scholarly journals Dendritic cells loaded with apoptotic antibody-coated tumor cells provide protective immunity against B-cell lymphoma in vivo

Blood ◽  
2008 ◽  
Vol 111 (3) ◽  
pp. 1504-1511 ◽  
Author(s):  
Suzanne N. Franki ◽  
Kristopher K. Steward ◽  
David J. Betting ◽  
Kamran Kafi ◽  
Reiko E. Yamada ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Tumor Antigens ◽  
B Cell Lymphoma ◽  
Lymphoma Cells ◽  
Term Survival ◽  
Dc Vaccine

Abstract The in vitro priming of tumor-specific T cells by dendritic cells (DCs) phagocytosing killed tumor cells can be augmented in the presence of antitumor monoclonal antibody (mAb). We investigated whether DCs phagocytosing killed lymphoma cells coated with tumor-specific antibody could elicit antitumor immunity in vivo. Irradiated murine 38C13 lymphoma cells were cocultured with bone marrow–derived DCs in the presence or absence of tumor-specific mAb. Mice vaccinated with DCs cocultured with mAb-coated tumor cells were protected from tumor challenge (60% long-term survival), whereas DCs loaded with tumor cells alone were much less effective. The opsonized whole tumor cell–DC vaccine elicited significantly better tumor protection than a traditional lymphoma idiotype (Id) protein vaccine, and in combination with chemotherapy could eradicate preexisting tumor. Moreover, the DC vaccine protected animals from both wild-type and Id-negative variant tumor cells, indicating that Id is not a major target of the induced tumor immunity. Protection was critically dependent upon CD8+ T cells, with lesser contribution by CD4+ T cells. Importantly, opsonized whole tumor cell–DC vaccination did not result in tissue-specific autoimmunity. Since opsonized whole tumor cell–DC and Id vaccines appear to target distinct tumor antigens, optimal antilymphoma immunity might be achieved by combining these approaches.

scholarly journals Alpha-Fetoprotein- and CD40Ligand-Expressing Dendritic Cells for Immunotherapy of Hepatocellular Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3375
Author(s):  
Annabelle Vogt ◽  
Farsaneh Sadeghlar ◽  
Tiyasha H. Ayub ◽  
Carlo Schneider ◽  
Christian Möhring ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
Dendritic Cells ◽  
Tumor Regression ◽  
Combined Therapy ◽  
Term Survival ◽  
Effector Cells ◽  
Tumor Environment ◽  
The Impact

Dendritic cells (DC) as professional antigen presenting cells are able to prime T-cells against the tumor-associated antigen α-fetoprotein (AFP) for immunotherapy of hepatocellular carcinoma (HCC). However, a strong immunosuppressive tumor environment limits their efficacy in patients. The co-stimulation with CD40Ligand (CD40L) is critical in the maturation of DC and T-cell priming. In this study, the impact of intratumoral (i.t.) CD40L-expressing DC to improve vaccination with murine (m)AFP-transduced DC (Ad-mAFP-DC) was analyzed in subcutaneous (s.c.) and orthotopic murine HCC. Murine DC were adenovirally transduced with Ad-mAFP or Ad-CD40L. Hepa129-mAFP-cells were injected into the right flank or the liver of C3H-mice to induce subcutaneous (s.c.) and orthotopic HCC. For treatments, 106 Ad-mAFP-transduced DC were inoculated s.c. followed by 106 CD40L-expressing DC injected intratumorally (i.t.). S.c. inoculation with Ad-mAFP-transduced DC, as vaccine, induced a delay of tumor-growth of AFP-positive HCC compared to controls. When s.c.-inoculation of Ad-mAFP-DC was combined with i.t.-application of Ad-CD40L-DC synergistic antitumoral effects were observed and complete remissions and long-term survival in 62% of tumor-bearing animals were achieved. Analysis of the tumor environment at different time points revealed that s.c.-vaccination with Ad-mAFP-DC seems to stimulate tumor-specific effector cells, allowing an earlier recruitment of effector T-cells and a Th1 shift within the tumors. After i.t. co-stimulation with Ad-CD40L-DC, production of Th1-cytokines was strongly increased and accompanied by a robust tumor infiltration of mature DC, activated CD4+-, CD8+-T-cells as well as reduction of regulatory T-cells. Moreover, Ad-CD40L-DC induced tumor cell apoptosis. Intratumoral co-stimulation with CD40L-expressing DC significantly improves vaccination with Ad-mAFP-DC in pre-established HCC in vivo. Combined therapy caused an early and strong Th1-shift in the tumor environment as well as higher tumor apoptosis, leading to synergistic tumor regression of HCC. Thus, CD40L co-stimulation represents a promising tool for improving DC-based immunotherapy of HCC.

