays for selected patients. We found that BAPCs were increased in the tumor microenvironment of 9 of 10 analyzed cancer types with site-specific variation. BAPCs were not increased in renal cell carcinoma, whereas we found a systemic increase with elevated fractions in tumor-infiltrating lymphocytes (TIL) and PBMCs of patients with colorectal cancer and gastroesophageal adenocarcinoma. BAPCs were localized in lymphoid follicles of tertiary lymphoid structures (TLS) and were enriched in tumors with increased numbers of TLSs. BAPCs isolated from tumor-draining lymph nodes of patients with cancer showed increased percentages of tumor antigen–specific B cells and induced responses of autologous T cells in vitro. Our results highlight the relevance of BAPCs as professional antigen-presenting cells in tumor immunity and provide a mechanistic rationale for the observed correlation of B-cell abundance and response to immune checkpoint inhibition.

Detailed list of used antibodies

Fig. S1. Flow cytometry staining of KLH and TRP2-specific B cells. Fig. S2. Quality control of CD40L-matured DCs. Fig. S3. Antigen-specific CD40B cells activate specific T cells. Fig. S4. T cells of immunized mice show normal percentages of Tregs. Fig. S5. Unstimulated OVA-B cells express homing molecules. Fig. S6. Preventive combinational immune intervention protects from tumor growth. Fig. S7. Combinational immunotherapy induces T cell-dependent anti-tumor immunity. Fig. S8 Human antigen-specific CD40B cells induce specific T-cell responses.

Cancer immunotherapy by therapeutic activation of T cells has demonstrated clinical potential. Approaches include checkpoint inhibitors and chimeric antigen receptor T cells. Here, we report the development of an alternative strategy for cellular immunotherapy that combines induction of a tumor-directed T-cell response and antibody secretion without the need for genetic engineering. CD40 ligand stimulation of murine tumor antigen-specific B cells, isolated by antigen-biotin tetramers, resulted in the development of an antigen-presenting phenotype and the induction of a tumor antigen-specific T-cell response. Differentiation of antigen-specific B cells into antibody-secreting plasma cells was achieved by stimulation with IL21, IL4, anti-CD40, and the specific antigen. Combined treatment of tumor-bearing mice with antigen-specific CD40-activated B cells and antigen-specific plasma cells induced a therapeutic antitumor immune response resulting in remission of established tumors. Human CEA or NY-ESO-1–specific B cells were detected in tumor-draining lymph nodes and were able to induce antigen-specific T-cell responses in vitro, indicating that this approach could be translated into clinical applications. Our results describe a technique for the exploitation of B-cell effector functions and provide the rationale for their use in combinatorial cancer immunotherapy. Cancer Immunol Res; 5(9); 730–43. ©2017 AACR.

Purpose:An increased risk to develop cancer is one of the most challenging negative side effects of long-term immunosuppression in organ transplant recipients and impaired cancer immunosurveillance is assumed as underlying mechanism. This study aims to elucidate transplant-related changes in the tumor immune microenvironment (TME) of cancer.Experimental Design:Data from 123 organ transplant recipients (kidney, heart, lung, and liver) were compared with historic data from non-immunosuppressed patients. Digital image analysis of whole-section slides was used to assess abundance and spatial distribution of T cells and tertiary lymphoid structures (TLS) in the TME of 117 tumor samples. Expression of programmed cell death 1 ligand 1 (PD-L1) and human-leucocyte-antigen class I (HLA-I) was assessed on tissue microarrays.Results:We found a remarkably reduced immune infiltrate in the center tumor (CT) regions as well as the invasive margins (IM) of post-transplant cancers. These differences were more pronounced in the IM than in the CT and larger for CD8+ T cells than for CD3+ T cells. The Immune-score integrating results from CT and IM was also lower in transplant recipients. Density of TLS was lower in cancer samples of transplant recipients. The fraction of samples with PD-L1 expression was higher in controls whereas decreased expression of HLA-I was more common in transplant recipients.Conclusions:Our study demonstrates the impact of immunosuppression on the TME and supports impaired cancer immunosurveillance as important cause of post-transplant cancer. Modern immunosuppressive protocols and cancer therapies should consider the distinct immune microenvironment of post-transplant malignancies.

Recent data imply that strengthening host immunity by checkpoint inhibition improves outcome in invasive fungal infections (IFI), particularly in candidiasis.To assess T-cell exhaustion in this context, we compared peripheral blood mononuclear cells (PBMCs) and serum samples of patients with invasive Candida albicans infection (IC, n = 21) to PBMCs or tumor-infiltrating lymphocytes (TILs) from cancer patients (n = 14) and PBMCs of healthy controls (n = 20). Type and differentiation of lymphocytes and expression of 29 immune-regulatory molecules were analyzed by flow cytometry. C. albicans specific responses were assessed by FluoroSpot (n = 8) and antibody measurement (n = 14).Fractions and phenotypes of lymphocyte subsets in PBMCs of IC patients were similar compared to PBMCs of controls, while they were different in TILs. PBMCs of patients with IC showed increased expression of immune-checkpoint molecules. The pattern of upregulated molecules was similar to TILs, but not present in PBMCs of control cancer patients. Fractions of T-cells expressing PD-1 and TIGIT were higher in IC patients that died. FluoroSpot analysis showed a Candida-specific IFN-y or IL-2 response in 5/8 patients, enhanced by addition of nivolumab in vitro.Together with preclinical data and preliminary evidence of clinical efficacy in mucormycosis, our results support clinical evaluation of immune-checkpoint inhibition in IFI treatment.NCT04533087; retrospectively registered on August 31, 2020.

