Cell-based Cancer Immunotherapy Research Articles

Targeting CD276 for T cell-based immunotherapy of breast cancer.

Breast cancer (BC) is the most common malignancy in women. Immunotherapy has revolutionized treatment options in many malignancies, and the introduction of immune checkpoint inhibition yielded beneficial results also in BC. However, many BC patients are ineligible for this T cell-based therapy, others do not respond or only briefly. Thus, there remains a high medical need for new therapies, particularly for triple-negative BC. CD276 (B7-H3) is overexpressed in several tumors on both tumor cells and tumor vessels, constituting a promising target for immunotherapy. We analyzed tumor samples of 25 patients using immunohistochemistry to assess CD276 levels. The potential of CC-3, a novel bispecific CD276xCD3 antibody, for BC treatment was evaluated using various functional in vitro assays. Pronounced expression of CD276 was observed in all analyzed tumor samples including triple negative BC. In analyses with BC cells, CC-3 induced profound T cell activation, proliferation, and T cell memory subset formation. Moreover, treatment with CC-3 induced cytokine secretion and potent tumor cell lysis. Our findings characterize CD276 as promising target and preclinically document the therapeutic potential of CC-3 for BC treatment, providing a strong rationale for evaluation of CC-3 in BC patients in a clinical trial for which the recruitment has recently started.

Preparation and Formulation of a New Therapeutic Supplement by the Combination of Dendritic Cells and IPI-549 (Eganelisib) for the Treatment of Breast Cancer in BALB/c Mice

: Dendritic cell-based cancer immunotherapy is considered an innovative and promising approach aimed at enhancing the host's immune response to combat tumors. Additionally, IPI-549 has been identified as a first-line therapeutic option for breast cancer treatment. The objective of this research was to develop and formulate a novel therapeutic supplement by combining dendritic cells with IPI-549 (Eganelisib) for breast cancer treatment. The concurrent administration of dendritic cells and IPI-549 (DC-IPI) was utilized to treat mice and elicit immunological responses triggered by vaccination. Tumor regression and overall survival rates were evaluated across five distinct experimental groups. The administration of tumor cell lysate alongside DC-IPI resulted in a significant reduction in tumor growth and a two- to three-fold increase in the survival duration of treated mice. DC-IPI, whether decorated with mannan or not, elicited stronger responses in terms of delayed-type hypersensitivity, lymphocyte proliferation, and CD107a expression. Moreover, our findings demonstrated a reduction in IL-4 production in the supernatants of splenocyte cultures. A significant reduction in BRCA1 mRNA levels was also observed following treatment with DC-IPI. In conclusion, our results suggest that the DC-IPI antigen delivery system exhibited substantial anti-tumor efficacy in a breast cancer mouse model, representing a potential advancement in immunotherapy for human breast cancer.

The E3 Ubiquitin Ligase FBXO38 Maintains the Antitumor Function of Natural Killer Cells by Sustaining IL15R Signaling.

Natural killer (NK) cells are the main innate antitumor effector cells but their function is often constrained in the tumor microenvironment. It has been reported that the E3 ligase FBXO38 accelerates PD-1 degradation in tumor-infiltrating T cells to unleash their cytotoxic function. In this study, we found that the transcriptional levels of FBXO38 in intratumoral NK cells of patients with cancer and tumor-bearing mice were significantly lower than in peritumoral NK cells. Conditional knockout of FBXO38 in NK cells accelerated tumor growth and increased tumor metastasis. FBXO38 deficiency resulted in impaired proliferation and survival of tumor-infiltrating NK (TINK) cells. Mechanistically, FBXO38 deficiency enhanced TGF-β signaling, including elevating expression of Smad2 and Smad3, which suppressed expression of the transcription factor Eomes and further reduced expression of surface IL15Rβ and IL15Rγc on NK cells. Consequently, FBXO38 deficiency led to TINK cell hyporesponsiveness to IL15. Consistent with these observations, FBXO38 mRNA expression was positively correlated with the proliferation of TINK cells in multiple human tumors. To study the therapeutic potential of FBXO38, mice bearing human tumors were treated with FBXO38 overexpressed human primary NK cells and showed a significant reduction in tumor size and prolonged survival. In conclusion, our results suggest that FBXO38 sustains NK-cell expansion and survival to promote antitumor immunity and have potential therapeutic implications as they suggest FBXO38 could be harnessed to enhance NK cell-based cancer immunotherapy.

