Inhibition of BRAF Sensitizes Thyroid Carcinoma to Immunotherapy by Enhancing tsMHCII-mediated Immune Recognition

2020 ◽  
Vol 106 (1) ◽  
pp. 91-107
Author(s):  
Jingtai Zhi ◽  
Peitao Zhang ◽  
Wei Zhang ◽  
Xianhui Ruan ◽  
Mengran Tian ◽  
...  
Keyword(s):  
T Cells ◽  
Mouse Model ◽  
Thyroid Carcinoma ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Immune Escape ◽  
Combined Treatment ◽  
Immune Recognition ◽  
Brafv600e Mutation ◽  
Tgf Β1

Abstract Context Multiple mechanisms play roles in restricting the ability of T-cells to recognize and eliminate tumor cells. Objective To identify immune escape mechanisms involved in papillary thyroid carcinoma (PTC) to optimize immunotherapy. Setting and Design iTRAQ analysis was conducted to identify proteins differentially expressed in PTC samples with or without BRAFV600E mutation. Molecular mechanisms regulating tumor cell evasion were investigated by in vitro modulations of BRAF/MAPK and related pathways. The pathological significance of identified tumor-specific major histocompatibility complex class II (tsMHCII) molecules in mediating tumor cell immune escape and targeted immune therapy was further evaluated in a transgenic mouse model of spontaneous thyroid cancer. Results Proteomic analysis showed that tsMHCII level was significantly lower in BRAFV600E-associated PTCs and negatively correlated with BRAF mutation status. Constitutive activation of BRAF decreased tsMHCII surface expression on tumor cells, which inhibited activation of CD4+ T-cells and led to immune escape. Pathway analysis indicated that the transforming growth factor (TGF)-β1/SMAD3-mediated repression of tsMHCII, which could be reversed by BRAF inhibition (BRAFi). Targeting this pathway with a combined therapy of BRAF inhibitor PLX4032 and anti-PD-1 antibody efficiently blocked tumor growth by increasing CD4+ T-cell infiltration in a transgenic PTC mouse model. Conclusions Our results suggest that BRAFV600E mutation in PTC impairs the expression of tsMHCII through the TGF-β1/SMAD3 pathway to enhance immune escape. Combined treatment with PLX4032 and anti-PD-1 antibody promotes recognition and elimination of PTC by the immune system in a pre-clinical mouse model, and therefore offers an effective therapeutic strategy for patients with advanced PTC.

scholarly journals Single-cell evaluation reveals shifts in the tumor-immune niches that shape and maintain aggressive lesions in the breast

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vidya C. Sinha ◽  
Amanda L. Rinkenbaugh ◽  
Mingchu Xu ◽  
Xinhui Zhou ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Mouse Model ◽  
Transition State ◽  
Tumor Cell ◽  
Single Cell ◽  
Tumor Cells ◽  
Breast Lesions ◽  
Aggressive Tumor ◽  
Insight Into

AbstractThere is an unmet clinical need for stratification of breast lesions as indolent or aggressive to tailor treatment. Here, single-cell transcriptomics and multiparametric imaging applied to a mouse model of breast cancer reveals that the aggressive tumor niche is characterized by an expanded basal-like population, specialization of tumor subpopulations, and mixed-lineage tumor cells potentially serving as a transition state between luminal and basal phenotypes. Despite vast tumor cell-intrinsic differences, aggressive and indolent tumor cells are functionally indistinguishable once isolated from their local niche, suggesting a role for non-tumor collaborators in determining aggressiveness. Aggressive lesions harbor fewer total but more suppressed-like T cells, and elevated tumor-promoting neutrophils and IL-17 signaling, disruption of which increase tumor latency and reduce the number of aggressive lesions. Our study provides insight into tumor-immune features distinguishing indolent from aggressive lesions, identifies heterogeneous populations comprising these lesions, and supports a role for IL-17 signaling in aggressive progression.

scholarly journals Single-cell evaluation reveals shifts in the tumor-immune niches that shape and maintain aggressive lesions in the breast

2021 ◽  
Author(s):  
Vidya C. Sinha ◽  
Amanda L. Rinkenbaugh ◽  
Mingchu Xu ◽  
Xinhui Zhou ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Mouse Model ◽  
Transition State ◽  
Tumor Cell ◽  
Single Cell ◽  
Tumor Cells ◽  
Breast Lesions ◽  
Aggressive Tumor ◽  
Insight Into