Purpose:An increased risk to develop cancer is one of the most challenging negative side effects of long-term immunosuppression in organ transplant recipients and impaired cancer immunosurveillance is assumed as underlying mechanism. This study aims to elucidate transplant-related changes in the tumor immune microenvironment (TME) of cancer.Experimental Design:Data from 123 organ transplant recipients (kidney, heart, lung, and liver) were compared with historic data from non-immunosuppressed patients. Digital image analysis of whole-section slides was used to assess abundance and spatial distribution of T cells and tertiary lymphoid structures (TLS) in the TME of 117 tumor samples. Expression of programmed cell death 1 ligand 1 (PD-L1) and human-leucocyte-antigen class I (HLA-I) was assessed on tissue microarrays.Results:We found a remarkably reduced immune infiltrate in the center tumor (CT) regions as well as the invasive margins (IM) of post-transplant cancers. These differences were more pronounced in the IM than in the CT and larger for CD8+ T cells than for CD3+ T cells. The Immune-score integrating results from CT and IM was also lower in transplant recipients. Density of TLS was lower in cancer samples of transplant recipients. The fraction of samples with PD-L1 expression was higher in controls whereas decreased expression of HLA-I was more common in transplant recipients.Conclusions:Our study demonstrates the impact of immunosuppression on the TME and supports impaired cancer immunosurveillance as important cause of post-transplant cancer. Modern immunosuppressive protocols and cancer therapies should consider the distinct immune microenvironment of post-transplant malignancies.

Clinicopathologic parameters of mice and patients with the corresponding survival significance analysis of SCLC bearing mice treated with vehicle, IgG control, anti-VEGF monotherapy, anti-PD-L1 monotherapy or anti-VEGF/anti-PD-L1 combination therapy

Supplementary Figure from Post-transplant Malignancies Show Reduced T-cell Abundance and Tertiary Lymphoid Structures as Correlates of Impaired Cancer Immunosurveillance

Supplementary Table from Post-transplant Malignancies Show Reduced T-cell Abundance and Tertiary Lymphoid Structures as Correlates of Impaired Cancer Immunosurveillance

Small cell lung cancer (SCLC) represents the most aggressive pulmonary neoplasm and is often diagnosed at late stage with limited survival, despite combined chemotherapies. We show in an autochthonous mouse model of SCLC that combined anti-VEGF/anti-PD-L1–targeted therapy synergistically improves treatment outcome compared with anti–PD-L1 and anti-VEGF monotherapy. Mice treated with anti–PD-L1 alone relapsed after 3 weeks and were associated with a tumor-associated PD-1/TIM-3 double-positive exhausted T-cell phenotype. This exhausted T-cell phenotype upon PD-L1 blockade was abrogated by the addition of anti-VEGF–targeted treatment. We confirmed a similar TIM-3–positive T-cell phenotype in peripheral blood mononuclear cells of patients with SCLC with adaptive resistance to anti–PD-1 treatment. Mechanistically, we show that VEGFA enhances coexpression of the inhibitory receptor TIM-3 on T cells, indicating an immunosuppressive function of VEGF in patients with SCLC during anti–PD-1-targeted treatment. Our data strongly suggest that a combination of anti-VEGF and anti–PD-L1 therapies can be an effective treatment strategy in patients with SCLC.Significance: Combining VEGF and PD-L1 blockade could be of therapeutic benefit to patients with small cell lung cancer. Cancer Res; 78(15); 4270–81. ©2018 AACR.

Supplementary data supporting an exhausted T cell phenotype in SCLC upon acquired resistance to PD1/PD-L1 blockade which is regulated by VEGF/VEGFR signaling and in addition, an immunosuppressive role of tumor-associated macrophages in the tumor microenvironment

The role of B cells in antitumor immunity and their impact on emerging immunotherapies is increasingly gaining attention. B-cell effector functions include not only secretion of antibodies, but also presentation of antigens to T cells. A physiologic B-cell subset with immunostimulatory properties was described in humans, defined by a high expression of CD86 and downregulation of CD21. We used multicolor flow cytometry and IHC to elucidate abundance and spatial distribution of these antigen-presenting B cells (BAPC) in blood (peripheral blood mononuclear cells, PBMC) and tumor samples of 237 patients with cancer. Antigen-specific T-cell responses to cancer testis antigens were determined using tetramer staining and sorted BAPCs in FluoroSpot assays for selected patients. We found that BAPCs were increased in the tumor microenvironment of 9 of 10 analyzed cancer types with site-specific variation. BAPCs were not increased in renal cell carcinoma, whereas we found a systemic increase with elevated fractions in tumor-infiltrating lymphocytes (TIL) and PBMCs of patients with colorectal cancer and gastroesophageal adenocarcinoma. BAPCs were localized in lymphoid follicles of tertiary lymphoid structures (TLS) and were enriched in tumors with increased numbers of TLSs. BAPCs isolated from tumor-draining lymph nodes of patients with cancer showed increased percentages of tumor antigen–specific B cells and induced responses of autologous T cells in vitro. Our results highlight the relevance of BAPCs as professional antigen-presenting cells in tumor immunity and provide a mechanistic rationale for the observed correlation of B-cell abundance and response to immune checkpoint inhibition.

T-cell prolymphocytic leukemia (T-PLL) is a poor-prognostic neoplasm. Differentiation stage and immune-effector functions of the underlying tumor cell are insufficiently characterized. Constitutive activation of the T-cell leukemia 1A (TCL1A) oncogene distinguishes the (pre)leukemic cell from regular postthymic T cells. We assessed activation-response patterns of the T-PLL lymphocyte and interrogated the modulatory impact by TCL1A. Immunophenotypic and gene expression profiles revealed a unique spectrum of memory-type differentiation of T-PLL with predominant central-memory stages and frequent noncanonical patterns. Virtually all T-PLL expressed a T-cell receptor (TCR) and/or CD28-coreceptor without overrepresentation of specific TCR clonotypes. The highly activated leukemic cells also revealed losses of negative-regulatory TCR coreceptors (eg, CTLA4). TCR stimulation of T-PLL cells evoked higher-than-normal cell-cycle transition and profiles of cytokine release that resembled those of normal memory T cells. More activated phenotypes and higher TCL1A correlated with inferior clinical outcomes. TCL1A was linked to the marked resistance of T-PLL to activation- and FAS-induced cell death. Enforced TCL1A enhanced phospho-activation of TCR kinases, second-messenger generation, and JAK/STAT or NFAT transcriptional responses. This reduced the input thresholds for IL-2 secretion in a sensitizer-like fashion. Mice of TCL1A-initiated protracted T-PLL development resembled such features. When equipped with epitope-defined TCRs or chimeric antigen receptors, these Lckpr-hTCL1Atg T cells gained a leukemogenic growth advantage in scenarios of receptor stimulation. Overall, we propose a model of T-PLL pathogenesis in which TCL1A enhances TCR signals and drives the accumulation of death-resistant memory-type cells that use amplified low-level stimulatory input, and whose loss of negative coregulators additionally maintains their activated state. Treatment rationales are provided by combined interception in TCR and survival signaling.