BTN3A1 expressed in cervical cancer cells promotes Vγ9Vδ2 T cells exhaustion through upregulating transcription factors NR4A2/3 downstream of TCR signaling

BackgroundClinical trials have shown that immunotherapy based on Vγ9Vδ2 T cells (Vδ2 T cells) is safe and well-tolerated for various cancers including cervical cancer (CC), but its overall treatment efficacy remains limited. Therefore, exploring the mechanisms underlying the suboptimal efficacy of Vδ2 T cell-based cancer immunotherapy is crucial for enabling its successful clinical translation.MethodsTumor samples from CC patients and CC cell line-derived xenograft (CDX) mice were analyzed using flow cytometry to examine the exhausted phenotype of tumor-infiltrating Vδ2 T cells. The interrelationship between BTN3A1 expression and Vδ2 T cells in CC, along with their correlation with patient prognosis, was analyzed using data from The Cancer Genome Atlas (TCGA) database. CC cell lines with BTN3A1 knockout (KO) and overexpression (OE) were constructed through lentivirus transduction, which were then co-cultured with expanded Vδ2 T cells, followed by detecting the function of Vδ2 T cells using flow cytometry. The pathways and transcription factors (TFs) related to BTN3A1-induced Vδ2 T cells exhaustion and the factors affecting BTN3A1 expression were identified by RNA-seq analysis, which was confirmed by flow cytometry, Western Blot, and gene manipulation.ResultsTumor-infiltrating Vδ2 T cells exhibited an exhausted phenotype in both CC patients and CDX mice. BTN3A1 expressed in CC is highly enhancing exhaustion markers, while reducing the secretion of effector molecules in Vδ2 T cells. Blocking TCR or knocking down nuclear receptor subfamily 4 group A (NR4A) 2/3 can reverse BTN3A1-induced exhaustion in Vδ2 T cells. On the other hand, IFN-γ secreted by Vδ2 T cells promoted the expression of BTN3A1 and PD-L1.ConclusionsThrough binding γδ TCRs, BTN3A1 expressed on tumor cells, which is induced by IFN-γ, can promote Vδ2 T cells to upregulate the expression of TFs NR4A2/3, thereby affecting their activation and expression of exhaustion-related molecules in the tumor microenvironment (TME). Therefore, targeting BTN3A1 might overcome the immunosuppressive effect of the TME on Vδ2 T cells in CC.

Oral administration of garlic-derived nanoparticles improves cancer immunotherapy by inducing intestinal IFNγ-producing γδ T cells.

Gamma-delta (γδ) T cell-based cancer immunotherapies represent a promising avenue for cancer treatment. However, their development is challenged by the limited expansion and differentiation of the cells ex vivo. Here we induced the endogenous expansion and activation of γδ T cells through oral administration of garlic-derived nanoparticles (GNPs). We found that GNPs could significantly promote the proliferation and activation of endogenous γδ T cells in the intestine, leading to generation of large amount of interferon-γ (IFNγ). Moreover GNP-treated mice showed increased levels of chemokine CXCR3 in intestinal γδ T cells, which can drive their migration from the gut to the tumour environment. The translocation of γδ T cells and IFNγ from the intestine to extraintestinal subcutaneous tumours remodels the tumour immune microenvironment and synergizes with anti-PD-L1, inducing robust antitumour immunity. Our study delineates mechanistic insight into the complex gut-tumour interactome and provides an alternative approach for γδ T cell-based immunotherapy.

Activation of dendritic cells by a synthesized small molecule for breast cancer vaccination.