Abstract There is an unmet clinical need for stratification of breast lesions as indolent or aggressive to tailor treatment. Here, single-cell transcriptomics and multiparametric imaging applied to a mouse model of breast cancer revealed that the aggressive tumor niche is characterized by an expanded basal-like population, specialization of tumor subpopulations, and mixed-lineage tumor cells potentially serving as a transition state between luminal and basal phenotypes. Despite vast tumor cell-intrinsic differences, aggressive and indolent tumor cells were functionally indistinguishable once isolated from their local niche, suggesting a role for non-tumor collaborators in determining aggressiveness. Aggressive lesions harbored fewer total but more suppressed-like T cells, and elevated tumor-promoting neutrophils and IL-17 signaling, disruption of which increased tumor latency and reduced the number of aggressive lesions. Our study provides insight into tumor-immune features distinguishing indolent from aggressive lesions, identifies heterogeneous populations comprising these lesions, and supports a role for IL-17 signaling in aggressive progression.

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 Participation of the H-2 antigens of tumor cells in their lysis by syngeneic T cells.

1976 ◽  
Vol 143 (3) ◽  
pp. 601-614 ◽  
Author(s):  
J W Schrader ◽  
G M Edelman
Keyword(s):  
T Cells ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Target Cell ◽  
Cytotoxic T Cells ◽  
Hybrid Origin ◽  
Target Cells ◽  
Cytotoxic Lymphocytes ◽  
Effector Cells

Cytotoxic T lymphocytes were generated in vitro against H-2 compatible or syngeneic tumor cells. In vitro cytotoxic activity was inhibited by specific anti-H2 sera, suggesting that H-2 antigens are involved in cell lysis. Two observations directly demonstrated the participation of the H-2 antigens on the tumor cells in their lysis by H-2-compatible T cells. First, coating of the H-2 antigens on the target tumor cell reduced the number of cells lysed on subsequent exposure to cytotoxic T cells. Second, when cytotoxic T cells were activated against an H-2 compatible tumor and assayed against an H-2-incompatible tumor, anti-H-2 serum that could bind to the target cell, but not to the cytotoxic lymphocyte, inhibited lysis. H-2 antigens were also shown to be present on the cytotoxic lymphocytes. Specific antisera reacting with these H-2 antigens, but not those of the target cell, failed to inhibit lysis when small numbers of effector cells were assayed against H-2-incompatible target cells or when effector cells of F1-hybrid origin and bearing two H-2 haplotypes were assayed against a tumor cell of one of the parental strains. These findings suggest that it is the H-2 antigens on the tumor cell and not those on the cytotoxic lymphocytes that are important in cell-mediated lysis of H-2-compatible tumor cells.

scholarly journals Arming T Cells with a gp100-Specific TCR and a CSPG4-Specific CAR Using Combined DNA- and RNA-Based Receptor Transfer

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 696 ◽  
Author(s):  
Bianca Simon ◽  
Dennis C. Harrer ◽  
Beatrice Schuler-Thurner ◽  
Gerold Schuler ◽  
Ugur Uslu
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Immune Escape ◽  
Cell Receptor ◽  
Adoptive T Cell Therapy ◽  
T Cell Therapy ◽  
Dna And Rna ◽  
Antigen Loss ◽  
Antigen Presenting

Tumor cells can develop immune escape mechanisms to bypass T cell recognition, e.g., antigen loss or downregulation of the antigen presenting machinery, which represents a major challenge in adoptive T cell therapy. To counteract these mechanisms, we transferred not only one, but two receptors into the same T cell to generate T cells expressing two additional receptors (TETARs). We generated these TETARs by lentiviral transduction of a gp100-specific T cell receptor (TCR) and subsequent electroporation of mRNA encoding a second-generation CSPG4-specific chimeric antigen receptor (CAR). Following pilot experiments to optimize the combined DNA- and RNA-based receptor transfer, the functionality of TETARs was compared to T cells either transfected with the TCR only or the CAR only. After transfection, TETARs clearly expressed both introduced receptors on their cell surface. When stimulated with tumor cells expressing either one of the antigens or both, TETARs were able to secrete cytokines and showed cytotoxicity. The confirmation that two antigen-specific receptors can be functionally combined using two different methods to introduce each receptor into the same T cell opens new possibilities and opportunities in cancer immunotherapy. For further evaluation, the use of these TETARs in appropriate animal models will be the next step towards a potential clinical use in cancer patients.

