T-cell Mediated Immunotherapy Research Articles

Impaired FADD/BID signaling mediates cross-resistance to immunotherapy in Multiple Myeloma

The treatment landscape in multiple myeloma (MM) is shifting from genotoxic drugs to immunotherapies. Monoclonal antibodies, immunoconjugates, T-cell engaging antibodies and CART cells have been incorporated into routine treatment algorithms, resulting in improved response rates. Nevertheless, patients continue to relapse and the underlying mechanisms of resistance remain poorly understood. While Impaired death receptor signaling has been reported to mediate resistance to CART in acute lymphoblastic leukemia, this mechanism yet remains to be elucidated in context of novel immunotherapies for MM. Here, we describe impaired death receptor signaling as a novel mechanism of resistance to T-cell mediated immunotherapies in MM. This resistance seems exclusive to novel immunotherapies while sensitivity to conventional anti-tumor therapies being preserved in vitro. As a proof of concept, we present a confirmatory clinical case indicating that the FADD/BID axis is required for meaningful responses to novel immunotherapies thus we report impaired death receptor signaling as a novel resistance mechanism to T-cell mediated immunotherapy in MM.

Nanomedicine for T-Cell Mediated Immunotherapy.

T-cell immunotherapy offers outstanding advantages in the treatment of various diseases, and with the selection of appropriate targets, efficient disease treatment can be achieved. T-cell immunotherapy has made great progress, but clinical results show that only a small proportion of patients can benefit from T-cell immunotherapy. The extensive mechanistic work outlines a blueprint for using T cells as a new option for immunotherapy, but also presents new challenges, including the balance between different fractions of T cells, the inherent T-cell suppression patterns in the disease microenvironment, the acquired loss of targets, and the decline of T-cell viability. The diversity, flexibility, and intelligence of nanomedicines give them great potential for enhancing T-cell immunotherapy. Here, how T-cell immunotherapy strategies can be adapted with different nanomaterials to enhance therapeutic efficacy is discussed. For two different pathological states, immunosuppression and immune activation, recent advances in nanomedicines for T-cell immunotherapy in diseases such as cancers, rheumatoid arthritis, systemic lupus erythematosus, ulcerative colitis, and diabetes are summarized. With a focus on T-cell immunotherapy, this review highlights the outstanding advantages of nanomedicines in disease treatment, and helps advance one's understanding of the use of nanotechnology to enhance T-cell immunotherapy.

ATM-TCR: TCR-Epitope Binding Affinity Prediction Using a Multi-Head Self-Attention Model.

TCR-epitope pair binding is the key component for T cell regulation. The ability to predict whether a given pair binds is fundamental to understanding the underlying biology of the binding mechanism as well as developing T-cell mediated immunotherapy approaches. The advent of large-scale public databases containing TCR-epitope binding pairs enabled the recent development of computational prediction methods for TCR-epitope binding. However, the number of epitopes reported along with binding TCRs is far too small, resulting in poor out-of-sample performance for unseen epitopes. In order to address this issue, we present our model ATM-TCR which uses a multi-head self-attention mechanism to capture biological contextual information and improve generalization performance. Additionally, we present a novel application of the attention map from our model to improve out-of-sample performance by demonstrating on recent SARS-CoV-2 data.

Midostaurin abrogates CD33-directed UniCAR and CD33-CD3 bispecific antibody therapy in acute myeloid leukaemia.

Combinatory therapeutic approaches of different targeted therapies in acute myeloid leukaemia are currently under preclinical/early clinical investigation. To enhance anti-tumour effects, we combined the tyrosine kinase inhibitor (TKI) midostaurin and T-cell mediated immunotherapy directed against CD33. Clinically relevant concentrations of midostaurin abrogated T-cell mediated cytotoxicity both after activation with bispecific antibodies and chimeric antigen receptor T cells. This information is of relevance for clinicians exploring T-cell mediated immunotherapy in early clinical trials. Given the profound inhibition of T-cell functionality and anti-tumour activity, we recommend specific FLT3 TKIs for further clinical testing of combinatory approaches with T-cell based immunotherapy.