Thermal ablative therapies are standard treatments for localized hepatocellular carcinoma (HCC). In addition to local tumor destruction, ablation leads to abscopal effects in distant lesions most likely mediated by an anti-tumor immune response. Although microwave ablation (MWA) is increasingly substituting other ablative techniques, its systemic immunostimulatory effects are poorly studied. We analyzed tumor-specific immune responses in peripheral blood of HCC patients after thermal ablation with regard to T cell responses and disease outcome. While comprehensive flow cytometric analyses in sequential samples of a prospective patient cohort (n = 23) demonstrated only moderate effects of MWA on circulating immune cell subsets, fluorospot analyses of specific T cell responses against seven tumor-associated antigens (TTAs) revealed de-novo or enhanced tumor-specific immune responses in 30% of patients. This anti-tumor immune response was related to tumor control as Interferon-y and Interleukin-5 T cell responses against TAAs were more frequent in patients with a long-time remission (> 1 year) after MWA (7/16) compared to patients suffering from an early relapse (0/13 patients) and presence of tumor-specific T cell response (IFN-y and/or IL-5) was associated to longer progression-free survival (27.5 vs. 10.0 months). Digital image analysis of immunohistochemically stained archival HCC samples (n = 18) of patients receiving combined MWA and resection revealed a superior disease-free survival of patients with high T cell abundance at the time of thermal ablation (37.4 vs. 13.1 months). Our data demonstrates remarkable immune-related effects of MWA in HCC patients and provides additional evidence for a combination of local ablation and immunotherapy in this challenging disease. Electronic supplementary material The online version of this article (10.1007/s00262-020-02734-1) contains supplementary material, which is available to authorized users.

Purpose Lymphocyte activation gene-3 (LAG3) is an immunosuppressive checkpoint molecule expressed on T cells. The frequency and distribution of LAG3 expression in oesophageal adenocarcinoma (EAC) is unknown. Aim of the study was the evaluation and distribution of LAG3 on tumour infiltrating lymphocytes (TILs) and correlation with clinico-pathological and molecular data. Methods We analysed tumor tissue samples using immunohistochemistry, multi-colour immunofluorescence and mRNA in-situ technology. The analyses were performed on a multi-spot tissue microarray (TMA) with 165 samples, followed by an evaluation on a single-spot TMA with 477 samples. These results were correlated with clinical and molecular tumour data. Results LAG3 expression on TILs was detectable in 10.5% on the multi-spot TMA and 11.4% on the single-spot TMA. There was a strong correlation between protein expression and mRNA expression (p p p = 0.046). The effect was even clearer in the group of patients with tumour stages > pT2 (70.2 vs 25.0 months; p = 0.037). Conclusion This is the first description of LAG3 expression on TILs in EAC, underscoring the importance of immunomodulation in EAC. Our data suggest an impact of LAG3 in a relevant subset of EAC. Therapeutic studies investigating the efficacy of LAG3 inhibition in EAC will also provide predictive evidence and relevance of the immunohistochemical determination of LAG3 expression.

The outcome in esophageal adenocarcinoma (EAC) is still poor with only 20% of patients in Western populations surviving for more than 5 years. Almost nothing is known about the precise composition of immune cells and their gene expression profiles in primary resected EACs and also nothing compared to neoadjuvant treated EACs. This study analyzes and compares immune profiles of primary resected and neoadjuvant treated esophageal adenocarcinoma and unravels possible targets for immunotherapy. We analyzed 47 EAC in total considering a set of 30 primary treatment-naive EACs and 17 neoadjuvant pretreated (12 × CROSS, 5 × FLOT) using the Nanostring's panel-based gene expression platform including 770 genes being important in malignant tumors and their immune micromileu. Most of the significantly altered genes are involved in the regulation of immune responses, T-and B cell functions as well as antigen processing. Chemokine-receptor axes like the CXCL9, -10,-11/CXCR3- are prominent in esophageal adenocarcinoma with a fold change of up to 9.5 promoting cancer cell proliferation and metastasis. ARG1, as a regulator of T-cell fate is sixfold down-regulated in untreated primary esophageal tumors. The influence of the currently used neoadjuvant treatment revealed a down-regulation of nearly all important checkpoint markers and inflammatory related genes in the local microenvironment. We found a higher expression of checkpoint markers like LAG3, TIM3, CTLA4 and CD276 in comparison to PD-L1/PD-1 supporting clinical trials analyzing the efficacy of a combination of different checkpoint inhibitors in EACs. We found an up-regulation of CD38 or LILRB1 as examples of additional immune escape mechanism. Electronic supplementary material The online version of this article (10.1007/s00262-019-02475-w) contains supplementary material, which is available to authorized users.

While classical Hodgkin lymphoma (HL) is highly susceptible to anti-programmed death protein 1 (PD1) antibodies, the exact modes of action remain controversial. To elucidate the circulating lymphocyte phenotype and systemic effects during anti-PD1 1st-line HL treatment we applied multicolor flow cytometry, FluoroSpot and NanoString to sequential samples of 81 HL patients from the NIVAHL trial (NCT03004833) compared to healthy controls. HL patients showed a decreased CD4 T-cell fraction, a higher percentage of effector-memory T cells and higher expression of activation markers at baseline. Strikingly, and in contrast to solid cancers, expression for 10 out of 16 analyzed co-inhibitory molecules on T cells (e.g., PD1, LAG3, Tim3) was higher in HL. Overall, we observed a sustained decrease of the exhausted T-cell phenotype during anti-PD1 treatment. FluoroSpot of 42.3% of patients revealed T-cell responses against ≥1 of five analyzed tumor-associated antigens. Importantly, these responses were more frequently observed in samples from patients with early excellent response to anti-PD1 therapy. In summary, an initially exhausted lymphocyte phenotype rapidly reverted during anti-PD1 1st-line treatment. The frequently observed IFN-y responses against shared tumor-associated antigens indicate T-cell-mediated cytotoxicity and could represent an important resource for immune monitoring and cellular therapy of HL.