Preclinical Evaluation Of Engineered T Cells In Multiple Myeloma: Uncovering a Mechanism Of Immune Escape

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4205-4205
Author(s):  
Zandra K. Klippel ◽  
Jeffrey Chou ◽  
Andrea M. H. Towlerton ◽  
Paul F Robbins ◽  
Lilien Voong ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
Tumor Cells ◽  
Cd8 T Cells ◽  
Peripheral Blood ◽  
Immune Escape ◽  
Adoptive Therapy ◽  
Myeloma Cells ◽  
Nsg Mice ◽  
Flow Cytometric

Abstract Introduction Adoptive immunotherapy is an increasingly effective modality of cancer therapy. The ability to redirect the antigenic specificity of patient-derived T cells toward autologous tumor cells through introduction of T-cell receptors (TCRs) or chimeric antigen receptors (CARs) enables reproducible manufacturing of tumor-reactive T cell products even in patients who carry few, if any, tumor-reactive T cells in their peripheral blood repertoire. We present the results of our pre-clinical studies of adoptive therapy with T cells transduced with a retroviral vector that encodes an enhanced-affinity (a95:LY) variant of the HLA-A*02:01-restricted, NY-ESO-1157-165-specific 1G4 TCR to redirect CD8+ T cells from HLA-A*02:01+ multiple myeloma patients to HLA-A*02:01+, NY-ESO-1-expressing myeloma cells. Methods CD3-stimulated peripheral blood mononuclear cells from HLA-A*02:01+ multiple myeloma patients were retrovirally transduced with the NY-ESO-1157-165-specific 1G4 a95:LY TCR. CD8+ TCR-transduced cells were isolated by flow cytometric sorting with a NY-ESO-1157-165/HLA-A*02:01 tetramer. The cytolytic activity of CD8+tetramer+ cells was evaluated by 51Cr release assay using as target cells the multiple myeloma cell lines U266 (HLA-A*02:01+ NY-ESO-1+) and UM-9 (HLA-A*02:01- NY-ESO-1+), and T2 cells with or without exogenous NY-ESO-1157-165 peptide. The U266 cell line was stably transduced with luciferase-containing retrovirus and used to develop a xenograft model of diffuse myeloma in NOD/scid/IL-2Rg-null (NSG) mice in order to evaluate the anti-myeloma activity of adoptive therapy with CD8+ TCR-transduced T cells. Mice that received TCR-transduced CD8+cells and developed disease were sacrificed, and human CD138+ cells were harvested from marrow and other sites for evaluation by flow cytometry, HLA-A typing, NY-ESO-1 expression, and loss of heterozygosity (LOH) analysis of the Major Histocompatibility Complex (MHC) on chromosome 6 with short tandem repeat (STR) probes to determine the mechanism of immune escape. Results CD8+ TCR-transduced cells were specifically cytolytic against HLA-A*02:01+, NY-ESO-1+ tumor cells. Intravenous injection of luciferase-transduced U266/Luc in sub-lethally irradiated NSG mice led to the development of a multiple myeloma-like disease. Mice that received U266/Luc without T cells (control) developed progressive disease within 2 weeks, and met criteria for euthanasia by week 9. Mice that received U266/Luc with sham-transduced cells developed myeloma more slowly, yet all met criteria for euthanasia by week 18 after U266/Luc injection. Of the 6 mice that received U266/Luc and NY-ESO-1-specific TCR-transduced CD8+ T cells, 4 did not have any evidence of myeloma by bioluminescence at the end of study (week 18), and 2 had low burden disease at that point. Kaplan-Meier survival analysis demonstrated significant improvement of overall survival in the mice that received TCR-transduced T cells (Log-rank test p< 0.0001). Flow cytometric analysis of human CD138+ cells isolated from the 2 mice that developed myeloma despite adoptive therapy with NY-ESO-1-specific T cells demonstrated selective loss of surface HLA-A*02 expression, with preserved expression of other MHC class I molecules. Real-time PCR analysis also confirmed preserved expression of HLA-A, B2M, and NY-ESO-1. Low resolution HLA-A typing of genomic DNA from myeloma cells from these 2 mice revealed loss of HLA-A*02, but retention of HLA-A*03. LOH analysis using 7 STR markers mapping to the MHC on chromosome 6p21.3 and 2 markers on chromosome 15 (control) demonstrated LOH in the MHC involving the HLA-A locus in myeloma cells from both of the mice that developed disease despite TCR-transduced T cells. The extent of LOH in the myeloma cells from the 2 mice was distinct. Conclusions LOH in the MHC as a mechanism of immune scape has been described in allogeneic transplantation for AML, but has not been described in multiple myeloma. We identified LOH affecting the HLA-A allele targeted by adoptively transferred TCR-transduced T cells. Given that NY-ESO-1-specific TCR-transduced cells have recently entered clinical testing, this mechanism of immune escape should be evaluated in patients that fail therapy despite persistence of adoptively transferred T cells. 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 T Cell Bispecific Antibodies: An Antibody-Based Delivery System for Inducing Antitumor Immunity