scholarly journals Cellular cytotoxicity is a form of immunogenic cell death

2020 ◽  
Vol 8 (1) ◽  
pp. e000325 ◽  
Author(s):  
Luna Minute ◽  
Alvaro Teijeira ◽  
Alfonso R Sanchez-Paulete ◽  
Maria C Ochoa ◽  
Maite Alvarez ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Dendritic Cells ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cd8 T Cells ◽  
Immunogenic Cell Death ◽  
Cell Debris ◽  
Tumor Cell Death ◽  
Mhc Multimer

BackgroundThe immune response to cancer is often conceptualized with the cancer immunity cycle. An essential step in this interpretation is that antigens released by dying tumors are presented by dendritic cells to naive or memory T cells in the tumor-draining lymph nodes. Whether tumor cell death resulting from cytotoxicity, as mediated by T cells or natural killer (NK) lymphocytes, is actually immunogenic currently remains unknown.MethodsIn this study, tumor cells were killed by antigen-specific T-cell receptor (TCR) transgenic CD8 T cells or activated NK cells. Immunogenic cell death was studied analyzing the membrane exposure of calreticulin and the release of high mobility group box 1 (HMGB1) by the dying tumor cells. Furthermore, the potential immunogenicity of the tumor cell debris was evaluated in immunocompetent mice challenged with an unrelated tumor sharing only one tumor-associated antigen and by class I major histocompatibility complex (MHC)-multimer stainings. Mice deficient inBatf3,Ifnar1andSting1were used to study mechanistic requirements.ResultsWe observe in cocultures of tumor cells and effector cytotoxic cells, the presence of markers of immunogenic cell death such as calreticulin exposure and soluble HMGB1 protein. Ovalbumin (OVA)-transfected MC38 colon cancer cells, exogenously pulsed to present the gp100 epitope are killed in culture by mouse gp100-specific TCR transgenic CD8 T cells. Immunization of mice with the resulting destroyed cells induces epitope spreading as observed by detection of OVA-specific T cells by MHC multimer staining and rejection of OVA+EG7 lymphoma cells. Similar results were observed in mice immunized with cell debris generated by NK-cell mediated cytotoxicity. Mice deficient inBatf3-dependent dendritic cells (conventional dendritic cells type 1, cDC1) fail to develop an anti-OVA response when immunized with tumor cells killed by cytotoxic lymphocytes. In line with this, cultured cDC1 dendritic cells uptake and can readily cross-present antigen from cytotoxicity-killed tumor cells to cognate CD8+T lymphocytes.ConclusionThese results support that an ongoing cytotoxic antitumor immune response can lead to immunogenic tumor cell death.

scholarly journals WDFY4 is required for cross-presentation in response to viral and tumor antigens

Science ◽  
2018 ◽  
Vol 362 (6415) ◽  
pp. 694-699 ◽  
Author(s):  
Derek J. Theisen ◽  
Jesse T. Davidson ◽  
Carlos G. Briseño ◽  
Marco Gargaro ◽  
Elvin J. Lauron ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Tumor Antigens ◽  
Critical Role ◽  
Tumor Rejection ◽  
Interleukin 12 ◽  
Cross Presentation ◽  
Histocompatibility Complex ◽  
Crispr Screen

During the process of cross-presentation, viral or tumor-derived antigens are presented to CD8+ T cells by Batf3-dependent CD8α+/XCR1+ classical dendritic cells (cDC1s). We designed a functional CRISPR screen for previously unknown regulators of cross-presentation, and identified the BEACH domain–containing protein WDFY4 as essential for cross-presentation of cell-associated antigens by cDC1s in mice. However, WDFY4 was not required for major histocompatibility complex class II presentation, nor for cross-presentation by monocyte-derived dendritic cells. In contrast to Batf3–/– mice, Wdfy4–/– mice displayed normal lymphoid and nonlymphoid cDC1 populations that produce interleukin-12 and protect against Toxoplasma gondii infection. However, similar to Batf3–/– mice, Wdfy4–/– mice failed to prime virus-specific CD8+ T cells in vivo or induce tumor rejection, revealing a critical role for cross-presentation in antiviral and antitumor immunity.

