bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Intravenous Injection of MVA Virus Targets CD8+ Lymphocytes to Tumors to Control Tumor Growth upon Combinatorial Treatment with a TLR9 Agonist
Authors: Fend Laetitia , Gatard-Scheikl Tanja , Kintz Jacqueline , Gantzer Murielle , Schaedler Emmanuelle , Rittner Karola , Cochin Sandrine , Fournel Sylvie , Préville Xavier
Published: March 2024

Abstract
Effector T-cell access to tumor tissue is a limiting step for clinical efficacy of antigen-specific T cell–based immunotherapies. Ectopic mouse tumor models, in which a subcutaneously (s.c.) implanted tumor is treated with s.c. or intramuscular therapeutic immunization, may not be optimal for targeting effector T cells to an organ-borne tumor. We used an orthotopic renal carcinoma model to evaluate the impact of injection routes on therapeutic efficacy of a Modified Vaccinia virus Ankara viral vector expressing the human mucin 1 tumor–associated xeno-antigen (MVA-MUC1). We show that intravenous (i.v.) administration of MVA-MUC1 displayed enhanced efficacy when compared with s.c. injection. Therapeutic efficacy of MVA-MUC1 was further enhanced by i.v. injection of a TLR9 agonist. In all cases, infiltration of tumor-bearing kidney by CD8+ lymphocytes was associated with control of tumor growth. Biodistribution experiments indicate that, following i.v. injection, MVA-encoded antigens are quickly expressed in visceral organs and, in particular, in splenic antigen-presenting cells, compared with those following s.c. injection. This appears to result in a faster generation of MUC1-specific CD8+ T cells. Lymphocytes infiltrating tumor-bearing kidneys are characterized by an effector memory phenotype and express PD-1 and Tim3 immune checkpoint molecules. Therapeutic efficacy was associated with a modification of the tumor microenvironment toward a Th1-type immune response and recruitment of activated lymphocytes. This study supports the clinical evaluation of MVA-based immunotherapies via the i.v. route. Cancer Immunol Res; 2(12); 1163–74. ©2014 AACR.
Data from Microvesicle Cargo of Tumor-Associated MUC1 to Dendritic Cells Allows Cross-presentation and Specific Carbohydrate Processing
Authors: Rughetti Aurelia , Rahimi Hassan , Belleudi Francesca , Napoletano Chiara , Battisti Federico , Zizzari Ilaria G. , Antonilli Morena , Bellati Filippo , Wandall Hans H. , Benedetti Panici Pierluigi , Burchell Joy M. , Torrisi Mara R. , Nuti Marianna
Published: March 2024

Abstract
Tumor-associated glycoproteins are a group of antigens with high immunogenic interest: The glycoforms generated by the aberrant glycosylation are tumor-specific and the novel glycoepitopes exposed can be targets of tumor-specific immune responses. The MUC1 antigen is one of the most relevant tumor-associated glycoproteins. In cancer, MUC1 loses polarity and becomes overexpressed and hypoglycosylated. Changes in glycan moieties contribute to MUC1 immunogenicity and can modify the interactions of tumor cells with antigen-presenting cells such as dendritic cells that would affect the overall antitumor immune response. Here, we show that the form of the MUC1 antigen, i.e., soluble or as microvesicle cargo, influences MUC1 processing in dendritic cells. In fact, MUC1 carried by microvesicles translocates from the endolysosomal/HLA-II to the HLA-I compartment and is presented by dendritic cells to MUC1-specific CD8+ T cells stimulating IFN-γ responses, whereas the soluble MUC1 is retained in the endolysosomal/HLA-II compartment independently by the glycan moieties and by the modality of internalization (receptor-mediated or non–receptor mediated). MUC1 translocation to the HLA-I compartment is accompanied by deglycosylation that generates novel MUC1 glycoepitopes. Microvesicle-mediated transfer of tumor-associated glycoproteins to dendritic cells may be a relevant biologic mechanism in vivo contributing to define the type of immunogenicity elicited. Furthermore, these results have important implications for the design of glycoprotein-based immunogens for cancer immunotherapy. Cancer Immunol Res; 2(2); 177–86. ©2013 AACR.
Data from Loss of CXCR4 in Myeloid Cells Enhances Antitumor Immunity and Reduces Melanoma Growth through NK Cell and FASL Mechanisms
Authors: Yang Jinming , Kumar Amrendra , Vilgelm Anna E. , Chen Sheau-Chiann , Ayers Gregory D. , Novitskiy Sergey V. , Joyce Sebastian , Richmond Ann
Published: March 2024

Abstract
The chemokine receptor, CXCR4, is involved in cancer growth, invasion, and metastasis. Several promising CXCR4 antagonists have been shown to halt tumor metastasis in preclinical studies, and clinical trials evaluating the effectiveness of these agents in patients with cancer are ongoing. However, the impact of targeting CXCR4 specifically on immune cells is not clear. Here, we demonstrate that genetic deletion of CXCR4 in myeloid cells (CXCR4MyeΔ/Δ) enhances the antitumor immune response, resulting in significantly reduced melanoma tumor growth. Moreover, CXCR4MyeΔ/Δ mice exhibited slowed tumor progression compared with CXCR4WT mice in an inducible melanocyte BrafV600E/Pten−/− mouse model. The percentage of Fas ligand (FasL)–expressing myeloid cells was reduced in CXCR4MyeΔ/Δ mice as compared with myeloid cells from CXCR4WT mice. In contrast, there was an increased percentage of natural killer (NK) cells expressing FasL in tumors growing in CXCR4MyeΔ/Δ mice. NK cells from CXCR4MyeΔ/Δ mice also exhibited increased tumor cell killing capacity in vivo, based on clearance of NK-sensitive Yac-1 cells. NK cell–mediated killing of Yac-1 cells occurred in a FasL-dependent manner, which was partially dependent upon the presence of CXCR4MyeΔ/Δ neutrophils. Furthermore, enhanced NK cell activity in CXCR4MyeΔ/Δ mice was also associated with increased production of IL18 by specific leukocyte subpopulations. These data suggest that CXCR4-mediated signals from myeloid cells suppress NK cell–mediated tumor surveillance and thereby enhance tumor growth. Systemic delivery of a peptide antagonist of CXCR4 to tumor-bearing CXCR4WT mice resulted in enhanced NK-cell activation and reduced tumor growth, supporting potential clinical implications for CXCR4 antagonism in some cancers. Cancer Immunol Res; 6(10); 1186–98. ©2018 AACR.
Data from Radretumab Radioimmunotherapy in Patients with Brain Metastasis: A 124I-L19SIP Dosimetric PET Study
Authors: Poli Gian Luca , Bianchi Claudia , Virotta Giorgio , Bettini Anna , Moretti Renzo , Trachsel Eveline , Elia Giuliano , Giovannoni Leonardo , Neri Dario , Bruno Andrea
Published: March 2024