Abstract B129: Human endogenous retroviruses as a potential reservoir for T-cell mediated cancer immunotherapy

Abstract Epigenetic modulation using DNA methyltransferase inhibitors (DNMTis), such as 5-azacytidine (5-aza-CR), have been shown to affect the cellular immunogenicity in vitro through upregulations of human endogenous retroviruses (HERV) leading to activation of the INFγ response pathway. HERVs comprise up to 8% of the human genome, and may hold a large reservoir of potential tumor antigens.We examined the in vivo efficacy of 5-aza-CR in terms of upregulations of HERV expression during standard treatment regimen, as well as the ability of such HERV transcripts to form T-cell antigens leading to measurable T-cell recognition upon treatment. We have studied 66 HERV genes that have been shown to be transcribed in human tissues. To identify HERV derived immune recognition, we generated a library of 1169 HERV derived potential antigenic peptides restricted to most abundant MHC class I molecules in the Caucasian population. Peripheral blood mononuclear cells (PBMCs) from a cohort of 19 patients and bone marrow samples from a cohort of 11 patients, treated with DNMTis for different hematological malignancies (MDS, AML, and CMML) were used to detect CD8+ T-cells reactive to ERV-derived peptides. We detected CD8+ T-cells specific to several HERV-derived peptides both in healthy and diseased individuals. Further, in an additional cohort of patients we examined expression level of these HERVs by RNA seq analysis and compared with healthy individuals demonstrating a disease associated upregulation of HERVs in hematological malignancies. Presence of T-cells reactive to HERV antigens and enhanced expression of HERVs in these malignancies suggest that HERVs may indeed provide a pool of shared tumor associated antigens. These antigens could potentially be enhanced through DNMTi treatment and may provide a target for T-cell mediated immunotherapy. Citation Format: Sunil Kumar Saini, Anne-Mette Bjerregaard, Andreas D. Ørskov, Ashwin Unnikrishnan, Staffan Holmberg, Govardhan Anande, Amalie Kai Bentzen, Zoltan Szallasi, Aron C. Eklund, Kirsten Grønbæk, Sine Reker Hadrup. Human endogenous retroviruses as a potential reservoir for T-cell mediated cancer immunotherapy [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B129.

Correction: Targeting Vascular Endothelial-Cadherin in Tumor-Associated Blood Vessels Promotes T-cell-Mediated Immunotherapy.

Correction: Targeting Vascular Endothelial-Cadherin in Tumor-Associated Blood Vessels Promotes T-cell-Mediated Immunotherapy.

Overexpression of adhesion molecules and barrier molecules is associated with differential infiltration of immune cells in non-small cell lung cancer

Immunotherapy is emerging as a promising option for lung cancer treatment. Various endothelial adhesion molecules, such as integrin and selectin, as well as various cellular barrier molecules such as desmosome and tight junctions, regulate T-cell infiltration in the tumor microenvironment. However, little is known regarding how these molecules affect immune cells in patients with lung cancer. We demonstrated for the first time that overexpression of endothelial adhesion molecules and cellular barrier molecule genes was linked to differential infiltration of particular immune cells in non-small cell lung cancer. Overexpression of endothelial adhesion molecule genes is associated with significantly lower infiltration of activated CD4 and CD8 T-cells, but higher infiltration of activated B-cells and regulatory T-cells. In contrast, overexpression of desmosome genes was correlated with significantly higher infiltration of activated CD4 and CD8 T-cells, but lower infiltration of activated B-cells and regulatory T-cells in lung adenocarcinoma. This inverse relation of immune cells aligns with previous studies of tumor-infiltrating B-cells inhibiting T-cell activation. Although overexpression of endothelial adhesion molecule or cellular barrier molecule genes alone was not predictive of overall survival in our sample, these genetic signatures may serve as biomarkers of immune exclusion, or resistance to T-cell mediated immunotherapy.

Targeting Vascular Endothelial-Cadherin in Tumor-Associated Blood Vessels Promotes T-cell-Mediated Immunotherapy.