2021 ◽  
Vol 14 (11) ◽  
pp. 1172
Author(s):  
Daisuke Kamakura ◽  
Ryutaro Asano ◽  
Masahiro Yasunaga
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Tumor Cell ◽  
Tumor Cells ◽  
T Cell Activation ◽  
Antitumor Immunity ◽  
Bispecific Antibodies ◽  
Tumor Site ◽  
Tumor Cell Death

As a breakthrough immunotherapy, T cell bispecific antibodies (T-BsAbs) are a promising antibody therapy for various kinds of cancer. In general, T-BsAbs have dual-binding specificity to a tumor-associated antigen and a CD3 subunit forming a complex with the TCR. This enables T-BsAbs to crosslink tumor cells and T cells, inducing T cell activation and subsequent tumor cell death. Unlike immune checkpoint inhibitors, which release the brake of the immune system, T-BsAbs serve as an accelerator of T cells by stimulating their immune response via CD3 engagement. Therefore, they can actively redirect host immunity toward tumors, including T cell recruitment from the periphery to the tumor site and immunological synapse formation between tumor cells and T cells. Although the low immunogenicity of solid tumors increases the challenge of cancer immunotherapy, T-BsAbs capable of immune redirection can greatly benefit patients with such tumors. To investigate the detailed relationship between T-BsAbs delivery and their T cell redirection activity, it is necessary to determine how T-BsAbs deliver antitumor immunity to the tumor site and bring about tumor cell death. This review article discusses T-BsAb properties, specifically their pharmacokinetics, redirection of anticancer immunity, and local mechanism of action within tumor tissues, and discuss further challenges to expediting T-BsAb development.

Multiple Myeloma as Target for γδ T Cell Mediated Immunotherapy - Expression of the Putative Vγ9Vδ2-TCR Ligand F1-ATPase on Myeloma Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3391-3391
Author(s):  
Volker Kunzmann ◽  
Judith Engert ◽  
Brigitte Kimmel ◽  
Martin Wilhelm ◽  
Hermann Einsele
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Surface Expression ◽  
Tumor Cell Lines ◽  
Myeloma Cells ◽  
F1 Atpase ◽  
Vγ9vδ2 T Cells

Abstract Activated Vγ9Vδ2 T cells, the major γδ T lymphocyte subset in humans, show cytolytic activity against various tumor cells. However, tumor antigens recognized by the TCR remained unkown so far. Recently, the ectopic surface expression of the F1-ATPase, normally expressed on the internal membrane of mitochondria, was implicated in tumor recognition of Vγ9Vδ2 T cells (Scotet E. et al., Immunity2005; 22:71–80). Surface expression of the a chain of the F1-ATPase (recognized by monoclonal antibody 7H10) strongly correlates with susceptibility of tumor cells against Vγ9Vδ2 T cell lysis. Different functions have been attributed to the ectopic expression of the F1-ATPase on the cell surface, including an immunoregulatory role induced by cell stress, receptor for angiostatin or regulation of lipoprotein transport through high-affinity apolipoprotein A-I binding. In this study we evaluated the surface expression of this F1-ATPase on hematopoetic tumor cell lines and on primary tumor cells from hematological malignancies. As already shown, the a subunit of F1-ATPase was clearly detected on several tumor cell lines which are consistently killed by activated Vγ9Vδ2 T cells (Daudi, K562, RPMI 8226), whereas the known Vγ9Vδ2 T cell resistant tumor cell lines (Raji, Jurkat) did not express detectable levels of the F1-ATPase. Analysis of 42 primary hematopoetic tumor cells (21 myeloma, 17 AML, 4 B-NHL) revealed frequent expression of F1-ATPase on primary myeloma cells (14/19 positive), whereas primary AML blasts (3/17 positive) and primary NHL cells (1/4 positive) expressed the putative Vγ9Vδ2-TCR ligand F1-ATPase less frequently. To further evaluate the functional role of F1-ATPase expression in Vγ9Vδ2 T cell mediated recognition of myeloma cells, cytotoxicity assays were performed. The mAb against the a subunit of F1-ATPase significantly decreased in vitro lysis of myeloma cells lines and primary myeloma cells by activated Vγ9Vδ2 T cells. These results suggests Vγ9Vδ2 TCR-dependent interactions between myeloma cells and Vγ9Vδ2 T cells and indicate that multiple myeloma should be considered as a major target for γδ T-cell mediated immunotherapy.

