scholarly journals Molecular Analysis of Elements of Melanoma Insensitivity to TCR-Engineered Adoptive Cell Therapy

2021 ◽  
Vol 22 (21) ◽  
pp. 11726
Author(s):  
Ali R. Jazirehi

Metastatic melanoma accounts for the highest number of skin cancer-related deaths. Traditional treatments are ineffective due to their inability to induce tumor regression at a high rate. Newer treatments such as immune checkpoint inhibitors (ICI), targeted therapy (BRAFi and MEKi), and T cell receptor (TCR)-engineered T cells aim to increase the ability of the host immune system to recognize and eradicate tumors. ICIs inhibit negative regulatory mechanisms and boost the antitumor activity of the host’s immune system, while targeted therapy directed against aberrant signaling molecules (BRAF and MEK) will block the uncontrolled proliferation and expansion of melanomas. The basis of the TCR-engineered T cell strategy is to transduce host T cells with antigen-specific TCRα/β chains to produce high-affinity T cells for tumor-associated antigens. TCR-transgenic T cells are expanded and activated ex vivo and reinfused into patients to increase the targeting of cancer cells. While these treatments have had varyingly favorable results, their efficacy is limited due to inherent or acquired resistance. Various mechanisms explain melanoma immune-resistance, including the loss or downregulation of the MCH/peptide complex, aberrant activity of signaling pathways, and altered dynamics of apoptotic machinery. Collectively, these mechanisms confer melanoma resistance to apoptotic stimuli delivered by T cells despite a fully functional and effective antitumor immune response. Identification of biomarkers, combination treatment, and the use of CAR T cells are among the approaches that can potentially circumvent melanoma’s resistance to immunotherapy.

2021 ◽  
Vol 12 ◽  
Author(s):  
Amrendra Kumar ◽  
Reese Watkins ◽  
Anna E. Vilgelm

The rationale behind cancer immunotherapy is based on the unequivocal demonstration that the immune system plays an important role in limiting cancer initiation and progression. Adoptive cell therapy (ACT) is a form of cancer immunotherapy that utilizes a patient’s own immune cells to find and eliminate tumor cells, however, donor immune cells can also be employed in some cases. Here, we focus on T lymphocyte (T cell)-based cancer immunotherapies that have gained significant attention after initial discoveries that graft-versus-tumor responses were mediated by T cells. Accumulating knowledge of T cell development and function coupled with advancements in genetics and data science has enabled the use of a patient’s own (autologous) T cells for ACT (TIL ACTs). In TIL ACT, tumor-infiltrating lymphocytes (TILs) are collected from resected tumor material, enhanced and expanded ex-vivo, and delivered back to the patient as therapeutic agents. ACT with TILs has been shown to cause objective tumor regression in several types of cancers including melanoma, cervical squamous cell carcinoma, and cholangiocarcinoma. In this review, we provide a brief history of TIL ACT and discuss the current state of TIL ACT clinical development in solid tumors. We also discuss the niche of TIL ACT in the current cancer therapy landscape and potential strategies for patient selection.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A812-A812
Author(s):  
Pia Aehnlich ◽  
Per Thor Straten ◽  
Ana Micaela Carnaz Simoes ◽  
Signe Skadborg ◽  
Gitte Olofsson

BackgroundAdoptive cell therapy (ACT) is an approved treatment option for certain hematological cancers and has also shown success for some solid cancers. Still, benefit and eligibility do not extend to all patients. ACT with Vγ9Vδ2 T cells is a promising approach to overcome this hurdle.MethodsIn this study, we explored the effect of different cytokine conditions on the expansion of Vγ9Vδ2 T cells in vitro.ResultsWe could show that Vγ9Vδ2 T cell expansion is feasible with two different cytokine conditions: (a) 1000U/ml interleukin (IL)-2 and (b) 100U/ml IL-2+100U/ml IL-15. We did not observe differences in expansion rate or Vγ9Vδ2 T cell purity between the conditions; however, IL-2/IL-15-expanded Vγ9Vδ2 T cells displayed enhanced cytotoxicity against tumor cells, also in hypoxia. While this increase in killing capacity was not reflected in phenotype, we demonstrated that IL-2/IL-15-expanded Vγ9Vδ2 T cells harbor increased amounts of perforin, granzyme B and granulysin in a resting state and release more upon activation. IL-2/IL-15-expanded Vγ9Vδ2 T cells also showed higher levels of transcription factor T-bet, which could indicate that T-bet and cytotoxic molecule levels confer the increased cytotoxicity.ConclusionsThese results advocate the inclusion of IL-15 into ex vivo Vγ9Vδ2 T cell expansion protocols in future clinical studies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ratchapong Netsrithong ◽  
Methichit Wattanapanitch