scholarly journals Long-term in vivo microscopy of CAR T cell dynamics during eradication of CNS lymphoma in mice

2019 ◽  
Vol 116 (48) ◽  
pp. 24275-24284 ◽  
Author(s):  
Matthias Mulazzani ◽  
Simon P. Fräßle ◽  
Iven von Mücke-Heim ◽  
Sigrid Langer ◽  
Xiaolan Zhou ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Growth ◽  
B Cell ◽  
B Cell Lymphoma ◽  
Therapeutic Effects ◽  
Term Survival ◽  
Car T Cells ◽  
Car T

T cells expressing anti-CD19 chimeric antigen receptors (CARs) demonstrate impressive efficacy in the treatment of systemic B cell malignancies, including B cell lymphoma. However, their effect on primary central nervous system lymphoma (PCNSL) is unknown. Additionally, the detailed cellular dynamics of CAR T cells during their antitumor reaction remain unclear, including their intratumoral infiltration depth, mobility, and persistence. Studying these processes in detail requires repeated intravital imaging of precisely defined tumor regions during weeks of tumor growth and regression. Here, we have combined a model of PCNSL with in vivo intracerebral 2-photon microscopy. Thereby, we were able to visualize intracranial PCNSL growth and therapeutic effects of CAR T cells longitudinally in the same animal over several weeks. Intravenous (i.v.) injection resulted in poor tumor infiltration of anti-CD19 CAR T cells and could not sufficiently control tumor growth. After intracerebral injection, however, anti-CD19 CAR T cells invaded deeply into the solid tumor, reduced tumor growth, and induced regression of PCNSL, which was associated with long-term survival. Intracerebral anti-CD19 CAR T cells entered the circulation and infiltrated distant, nondraining lymph nodes more efficiently than mock CAR T cells. After complete regression of tumors, anti-CD19 CAR T cells remained detectable intracranially and intravascularly for up to 159 d. Collectively, these results demonstrate the great potential of anti-CD19 CAR T cells for the treatment of PCNSL.

Therapeutic Antimyeloma Effect of Dendritic-Tumor Cells Hybrids Transduced with Adenovirus Encoding CD40L.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1709-1709
Author(s):  
Eva Alvarez ◽  
Esther Moga ◽  
Jorge Sierra ◽  
Javier Briones
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Tumor Cells ◽  
Antitumor Effect ◽  
Tumor Antigens ◽  
Recombinant Adenovirus ◽  
Lymphoid Tissues ◽  
Term Survival ◽  
Mhc Ii