Induction of Anti-Cancer Effects by Targeting Alloreactive Intentionally Mismatched T Cells and NK Cells to Tumor Cells Using Bi-Specific Trifunctional Antibodies.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3245-3245
Author(s):  
Shoshana Morecki ◽  
Horst Lindhofer ◽  
Elena Yacovlev ◽  
Yael Gelfand ◽  
Shimon Slavin
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
Tumor Cell ◽  
Nk Cells ◽  
Tumor Cells ◽  
Bispecific Antibody ◽  
Tumor Inoculation ◽  
Anti Cancer ◽  
Second Tumor ◽  
Donor Lymphocytes

Abstract Engraftment of donor stem cells induces host vs graft unresponsiveness thus allowing durable engraftment of donor lymphocytes which can induce graft vs malignancy (GVM) effects following transplantation of MHC compatible donor stem cells. Unfortunately, graft vs host disease (GVHD) frequently results in major toxicity and mortality and limits the clinical efficacy of cell therapy. Although the intensity of GVM effects can be improved by using mismatched donors GVM effects cannot be induced in recipients of haploidentically mismatched allografts because of anticipated lethal GVHD. We have attempted to induce GVM effects by intentionally mismatched donor lymphocytes by targeting donor derived T cells and NK cells activated by rIL-2 to cancer cells, in order to improve the efficacy of the GVL effects on the one hand and prevent or minimize GVHD by targeting alloreactive cells to the tumor cells that need to be eliminated using bispecific tri-functional antibodies, on the other. A trifunctional bispecific antibody (BiLu) directed against murine CD3 and human epithelial-cell adhesion molecule (EpCAM), was administered concomitantly with naïve or IL-2 activated donor splenocytes to mice inoculated with a murine model of melanoma cells transfected with human EpCAM (B16-EpCAM). A total of 10/20 and 32/38 mice treated with BiLu and naïve or IL-2 activated donor splenocytes, respectively, were tumor-free survivors without GVHD for >250 days following tumor inoculation. Out of 28 of the disease free survivors (DFS) without GVHD, treated with IL-2 activated splenocytes and BiLu, 24 mice were resistant to a second tumor inoculum (104) given >250 days following the first tumor inoculation. In contrast, only 8 of the 18 DFS mice treated with naïve splenocytes and BiLu, and 5 of the 10 DFS controls treated with BiLu only, resisted the second tumor challenge. Induction of anti-tumor immunity by IL-2 activated cells and BiLu was more efficient and long-lasting in mice previously injected with a lethal first tumor cell dose (5×104) than in mice inoculated with a sub-lethal tumor cell dose (5×103). Interestingly, a similar infusion of donor cells labeled with bi-specific anti-EpCAM and anti-CD3 following allogeneic stem cell transplantation for metastatic breast cancer did not result in augmentation of GVHD. In conclusion, concomitant inoculation of alloreactive donor lymphocytes and trifunctional bispecific antibody can be effective for targeting of killer T and NK cells to tumor cells while avoiding GVHD, as well as for induction of long-lasting anti-cancer immunity, most likely due to presentation of tumor antigen to T cells by antigen presenting cells (dendritic cells) expressing Fc receptor binding to the Fc portion of the bi-specific antibody.

Sign in / Sign up

Export Citation Format

Share Document