Adoptive cell therapy (ACT) using chimeric antigen receptor (CAR) T cells holds impressive clinical outcomes especially in patients who are refractory to other kinds of therapy. However, many challenges hinder its clinical applications. For example, patients who undergo chemotherapy usually have an insufficient number of autologous T cells due to lymphopenia. Long-term ex vivo expansion can result in T cell exhaustion, which reduces the effector function. There is also a batch-to-batch variation during the manufacturing process, making it difficult to standardize and validate the cell products. In addition, the process is labor-intensive and costly. Generation of universal off-the-shelf CAR T cells, which can be broadly given to any patient, prepared in advance and ready to use, would be ideal and more cost-effective. Human induced pluripotent stem cells (iPSCs) provide a renewable source of cells that can be genetically engineered and differentiated into immune cells with enhanced anti-tumor cytotoxicity. This review describes basic knowledge of T cell biology, applications in ACT, the use of iPSCs as a new source of T cells and current differentiation strategies used to generate T cells as well as recent advances in genome engineering to produce next-generation off-the-shelf T cells with improved effector functions. We also discuss challenges in the field and future perspectives toward the final universal off-the-shelf immunotherapeutic products.


2020 ◽  
Vol 8 (2) ◽  
pp. e001439 ◽  
Author(s):  
Rafael Cubas ◽  
Zia Khan ◽  
Qian Gong ◽  
Marina Moskalenko ◽  
Huizhong Xiong ◽  
...  

BackgroundCancer immunotherapy has evolved from interferon-alpha (IFNα) and interleukin-2 in the 1980s to CTLA-4 and PD-1/PD-L1 checkpoint inhibitors (CPIs), the latter highlighting the importance of enhancing T-cell functions. While the search for novel immunomodulatory pathways continues, combination therapies augmenting multiple pathways can also increase efficacy. The association of autoimmune-related adverse events with clinical efficacy following CPI treatment has been inferred and suggests that breaking tolerance thresholds associated with autoimmunity may affect host immune responses for effective cancer immunotherapy.ResultsHere, we show that loss of autoimmune associated PTPN22, a key desensitization node for multiple signaling pathways, including IFNα receptor (IFNAR) and T-cell receptor, can augment tumor responses. Implantation of syngeneic tumors in Ptpn22-/- mice led to expansion and activation of peripheral and intratumoral T cells and, in turn, spontaneous tumor regression as well as enhanced responses in combination with anti-PD-L1 treatment. Using genetically modified mice expressing a catalytically inactive PTPN22 or the autoimmunity-associated human single-nucleotide polymorphism variant, augmentation of antitumor immunity was dependent on PTPN22 phosphatase activity and partially on its adaptor functions. Further, antitumor responses were dependent on both CD4+ and CD8+T cells and, in part, IFNAR function. Finally, we demonstrate that the autoimmune susceptibility Ptpn22(C1858T) variant is associated with lower risk of developing non-melanoma skin cancers, improved overall survival and increased risk for development of hyperthyroidism or hypothyroidism following atezolizumab (anti-PD-L1) treatment.ConclusionsTogether, these data suggest that inhibition of PTPN22 phosphatase activity may provide an effective therapeutic option for cancer immunotherapy and that exploring genetic variants that shift immune tolerance thresholds may serve as a paradigm for finding new cancer immunotherapy targets.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5255-5255
Author(s):  
Heather J. Symons ◽  
M. Yair Levy ◽  
Jie Wang ◽  
Xiaotao Zhou ◽  
Ephraim J. Fuchs