Background Classical human leukocyte antigen (HLA) class I molecules are expressed by most somatic cells and present peptides to cytotoxic T cells. The HLA-genotype of an individual contains up to six different HLA-I molecules and defines the repertoire of peptides that can be presented to cytotoxic T cells. Homozygosity for one or more HLA-loci could translate in a smaller repertoire of tumour neoantigens possibly presented to cytotoxic T cells in an individual and potentially predispose such individuals with a disadvantage to fight a nascent tumour. Material and Methods High-resolution HLA-genotyping from germline normal DNA of 80 esophago-gastric adenocarcinoma (EGA) patients was performed with the NGS method by Illumina. Whole exome sequencing (WES) was performed on tumor tissue and normal peripheral blood cells (n=39). The data were processed, and non-synonymous mutations were called. The amount of potential high-affinity binders derived from 10 cancer testis antigens (CTAs) frequently expressed in EGA and non-synonymous mutations obtained from WES data were determined using an in-silico approach for MHC-binding (IEDB.org). RNA-extraction and gene expression profiling were performed using the NanoString technology. Results We compared the frequency of HLA homozygosity in EGA patients to an HLA-matched reference population derived from a large cohort of bone marrow donors (n=7.615 out of 615.017 donors). We demonstrate that EGA patients are more likely to be homozygous for at least one HLA-I gene than the control population. In EGA patients, 35% of HLA-A, -B, and -C alleles were homozygous in comparison with 19% of HLA alleles among the HLA-matched general population. This difference corresponded to an odds ratio (OR) for homozygosity of 2.282 (95% confidence interval (CI) 1.442-3.615, p Conclusion Our results highlight the effect of HLA-I homozygosity on the immunopeptidome as important prerequisite of anti-tumor immunity. The high frequency of genomic HLA-I homozygosity observed in the EGA cohort may reflect an increased cancer risk for these patients. Together with previous reports demonstrating reduced survival after checkpoint therapy, our study suggests consideration of germ-line HLA-homozygosity for the design and interpretation of immunotherapeutic trials. Disclosure Information M.A. Garcia-Marquez: None. M. Thelen: None. E. Bauer: None. K. Wennhold: None. J. Lehmann: None. D. Keller: None. B. Gathof: None. L. Maas: None. J. George: None. C. Bruns: None. A. Quaas: None. M. von Bergwelt-Baildon: C. Other Research Support (supplies, equipment, receipt of drugs or other in-kind support); Modest; Astellas, Roche, MSD. D. Speakers Bureau/Honoraria (speakers bureau, symposia, and expert witness); Modest; BMS. M. Peifer: None. H.A. Schloser: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Significant; Astra Zeneca. D. Speakers Bureau/Honoraria (speakers bureau, symposia, and expert witness); Modest; BMS.

Background Immunosuppressive medication is mandatory in the majority of solid organ transplant recipients to reduce the risk of allograft rejection. An increased risk to develop cancer is a negative side effect of long-term immunosuppression and impaired cancer immunosurveillance is assumed as underlying mechanism. However, the impact of immunosuppression on the tumor immune microenvironment (TME) is poorly understood. In this study we aimed to elucidate differences between immune infiltrates of post-transplant malignancies and cancer of non-immunosuppressed patients. Materials and Methods 117 resected tumor samples of 80 organ transplant (kidney, heart, lung and liver) recipients were included. Immunohistochemistry and digital image analysis of whole section slides was used to quantify T- (CD3, CD8) and B-cell (CD20) abundance in the TME of 14 different cancer types. These data were used to calculate the Immune-score and to quantify tertiary lymphoid structures in the TME. Expression of Human-Leucocyte-Antigen-I (HLA-I) and programmed cell death ligand 1 (PD-L1) were analyzed in tissue microarrays. Clinical parameters were included in statistical analyses. Results The increased risk of cancer in organ transplant recipients was reflected by a remarkably reduced immune infiltrate in the central region (CT) and the surrounding tissue (invasive margin, IM) of cancer areas. T cell abundance was decreased in IM and CT of skin (814 vs. 1440 CD3+ cells/mm2, p Conclusions Our study demonstrates that post-transplant malignancies show a low immune infiltrate and supports the hypothesis of reduced anti-tumor immune response as an important mechanism underlying increased risk of cancer in organ transplant recipients. Optimized immunosuppressive protocols may be able to reduce cancer incidence and cancer therapies need to consider the distinct immune microenvironment of post-transplant malignancies. Disclosure Information S. Schran: None. R. Datta: None. O. Persa: None. C. Aguilar: None. M. Thelen: None. J. Lehmann: None. M. Garcia-Marquez: None. K. Wennhold: None. A. Quaas: None. C. Bruns: None. C. Mauch: None. H. Loser: None. D. Stippel: None. H. Schloser: None.