Abstract
Radioimmunotherapy (RIT) with 131I-labeled L19SIP (radretumab; a small immunoprotein format antibody directed against the ED-B domain of fibronectin; ∼80 kDa molecular weight) has been investigated in several clinical trials. Here, we describe the use of immuno-PET imaging with iodine-124 (124I)–labeled L19SIP to predict doses delivered to tumor lesions and healthy organs by a subsequent radretumab RIT in patients with brain metastases from solid cancer. Bone marrow doses were evaluated both during the diagnostic phase and posttherapy, measuring activities in blood (germanium detector) and whole body (lanthanum bromide detector). Expected doses for radretumab administration (4,107 MBq/m2) were calculated from data obtained after administration of an average of 167 MBq 124I-L19SIP to 6 patients. To assess lesion average doses, the positron emission tomography (PET) scanner was calibrated for the use of 124I with an International Electrotechnical Commission (IEC) Body Phantom and recovery coefficients were calculated. The average dose to bone red marrow was 0.21 Gy/GBq, with high correlation between provisional and actual posttherapy doses. Although the fraction of injected activity in normal organs was similar in different patients, the antibody uptake in the neoplastic lesions varied by as much as a factor of 60. Immuno-PET with 124I-labeled L19SIP offers significant advantages over conventional 131I imaging, in particular accuracy of dosimetric results. Furthermore, the study indicates that antibody uptake can be highly variable even in different lesions of the same patient and that immuno-PET procedures may guide product development with armed antibodies. Cancer Immunol Res; 1(2); 134–43. ©2013 AACR.
Data from PI3Kγ Activates Integrin α4 and Promotes Immune Suppressive Myeloid Cell Polarization during Tumor Progression
Authors: Foubert Philippe , Kaneda Megan M. , Varner Judith A.
Published: March 2024

Abstract
Immunosuppressive myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) accumulate in tumors where they inhibit T cell–mediated antitumor immune responses and promote tumor progression. Myeloid cell PI3Kγ plays a role in regulating tumor immune suppression by promoting integrin α4–dependent MDSC recruitment to tumors and by stimulating the immunosuppressive polarization of MDSCs and TAMs. Here, we show that integrin α4 promotes immunosuppressive polarization of MDSCs and TAMs downstream of PI3Kγ, thereby inhibiting antitumor immunity. Genetic or pharmacological suppression of either PI3Kγ or integrin α4 blocked MDSC recruitment to tumors and also inhibited immune suppressive myeloid cell polarization, thereby reducing expression of IL10 and increasing expression of IL12 and IFNγ within tumors. Inhibition of PI3Kγ or integrin α4 within tumors stimulated dendritic cell and CD8+ T-cell recruitment and maturation, as well as tumor cell cytotoxicity in vivo, thereby inhibiting tumor growth. As blockade of PI3Kγ or integrin α4 prevents accumulation of MDSC and reduces myeloid cell expression of immunosuppressive factors that stimulate tumor immune escape, these results highlight PI3Kγ and integrin α4 as targets for the design of cancer therapeutics. Cancer Immunol Res; 5(11); 957–68. ©2017 AACR.
Data from Escalating Regulation of 5T4-Specific IFN-γ+ CD4+ T Cells Distinguishes Colorectal Cancer Patients from Healthy Controls and Provides a Target for In Vivo Therapy
Authors: Scurr Martin , Bloom Anja , Pembroke Tom , Srinivasan Rohit , Brown Clare , Smart Kathryn , Bridgeman Hayley , Davies Mike , Hargest Rachel , Phillips Simon , Christian Adam , Hockey Tom , Gallimore Awen , Godkin Andrew
Published: March 2024

Abstract
The relationship between the adaptive CD4+ T-cell response and human cancer is unclear. The oncofetal antigen 5T4 is expressed in many human carcinomas, including colorectal cancer cells, but has limited expression on normal tissues. We previously identified anti-5T4 CD4+ T cells in a proportion of patients with colorectal cancer, and we extended this study to examine whether the quality or quantity of the T-cell response reflects tumor stage. An overlapping peptide library spanning 5T4 was used as a target to enumerate cognate IFN-γ+ CD4+ T cells [measured as spot-forming cells (SFC)/105 cultured T cells] in peripheral blood–derived lymphocytes following a 14-day in vitro culture period comparing patients preoperatively (n = 27) to healthy controls (n = 17). Robust 5T4-specific T-cell responses were present in 100% of healthy donors. There was a steady loss of T-cell responses with advancing tumors with a significant negative correlation from stage I to III (P = 0.008). The predictability of the decline meant <200 SFC/105 were only found in subjects with stage III colorectal cancer. The mechanism of loss of T-cell response is independent of HLA-DR type or patient age but does correspond to increases in Foxp3+ regulatory T cells (Treg). Using low-dose cyclophosphamide to reduce the proportion of Tregs in vivo resulted in increased anti-5T4 T-cell responses in patients with colorectal cancer. The selective loss of 5T4-specific IFN-γ+ CD4+ T-cell responses implies a link between tumor stage and antitumor Th1 effector function; depleting Tregs can enhance such responses. Cancer Immunol Res; 1(6); 416–25. ©2013 AACR.
Data from Phenotypic and Functional Activation of Hyporesponsive KIRnegNKG2Aneg Human NK-Cell Precursors Requires IL12p70 Provided by Poly(I:C)-Matured Monocyte-Derived Dendritic Cells
Authors: Curran Shane A. , Romano Emanuela , Kennedy Michael G. , Hsu Katharine C. , Young James W.
Published: March 2024