Abstract Dendritic cells (DCs) are the main antigen presenting cells and play a pivotal role in the stimulation of T-cell immune responses. DCs cultured in the presence of a single tumor antigen can elicit an immune response against tumor cells expressing that antigen. However, simultaneous use of several tumor antigens may be advantageous since polyclonal activation of T cells against different tumor antigens may be a better approach to eradicate tumor cells. In this sense, fusions of dendritic and tumor cells (FCs) show a broad spectrum of tumor antigens, both known and unidentified, to be presented by class I and II MHC. Although prophylactic vaccines were successful in murine models, the results in the therapeutic setting have been unsatisfactory. We hypothesised that enhancing costimulation of FCs would help to break tumor tolerance once the tumor is established. To this purpose, we transduced FCs with a recombinant adenovirus encoding CD40L (AdvCD40L or AdvGFP as control) and we studied the therapeutic antitumoral effect of the administration of FC-CD40L in a murine model of myeloma. DCs obtained from day 7-bone marrow cultures of Balb/c mice were fused with tumor cells, a syngeneic murine myeloma cell line (4TOO). FCs hybrids were generated with PEG and selected after culturing in HAT medium plus GM-CSF for 7 days. FC were quantified by determining the percentage of cells that coexpress specific DC (CD11c) and tumor markers (CD138). Mean fusion efficiency was 30% (20–40%) and FCs expressed moderate levels of CD80, CD83, CD86, CD54, CD40 and MHC II and did not express CD40L. FC-CD40L showed a significant increase of expression of costimulatory molecules (CD80, CD86, CD54, and MHC II) compared to FC-GFP (p=0.011). Moreover, in a syngeneic mixed lymphocyte reaction, FC-CD40L induced a two-fold higher T-cell proliferation than FC-GFP or FC alone. In addition, FC-CD40L had improved migration to lymphoid tissues, preferentially to spleen, in comparison with FC-GFP (2.8% versus 1.6%). The antitumor effect of FC-CD40L was analyzed in vivo. Mice (n=10 per group) were injected i.v. with 2.5×105 tumor cells and treated with irradiated FC, FC-GFP or FC-CD40L (1×106 cells each) on days 2, 6 and 10 after tumor challenge. 40% of mice treated with FC-CD40L had long-term survival (>120 days). In contrast, all of mice treated with FC or FC-GFP died between days 25 and 35 (p=0.012). In parallel, treatment with mixed cells (not fused DC+ tumor cells), mix transduced with AdvGFP, or mix transduced with AdvCD40L did not provide any significant antitumor effect. We conclude that FCs transduced with AdvCD40L better stimulate in vitro and in vivo immune responses than FC alone and may provide a new strategy for treating patients with multiple myeloma or lymphoma.

In Vitro and In Vivo Effects of CT-011, a Humanized Anti–PD-1 Monoclonal Antibody, in Combination with Rituximab against Human B-Cell Lymphomas.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 724-724
Author(s):  
Fuliang Chu ◽  
Myriam Foglietta ◽  
Hong Qin ◽  
Rakesh Sharma ◽  
Qing Yi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
B Cell ◽  
Nk Cells ◽  
Tumor Cells ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
In Vivo Effects ◽  
Human B Cell