T-cell infiltration of solid tumors is associated with improved prognosis and favorable responses to immunotherapy. Mechanisms that enable tumor infiltration of CD8+ T cells have not been defined, nor have drugs that assist this process been discovered. Here we address these issues with a focus on VE-cadherin, a major endothelial cell-specific junctional protein that controls vascular integrity. A decrease in VE-cadherin expression is associated with tumor pathology. We developed an oligonucleotide-based inhibitor (CD5-2), which disrupted the interaction of VE-cadherin with its regulator miR-27a, resulting in increased VE-cadherin expression. Administration of CD5-2 in tumor-bearing mice enhanced expression of VE-cadherin in tumor endothelium, activating TIE-2 and tight junction pathways and normalizing vessel structure and function. CD5-2 administration also enhanced tumor-specific T-cell infiltration and spatially redistributed CD8+ T cells within the tumor parenchyma. Finally, CD5-2 treatment enhanced the efficacy of anti-PD-1 blocking antibody. Our work establishes a role for VE-cadherin in T-cell infiltration in tumors and offers a preclinical proof of concept for CD5-2 as a therapeutic modifier of cancer immunotherapy via effects on the tumor vasculature. Cancer Res; 77(16); 4434-47. ©2017 AACR.

B7-H3 as a promising target for cytotoxicity T cell in human cancer therapy.

Targeting B7-H3 over-expressed tumor cells with anti-B7-H3 monoclonal antibodies inhibits tumor growth. Here we demonstrated the expression of B7 family homologue 3 (B7-H3) in a wide range of human tumor cells and further investigated whether B7-H3 could be served as a target for T-cell mediated immunotherapy against human cancers. The specific cytotoxic activity of activated T cell (ATC) armed with a novel anti-CD3 x anti-B7-H3 bispecific antibody (B7-H3Bi-Ab) against tumor cell was evaluated in vitro and in vivo. In contrast with unarmed ATC, an increase in cytotoxic activity of B7-H3Bi-armed ATC against tumor cells was observed at effector/target (E/T) ratios of 5:1, 10:1, and 20:1. Moreover, B7-H3Bi-armed ATC secreted more IFN-γ, TNF-α and IL-2 than unarmed ATC. Infusion of B7-H3Bi-armed ATC inhibited tumor growth in severe combined immunodeficiency (SCID) xenograft models, along with a significant survival benefit. Therefore, treatment with novel B7-H3Bi-armed ATC will be a promising strategy for current cancer immunotherapy.

Colorectal cancer vaccines in clinical trials

This article elucidates current strategies of active immunotherapy for colorectal cancer patients with a focus on T-cell mediated immunotherapy. Poor prognosis of especially stage III and IV colorectal cancer patients emphasizes the need for advanced therapeutic intervention. Here, we refer to clinical trials using either tumor cell-derived vaccines or tumor antigen vaccines with a special interest on safety, induced immune responses, clinical benefit and efforts to improve the clinical impact of these vaccines in the context of colorectal cancer treatment.

Abstract 1929: CD4+ and CD8+ neu-reactive T cells are sensitized by breast cancer stem-like cells (BCSC) in tolerized Her-2/neu transgenic mice and can mediate tumor regression upon adoptive transfer

Abstract There is growing evidence that a variety of tumors including breast cancer may be driven by a small subset of cancer stem/progenitor cells that exhibit chemotherapeutic resistance and cause tumor relapse. The eradication of this small subset of cells might improve therapeutic outcome. However, it is unknown whether breast cancer stem/progenitor cells are susceptible to T-cell mediated immunotherapy. We used defined serum-free conditions to establish primary neupos BCSC lines. Spontaneous breast tumors arising in neu-N transgenic mice were passaged in vivo to generate progressor lines and tumors were harvested and prepared as a single cell suspension. Paired aliquots of tumor cells were cultured in either serum-free medium supplemented with EGF and bFGF to derive BCSC sub-lines, or alternatively in standard serum-containing medium to generate mouse mammary carcinoma (MMC) sub-lines. The BCSC cells display morphologic characteristics of breast cancer stem/progenitor cells, such as non-attached growth in spheroid colonies, and high expression of CD44. We vaccinated neu-N transgenic mice with 2×107 irradiated MMC10-BCSC or its paired cell line MMC10-AD and harvested vaccine-draining lymph nodes 9 days later. Antigen-primed CD62Llow cells were isolated using MACS beads and CD62LlowCD4+ or CD62LlowCD8+ T cells were additionally purified and stimulated with anti-CD3/IL-2/IL-7 for two stimulation cycles. Adoptive transfer of 3×107 CD62Llow CD4+ cells from MMC10-BCSC-draining LNs effectively eradicated pulmonary metastases (p<0.001). By contrast, 3×107 CD62Llow CD4+ T cells from MMC10-AD-draining LNs was sub-therapeutic (p>0.05 vs. control). In an independent experiment, adoptive transfer of 3×107 CD8+ T cells sensitized by MMC10-BCSCs mediated the regression of established MMC10 pulmonary metastasis (p<0.001), whereas 6×107 CD8+ cells primed by MMC10-AD was ineffective. More importantly, adoptive transfer of 4 × 107 in vitro-activated CD8+ cells combined with 2×107 CD4+ cells derived from LNs draining MMC10-BCSCs are effective against the parental MMC10 line as well as an independently derived neupos line MMC-1. Also, transfer of either 3×107 CD4+ or CD8+ T cells from LNs draining MMC10-BCSCs effectively mediated regression of established 3-day neupos MMC4 pulmonary metastasis. In conclusion, irradiated whole tumor cell vaccines derived from neupos BCSCs can prime T-cells in neu-tolerant hosts. Although this immune response is insufficient to prevent progressive tumor growth, highly activated effector function and large numbers of CD4+ and CD8+ T cells can be generated through in vitro activation with anti-CD3/IL-2/IL-7 stimulation. Either CD4+ or CD8+ T cells are cross-protective against other neu-positive tumor metastases indicating that this approach provides MHC class I and II immune responses. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1929.