Background Tumor-associated antigens (TAAs) and especially cancer testis antigens (CTAs) are classical tumor-specific targets for immunotherapies. As TAAs are shared between patients, strategies aiming to exploit these targets are scalable and potentially applicable across different types of cancer. Loss of target antigens and other mechanisms of immune escape have limited the success of CTA-directed immunotherapy. CAR T cells and other highly effective cellular therapies have renewed the interest in TAAs. Especially combined targeting of multiple antigens appears highly promising as recently shown in lymphoma. In our study, we aimed to characterize CTA-expression patterns and their impact on endogenous T-cell responses, T-cell abundance and antigen-presentation in esophago-gastric adenocarcinoma (EGA). Materials and Methods 41 treatment-naive EGA patients were included in our study. RNA of tumor and patient-matched healthy tissue was isolated and used for NanoString based RNA expression analysis of 26 CTAs and 25 genes associated with antigen-presentation. Based on CTA expression, 10 peptide pools were selected and co-cultured with peripheral blood mononuclear cells (PBMCs, n=21) to determine cellular anti-tumor immune responses in a FluoroSpot assay. T-cell abundance was assessed using immunohistochemistry (CD3, CD8) and digital image analyses of tumor area and invasive margin. Autologous CD40 activated B cells were used to expand antigen-specific T cells using peptide pools of CTAs. Results NanoString analysis revealed pronounced differences regarding CTA expression, with CEP55 and MAGEA3/6 showing strong expression, while NY-ESO-1 or MAGEA1 were only weakly expressed. 68.3% (28/41) of the patients showed expression of ≥ 5/10 analyzed TAAs simultaneously. In line with the frequent expression, 75.0% of the patients showed a cellular response against at least one of the TAAs. T-cell responses were most frequently detected to Survivin and NY-ESO-1 (65.0% and 52.6% of patients, respectively), while only 20.0% responded to CEP55 or TTK peptide pools. Overall, 6/20 patients showed cellular responses against ≥5 TAAs simultaneously. We found a strong correlation of T-cell abundance and antigen-presentation. In addition, patients with a high Immune-Score showed increased TAA expression. Finally, we demonstrate feasibility of TAA-specific T-cell expansion using CD40 activated B cells as potential strategy to induce or enhance TAA immune responses in EGA. Conclusions Our study highlights the importance of TAAs in EGA. The identified antigens are highly relevant for immunomonitoring of clinical trials and as targets for immunotherapy. Personalized immunotherapeutic strategies targeting EGA-specific or even patient specific TAAs appear highly promising in this challenging disease. Disclosure Information M. Thelen: None. M. Garcia-Marquez: None. J. Lehmann: None. D. Keller: None. E. Preugszat: None. M. von Bergwelt-Baildon: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Modest; Astellas, Roche, MSD. D. Speakers Bureau/Honoraria (speakers bureau, symposia, and expert witness); Modest; BMS. F. Consultant/Advisory Board; Modest; BMS. H.A. Schloser: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Significant; Astra Zeneca.

Background Tertiary lymphocyte structures (TLS) can be detected in the tumor microenvironment across a wide range of cancer types and are associated with increased patient survival and susceptibility to immune checkpoint inhibition. However, evidence for the functional significance of TLS on humoral and cellular immunity is scarce. In this study, we combine assessment of abundance and spatial distribution of TLS with expression levels of 10 tumor associated antigens (TAAs) and functional analyses of T cell responses to these antigens. Materials and Methods 52 treatment naive cancer patients across 5 tumor types (NSCLC, CRC, RCC, HCC and BCA) were included. Presence and localization of TLS was assessed in immunohistochemical stainings (CD20) of whole section slides from FFPE embedded tumor samples. B cell clusters were quantified in the whole tumor region and in two different tumor margins (300 µm, 2000 µm). A panel of 30 cancer testis antigens was selected via GEPIA software (TCGA Database) and their expression in our cohort was determined using NanoString based RNA expression analysis of tumor samples and patient-matched healthy tissue. The 10 peptide pools with the largest cross-cancer overlap were selected based on our NanoString results. 2-color Fluorospot assays (IFN-γ and IL-2) were applied to assess the frequency of tumor-specific T-cell responses in patient PBMCs (triplicates for each TAA). Results CD20 immunohistochemistry and enumeration of intra- and peritumoral TLS revealed different distribution patterns of TLS/mm2 with the largest proportion in the 300 µm margin (p Conclusions The observed findings underline the importance of TLS as a novel biomarker and a possible association to cellular responses may even enhance their prognostic value. Our planned analyses of combined humoral immune responses will further elucidate the role of TLS in anti-tumor immune response of the analyzed cancer types. A combined targeting of a predefined or personalized set of included TAAs appears promising across the different cancer types. Disclosure Information E. Preugszat: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Modest; Koeln Fortune Program, Faculty of Medicine, University of Cologne. M. Thelen: None. M. Garcia-Marquez: None. J. Lehmann: None. D. Keller: None. M. von Bergwelt-Baildon: Other; Modest; Honoraria for advisory boards, for invited talks from BMS and financial support for research projects from Astellas, Roche and MSD. H.A. Schloser: Other; Significant; Financial support for research projects from Astra Zeneca.

BackgroundSpecific immune response is a hallmark of cancer immunotherapy and shared tumor-associated antigens (TAAs) are important targets. Recent advances using combined cellular therapy against multiple TAAs renewed the interest in this class of antigens. Our study aims to determine the role of TAAs in esophago-gastric adenocarcinoma (EGA).MethodsRNA expression was assessed by NanoString in tumor samples of 41 treatment-naïve EGA patients. Endogenous T cell and antibody responses against the 10 most relevant TAAs were determined by FluoroSpot and protein-bound bead assays. Digital image analysis was used to evaluate the correlation of TAAs and T-cell abundance. T-cell receptor sequencing, in vitro expansion with autologous CD40-activated B cells (CD40Bs) and in vitro cytotoxicity assays were applied to determine specific expansion, clonality and cytotoxic activity of expanded T cells.Results68.3% of patients expressed ≥5 TAAs simultaneously with coregulated clusters, which were similar to data from The Cancer Genome Atlas (n=505). Endogenous cellular or humoral responses against ≥1 TAA were detectable in 75.0% and 53.7% of patients, respectively. We found a correlation of T-cell abundance and the expression of TAAs and genes related to antigen presentation. TAA-specific T-cell responses were polyclonal, could be induced or enhanced using autologous CD40Bs and were cytotoxic in vitro. Despite the frequent expression of TAAs co-occurrence with immune responses was rare.ConclusionsWe identified the most relevant TAAs in EGA for monitoring of clinical trials and as therapeutic targets. Antigen-escape rather than missing immune response should be considered as mechanism underlying immunotherapy resistance of EGA.