e13149 Background: Dendritic cell-based vaccination is a promising immunotherapy for treating various types of cancer. However, tumor-loaded dendritic cells alone have limited treatment efficacy. We have designed a small molecule mimicking the action of damage-associated molecular pattern molecules as an adjuvant for activating dendritic cells in vitro, which demonstrated augmented treatment efficacy. Methods: We aimed at exploring the roles of the synthesized small molecule in augmenting the efficacy of dendritic cell-based cancer vaccination to target triple negative breast cancer. Breast cancer mouse model is constructed using a 4T1 tumor cell line. Data were analyzed using a two-tailed unpaired t-test. Results: Mouse dendritic cells could be activated in vitro by the small molecule as an adjuvant evidenced by increased expression of MHC-I, MHC-II and CD40. Augmented motility of dendritic cells was also observed after treatment with the adjuvant. The signaling of NFkB is remarkably activated in dendritic cells by the adjuvant, which facilitates the maturation of dendritic cells. Engraftment of adjuvant-primed dendritic cells loaded with 4T1 tumor antigen into 4T1 tumor-bearing mice efficiently reduced the tumor size and improved survival, compared with the group treated with dendritic cells only. After injection of adjuvant-activated dendritic cells, both CD4 T cell and CD8 T cell populations were expanded in the spleen and lymph nodes draining the tumor sites. Furthermore, the adjuvant could promote the production of IFN-γ and IL-2, cytokines required for T cell activation and expansion. Next, splenocytes were obtained from individual mice after dendritic cell-based treatment. Upon re-encounter with the tumor antigen in vitro, remarkable expansion of T cell populations with a memory cell feature was confirmed in splenocytes derived from mice that received adjuvant-treated dendritic cells. Consistently, production of TNF-α, IFN-γ and granzyme B, was profoundly increased in these T cells associated with the adjuvant treatment. Conclusions: Our work suggests a novel dendritic cell-based cancer immunotherapy by using a small molecule mimicking the action of damage-associated molecular pattern molecules, which have documented immune potentiation activities.

Payload-delivering engineered γδ T cells display enhanced cytotoxicity, persistence, and efficacy in preclinical models of osteosarcoma.

T cell-based cancer immunotherapy has typically relied on membrane-bound cytotoxicity enhancers such as chimeric antigen receptors expressed in autologous αβ T cells. These approaches are limited by tonic signaling of synthetic constructs and costs associated with manufacturing. γδ T cells are an emerging alternative for cellular therapy, having innate antitumor activity, potent antibody-dependent cellular cytotoxicity, and minimal alloreactivity. We present an immunotherapeutic platform technology built around the innate properties of the Vγ9Vδ2 T cell, harnessing specific characteristics of this cell type and offering an allocompatible cellular therapy that recruits bystander immunity. We engineered γδ T cells to secrete synthetic tumor-targeting opsonins in the form of an scFv-Fc fusion protein and a mitogenic IL-15Rα-IL-15 fusion protein (stIL15). Using GD2 as a model antigen, we show that GD2-specific opsonin-secreting Vγ9Vδ2 T cells (stIL15-OPS-γδ T cells) have enhanced cytotoxicity and promote bystander activity of other lymphoid and myeloid cells. Secretion of stIL-15 abrogated the need for exogenous cytokine supplementation and further mediated activation of bystander natural killer cells. Compared with unmodified γδ T cells, stIL15-OPS-γδ T cells exhibited superior in vivo control of subcutaneous tumors and persistence in the blood. Moreover, stIL15-OPS-γδ T cells were efficacious against patient-derived osteosarcomas in animal models and in vitro, where efficacy could be boosted with the addition of zoledronic acid. Together, the data identify stIL15-OPS-γδ T cells as a candidate allogeneic cell therapy platform combining direct cytolysis with bystander activation to promote tumor control.

Venetoclax acts as an immunometabolic modulator to potentiate adoptive NK cell immunotherapy against leukemia

Natural killer (NK) cell-based immunotherapy holds promise for cancer treatment; however, its efficacy remains limited, necessitating the development of alternative strategies. Here, we report that venetoclax, an FDA-approved BCL-2 inhibitor, directly activates NK cells, enhancing their cytotoxicity against acute myeloid leukemia (AML) both invitro and invivo, likely independent of BCL-2 inhibition. Through comprehensive approaches, including bulk and single-cell RNA sequencing, avidity measurement, and functional assays, we demonstrate that venetoclax increases the avidity of NK cells to AML cells and promotes lytic granule polarization during immunological synapse (IS) formation. Notably, we identify a distinct CD161lowCD218b+ NK cellsubpopulation that exhibits remarkable sensitivity to venetoclax treatment. Furthermore, venetoclax promotes mitochondrial respiration and ATP synthesis via the NF-κB pathway, thereby facilitating IS formation in NK cells. Collectively, our findings establish venetoclax as a multifaceted immunometabolic modulator of NK cell function and provide a promising strategy for augmenting NK cell-based cancer immunotherapy.