Abstract The “allogeneic effect” refers to the induction of host B cell antibody synthesis or host T cell cytotoxicity, including tumoricidal activity, by an infusion of allogeneic lymphocytes. We have previously shown that treatment of mice with cyclophosphamide (Cy) followed by infusion of CD8+ T cell-depleted allogeneic spleen cells (Cy + CD8− DLI) induces anti-tumor activity in a model of minimal residual leukemia, even though the donor cells are eventually rejected by the host immune system. The purpose of the current investigation was to test the activity of Cy + CD8− DLI in the treatment of well-established cancer, and to characterize the mechanisms of the anti-tumor effect. BALB/c mice were inoculated intravenously (IV) with the syngeneic A20 lymphoma/leukemia or the RENCA renal cell carcinoma on day 0 and were then treated with nothing, Cy alone on day 14, or Cy + CD8− DLI from MHC-mismatched C57BL/6 donors on day 15. In both tumor models, the combination of Cy + CD8− DLI significantly prolonged survival compared to mice treated with nothing or with Cy alone. While depletion of CD4+ T cells from the DLI significantly diminished the beneficial effect of CD8− DLI, purified CD4+ T cells alone were inactive, demonstrating that donor CD4+ T cells and another population of cells were required for optimal anti-tumor activity. Several observations pointed to an active role for the host immune system in the anti-tumor activity of Cy + CD8− DLI. First, host T cells participated in the anti-tumor effect of treatment with Cy alone, since the drug’s activity was diminished in tumor-bearing scid mice or in normal BALB/c mice depleted of T cells. Second, while Cy + CD8− DLI caused no GVHD in tumor-bearing but immunocompetent BALB/c recipients, it caused fatal acute GVHD in either tumor-bearing scid or T-cell depleted BALB/c mice. Finally, the anti-tumor effect of Cy + CD8- DLI was also significantly inhibited in BALB/c mice that were depleted of CD8+ T cells. These results demonstrate that transiently engrafting T cells administered after Cy can induce significant anti-tumor effects against both solid and liquid tumors. We propose that upon recognition of alloantigen on host antigen-presenting cells (APCs), allogeneic donor CD4+ T cells deliver activating ligands to the APCs, thereby generating effective “help” to break tolerance in tumor-specific host CD8+ T cells. This mechanism may correspond to the “allogeneic effect” in the anti-tumor response described over three decades ago.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xiaoyun Li ◽  
Jingling Tang ◽  
Hang Du ◽  
Xinjun Wang ◽  
Liyun Wu ◽  
...  

Purpose. This study is aimed at immunologically characterizing sentinel lymph nodes (SNs) in colorectal cancer (CRC) patients and identifying changes in immunological phenotype and function of SNs isolated from the tumor immunosuppressive microenvironment. Methods. A total of 53 pairs of matched SNs and non-SNs (NSNs) were collected by using a lymph node tracer dye. Flow cytometry was performed to detect the immunophenotype of T cells as well as the expression of activation and inhibitory markers. Differential expression and distribution of characteristic immune cell markers were analyzed by multiplex immunohistochemistry (mIHC). Transcriptomics analysis was conducted to compare the differences in the expression of immune-related genes among lymph nodes. The ex vivo culture of lymph nodes was carried out to examine changes in immunological phenotypes and functions. Results. Compared with NSNs, SNs harbored a significantly higher percentage of regulatory T cells (Tregs) but a lower proportion of MoMDSCs. As indicated in the mIHC assays, Tregs, T follicular helper (Tfh) cells, and M2 macrophages were mainly distributed in cortical areas, germinal centers, and subcapsular sinus areas, respectively, while significantly higher numbers of Tregs and Tfh cells were detected in SNs as compared to NSNs. Moreover, GSEA revealed that T cell activation genes and CD8+ T cell exhaustion-related genes are enriched in SNs and NSNs, respectively. The ex vivo culture led to an increase in the proportion of CD4+ cells, while activating T cells in SNs. In addition, SNs displayed a higher increase in the expression of cytokines IFN-γ, TNF-α, and sFas than NSNs. Conclusion. SNs are shown to be in an immune active state in vivo, while highly expressing inhibitory cytokines and suppressive markers. The ex vivo culture enhanced antitumor immunological function of SN-T cells, providing a starting material for adoptive cell therapy for CRC.