Autologous CMV-Specific T Cells as Effector Cells in Immunotherapy of B Cell Chronic Lymphocytic Leukemia.

Introduction. B cell Chronic Lymphocytic Leukemia (B-CLL) is prototypic for human cancers that escape immune surveillance. These cells not only lack immunogenic tumor-specific epitopes but also express low levels of surface molecules that are necessary for optimal interaction with naive T cells. Different strategies have been tried to generate B-CLL specific T cells that can be used for adoptive immunotherapy. Yet it is uncertain whether these T cell specific responses are strong enough to eliminate the neoplastic clone. Previously, we have demonstrated that CMV seropositive patients with B-CLL have significantly increased relative and absolute numbers of CD8+ T cells exhibiting a CD45RA+CD27− cytotoxic CMV specific phenotype. In the present study we investigated the possibility to direct these in vivo generated CMV specific effector cells to the poorly immunogenic B-CLL cells.Results. A considerable fraction (6%; range 1.0 to 16.4) of the circulating CD8+ T cell pool of the four B-CLL patients studied consisted of CMV-specific T cells, as visualized with either tetrameric HLA-A2.1/NLVPMVATV complexes or HLA-B7.2/TPRVTGGGAM complexes. Activation of these cells by CMV-peptide in the presence of IL-2 at day 0, and restimulation at day 8 with either CMV peptide loaded EBV transformed cell-lines or autologous peptide-loaded B-CLL cells, resulted in a near 100-fold absolute expansion of tetramer positive CD8+ T cells (on average 1.9 x 106 at day 0, and 2.2 x 108 at week 3). These in vitro restimulated CMV-specific T cells were non-cytotoxic for non-peptide loaded B-CLL cells, but showed a very efficient killing of CMV peptide loaded B-CLL cells, with a 50% specific lysis at an effector:target ratio as low as 4:1. Thus, despite their general anti-apoptotic profile, B-CLL cells are excellent targets and undergo apoptosis after CTL attack. This CTL specific killing was found to be completely dependent on the granzyme and perforin pathway. Finally we showed that the CMV specific effector cells in B-CLL patients do not need restimulation to effectuate a cytotoxic response towards CMV peptide loaded B-CLL cells.Conclusion. Directing virus-specific T cells to B-CLL tumors may overcome the inadequate immunostimulatory capacity of these cells and could be exploited for T-cell mediated immunotherapy.

Autologous cytomegalovirus-specific T cells as effector cells in immunotherapy of B cell chronic lymphocytic leukaemia.

B-cell chronic lymphocytic leukaemia (B-CLL) cells express low levels of co-stimulatory molecules and therefore fail to induce activation and differentiation of tumour-specific T cells. We have shown that patients with B-CLL have considerably expanded numbers of cytomegalovirus (CMV) reactive CD8(+) T cells. This study demonstrated that B-CLL cells loaded with CMV peptide not only promoted the ex vivo expansion of autologous, in vivo-generated virus-specific T cells, but also constituted excellent target cells for these cytotoxic T cells, even without ex vivo re-stimulation. Directing virus-specific T cells to B-CLL may overcome the inadequate immunostimulatory capacity of these cells, which could be exploited for T-cell mediated immunotherapy.