Targeting TGFβ-activated kinase-1 activation in microglia reduces CAR T immune effector cell-associated neurotoxicity syndrome.

Cancer immunotherapy with chimeric antigen receptor (CAR) T cells can cause immune effector cell-associated neurotoxicity syndrome (ICANS). However, the molecular mechanisms leading to ICANS are not well understood. Here we examined the role of microglia using mouse models and cohorts of individuals with ICANS. CD19-directed CAR (CAR19) T cell transfer in B cell lymphoma-bearing mice caused microglia activation and neurocognitive deficits. The TGFβ-activated kinase-1 (TAK1)-NF-κB-p38 MAPK pathway was activated in microglia after CAR19 T cell transfer. Pharmacological TAK1 inhibition or genetic Tak1 deletion in microglia using Cx3cr1CreER:Tak1fl/fl mice resulted in reduced microglia activation and improved neurocognitive activity. TAK1 inhibition allowed for potent CAR19-induced antilymphoma effects. Individuals with ICANS exhibited microglia activation in vivo when studied by translocator protein positron emission tomography, and imaging mass cytometry revealed a shift from resting to activated microglia. In summary, we prove a role for microglia in ICANS pathophysiology, identify the TAK1-NF-κB-p38 MAPK axis as a pathogenic signaling pathway and provide a rationale to test TAK1 inhibition in a clinical trial for ICANS prevention after CAR19 T cell-based cancer immunotherapy.

Empowering γδ T-cell functionality with vitamin C.

Vitamin C (ascorbic acid) is a potent antioxidant and a cofactor for various enzymes including histone demethylases and methylcytosine dioxygenases. Vitamin C also exerts direct cytotoxicity toward selected tumor cells including colorectal carcinoma. Moreover, vitamin C has been shown to impact immune cell differentiation at various levels including maturation and/or functionality of T cells and their progenitors, dendritic cells, B cells, and NK cells. γδ T cells have recently attracted great interest as effector cells for cell-based cancer immunotherapy, due to their HLA-independent recognition of a large variety of tumor cells. While γδ T cells can thus be also applied as an allogeneic off-the-shelf product, it is obvious that the effector function of γδ T cells needs to be optimized to ensure the best possible clinical efficacy. Here we review the immunomodulatory mechanisms of vitamin C with a special focus on how vitamin C enhances the effector function of γδ T cells. We also discuss future directions of how vitamin C can be used in the clinical setting to boost the efficacy of adoptive cell therapies.

Abstract LB363: A novel humanized NKP46 mouse model to support xenograft studies evaluating NK cell-based cancer immunotherapies

Abstract The NKP46 receptor is expressed by all NK cells, and plays a key role in the recognition and activation of NK cells against tumor cells. Cross-linking of NKp46 by monoclonal antibodies triggers both NK cell cytotoxic activity and cytokine release. As the only NCR present in mice, NKP46 is well conserved, but differences between the murine and human NKP46 protein necessitate use of humanized mice for evaluating preclinical efficacy of novel NKP46-targeting antibodies. Previously, we established humanized NKP46 mice on immunocompetent backgrounds for evaluating antibody efficacy in preventing growth of syngeneic tumor models. However, xenograft models in immunodeficient mice have also been widely employed as important in vivo models. Here, we describe a novel humanized NKP46 mouse on the CB-17-SCID background in order to inoculate human tumor cells for therapeutic efficacy testing. In this model, using gene editing technology, the portion of the mouse NKp46 gene encoding the extracellular domain was replaced by the corresponding human NKP46 coding sequences. Human NKP46 protein expression was confirmed on NK cells derived from splenocytes and bone marrow of B-hNKP46 mice(CB17-SCID) by flow cytometry. Subsequently, assessment of leukocyte populations in the humanized model indicated no significant alterations in the percentages of NK cells, dendritic cells, granulocytes, monocytes and macrophages in the spleen, bone marrow or blood of the humanized mice compared with wild-type CB17-SCID mice. Finally, tumor efficacy studies demonstrate that treatment with an anti-human NKP46 antibody significantly reduced BxPC-3 tumor growth at a range of doses in homozygous hNKP46 mice compared to PBS-injected controls. In summary, humanized B-hBKP46 mice(CB17-SCID) provide a suitable model for evaluating the efficacy of anti-human NKP46 antibody candidates. Citation Format: Zhenlan Niu, Yongshun Li, Xiaofei Zhou, Jiawei Yao, Qingcong Lin, Meiqi Zhang, Qingqing Xu. A novel humanized NKP46 mouse model to support xenograft studies evaluating NK cell-based cancer immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB363.