Abstract
A functionally responsive natural killer (NK)–cell repertoire requires the acquisition of inhibitory NKG2A and killer immunoglobulin-like receptors (KIR) through pathways that remain undefined. Functional donor NK cells expressing KIRs for non-self class I MHC ligands contribute to a positive outcome after allogeneic hematopoietic stem cell transplantation (alloHSCT) by targeting HLA-matched recipient leukemic cells. Insofar as circulating donor conventional dendritic cells (DC) reconstitute with comparable kinetics with donor NK cells after alloHSCT, we used hyporesponsive KIRnegNKG2Aneg precursor cells to evaluate how specific DC subtypes generate a functionally active NK-cell repertoire. Both monocyte-derived DCs (moDC) and Langerhans-type DCs (LC) induce KIRnegNKG2Aneg precursor cells to express the inhibitory receptors NKG2A and KIR, without requiring cell proliferation. Poly(I:C)-matured moDCs significantly augmented the expression of NKG2A, but not KIR, in an IL12p70-dependent manner. Although all DC-stimulated KIRnegNKG2Aneg cells were able to acquire cytolytic activity against class I MHC-negative targets, the ability to secrete IFNγ was restricted to cells that were stimulated by IL12p70-producing, poly(I:C)-matured moDCs. This critical ability of poly(I:C)-matured moDCs to provide IL12p70 to developing KIRnegNKG2Aneg precursors results in a dominant, multifunctional, NKG2Apos NK-cell population that is capable of both cytolysis and IFNγ production. Poly(I:C)-matured moDCs are, therefore, the most effective conventional DC subtype for generating a functionally competent NK-cell repertoire by an IL12p70-dependent mechanism. Cancer Immunol Res; 2(10); 1000–10. ©2014 AACR.
Data from Effect of Montanide and Poly-ICLC Adjuvant on Human Self/Tumor Antigen-Specific CD4+ T Cells in Phase I Overlapping Long Peptide Vaccine Trial
Authors: Tsuji Takemasa , Sabbatini Paul , Jungbluth Achim A. , Ritter Erika , Pan Linda , Ritter Gerd , Ferran Luis , Spriggs David , Salazar Andres M. , Gnjatic Sacha
Published: March 2024

Abstract
Vaccination of patients with ovarian cancer with overlapping long peptides (OLP) from cancer-testis antigen NY-ESO-1 and poly-ICLC in Montanide-ISA-51 (Montanide) was found to consistently induce integrated immune responses (antibody, CD4+, and CD8+ T cells). Using detailed methods, we investigated the respective effects of poly-ICLC and Montanide adjuvant on pre- and postvaccine NY-ESO-1–specific CD4+ T cells, because of their central function for induction and maintenance of both antibody and CD8+ T cells. Polyclonal NY-ESO-1–specific CD4+ T-cell lines were generated from 12 patients using CD154-based selection of precursors before and after vaccination with (i) OLP alone, (ii) OLP in Montanide, or (iii) OLP and poly-ICLC in Montanide. Kinetics, quantification, fine specificity, avidity, and cytokine-producing pattern were analyzed in depth and compared between vaccine cohorts. Vaccination with OLP alone did not elicit CD4+ T-cell responses; it suppressed high-avidity CD4+ T-cell precursors that recognized naturally processed NY-ESO-1 protein before vaccination. Emulsification of OLP in Montanide was required for the expansion of high-avidity NY-ESO-1–specific CD4+ T-cell precursors. Poly-ICLC significantly enhanced CD4+ Th1 responses while suppressing the induction of interleukin (IL)-4–producing Th2 and IL-9–producing Th9 cells. In summary, Montanide and poly-ICLC had distinct and cooperative effects for the induction of NY-ESO-1–specific Th1 cells and integrated immune responses by OLP vaccination. These results support the use of admixing poly-ICLC in Montanide adjuvant to rapidly induce antitumor type I immune responses by OLP from self/tumor antigens in human cancer vaccines. Cancer Immunol Res; 1(5); 340–50. ©2013 AACR.
Data from Role of Crosslinking for Agonistic CD40 Monoclonal Antibodies as Immune Therapy of Cancer
Authors: Richman Lee P. , Vonderheide Robert H.
Published: March 2024

Abstract
Agonists of the TNF superfamily of receptors hold promise as novel therapy for cancer. Recent data on agonistic antimurine TNF receptors (TNFR) such as CD40 suggest that the specific engagement of Fc receptor (FcR) is required for optimal antitumor effects, prompting calls to engineer antihuman CD40 and other TNFR monoclonal antibodies (mAb) accordingly. CP-870,893 is a fully human anti-CD40 mAb, selected in part because it is an immunoglobulin G2 (IgG2), which is presumed to have poor reactivity with FcR; however, CP-870,893 has been evaluated in multiple clinical trials with beneficial activity in patients with melanoma, pancreatic, and other cancers. Here, we confirmed that the activity of antimurine CD40 mAb was dependent on FcγRIIB engagement, was decreased significantly in FcγRIIB−/− mice, and upon Fc-crosslinking antimouse CD40 mAb enhanced the activation of antigen-presenting cells. In contrast, the CP-870,893-mediated activation of human B cells was not enhanced with anti-IgG crosslinking nor abrogated when used as an F(ab)′2 reagent. Crosslinking of CP-870,893 using the CD32-expressing K562 cells yielded an Fc-dependent modest increase in the expression of some activation markers relative to that of the soluble CP-870,893 mAb. Classic Fc-dependent functions such as antibody-dependent cellular cytotoxicity (ADCC) and complement-mediated cytotoxicity (CMC) were minimal for CP-870,893 as compared with the IgG1 anti-CD20 mAb rituximab, which mediated both ADCC and CMC in parallel assays. Antimouse CD40 mAb competed for the CD40 ligand binding site, but CP-870,893 did not. Thus, Fc crosslinking is not an essential requirement for agonistic antihuman CD40 mAbs, in which potency is more dependent on the CD40 epitope recognized and the strength of the signal achieved. Cancer Immunol Res; 2(1); 19–26. ©2013 AACR.
Data from Ipilimumab Treatment Results in an Early Decrease in the Frequency of Circulating Granulocytic Myeloid-Derived Suppressor Cells as well as Their Arginase1 Production
Authors: de Coaña Yago Pico , Poschke Isabel , Gentilcore Giusy , Mao Yumeng , Nyström Maria , Hansson Johan , Masucci Giuseppe V. , Kiessling Rolf
Published: March 2024