While classical Hodgkin lymphoma (HL) is highly susceptible to anti-programmed death protein 1 (PD1) antibodies, the exact modes of action remain controversial. To elucidate the circulating lymphocyte phenotype and systemic effects during anti-PD1 1st-line HL treatment we applied multicolor flow cytometry, FluoroSpot and NanoString to sequential samples of 81 HL patients from the NIVAHL trial (NCT03004833) compared to healthy controls. HL patients showed a decreased CD4 T-cell fraction, a higher percentage of effector-memory T cells and higher expression of activation markers at baseline. Strikingly, and in contrast to solid cancers, expression for 10 out of 16 analyzed co-inhibitory molecules on T cells (e.g., PD1, LAG3, Tim3) was higher in HL. Overall, we observed a sustained decrease of the exhausted T-cell phenotype during anti-PD1 treatment. FluoroSpot of 42.3% of patients revealed T-cell responses against ≥1 of five analyzed tumor-associated antigens. Importantly, these responses were more frequently observed in samples from patients with early excellent response to anti-PD1 therapy. In summary, an initially exhausted lymphocyte phenotype rapidly reverted during anti-PD1 1st-line treatment. The frequently observed IFN-y responses against shared tumor-associated antigens indicate T-cell-mediated cytotoxicity and could represent an important resource for immune monitoring and cellular therapy of HL.

The immune response against cancer is orchestrated by various parameters and site-dependent specificities have been poorly investigated. In our analyses of ten different cancer types, we describe elevated infiltration by regulatory T cells as the most common feature, while other lymphocyte subsets and also expression of immune-regulatory molecules on tumor-infiltrating lymphocytes showed site-specific variation. Multiparametric analyses of these data identified similarities of renal and liver or lung with head and neck cancer. Co-expression of immune-inhibitory ligands on tumor cells was most frequent in colorectal, lung and ovarian cancer. Genes related to antigen presentation were frequently dysregulated in liver and lung cancer. Expression of co-inhibitory molecules on tumor-infiltrating T cells accumulated in advanced stages while T-cell abundance was related to enhanced expression of genes related to antigen presentation. Our results promote evaluation of cancer-specific or even personalized immunotherapeutic combinations to overcome primary or secondary resistance as major limitation of immune-checkpoint inhibition.

The role of B cells in antitumor immunity and their impact on emerging immunotherapies is increasingly gaining attention. B-cell effector functions include not only secretion of antibodies, but also presentation of antigens to T cells. A physiologic B-cell subset with immunostimulatory properties was described in humans, defined by a high expression of CD86 and downregulation of CD21. We used multicolor flow cytometry and IHC to elucidate abundance and spatial distribution of these antigen-presenting B cells (BAPC) in blood (peripheral blood mononuclear cells, PBMC) and tumor samples of 237 patients with cancer. Antigen-specific T-cell responses to cancer testis antigens were determined using tetramer staining and sorted BAPCs in FluoroSpot assays for selected patients. We found that BAPCs were increased in the tumor microenvironment of 9 of 10 analyzed cancer types with site-specific variation. BAPCs were not increased in renal cell carcinoma, whereas we found a systemic increase with elevated fractions in tumor-infiltrating lymphocytes (TIL) and PBMCs of patients with colorectal cancer and gastroesophageal adenocarcinoma. BAPCs were localized in lymphoid follicles of tertiary lymphoid structures (TLS) and were enriched in tumors with increased numbers of TLSs. BAPCs isolated from tumor-draining lymph nodes of patients with cancer showed increased percentages of tumor antigen-specific B cells and induced responses of autologous T cells

Background Secondary lymphoid organs (SLO) are involved in induction and enhancement of anti-tumor immune responses on different tumor entities. Recent evidence suggests that anti-tumor immune responses may also be induced or enhanced in the tumor microenvironment in so called tertiary lymphoid structures (TLS). It is assumed that TLS represent a hotspot for T cell priming, B cell activation, and differentiation, leading to cellular and humoral anti-tumor immune response. Methods FFPE-slides of 120 primary pancreatic ductal adenocarcinoma (PDAC) patients were immunohistochemically (IHC) stained for CD20, CD3, CD8 and HLA-ABC to analyze spatial distribution of tumor-infiltrating lymphocytes. 5-color immunofluorescence staining was performed to further investigate structural components of TLS in comparison to lymphoid follicles in SLOs. Microscope-based laser microdissection and Nanostring-base RNA expression analysis were used to compare gene expression in PDAC, TLS, SLOs and normal pancreatic tissue. Results TLS were frequently detected in PDAC and were mainly localized along the invasive tumor margin. In less than 10% of the cases TLS were infiltrating the tumors. Interestingly, 20% of the patients had no TLS. Results of TLS will be correlated with clinical parameters, Immunoscore and immune escape mechanisms. 5-color Immunofluorescence staining revealed similar organization and function of TLS and SLO. Finally, gene expression analyzed by Nanostring revealed largely overlapping expression patterns in TLS and SLO. Conclusions The results clearly demonstrate close similarities between SLO and TLS in terms of composition, distribution and gene expression Patterns. Disclosure Information M. Thelen: None. M.A. Garcia-Marquez: None. T. Nestler: None. S. Wagener-Ryczek: None. J. Lehmann: None. E. Staib: None. F. Popp: None. F. Gebauer: None. P. Lohneis: None. M. Odenthal: None. S. Merkelbach-Bruse: None. C. Bruns: None. K. Wennhold: None. M. von Bergwelt-Baildon: None. H.A. Schloser: None.