Abstract Abstract 724 Background: Programmed death (PD)–1 is an inhibitory receptor that impairs the function of activated T-cells and natural killer (NK) cells when engaged by its ligands PD-L1 or PD-L2. We have previously demonstrated that PD-1 is markedly up-regulated in intratumoral and peripheral blood CD4+ and CD8+ T cells in patients with follicular lymphoma (FL), a finding associated with impaired T-cell function, suggesting that PD-1 blockade may improve FL immune control. CT-011, a humanized anti PD-1 monoclonal antibody, was previously studied in a phase I clinical trial in patients with advanced hematological malignancies. CT-011 was well tolerated and induced sustained elevations of CD4+ T cells in the peripheral blood. More importantly, apparent clinical benefit was observed in six patients, including one patient with FL who had large tumor masses that achieved a durable complete remission lasting >14 months. Here, we studied the in vitro and in vivo effects of CT-011 on T-cell and/or NK-cell immune responses against human B-cell lymphoma and the hypothesis that CT-011 may improve tumor control when combined with rituximab, a chimeric anti-CD20 monoclonal antibody for the treatment of human FL. Materials and Methods: To determine the effects of CT-011 on antitumor T cells, intratumoral T cells were isolated from primary FL tumor samples, and cultured with or without autologous tumor cells in the presence or absence of CT-011 or isotype control antibody (50 μg/ml each) for 5 days, and tested for proliferation by 3H thymidine incorporation assay. To determine the effects of CT-011 on NK cells, peripheral blood mononuclear cells (PBMCs) derived from normal donors or patients with FL were cultured in the presence or absence of CT-011 (50 μg/ml) with or without IL-2 for 96 hours and analyzed for expression of various activating receptors including CD16, CD32, CD64, Fas ligand, NKG2D, NKp30, NKp44, and NKp46. The in vivo effects of CT-011 were tested in two B-cell lymphoma xenograft models. Ramos and RL lymphoma tumor cells were injected subcutaneously into nude and SCID mice, respectively, and CT-011 (10 μg/mouse) was injected weekly with or without rituximab starting approximately 7–10 days after tumor inoculation. Results: We observed that CT-011 significantly increased the proliferation of intratumoral T cells in response to autologous tumor cells compared with isotype control antibody. Treatment with CT-011 enhanced the expression of Fas ligand, CD32, CD64, and NKp30 on human NK cells in the presence of IL-2 as compared with PBMCs treated with IL-2 alone or media control. In the RL lymphoma xenograft model in SCID mice, treatment with CT-011 significantly delayed tumor growth (P≤0.05) and improved survival (P≤0.01) compared with control mice injected with saline. In a Ramos lymphoma xenograft model in nude mice, treatment with CT-011 and rituximab eradicated established tumors in a significant proportion of mice (P≤0.05) and markedly improved survival compared with rituximab alone or saline. Conclusions: Taken together, these studies suggest that blockade of PD-1 with CT-011 enhances the function of anti-tumor T-cells and augments the expression of activating receptors on NK cells. Treatment with CT-011 led to improved tumor control against human B-cell lymphoma in xenograft models and the combined use of CT-011 and rituximab was more effective that rituximab alone. These results provide the rationale to test the combination of CT-011 with rituximab in patients with B-cell lymphoma, given that the combination is likely to be complementary and may even be synergistic, leading to enhanced clinical efficacy without increasing toxicity. The development of such approaches that activate both the innate (NK-cells) and adaptive (T-cells) immune systems is likely to minimize the emergence of immune escape variants and improve clinical outcome in patients with lymphoma. A clinical trial evaluating CT-011 in combination with rituximab is planned in patients with relapsed FL. Disclosures: Rodionov: Cure Tech Ltd.: Employment. Rotem-Yehudar:Cure Tech Ltd.: Employment.