Abstract
Blocking the immune checkpoint molecule CTL antigen-4 (CTLA-4) with ipilimumab has proven to induce long-lasting clinical responses in patients with metastatic melanoma. To study the early response that takes place after CTLA-4 blockade, peripheral blood immune monitoring was conducted in five patients undergoing ipilimumab treatment at baseline, three and nine weeks after administration of the first dose. Along with T-cell population analysis, this work was primarily focused on an in-depth study of the myeloid-derived suppressor cell (MDSC) populations. Ipilimumab treatment resulted in lower frequencies of regulatory T cells along with reduced expression levels of PD-1 at the nine-week time point. Three weeks after the initial ipilimumab dose, the frequency of granulocytic MDSCs was significantly reduced and was followed by a reduction in the frequency of arginase1-producing CD3− cells, indicating an indirect in trans effect that should be taken into account for future evaluations of ipilimumab mechanisms of action. Cancer Immunol Res; 1(3); 158–62. ©2013 AACR.
Data from Successful Treatment of HIV-Associated Kaposi Sarcoma with Immune Checkpoint Blockade
Authors: Galanina Natalie , Goodman Aaron M. , Cohen Philip R. , Frampton Garrett M. , Kurzrock Razelle
Published: March 2024

Abstract
Kaposi sarcoma (KS) is an incurable, human immunodeficiency virus (HIV)-associated malignancy. We reviewed 320 immunotherapy-treated patient records. Seventeen had HIV-associated malignancies, including nine men with KS. Median viral load was 20 copies/mL (range, undetectable to 549,704) and median CD4 count was 256 cells/μL (range, 10–603). Eight patients received nivolumab and one received pembrolizumab. Six patients (67%) achieved partial (N = 5) or complete remission (N = 1). No drug-related grade >2 toxicities occurred. In seven patients, CD4 counts increased (P = 0.09). Tissue and/or blood-derived circulating tumor DNA (ctDNA) was evaluated by next-generation sequencing. Four evaluable patients each showed anomalies in distinct genes: TP53, KRAS, TLL2, PTPN6 (tissue and/or ctDNA), and NF1 (ctDNA). Tumor mutational burden was low, and PD-L1 immunohistochemistry was negative (three and four assessable patients, respectively). Responders included patients with low CD4 counts, high HIV load, and/or visceral disease. In summary, checkpoint blockade demonstrated significant antitumor activity and low toxicity in patients with HIV-associated KS. Cancer Immunol Res; 6(10); 1129–35. ©2018 AACR.
Data from Polyamine-Blocking Therapy Reverses Immunosuppression in the Tumor Microenvironment
Authors: Hayes Candace S. , Shicora Allyson C. , Keough Martin P. , Snook Adam E. , Burns Mark R. , Gilmour Susan K.
Published: March 2024

Abstract
Correcting T-cell immunosuppression may unleash powerful antitumor responses; however, knowledge about the mechanisms and modifiers that may be targeted to improve therapy remains incomplete. Here, we report that polyamine elevation in cancer, a common metabolic aberration in aggressive lesions, contributes significantly to tumor immunosuppression and that a polyamine depletion strategy can exert antitumor effects that may also promote immunity. A polyamine-blocking therapy (PBT) that combines the well-characterized ornithine decarboxylase (ODC) inhibitor difluoromethylornithine (DFMO) with AMXT 1501, a novel inhibitor of the polyamine transport system, blocked tumor growth in immunocompetent mice but not in athymic nude mice lacking T cells. PBT had little effect on the proliferation of epithelial tumor cells, but it increased the number of apoptotic cells. Analysis of CD45+ tumor immune infiltrates revealed that PBT decreased levels of Gr-1+CD11b+ myeloid suppressor cells and increased CD3+ T cells. Strikingly, in a model of neoadjuvant therapy, mice administered with PBT one week before surgical resection of engrafted mammary tumors exhibited resistance to subsequent tumor rechallenge. Collectively, our results indicate that therapies targeting polyamine metabolism do not act exclusively as antiproliferative agents, but also act strongly to prevent immune escape by the tumor. PBT may offer a general approach to heighten immune responses in cancer. Cancer Immunol Res; 2(3); 274–85. ©2013 AACR.
Data from Combined Targeting of Costimulatory (OX40) and Coinhibitory (CTLA-4) Pathways Elicits Potent Effector T Cells Capable of Driving Robust Antitumor Immunity
Authors: Redmond William L. , Linch Stefanie N. , Kasiewicz Melissa J.
Published: March 2024