2019 ◽  
Vol 23 (5) ◽  
pp. 537-544 ◽  
Author(s):  
Arunima Sivanand ◽  
Philip Surmanowicz ◽  
Raed Alhusayen ◽  
Peter Hull ◽  
Ivan V Litvinov ◽  
...  

Mycosis fungoides (MF) and Sézary syndrome (SS) are chronic, progressive primary cutaneous T-cell lymphomas (CTCLs) for which there are no curative treatments. Skin-directed therapies, such as phototherapy, radiation therapy, or topical nitrogen mustard, provide only short-term remissions. Numerous attempts with different chemotherapeutic regimes failed to achieve meaningful clinical responses. Immunotherapy seems to be a promising avenue to achieve long-term disease control in CTCL. There is compelling evidence indicating that MF and SS are immunogenic lymphomas, which can be recognized by the patient’s immune system. However, CTCL uses different strategies to impair host’s immunity, eg, via repolarizing the T-cell differentiation from type I to type II, recruiting immunosuppressive regulatory T-cells, and limiting the repertoire of lymphocytes in the circulation. Many currently used therapies, such as interferon-α, imiquimod, extracorporeal phototherapy, and allogeneic bone marrow transplant, seem to exert their therapeutic effect via activation of the antitumor cytotoxic response and reconstitution of the host’s immune system. It is likely that novel immunotherapies such as immune checkpoint inhibitors, cancer vaccines, and chimeric antigen receptor-T cells will help to manage CTCL more efficiently. We also discuss how current genomic techniques, such as estimating the mutational load by whole genome sequencing and neoantigen calling, are likely to provide clinically useful information facilitating personalized immunotherapy of CTCL.


Immuno ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 160-173
Author(s):  
Apolline de Folmont ◽  
Jean-Henri Bourhis ◽  
Salem Chouaib ◽  
Stéphane Terry

Evading the immune system is one of the hallmarks of cancer. Tumors escape anti-tumor immunity through cell-intrinsic means and the assembly of an immunosuppressive tumor microenvironment. By significantly boosting the host immune system, cancer immunotherapies targeting immune checkpoint receptors (CTLA-4 and PD-1) improved survival in patients even with cancers previously considered rapidly fatal. Nevertheless, an important group of patients is refractory or relapse rapidly. The factors involved in the heterogeneous responses observed are still poorly understood. Other immunotherapeutic approaches are being developed that may widen the options, including adoptive cell therapy using CAR-T cells alone or in combination. Despite impressive results in B cell malignancies, many caveats and unanswered questions remain in other cancers, thus limiting the potential of this approach to treat aggressive diseases. In particular, a complex TME could impair the survival, proliferation, and effector functions of CAR-T cells. Recent reports highlight the potential of targeting TGF-β signaling to improve CAR-T cell therapy. TGF-β is a well-known regulatory cytokine with pleiotropic effects in the TME, including immunosuppression. This review summarizes recent work investigating the potential effects of TGF-β within the TME, with a focus on CAR-T behavior and efficacy. We also discuss several key questions to be addressed to accelerate clinical translation of this approach.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A912-A912
Author(s):  
Yongjoon Lee ◽  
Seung Hyuck Jeon ◽  
A Yeong Park ◽  
Suyeon Jo ◽  
Jinhwa Lee ◽  
...  