CMV-Specific T-Cells Are More Effective Than WT-1-Specific T-Cells in Eradicating Clonogenic Tumor Cells Co-Expressing CMVpp65 and WT-1 in-Vivo and Both Types of T-Cells Are Functionally Augmented in the Presence of IL-15/IL-15Rα

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 646-646 ◽  
Author(s):  
Aisha Hasan ◽  
Dana Bakalar ◽  
Annamalai Selvakumar ◽  
Gloria C Koo ◽  
Ekaterina Doubrovina ◽  
...  
Keyword(s):  
T Cells ◽  
Ovarian Carcinoma ◽  
Tumor Cells ◽  
Tumor Antigen ◽  
Tumor Antigens ◽  
Human Tumor ◽  
Relative Efficacy ◽  
Comparative Efficacy ◽  
Anti Tumor Activity

Abstract Abstract 646 Adoptively transferred virus or tumor antigen-specific T-cells have demonstrated efficacy in initial clinical trials, but while clearance of viral infection is sustained, responses to tumor-specific T-cells are usually short-lived. Therefore, current efforts are focused on distinguishing attributes of virus-specific T-cells that contribute to their persistence and formulating strategies to sustain anti-tumor effects of T-cell (TC) therapies. We have developed an in-vivo model to compare the relative efficacy of T-cells specific for a tumor antigen (WT-1) versus T-cells specific for a viral antigen (CMVpp65) using human colon carcinoma cells that express the oncofetal protein WT-1 which were transduced to co-express CMVpp65 (WT-1[+] cocapp65) as a surrogate system. Groups of 6 NOD/Scid-IL2Rgc-KO/J mice (NSG) were each subcutaneously injected with 3 × 105 WT-1 [+] cocapp65 on the R flank. Each animal was also injected with 3 × 105 cells from a WT-1[+] ovarian carcinoma cell line (SKOV3-A2) on the L shoulder to compare the efficacy of WT-1 specific T-cells (WT1-CTLs) against different WT-1 [+] tumor cell types. Expression of WT-1 protein is lower in SKOV3-A2 than in cocapp65 cells. Both tumors are HLA A0201[+] and were transduced to express a GFP-firefly luciferase gene. T-cells were administered intravenously 5 days after tumor injection to enable vascularization and tumor growth was quantitated using bioluminescence. These experiments evaluated (1) the relative capacity of CMVpp65 specific T-cells (CMV-CTLs) versus WT-1 CTLs to eradicate WT1[+] cocapp65 cells that co-express a viral and tumor antigen (2) the relative efficacy of WT-1 CTLs against 2 different HLA A0201 [+] WT-1 expressing tumors; an ovarian carcinoma and a colon carcinoma, and (3) the contribution of IL-15/15Rα complex in augmenting the efficacy of antigen specific T-cells by using intraperitoneally (i.p) injected Baf-3 cells transduced to express human IL-15/15Rα complex. The treatment groups were as follows: (1) Control – no T-cells + IL-2 (2000 U) (2) Control – no T-cells + IL-15/IL-15Rα (5 × 106 baf-3 cells) (3) WT1 CTLs + IL-2 (2000 U) (4) CMV-CTLs + IL-2 (2000 U) (5) WT1 CTLs + IL-15/IL-15Rα (5 × 106 baf-3 cells) (6) CMV-CTLs + IL-15/IL-15Rα (5 × 106 baf-3 cells). IL-2 and irradiated baf-3 cells were administered intraperitoneally twice weekly. When the doses of antigen specific interferon gamma (IFNg) [+] T-cells were equivalent in the infused CMVpp65 and WT1 specific T-cells, the CMV-CTLs induced greater, and more sustained suppression of the growth of the WT-1[+] cocapp65 cells in-vivo than the WT-1 CTLs (Fig.1). The anti-tumor activity of the WT-1 CTLs was greater against WT-1[+] cocapp65 than against the WT-1[+] ovarian carcinoma (SKOV3-A2), potentially reflecting the higher expression of WT-1 in cocapp65. The SKOV3-A2 tumor began to re-grow by 24 days post T-cell infusion approaching the size of control tumors by day 38, while the WT-1[+] cocapp65 still demonstrated slower growth through day 38. The addition of IL-15/15Rα increased the efficacy of the transferred T-cells, the difference being more pronounced for the anti-tumor activity of WT-1 CTLs. Fig. 1 Comparative Efficacy of CMV and WT-1 CTLs against Human Tumor Targets Co-expressing CMVpp65 and WT-1 Fig. 1. Comparative Efficacy of CMV and WT-1 CTLs against Human Tumor Targets Co-expressing CMVpp65 and WT-1 These studies demonstrate that equivalent doses of IFNg[+] WT-1 CTLs can also suppress WT-1[+] cocapp65 tumor xenografts, but are less effective than CMV-CTLs, and that IL-15 supplementation augments the cytotoxic activity of the CTLs in-vitro and enhances the duration of the anti-tumor effects in-vivo. This model permits side by side comparisons of the anti-tumor activity of human T-cells directed against viral and tumor antigens expressed on the same clonogenic human tumor target. Because both responses are directed against the same cells, this model could thereby facilitate identification of the distinguishing features of T-cells specific for viral or tumor antigens as well as differences in the presentation of viral and oncofetal “self” antigens by tumor cells that contribute to disparities in their anti-tumor activity and persistence in-vivo. Disclosures: No relevant conflicts of interest to declare.

A CD3 x FRα T-cell engaging bispecific antibody for efficient killing of ovarian cancer cells with minimal cytokine release.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e18050-e18050
Author(s):  
Ben Buelow ◽  
Brian Avanzino ◽  
Aarti Balasubramani ◽  
Andrew Boudreau ◽  
Laura Davison ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cytokine Production ◽  
Cell Cytotoxicity ◽  
Cytokine Release ◽  
Limited Efficacy ◽  
Human T Cells