Abstract
Ligation of the TNF receptor family costimulatory molecule OX40 (CD134) with an agonist anti-OX40 monoclonal antibody (mAb) enhances antitumor immunity by augmenting T-cell differentiation as well as turning off the suppressive activity of the FoxP3+CD4+ regulatory T cells (Treg). In addition, antibody-mediated blockade of the checkpoint inhibitor CTLA-4 releases the “brakes” on T cells to augment tumor immunotherapy. However, monotherapy with these agents has limited therapeutic benefit particularly against poorly immunogenic murine tumors. Therefore, we examined whether the administration of agonist anti-OX40 therapy in the presence of CTLA-4 blockade would enhance tumor immunotherapy. Combined anti-OX40/anti-CTLA-4 immunotherapy significantly enhanced tumor regression and the survival of tumor-bearing hosts in a CD4 and CD8 T cell–dependent manner. Mechanistic studies revealed that the combination immunotherapy directed the expansion of effector T-bethigh/Eomeshigh granzyme B+ CD8 T cells. Dual immunotherapy also induced distinct populations of Th1 [interleukin (IL)-2, IFN-γ], and, surprisingly, Th2 (IL-4, IL-5, and IL-13) CD4 T cells exhibiting increased T-bet and Gata-3 expression. Furthermore, IL-4 blockade inhibited the Th2 response, while maintaining the Th1 CD4 and effector CD8 T cells that enhanced tumor-free survival. These data demonstrate that refining the global T-cell response during combination immunotherapy can further enhance the therapeutic efficacy of these agents. Cancer Immunol Res; 2(2); 142–53. ©2013 AACR.
Data from Apoptosis-Regulated Low-Avidity Cancer-Specific CD8+ T Cells Can Be Rescued to Eliminate HER2/neu–Expressing Tumors by Costimulatory Agonists in Tolerized Mice
Authors: Black Chelsea M. , Armstrong Todd D. , Jaffee Elizabeth M.
Published: March 2024

Abstract
A major barrier to vaccines in cancer treatment is their failure to activate and maintain a complete cancer-specific CD8+ effector T-cell repertoire. Low-avidity T cells are more likely to escape clonal deletion in the thymus when compared with high-avidity T cells, and therefore comprise the major population of effector T cells available for activation in patients with cancer. However, low-avidity T cells fail to traffic into the tumor microenvironment and function in eradicating tumor under optimal vaccination conditions as opposed to high-avidity T cells that escape clonal deletion and function in tumor killing. We used high- and low-avidity T-cell receptor transgenic CD8+ T cells specific for the immunodominant epitope HER2/neu (RNEU420–429) to identify signaling pathways responsible for the inferior activity of the low-avidity T cells. Adoptive transfer of these cells into tumor-bearing vaccinated mice identified the members of apoptosis pathways that are upregulated in low-avidity T cells. The increased expression of proapoptotic proteins by low-avidity T cells promoted their own cell death and also that of other tumor-specific CD8+ T cells within their local environment. Importantly, we show that this proapoptotic effect can be overcome by using a strong costimulatory signal that prevents the activation-induced cell death and enables the low-avidity T cells to traffic into the tumor and assist in tumor clearance. These findings identify new therapeutic opportunities for activating the most potent anticancer T-cell responses. Cancer Immunol Res; 2(4); 307–19. ©2014 AACR.
Data from Functional TCR Retrieval from Single Antigen-Specific Human T Cells Reveals Multiple Novel Epitopes
Authors: Simon Petra , Omokoko Tana A. , Breitkreuz Andrea , Hebich Lisa , Kreiter Sebastian , Attig Sebastian , Konur Abdo , Britten Cedrik M. , Paret Claudia , Dhaene Karl , Türeci Özlem , Sahin Ugur
Published: March 2024

Abstract
The determination of the epitope specificity of disease-associated T-cell responses is relevant for the development of biomarkers and targeted immunotherapies against cancer, autoimmune, and infectious diseases. The lack of known T-cell epitopes and corresponding T-cell receptors (TCR) for novel antigens hinders the efficient development and monitoring of new therapies. We developed an integrated approach for the systematic retrieval and functional characterization of TCRs from single antigen-reactive T cells that includes the identification of epitope specificity. This is accomplished through the rapid cloning of full-length TCR-α and TCR-β chains directly from single antigen-specific CD8+ or CD4+ T lymphocytes. The functional validation of cloned TCRs is conducted using in vitro–transcribed RNA transfer for expression of TCRs in T cells and HLA molecules in antigen-presenting cells. This method avoids the work and bias associated with repetitive cycles of in vitro T-cell stimulation, and enables fast characterization of antigen-specific T-cell responses. We applied this strategy to viral and tumor-associated antigens (TAA), resulting in the retrieval of 56 unique functional antigen-specific TCRs from human CD8+ and CD4+ T cells (13 specific for CMV-pp65, 16 specific for the well-known TAA NY-ESO-1, and 27 for the novel TAA TPTE), which are directed against 39 different epitopes. The proof-of-concept studies with TAAs NY-ESO-1 and TPTE revealed multiple novel TCR specificities. Our approach enables the rational development of immunotherapy strategies by providing antigen-specific TCRs and immunogenic epitopes. Cancer Immunol Res; 2(12); 1230–44. ©2014 AACR.
Data from Tumoral Immune Suppression by Macrophages Expressing Fibroblast Activation Protein-α and Heme Oxygenase-1
Authors: Arnold James N. , Magiera Lukasz , Kraman Matthew , Fearon Douglas T.
Published: March 2024

Abstract
The depletion of tumor stromal cells that are marked by their expression of the membrane protein fibroblast activation protein-α (FAP) overcomes immune suppression and allows an anticancer cell immune response to control tumor growth. In subcutaneous tumors established with immunogenic Lewis lung carcinoma cells expressing ovalbumin (LL2/OVA), the FAP+ population is comprised of CD45+ and CD45− cells. In the present study, we further characterize the tumoral FAP+/CD45+ population as a minor subpopulation of F4/80hi/CCR2+/CD206+ M2 macrophages. Using bone marrow chimeric mice in which the primate diphtheria toxin receptor is restricted either to the FAP+/CD45+ or to the FAP+/CD45− subset, we demonstrate by conditionally depleting each subset that both independently contribute to the immune-suppressive tumor microenvironment. A basis for the function of the FAP+/CD45+ subset is shown to be the immune inhibitory enzyme, heme oxygenase-1 (HO-1). The FAP+/CD45+ cells are the major tumoral source of HO-1, and an inhibitor of HO-1, Sn mesoporphyrin, causes the same extent of immune-dependent arrest of LL2/OVA tumor growth as does the depletion of these cells. Because this observation of immune suppression by HO-1 expressed by the FAP+/CD45+ stromal cell is replicated in a transplanted model of pancreatic ductal adenocarcinoma, we conclude that pharmacologically targeting this enzyme may improve cancer immunotherapy. Cancer Immunol Res; 2(2); 121–6. ©2013 AACR.
Data from Myeloid-Derived Suppressor Cells Attenuate TH1 Development through IL-6 Production to Promote Tumor Progression
Authors: Tsukamoto Hirotake , Nishikata Ryutaro , Senju Satoru , Nishimura Yasuharu
Published: March 2024