Abstract 15: Massively parallel base-editing screens to map variant effects on anti-tumor hallmarks of primary human T cells and improve cell-based cancer immunotherapies

Abstract Base editing enables precise generation of single nucleotide variants, but large-scale screening in primary human T cells has been limited by low editing efficiency. Here, we developed a high-throughput approach for highly efficient, massively parallel adenine and cytosine base-editor screening in primary human T cells. We performed multiple large-scale pooled screens editing 108 genes with central functions in T cells and whole-gene tiling mutagenesis of selected genes. All screens were functionally read out to capture the effect of variants on hallmarks of T cell anti-tumor immunity, including activation, proliferation, long-term persistence, and cytokine production. We discovered a broad landscape of gain-of-function and loss-of-function mutations and characterized their impact across multiple axes of T cell functions. Among others, we identified gain-of-function mutations in PIK3CD and its regulatory subunit PIK3R1, LCK, AKT1, and loss-of-function mutants of CTLA-4, driving increased T cell polyfunctionality. We validated several of these mutations by probing downstream signaling and functional outputs. To demonstrate the feasibility of using such screen results for improving cell-based cancer immunotherapies, we used human T cells with engineered T cell receptors recognizing specific epitopes in melanoma models. We base-edited these T cells with mutations identified in our screens and demonstrate that these mutations indeed significantly enhance cytotoxic cytokine production and tumor-lytic capacity with minimal off-target activity. Lastly, we also provide proof-of-feasibility for high-efficiency combinatorial base-editing in T cells. This study presents a framework for large-scale base editing screens with multi-dimensional functional readouts in cells that are typically difficult to molecularly engineer in a precise manner. This work also has important therapeutic implications: T cells are the substrate for clinically active cell-based therapies, such as adoptive transfer of tumor-infiltrating lymphocytes (TILs) or chimeric-receptor antigen T (CAR-T) cells. Our screen-informed base editing to achieve an improved T cell product against melanoma exemplifies the therapeutic power of generating synthetic protein variants that improve a wide range of existing and future T cell-based cancer immunotherapies. Citation Format: Zachary Hudson Walsh, Parin Shah, Neeha Kothapalli, Gergo Nikolenyi, Shivem Shah, Giuseppe Leuzzi, Neil Vasan, Mohammed AlQuarishi, Alberto Ciccia, Johannes Melms, Benjamin Izar. Massively parallel base-editing screens to map variant effects on anti-tumor hallmarks of primary human T cells and improve cell-based cancer immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 15.

Abstract 3976: Single-cell TCRɑ/β and TCRγ/δ immune receptor profiling and immunophenotyping using a 96-well plate sorted-cell approach

Abstract Single-cell immune receptor profiling is a revolutionary approach that allows investigators to combine clonotype repertoire identification with paired-chain information and the phenotype of cells (e.g., cell subtype). Single-cell immune receptor profiling can be performed using a medium-throughput approach (1,000-5,000 cells) using microwell arrays or droplet microfluidics technologies. However, these assays are more complicated to run and require expensive reagents and limited sequencing throughput when compared to bulk immune receptor profiling methods. Here, we describe a low-throughput, single-cell immune profiling strategy using sorted cells in 96-well plates. The plate is pre-aliquoted with either T-cell receptor (TCR) ɑ/β or TCR γ/δ primers along with 30 crucial T-cell markers. We perform multiplex RT-PCR amplification and sequencing of the CDR3 regions. The resulting data provides the abundant clonotype counts along with the chain pairing information for these ɑ/β and γ/δ chains, together with the T-cell subtype information using gene-expression profiles. By analyzing the TCR gene rearrangement at the single-cell level, researchers can better understand T cell development, proliferation, and clonality, which are crucial for studying diseases such as cancer, immunodeficiency, and autoimmunity. Furthermore, single-cell TCR sequencing when combined with RNA sequencing datasets, facilitates the identification of γδ T cells. This method provides a standardized tool for identifying potential γδ T cell-based cancer immunotherapies. The technology's cost-effectiveness and ability to analyze clonotypes and immunophenotypes of cells in a single assay make it a valuable tool for unraveling the immune dynamics in various diseases. Citation Format: Alex Chenchik, Tianbing Liu, Mikhail Makhanov, Dongfang Hu, Lester Kobzik, Khadija Ghias, Paul Diehl. Single-cell TCRɑ/β and TCRγ/δ immune receptor profiling and immunophenotyping using a 96-well plate sorted-cell approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3976.