e18050 Background: Ovarian Cancer (OvCa) is the leading cause of gynecologic cancer mortality in women. Since the introduction of platinum-based chemotherapy there has been little change in the prognosis of OvCa patients, with < 30% overall survival in advanced disease, creating an urgent medical need for novel therapies. Few ovarian epithelium-specific surface proteins are suited for Ab targeting. However, studies have shown folate receptor α (FRα) to be highly over-expressed in OvCa; expression level and stage correlate, and FRα is absent or minimally expressed in normal tissues. However, naked Ab therapy has shown limited efficacy while CAR-T therapy has been plagued by toxicity and limited efficacy. ADCs have demonstrated some activity but present the risk of toxin-mediated side effects. Using Teneobio’s unique antibody discovery platform, we have developed a CD3 x FRα T-BsAb that retains the potent cytotoxicity of other T-cell redirecting therapies but with significantly reduced cytokine release. Methods: Antibodies targeting CD3 and FRα were generated via immunization of our proprietary transgenic animals. Candidate antibodies were selected by repertoire deep sequencing of B-cells from draining lymph nodes, high-throughput gene assembly, recombinant expression, and functional screening. Bispecific antibodies targeting CD3 and FRα were assembled and evaluated for their ability to selectively activate primary human T-cells and mediate killing of FRα+ tumor cells in vitro and in vivo. T-cell activation surface markers, cytokine production and tumor cell cytotoxicity were measured. Results: Primary human T-cells were activated only in the presence of both the CD3 x FRα T-BsAb and FRα (either recombinant or cell-surface protein). Potent and selective cytotoxicity against FRα+ tumor cells was observed in co-cultures of primary human T-cells and OvCa tumor cell lines. Strikingly, our T-BsAb mediated comparable tumor cell cytotoxicity to CD3 x FRα T-BsAbs containing a high affinity anti-CD3 domain but with significantly reduced cytokine production. Our Ab showed preliminary evidence of tumor growth inhibition in xenograft models of OvCa in vivo. Conclusions: We have created a novel CD3 x FRα T-BsAb that mediates T-cell killing of FRα+ tumor cells with minimal production of cytokines. This molecule may improve safety, efficacy, and offer opportunities for combination therapy to treat OvCa.

scholarly journals The Injury Response to DNA Damage Promotes Anti-Tumor Immunity

2020 ◽  
Author(s):  
Ganapathy Sriram ◽  
Lauren Milling ◽  
Jung-Kuei Chen ◽  
Wuhbet Abraham ◽  
Erika D. Handly ◽  
...  
Keyword(s):  
Dna Damage ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Immune Checkpoint ◽  
Ex Vivo ◽  
Injured Cell ◽  
Ifn Γ

ABSTRACTInhibition of immune checkpoints has shown promising results in the treatment of certain tumor types. However, the majority of cancers do not respond to immune checkpoint inhibition (ICI) treatment, indicating the need to identify additional modalities that enhance the response to immune checkpoint blockade. In this study, we identified a tumor-tailored approach using ex-vivo DNA damaging chemotherapy-treated tumor cells as a live injured cell adjuvant. Using an optimized ex vivo system for dendritic cell-mediated T-cell IFN-γ induction in response to DNA-damaged tumor cells, we identified specific dose-dependent treatments with etoposide and mitoxantrone that markedly enhance IFN-γ production by T-cells. Unexpectedly, the immune-enhancing effects of DNA damage failed to correlate with known markers of immunogenic cell death or with the extent of apoptosis or necroptosis. Furthermore, dead tumor cells alone were not sufficient to promote DC cross-presentation and induce IFN-γ in T-cells. Instead, the enhanced immunogenicity resided in the fraction of injured cells that remained alive, and required signaling through the RIPK1, NF-kB and p38MAPK pathways. Direct in vivo translation of these findings was accomplished by intra-tumoral injection of ex vivo etoposide-treated tumor cells as an injured cell adjuvant, in combination with systemic anti-PD1/CTLA4 antibodies. This resulted in increased intra-tumoral CD103+ dendritic cells and circulating tumor antigen-specific CD8+ T-cells, leading to enhanced anti-tumor immune responses and improved survival. The effect was abrogated in BATF3-deficient mice indicating that BATF3+ DCs are required for appropriate T-cell stimulation by live but injured DNA-damaged tumor cells. Notably, injection of the free DNA-damaging drug directly into the tumor failed to elicit such an enhanced anti-tumor response as a consequence of simultaneous damage to dendritic cells and T-cells. Finally, the DNA damage induced injured cell adjuvant and systemic ICI combination, but not ICI alone, induced complete tumor regression in a subset of mice who were then able to reject tumor re-challenge, indicating induction of a long-lasting anti-tumor immunological memory by the injured cell adjuvant treatment in vivo.