Abstract
Collaborative action between tumor cells and host-derived suppressor cells leads to peripheral tolerance of T cells to tumor antigens. Here, we showed that in tumor-bearing mice, generation of tumor antigen-specific effector T-helper cells (TH1) was significantly attenuated, and impaired TH1 differentiation was restored by the temporal blockade of interleukin (IL)-6 activity at the T-cell priming phase. Furthermore, we found that Gr-1+ myeloid-derived suppressor cells (MDSC) served as a source of IL-6 in tumor-bearing mice. Adoptive transfer of effector CD4+ T cells revealed that MDSC-sensitized effector CD4+ T cells were less potent in mounting antitumor immune responses, although effector T cells generated together with Gr-1+ cells from tumor-free mice eradicated established tumors. CD8+ T cells, IFN-γ, and MHC-class II expression in host mice were indispensable for the antitumor activity initiated by effector CD4+ T cells. Despite comparable suppressive activity of IL-6+/+ and IL-6−/− MDSC on primary T-cell activation, transfer of IL-6+/+ MDSC, but not IL-6−/− MDSC, dampened the efficient induction of effector TH1 cells and counteracted CD4+ T cell–mediated antitumor immunity including cognate help for CD8+ T cells in vivo. These findings suggest that, apart from the inhibitory effects on primary T-cell activation, MDSC promote tumor progression by attenuating functional differentiation of tumor-specific CD4+ T cells into effector TH1 cells through IL-6 production to promote tumor progression. This novel mode of MDSC-induced tolerance of effector CD4+ T cells should be considered as the basis for the rational design of effective T cell–mediated antitumor therapies. Cancer Immunol Res; 1(1); 64–76. ©2013 AACR.
Data from Enhancement of Tumor-Reactive Cytotoxic CD4+ T-cell Responses after Ipilimumab Treatment in Four Advanced Melanoma Patients
Authors: Kitano Shigehisa , Tsuji Takemasa , Liu Caillian , Hirschhorn-Cymerman Daniel , Kyi Chrisann , Mu Zhenyu , Allison James P. , Gnjatic Sacha , Yuan Jianda D. , Wolchok Jedd D.
Published: March 2024

Abstract
CD4+ T cells provide help to enhance and sustain cytotoxic CD8+ T-cell responses. A direct lytic role for this cell population in mouse models further supports the use of tumor-reactive CD4+ T cells for cancer immunotherapy. CTLA-4 blockade has been shown to expand antigen-specific cytotoxic CD4+ T cells in mouse models. We took advantage of spontaneous immunity to the NY-ESO-1 cancer-testis antigen to investigate quantitative and qualitative changes in antigen-specific CD4+ T-cell responses after ipilimumab (anti-CTLA-4 monoclonal antibody) treatment in patients with advanced melanoma. Four patients with NY-ESO-1 seropositive melanoma were chosen upon the availability of suitable blood specimens for characterizing the functions of NY-ESO-1 antigen-specific CD4+ T-cell response by enzyme-linked immunospot (ELISPOT), intracellular cytokine staining (ICS), and cytotoxicity assays. Multiple NY-ESO-1 antigen-specific CD4+ T-cell responses with TH1 dominance were induced or enhanced after ipilimumab treatment in peripheral blood in all four patients. NY-ESO-1 antigen–specific CD4+ T-cell lines established from all four patients after ipilimumab treatment recognized naturally processed NY-ESO-1 protein in antigen-presenting cells, expressed master transcription factor Eomesodermin (Eomes), and secreted perforin and Granzyme B. Finally, we showed that these NY-ESO-1 antigen-specific CD4+ T-cell lines directly lysed autologous melanoma cell lines expressing NY-ESO-1 in an MHC class II restricted manner. Our results show that antigen-specific cytotoxic CD4+ T-cell responses are induced after ipilimumab therapy in human cancer patients. Ipilimumab may induce the expression of lytic granules on antigen-specific cytotoxic CD4+ T cells via Eomes, revealing a novel consequence of immunologic checkpoint blockade. Cancer Immunol Res; 1(4); 235–44. ©2013 AACR.
Data from Splenectomy Promotes Indirect Elimination of Intraocular Tumors by CD8+ T Cells That Is Associated with IFNγ- and Fas/FasL-Dependent Activation of Intratumoral Macrophages
Authors: Miller Maxine R. , Mandell Jonathan B. , Beatty Kelly M. , Harvey Stephen A.K. , Rizzo Michael J. , Previte Dana M. , Thorne Stephen H. , McKenna Kyle C.
Published: March 2024

Abstract
Ocular immune privilege (IP) limits the immune surveillance of intraocular tumors as certain immunogenic tumor cell lines (P815, E.G7-OVA) that are rejected when transplanted in the skin grow progressively when placed in the anterior chamber of the eye. As splenectomy (SPLNX) is known to terminate ocular IP, we characterized the immune mechanisms responsible for rejection of intraocular tumors in SPLNX mice as a first step toward identifying how to restore tumoricidal activity within the eye. CD8+ T cells, IFNγ, and FasL, but not perforin, or TNFα were required for the elimination of intraocular E.G7-OVA tumors that culminated in destruction of the eye (ocular phthisis). IFNγ and FasL did not target tumor cells directly as the majority of SPLNX IFNγR1−/− mice and Fas-defective lpr mice failed to eliminate intraocular E.G7-OVA tumors that expressed Fas and IFNγR1. Bone marrow chimeras revealed that IFNγR1 and Fas expression on immune cells was most critical for rejection, and SPLNX increased the frequency of activated macrophages (Mφ) within intraocular tumors in an IFNγ- and Fas/FasL-dependent manner, suggesting an immune cell target of IFNγ and Fas. As depletion of Mφs limited CD8 T cell–mediated rejection of intraocular tumors in SPLNX mice, our data support a model in which IFNγ- and Fas/FasL-dependent activation of intratumoral Mφs by CD8+ T cells promotes severe intraocular inflammation that indirectly eliminates intraocular tumors by inducing phthisis, and suggests that immunosuppressive mechanisms that maintain ocular IP interfere with the interaction between CD8+ T cells and Mφs to limit the immunosurveillance of intraocular tumors. Cancer Immunol Res; 2(12); 1175–85. ©2014 AACR.
Data from Leveraging TCR Affinity in Adoptive Immunotherapy against Shared Tumor/Self-Antigens
Authors: Miller Aaron M. , Bahmanof Milad , Zehn Dietmar , Cohen Ezra E.W. , Schoenberger Stephen P.
Published: March 2024