Background Immune-checkpoint inhibition (CKI) demonstrated remarkable therapeutic efficacy in several kinds of cancer. However, immune escape mechanisms lead to primary or secondary resistance in the majority of patients. Most predictive biomarkers failed, as the primary target of CKI is not the tumor cell itself, but the crosstalk between immune- and cancer cells. We aimed to characterize the immune evasion landscape in primary tumors across different entities. Materials and Methods Expression of 32 immune-regulatory molecules on lymphocytes was analyzed in peripheral blood and tumor infiltrating lymphocytes (TILs) of 146 primary tumor patients across 10 different entities using flow cytometry. NanoString was applied to determine RNA expression of the respective ligands and 20 genes associated with antigen presentation. Expression of coinhibitory ligands on tumor cells was assessed by immunohistochemistry. To quantify the immune cell infiltration, digital pathology was used and the Immunoscore was generated for each patient. Results While an increase of regulatory T cells was a common feature across all entities, we found site-specific differences regarding other lymphocyte subsets and expression of immune-regulatory molecules by TILs and tumor cells. Expression of co-inhibitory molecules on tumor infiltrating T cells accumulated especially in advanced stage cancers whereas immune cell infiltration was mainly associated with enhanced antigen presentation. Co-expression of multiple immune-inhibitory ligands was most frequent in colorectal, lung and ovarian carcinoma. Genes related to antigen presentation were frequently dysregulated in seminoma, liver and lung cancer. Conclusions Immune evasion is a common feature of cancer and frequently detected co-occurrence of multiple mechanisms probably contributes to resistance against immunotherapy. We describe substantial heterogeneity regarding immune escape mechanisms between patients with the same primary tumor. Individualized immunotherapeutic strategies based on pretherapeutic evaluation of the immune evasion landscape might help to improve response to CKI. Disclosure Information M. Thelen: None. K. Wennhold: None. J. Lehmann: None. E. Staib: None. M.A. Garcia Marquez: None. P. Lohneis: None. A. Lechner: None. S. Wagener-Ryczek: None. P.S. Plum: None. D. Pfister: None. F. Dorr: None. D. Beutner: None. F. Thangarajah: None. D. Ratiu: None. W. Malter: None. S. Merkelbach-Bruse: None. C.J. Bruns: None. A. Quaas: None. M.S. von Bergwelt-Baildon: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Significant; Astellas. F. Consultant/Advisory Board; Modest; Bristol-Myers Squibb. H.A. Schloser: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Significant; Astra Zeneca.

Background Despite early surgical debridement and application of systemic antifungal drugs, invasive fungal infections by mucor spp. are still associated with a very poor prognosis in immunocompromised patients. Due to their lack of immune defense, targeted treatment strategies reversing the hyporesponsiveness of the immune system by immune checkpoints might improve patients’ outcome. Until today, a successful recovery of mucormycosis after receiving anti-PD-1 antibody is only described once for a polytrauma patient. Therefore, we here describe the first immunosuppressed patient treated with nivolumab for invasive mucormycosis with aspergillus coinfection. Materials and Methods A 51-year-old woman from Germany with acute myeloid leukemia (AML) relapse after allogenic hematopoietic stem cell transplantation was treated with azacitidine and lenalidomide. She acquired an invasive fungal infection with mucor species Lichtheimia ramosa combined with Aspergillus fumigatus in functional pancytopenia. Three surgical pansinusrevisions were performed and high dose i.v. antifungal treatment with liposomal amphotericin B and isavuconazole was initiated. Due to missing treatment response with daily mucor progression nivolumab 240 mg was administered and complemented by interferon γ (100µg s.c. 5 doses). Administration was repeated every 2 weeks (in total 4 doses of nivolumab, but only 10 doses of interferon γ due to recurrent fever episodes) and simultaneously i.v. antifungal treatment was deescalated. Blood samples were collected before (baseline treatment (BT)) as well as 2 weeks (under treatment (UT) 1) and 5 weeks (UT2) after treatment initiation with nivolumab. Peripheral blood mononuclear cells were isolated and flow cytometry analyses of lymphocytic subsets were performed. Results Ten days after first dose of nivolumab, long-term local hemostasis was achieved. Local symptoms disappeared, sinusitis complaints improved, and inflammation values decreased significantly. Sixteen days after treatment initiation a CT scan revealed a partial remission of mucormycosis invasion. Follow-up CT scans showed a stable disease. Expression of PD-1 on T cells was monitored as proof of concept from BT on and showed a significant reduction from 34.7% to 3.3% (UT1) and 1.38% (UT2). Both activation markers CD86 and CD69 showed an increase from BT to UT1. T cells showed high maturation markers throughout monitoring, while B cell maturation increased from BT to UT1/2. Nine weeks after diagnosis and despite long-term neutropenia the patient was still clinically stable under nivolumab treatment and discharged with continued deescalated antimycotic treatment. A bone marrow biopsy revealed a further progression of AML relapse. After 3 weeks during follow-up mucormycosis was still clinically stable. Ten days later the patient developed fever up to 39.5°C, but refused to seek medical attention due to unfavorable prognosis of AML and died two days later from septic shock combined with disseminated intravascular coagulation. Conclusions In immunocompromised hematological patients with invasive fungal infections, immune checkpoint inhibition is capable of reversing an infection-induced immunosuppressive phenotype. Therefore, it might complement the treatment of invasive fungal infections and should be evaluated in future clinical trials. Disclosure Information N. Mueller: None. J. Banck: None. S. Mellinghoff: None. H. Schlosser: None. M. Thelen: None. P. Koehler: None. F. Schrotzlmair: None. O. Cornely: None. L.H. Lindner: None. M. von Bergwelt-Baildon: None.