Abstract 5519: Enlarged metastasis-free tumor-draining lymph node is a marker of tumor invasion in local tissues with an active NK cell-mediated immunity

Abstract Background: Colorectal cancer (CRC) is the third most common cancer worldwide, accounting for about 10% of all new cancer cases. The tumor-draining lymph node (TDLN) is a key site for the development of anti-tumor immunity that has been reported to be involved in both CD8+ T and NK cells. As a major role of innate immunity, NK cells can produce IFN-γ, perforin and granzyme to eliminate tumor cells in the early stages of cancer development. This study aimed to investigate the difference of clinicopathological and immunological profiles in local tissues between CRC patients with enlarged and non-enlarged metastasis-free TDLNs. Methods: The patient cohort was obtained from the NEPDC cohort (No. 2015CB554000). A total of 45 patients with pathologically confirmed stage I-II colorectal cancer were included in this study. Based on the MRI, these patients were divided into enlarged and non-enlarged TDLN groups (lymph nodes >/= 5mm and lymph nodes < 5mm). We collected the tumor tissue and tumor-adjacent normal tissue that was 2 cm away from the tumor lesion. The genomic DNA of the tumor and tumor-adjacent normal tissues was treated with bisulfite and analyzed with the EPIC methylation array. The MeTMEC algorithm based on the methylation profile estimated subsequent cell abundance in these patient tissues. Results: The study sample was comprised of 22 enlarged TDLN and 23 non-enlarged TDLN patients. There were 4 T1-T2 and 18 T3-T4 patients in the enlarged TDLN group, with 12 T1-T2 and 11 T3-T4 patients in the non-enlarged TDLN group. The proportion of T3-T4 patients in the enlarged TDLN group was higher than that in the non-enlarged TDLN group (p=0.017, Chi-squared test), suggesting an advanced invasion in the local tissue of patients with enlarged TDLN. Then, the abundance of monocytes, dendritic cells, macrophages, neutrophils, eosinophils, Treg cells, naive T cells, memory T cells, CD8+ T cells, NK cells, and B cells in the tumor and tumor-adjacent normal tissues were inferred with the MeTMEC algorithm by using DNA methylation profile. In the T1-T2 subset, we found that the infiltration of NK cells in the tumor-adjacent normal tissues was significantly more abundant in the enlarged TDLN group compared with the non-enlarged TDLN group (p=0.021, t-test), suggesting an active immune response of NK cells for potential local tumor control. No significant difference in other immune cells was observed between the two groups. Conclusion: Enlarged TDLN indicates an advanced invasion of tumors in local tissues with an active NK cell-mediated immunity. Our findings suggest that enlarged metastasis-free TDLN might be a promising marker for NK cell-based cancer immunotherapy. Key words: Colorectal Cancer, Lymph Nodes, Natural Killer Cells Citation Format: Zixiao Wan, Huichuan Yu. Enlarged metastasis-free tumor-draining lymph node is a marker of tumor invasion in local tissues with an active NK cell-mediated immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5519.

Mucosal-associated invariant T cells in cancer: dual roles, complex interactions and therapeutic potential.

Mucosal-associated invariant T (MAIT) cells play diverse roles in cancer, infectious diseases, and immunotherapy. This review explores their intricate involvement in cancer, from early detection to their dual functions in promoting inflammation and mediating anti-tumor responses. Within the solid tumor microenvironment (TME), MAIT cells can acquire an 'exhausted' state and secrete tumor-promoting cytokines. On the other hand, MAIT cells are highly cytotoxic, and there is evidence that they may have an anti-tumor immune response. The frequency of MAIT cells and their subsets has also been shown to have prognostic value in several cancer types. Recent innovative approaches, such as programming MAIT cells with chimeric antigen receptors (CARs), provide a novel and exciting approach to utilizing these cells in cell-based cancer immunotherapy. Because MAIT cells have a restricted T cell receptor (TCR) and recognize a common antigen, this also mitigates potential graft-versus-host disease (GVHD) and opens the possibility of using allogeneic MAIT cells as off-the-shelf cell therapies in cancer. Additionally, we outline the interactions of MAIT cells with the microbiome and their critical role in infectious diseases and how this may impact the tumor responses of these cells. Understanding these complex roles can lead to novel therapeutic strategies harnessing the targeting capabilities of MAIT cells.