Abstract
Adoptive cellular therapy (ACT) using T-cell receptor (TCR)–engineered lymphocytes holds promise for eradication of disseminated tumors but also an inherent risk of pathologic autoimmunity if targeted antigens or antigenic mimics are expressed by normal tissues. We evaluated whether modulating TCR affinity could allow CD8+ T cells to control tumor outgrowth without inducing concomitant autoimmunity in a preclinical murine model of ACT. RIP-mOVA mice express a membrane-bound form of chicken ovalbumin (mOVA) as a self-antigen in kidney and pancreas. Such mice were implanted with OVA-expressing ID8 ovarian carcinoma cells and subsequently treated with CD8+ T lymphocytes (CTL) expressing either a high-affinity (OT-I) or low-affinity (OT-3) OVA-specific TCR. The effects on tumor growth versus organ-specific autoimmunity were subsequently monitored. High-affinity OT-I CTLs underwent activation and proliferation in both tumor-draining and pancreatic lymph nodes, leading to both rapid eradication of ID8-OVA tumors and autoimmune diabetes in all treated mice. Remarkably, the low-affinity OT-3 T cells were activated only by tumor-derived antigen and mediated transient regression of ID8-OVA tumors without concomitant autoimmunity. The OT-3 cells eventually upregulated inhibitory receptors PD-1, TIM-3, and LAG-3 and became functionally unresponsive, however, allowing the tumors in treated mice to reestablish progressive growth. Antibody-mediated blockade of the inhibitory receptors prevented exhaustion and allowed tumor clearance, but these mice also developed autoimmune diabetes. The findings reveal that low-affinity TCRs can mediate tumor regression and that functional avidity can discriminate between tumor-derived and endogenous antigen, while highlighting the risks involved in immune-checkpoint blockade on endogenous self-reactive T cells.
Data from CD30-Redirected Chimeric Antigen Receptor T Cells Target CD30+ and CD30− Embryonal Carcinoma via Antigen-Dependent and Fas/FasL Interactions
Authors: Hong Lee K. , Chen Yuhui , Smith Christof C. , Montgomery Stephanie A. , Vincent Benjamin G. , Dotti Gianpietro , Savoldo Barbara
Published: March 2024

Abstract
Tumor antigen heterogeneity limits success of chimeric antigen receptor (CAR) T-cell therapies. Embryonal carcinomas (EC) and mixed testicular germ cell tumors (TGCT) containing EC, which are the most aggressive TGCT subtypes, are useful for dissecting this issue as ECs express the CD30 antigen but also contain CD30−/dim cells. We found that CD30-redirected CAR T cells (CD30.CAR T cells) exhibit antitumor activity in vitro against the human EC cell lines Tera-1, Tera-2, and NCCIT and putative EC stem cells identified by Hoechst dye staining. Cytolytic activity of CD30.CAR T cells was complemented by their sustained proliferation and proinflammatory cytokine production. CD30.CAR T cells also demonstrated antitumor activity in an in vivo xenograft NOD/SCID/γcnull (NSG) mouse model of metastatic EC. We observed that CD30.CAR T cells, while targeting CD30+ EC tumor cells through the CAR (i.e., antigen-dependent targeting), also eliminated surrounding CD30− EC cells in an antigen-independent manner, via a cell–cell contact-dependent Fas/FasL interaction. In addition, ectopic Fas (CD95) expression in CD30+ Fas− EC was sufficient to improve CD30.CAR T-cell antitumor activity. Overall, these data suggest that CD30.CAR T cells might be useful as an immunotherapy for ECs. Additionally, Fas/FasL interaction between tumor cells and CAR T cells can be exploited to reduce tumor escape due to heterogeneous antigen expression or to improve CAR T-cell antitumor activity. Cancer Immunol Res; 6(10); 1274–87. ©2018 AACR.
Data from Suboptimal T-cell Therapy Drives a Tumor Cell Mutator Phenotype That Promotes Escape from First-Line Treatment
Authors: Evgin Laura , Huff Amanda L. , Kottke Timothy , Thompson Jill , Molan Amy M. , Driscoll Christopher B. , Schuelke Matthew , Shim Kevin G. , Wongthida Phonphimon , Ilett Elizabeth J. , Smith Karen Kaluza , Harris Reuben S. , Coffey Matt , Pulido Jose S. , Pandha Hardev , Selby Peter J. , Harrington Kevin J. , Melcher Alan , Vile Richard G.
Published: March 2024