BackgroundImmune checkpoint inhibitors (ICIs) including anti-CTLA-4, anti-PD-1, and anti-PD-L1 have been clinically used for the treatment of various types of cancer. However, ICIs have a limited efficacy, and it is required to develop a strategy to enhance the efficacy of ICIs. Hematopoietic progenitor kinase 1 (HPK1) was recently known to inhibit T cell receptor (TCR) signaling by targeting SLP76 thus suppress T-cell effector functions.MethodsIn the present study, we examined the expression of HPK-1 and SLP76 in tumor-infiltrating lymphocytes (TILs) obtained from renal cell carcinoma tissues, in relation with the expression of PD-1 and other immune checkpoint receptors by performing flow cytometry analysis. In addition, we examined if inhibition of the kinase activity of HPK1 by CMPD0914, that is a potent, selective and orally available HPK1 inhibitor, enhanced effector functions of tumor-infiltrating CD8+ T cells in the presence of anti-PD-1 blocking antibodies.ResultsFirst, we found that HPK1 and SLP76 are expressed in both CD8+ and CD4+ T cells including Foxp3+ regulatory T cells irrespective of PD-1 expression. Intriguingly, the expression levels of HPK1 and SLP76 were significantly higher in the PD-1bright population compared to the PD-1- or PD-1dim populations. Further characterization revealed that HPK1 and SLP76 were highly expressed in CD8+ T-cell populations expressing TOX, a transcription regulator of T-cell exhaustion, or TCF-1, a transcription factor related to progenitor-like exhausted T cells. In ex vivo functional assays, anti-PD-1 treatment increased the production of IFN-γ and TNF, and the expression of a proliferation marker, Ki-67 among tumor-infiltrating CD8+ T cells. Interestingly, the effects of anti-PD-1 treatment were further enhanced by the combination treatment with CMPD0914.ConclusionsIn summary, we demonstrated that HPK1 and SLP76 are expressed by human tumor-infiltrating T cells, particularly PD-1brightCD8+ T cells, and that anti-PD-1-induced T-cell reinvigoration is significantly enhanced by an HPK1 inhibitor, CMPD0914, rationalizing the combination of anti-PD1/PD-L1 and HPK1 inhibitors for the treatment of cancer.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A299-A299
Author(s):  
Meghan Zuck ◽  
Huyen Dinh ◽  
Valerie Wall ◽  
Sam Lam ◽  
Ramya Chandrasekaran ◽  
...  

BackgroundThe inhibitory receptor leukocyte immunoglobulin-like receptor subfamily B member 2 (LILRB2, ILT4), is expressed on immunosuppressive myeloid cells, and has emerged as a key immune checkpoint in the tumor microenvironment (TME). Interaction of LILRB2 with the HLA class I ligands (e.g., HLA-G, HLA-A, etc.) mediates immune suppression by myeloid cells and promotes tumor immune evasion. Targeting this pathway in the TME may enhance efficacy of T cell checkpoint inhibitors. Antibodies targeting LILRB2 are currently being evaluated in clinical trials for the treatment of cancer.MethodsAnti-LILRB2 antibodies were cloned from B cells derived from rabbits immunized with human LILRB2 recombinant protein. Cells were cultured at clonal density, and IgG antibodies in supernatants were evaluated for binding to human and cynomolgus LILRB2. Variable-regions from positive hits were sequenced, cloned, and expressed as recombinant rabbit-human chimeras. Anti-LILRB2 chimeric antibodies were evaluated in a panel of functional and phenotypic assays using primary human macrophages and T cells, and then prioritized for evaluation in a humanized NSG-SGM3 tumor model.ResultsTwenty-seven rabbit anti-LILRB2 clones were selected and expressed as rabbit-human IgG4 chimeras based on binding to recombinant human LILRB2 protein and blocking of HLA-G binding to LILRB2. A subset of chimeric clones demonstrated binding to stably expressing LILRB2 cells, and lack of binding to other LILRB or LILRA family members by enzyme-linked immunosorbent assay and by flow cytometry of transiently transfected HEK cells. Lead clones were identified based on their ability to block interaction of LILRB2 to HLA-G expressed on tumor cells, and activity in functional cell-based assays modeling LILRB2-mediated immune suppression. These clones enhanced LPS-induced IFN-γ production by PBMCs and increased the release of TNF-α by CD40L-activated macrophages. Selected clones also relieved M2c-macrophage-mediated immune suppression in a M2c/CD8+ T cell coculture assay by restoring T-cell proliferation and secretion of pro-inflammatory cytokines. Importantly, lead chimeric LILRB2 clones demonstrated in vivo efficacy with significant tumor growth inhibition and tumor regression in an SK-MEL-5 tumor model in humanized NSG-SGM3 mice.ConclusionsWe identified novel anti-LILRB2 antibodies that restore innate and adaptive immune responses by modulating immunosuppressive macrophages. These data provide a strong rationale for further development of these antibodies as an anti-cancer immunotherapy.


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