Background Thermal ablative therapies, such as microwave ablation (MWA) or radiofrequency ablation (RFA), are standard treatments for HCC. In addition to the local tumor destruction, abscopal effects (a reduction of a tumor mass in areas that were not included in the thermal ablation) could be observed. These systemic effects may be mediated by anti-tumor immune response, which has been described for RFA. MWA is rapidly replacing RFA, but systemic immunostimulatory effects of MWA treatment have been poorly studied. Materials and Methods Patients receiving MWA for localized HCC were included in this study. Effects of MWA on peripheral blood mononuclear cells (PBMC) of HCC patients treated with MWA were analyzed by multicolor flow cytometry. Tumor-specific immune responses against 7 shared tumor antigens were analyzed using peptide pools in 3-color Fluorospot assays (Interferon-y/Interleukin-5/Interleukin-10). The impact of type, density and localization of tumor-infiltrating lymphocytes was assessed by immunohistochemistry (IHC) of CD3, CD4, CD8, FoxP3, CD38 and CD20 and digital image analyses (Immunoscore) of tumor specimens in an additional cohort of patients who received combined surgical resection and thermal ablation. Results While comprehensive flow cytometric analyses in sequential samples (day 0, 7 and 90) of a prospective patient cohort (n=23) demonstrated only moderate effects of MWA on circulating immune cell subsets, Fluorospot analyses revealed de novo or enhanced tumor-specific immune responses in 30% of these patients. This anti-tumor immune response was related to tumor control. Interferon-y and Interleukin-5 T cell responses against cancer testis antigens were more frequent in patients with a long-time remission (>12 months) after MWA (7/16) compared to patients suffering from an early relapse (0/13 patients). Presence of tumor-specific T cell response (Interferon-y and/or Interleukin-5) was associated to longer progression-free survival (15.0 vs. 10.0 months). Immunohistochemical analyses of resected tumor samples revealed that a high T cell infiltration in a second tumor lesion at the time of thermal ablation was associated with superior disease-free survival (37.4 vs. 13.1 months). Conclusions Our data demonstrates remarkable immune-related effects of MWA in HCC patients. This study and provides additional evidence for a combination of thermal ablation and immunotherapy in this challenging disease. Funding ‘Koeln Fortune’ and ‘CAP-CMMC’ local research grant (to P.G. and H.A.S.) supported our research. Disclosure Information E. Staib: None. K. Leuchte: None. M. Thelen: None. P. Godel: None. A. Lechner: None. P. Zentis: None. M. Garcia-Marquez: None. D. Waldschmidt: None. R.R. Datta: None. R. Wahba: None. C. Wybranski: None. T. Zander: None. A. Quaas: None. U. Drebber: None. D.L. Stippel: None. C. Bruns: None. K. Wennhold: None. M. von Bergwelt-Baildon: None. H.A. Schlosser: None.

BackgroundThe costimulatory receptor 4-1BB (CD137, TNFRSF9) plays an important role in sustaining effective T cell immune responses and is investigated as target for cancer therapy. Systemic 4-1BB directed therapies elicit toxicity or low efficacy, which significantly hampered advancement of 4-1BB-based immunotherapy. Therefore, targeted delivery of 4-1BB agonist to the tumor side is needed for eliciting antitumor efficacy while avoiding systemic toxicity.MethodsWe analyzed the immunostimulatory properties of a fibroblast activation protein (FAP)-targeted 4-1BB agonist (FAP-4-1BBL) by assessing tumor-infiltrating lymphocytes’ (TIL) activity from patients with non-small cell lung cancer and epithelial ovarian cancer.ResultsCombination treatment with FAP-4-1BBL and T cell receptor stimulation by either anti-CD3 or T cell bispecific antibodies significantly enhanced TIL activation and effector functions, including T cell proliferation, secretion of proinflammatory cytokines and cytotoxicity. Notably, costimulation with FAP-4-1BBL led to de novo secretion of interleukin (IL)−13. This was associated with cytokine-mediated tumor cell apoptosis, which was partially dependent on IL-13 alpha 1/2 receptors and STAT6 phosphorylation.ConclusionsOur study provides mechanistic insights into T cell stimulation induced by FAP-4-1BBL in primary human tumors and supports the investigation of FAP-4-1BBL compound in early clinical trials.

Single‐cell transcriptomics have revolutionized our understanding of the cell composition of tumors and allowed us to identify new subtypes of cells. Despite rapid technological advancements, single‐cell analysis remains resource‐intense hampering the scalability that is required to profile a sufficient number of samples for clinical associations. Therefore, more scalable approaches are needed to understand the contribution of individual cell types to the development and treatment response of solid tumors such as esophageal adenocarcinoma where comprehensive genomic studies have only led to a small number of targeted therapies. Due to the limited treatment options and late diagnosis, esophageal adenocarcinoma has a poor prognosis. Understanding the interaction between and dysfunction of individual cell populations provides an opportunity for the development of new interventions. In an attempt to address the technological and clinical needs, we developed a protocol for the separation of esophageal carcinoma tissue into leukocytes (CD45+), epithelial cells (EpCAM+), and fibroblasts (two out of PDGFRα, CD90, anti‐fibroblast) by fluorescence‐activated cell sorting and subsequent RNA sequencing. We confirm successful separation of the three cell populations by mapping their transcriptomic profiles to reference cell lineage expression data. Gene‐level analysis further supports the isolation of individual cell populations with high expression of CD3, CD4, CD8, CD19, and CD20 for leukocytes, CDH1 and MUC1 for epithelial cells, and FAP, SMA, COL1A1, and COL3A1 for fibroblasts. As a proof of concept, we profiled tumor samples of nine patients and explored expression differences in the three cell populations between tumor and normal tissue. Interestingly, we found that angiogenesis‐related genes were upregulated in fibroblasts isolated from tumors compared with normal tissue. Overall, we suggest our protocol as a complementary and more scalable approach compared with single‐cell RNA sequencing to investigate associations between clinical parameters and transcriptomic alterations of specific cell populations in esophageal adenocarcinoma., Little is known about the interactions between the different intratumoral cell types, that is, epithelial tumor cells, cancer‐associated fibroblasts, and immune cells. We developed a scalable and cost‐effective workflow to separate these cell types from esophageal adenocarcinoma (EAC) biopsies using fluorescence‐activated cell sorting and subsequent RNA sequencing. Using this approach, we characterize these cell types in EAC and normal tissue.

ZusammenfassungVerbandsstrafen bilden ein wichtiges Instrument, um Disziplin innerhalb einer Gesellschaft herzustellen. Anlässlich eines aktuellen BGH-Beschlusses zeigt der Beitrag auf, welche formellen und materiellen Anforderungen die Rechtsprechung an Verbandsstrafen in den Satzungen von Genossenschaften stellt. Zentrale Bedeutung erlangen das Kartellverbot des § 1 GWB und die Rechtsfigur der Genossenschaftsimmanenz.