Abstract
Antitumor T-cell responses raised by first-line therapies such as chemotherapy, radiation, tumor cell vaccines, and viroimmunotherapy tend to be weak, both quantitatively (low frequency) and qualitatively (low affinity). We show here that T cells that recognize tumor-associated antigens can directly kill tumor cells if used at high effector-to-target ratios. However, when these tumor-reactive T cells were present at suboptimal ratios, direct T-cell–mediated tumor cell killing was reduced and the ability of tumor cells to evolve away from a coapplied therapy (oncolytic or suicide gene therapy) was promoted. This T-cell–mediated increase in therapeutic resistance was associated with C to T transition mutations that are characteristic of APOBEC3 cytosine deaminase activity and was induced through a TNFα and protein kinase C–dependent pathway. Short hairpin RNA inhibition of endogenous APOBEC3 reduced rates of tumor escape from oncolytic virus or suicide gene therapy to those seen in the absence of antitumor T-cell coculture. Conversely, overexpression of human APOBEC3B in tumor cells enhanced escape from suicide gene therapy and oncolytic virus therapy both in vitro and in vivo. Our data suggest that weak affinity or low frequency T-cell responses against tumor antigens may contribute to the ability of tumor cells to evolve away from first-line therapies. We conclude that immunotherapies need to be optimized as early as possible so that, if they do not kill the tumor completely, they do not promote treatment resistance.
Data from T Cells Bearing a Chimeric Antigen Receptor against Prostate-Specific Membrane Antigen Mediate Vascular Disruption and Result in Tumor Regression
Authors: Santoro Stephen P. , Kim Soorin , Motz Gregory T. , Alatzoglou Dimitrios , Li Chunsheng , Irving Melita , Powell Daniel J. , Coukos George
Published: March 2024

Abstract
Aberrant blood vessels enable tumor growth, provide a barrier to immune infiltration, and serve as a source of protumorigenic signals. Targeting tumor blood vessels for destruction, or tumor vascular disruption therapy, can therefore provide significant therapeutic benefit. Here, we describe the ability of chimeric antigen receptor (CAR)–bearing T cells to recognize human prostate–specific membrane antigen (hPSMA) on endothelial targets in vitro as well as in vivo. CAR T cells were generated using the anti-PSMA scFv, J591, and the intracellular signaling domains: CD3ζ, CD28, and/or CD137/4-1BB. We found that all anti-hPSMA CAR T cells recognized and eliminated PSMA+ endothelial targets in vitro, regardless of the signaling domain. T cells bearing the third-generation anti-hPSMA CAR, P28BBζ, were able to recognize and kill primary human endothelial cells isolated from gynecologic cancers. In addition, the P28BBζ CAR T cells mediated regression of hPSMA-expressing vascular neoplasms in mice. Finally, in murine models of ovarian cancers populated by murine vessels expressing hPSMA, the P28BBζ CAR T cells were able to ablate PSMA+ vessels, cause secondary depletion of tumor cells, and reduce tumor burden. Taken together, these results provide a strong rationale for the use of CAR T cells as agents of tumor vascular disruption, specifically those targeting PSMA. Cancer Immunol Res; 3(1); 68–84. ©2014 AACR.
Data from Correlation of PD-L1 Surface Expression on Leukemia Cells with the Ratio of PD-L1 mRNA Variants and with Electrophoretic Mobility
Authors: Brodská Barbora , Otevřelová Petra , Kuželová Kateřina
Published: March 2024

Abstract
The expression on the surface of tumor cells of ligands for the PD-1 inhibitory receptor prevents the antitumor immune response and is considered to be a negative prognostic factor in a variety of solid tumors as well as in hematologic malignancies. To determine if it were possible to analyze PD-L1 with PCR-based methods, we assessed the expression of PD-L1 in primary samples from patients with acute myeloid leukemia, in healthy donors, and in a panel of cell lines, by means of flow cytometry, RT-PCR, and Western blotting. Although the surface density of the protein was not correlated with the amount of expressed full-length mRNA, we found a statistically significant positive correlation between PD-L1 surface density and the ratio of two transcript variants (variant 1/variant 2). Our PCR-based method allows for retrospective examination of PD-L1 surface expression from frozen cDNA samples, without the need for a reference gene. Our results also suggest that variant 2, which is produced by alternative splicing, negatively regulates PD-L1 protein expression on the cell surface. In addition, PD-L1 exposition on the cell surface is clearly associated with a shift of electrophoretic mobility, observed on Western blots. This finding can explain the relatively large variability in PD-L1 apparent molecular weight reported in the literature and offers an alternate means for the assessment of PD-L1 surface expression. Cancer Immunol Res; 4(10); 815–9. ©2016 AACR.
Data from Simultaneous Targeting of FcγRs and FcαRI Enhances Tumor Cell Killing
Authors: Brandsma Arianne M. , ten Broeke Toine , Nederend Maaike , Meulenbroek Laura A.P.M. , van Tetering Geert , Meyer Saskia , Jansen J.H. Marco , Beltrán Buitrago M. Alejandra , Nagelkerke Sietse Q. , Németh István , Ubink Ruud , Rouwendal Gerard , Lohse Stefan , Valerius Thomas , Leusen Jeanette H.W. , Boross Peter
Published: March 2024

Abstract
Efficacy of anticancer monoclonal antibodies (mAb) is limited by the exhaustion of effector mechanisms. IgG mAbs mediate cellular effector functions through FcγRs expressed on effector cells. IgA mAbs can also induce efficient tumor killing both in vitro and in vivo. IgA mAbs recruit FcαRI-expressing effector cells and therefore initiate different effector mechanisms in vivo compared with IgG. Here, we studied killing of tumor cells coexpressing EGFR and HER2 by the IgG mAbs cetuximab and trastuzumab and their IgA variants. In the presence of a heterogeneous population of effector cells (leukocytes), the combination of IgG and IgA mAbs to two different tumor targets (EGFR and HER2) led to enhanced cytotoxicity compared with each isotype alone. Combination of two IgGs or two IgAs or IgG and IgA against the same target did not enhance cytotoxicity. Increased cytotoxicity relied on the presence of both the peripheral blood mononuclear cell and the polymorphonuclear (PMN) fraction. Purified natural killer cells were only cytotoxic with IgG, whereas cytotoxicity induced by PMNs was strong with IgA and poor with IgG. Monocytes, which coexpress FcγRs and FcαRI, also displayed increased cytotoxicity by the combination of IgG and IgA in an overnight killing assay. Coinjection of cetuximab and IgA2-HER2 resulted in increased antitumor effects compared with either mAb alone in a xenograft model with A431-luc2-HER2 cells. Thus, the combination of IgG and IgA isotypes optimally mobilizes cellular effectors for cytotoxicity, representing a promising novel strategy to improve mAb therapy. Cancer Immunol Res; 3(12); 1316–24. ©2015 AACR.