Apoptotic Lymphoma Cells Evoke a Pro-Senescent Stromal Signal That Limits Lymphoma Development.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2392-2392
Author(s):  
Maurice Reimann ◽  
Soyoung Lee ◽  
Christoph Loddenkemper ◽  
Jan Dörr ◽  
Vedrana Tabor ◽  
...  
Keyword(s):  
B Cell ◽  
Tumor Cells ◽  
Transgenic Mouse ◽  
Cellular Senescence ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Lymphoma Cells ◽  
Anti Cancer ◽  
Mouse Lymphoma

Abstract Abstract 2392 Poster Board II-369 Introduction: Cancer entities frequently exhibiting constitutive Myc expression, such as aggressive B-cell lymphomas, typically display significant amounts of apoptotic cell death. So far, cellular senescence as another cell-autonomous oncogene-inducible safeguard program has been recognized in RAS/BRAF-driven scenarios but not as a bona fide Myc-evoked anti-cancer mechanism. Understanding how oncogenic Myc may provoke not only apoptosis but cellular senescence as a failsafe mechanism to counter tumor development has broad implications for the clinical presentation and therapeutic strategies in frequently Myc-driven lymphoma entities such as Burkitt's lymphoma and diffuse large B-cell lymphoma (DLBCL). Results: Using the Burkitt's like Eμ-myc transgenic mouse lymphoma model, we show here that cellular senescence serves as another crucial anti-neoplastic barrier during Myc-driven tumorigenesis in addition to apoptosis. Eμ-myc lymphomas harbor a substantial fraction of senescent tumor cells, that stain positive for histone H3 lysine 9 (H3K9)-trimethylation. Lymphomas lacking the H3K9 methyltransferase Suv39h1 display no senescence and develop significantly faster, although apoptosis is not affected by Suv39h1 deficiency. While Myc, unlike other Ras-type oncogenes, shows rather modest pro-senescent activity in vitro, we identified the cytostatic cytokine TGF-β as the main paracrine senescence trigger in vivo. When neutralizing TGF-β action during Myc-driven lymphomagenesis utilizing a secretable TGF-β receptor II ecto-domain, senescence is completely blunted and tumor latency is significantly shortened. We identify macrophages, but not lymphoma cells, as the main source of exogenous TGF-β, that is secreted upon phagocytosis of apoptotic lymphoma cells. Lymphomas harboring a Bcl2-mediated apoptotic block presented with a much lower frequency of both infiltrating macrophages and senescent cells in vivo, suggesting that there is a functional link between cell-autonomous Myc-triggered apoptosis and non-cell-autonomous, macrophage-induced senescence. Both pharmacological suppression of TGF-β production in macrophages via the angiotensin-converting enzyme (ACE) inhibitor lisinopril and depletion of macrophages in Eμ-myc lymphoma-harboring mice by systemic exposure to clodronate resulted in a profound reduction of senescence, thereby underscoring the important role for tumor-infiltrating macrophages in TGF-β-mediated senescence in vivo. We recapitulated components of such a mechanism in human aggressive B-cell lymphomas, a frequently Myc-activated entity where TGF-β1 signaling has previously been identified as a component of the prognostically favourable “stromal-1” signature (Lenz-G et al., NEJM, 2008). A panel of 30 DLBCL samples was sub-divided based on Ki67 immunoreactivity into a very high proliferation (Ki67hi; ≥80% Ki67-positive cells) and a lower proliferation (Ki67lo; <80% Ki67-positive cells) group. Ki67lo samples exhibited a higher frequency of H3K9me3-positive cells, indicative of cellular senescence. Importantly, the Ki67lo group also presented with a higher fraction of apoptotic cells, more lymphoma-infiltrating macrophages, and a stronger reactivity for the TGF-β signaling mediator Smad3-P, thereby representing a subgroup in DLBCL that displays features highly reminiscent of the macrophage-derived mechanism of senescence induction. Conclusions: Our study expands the relevance of oncogene-induced senescence to Myc-driven cancers and demonstrates that different tumor suppressor programs - such as apoptosis and senescence - are enforced in an interdependent fashion between the tumor- and non-malignant stroma cells during lymphomagenesis. Utilizing the Eμ-myc transgenic mouse lymphoma model and furthermore supported by evidence from human aggressive B-cell lymphoma samples, this study establishes a novel network of heterotypic cell-cell interactions within a tumor in which apoptotic tumor cells induce a paracrine response in non-malignant bystander cells that limits lymphomagenesis by cellular senescence. Given the anti-cancer relevance of senescence and the demonstrated inducibility of senescence by a non-DNA damaging cytokine, such as TGF-β, these findings open the exciting perspective to utilize Suv39h1/H3K9me3-mimicking approaches for future cancer therapies. Disclosures: No relevant conflicts of interest to declare.

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