Euphohelioscopin A enhances NK cell antitumor immunity through GSDME-triggered pyroptosis.

Immune evasion by cancer cells poses a significant challenge for natural killer cell-based immunotherapy. Pyroptosis, a newly discovered form of programmed cell death, has shown great potential for enhancing the antitumor immunity of natural killer cells. Consequently, targeting pyroptosis has become an attractive strategy for boosting natural killer cell activity against cancer. In this study, various assays were conducted, including natural killer cell cytotoxicity assays, flow cytometry, xenograft tumor models, real-time polymerase chain reaction, and enzyme-linked immunosorbent assay, to assess natural killer cell-mediated cell killing, as well as gene and protein expressions. The results indicated that euphohelioscopin A, a potential pyroptosis activator, enhances natural killer cell-mediated lysis of tumor cells, resulting in inhibiting tumor growth that could be reversed by natural killer cell depletion. Furthermore, we found that euphohelioscopin A significantly enhanced IFNγ production in natural killer cells and synergistically upregulated GSDME with IFNγ in cancer cells. Euphohelioscopin A also increased the cleavage of GSDME, promoting granzyme B-induced pyroptosis, which could be reversed by GSDME knockdown and IFNγ blockade. Overall, the findings suggested that euphohelioscopin A enhanced natural killer cell-mediated killing of cancer cells by triggering pyroptosis, making euphohelioscopin A a promising pyroptosis activator with great potential for use in natural killer cell-based cancer immunotherapy.

A novel type-2 innate lymphoid cell-based immunotherapy for cancer.

Cell-based cancer immunotherapy has achieved significant advancements, providing a source of hope for cancer patients. Notwithstanding the considerable progress in cell-based immunotherapy, the persistently low response rates and the exorbitant costs associated with their implementation still present a formidable challenge in clinical settings. In the landscape of cell-based cancer immunotherapies, an uncharted territory involves Type 2 innate lymphoid cells (ILC2s) and interleukin-33 (IL-33) which promotes ILC2 functionality, recognized for their inherent ability to enhance immune responses. Recent discoveries regarding their role in actuating cytolytic T lymphocyte responses, including curbing tumor growth rates and hindering metastasis, have added a new dimension to our understanding of the IL-33/ILC2 axis. These recent insights may hold significant promise for ILC2 cell-based immunotherapy. Nevertheless, the prospect of adoptively transferring ILC2s to confer immune protection against tumors has yet to be investigated. The present study addresses this hypothesis, revealing that ILC2s isolated from the lungs of tumor-bearing mice, and tumor infiltrating ILC2s when adoptively transferred after tumor establishment at a ratio of one ILC2 per sixty tumor cells, leads to an influx of tumor infiltrating CD4+ and CD8+ T lymphocytes as well as tumor infiltrating eosinophils resulting in a remarkable reduction in tumor growth. Moreover, we find that post-adoptive transfer of ILC2s, the number of tumor infiltrating ILC2s is inversely proportional to tumor size. Finally, we find corollaries of the IL-33/ILC2 axis enhancing the infiltration of eosinophils in human prostate carcinomas patients' expressing high levels of IL-33 versus those expressing low levels of IL-33. Our results underscore the heightened efficacy of adoptively transferred ILC2s compared to alternative approaches, revealing an approximately one hundred fifty-fold superiority on a cell-per-cell basis over CAR T-cells in the specific targeting and elimination of tumors within the same experimental model. Overall, this study demonstrates the functional significance of ILC2s in cancer immunosurveillance and provides the proof of concept of the potential utility of ILC2 cell-based cancer immunotherapies.

The FLRT3-UNC5B checkpoint pathway inhibits T cell-based cancer immunotherapies.

Cancers exploit coinhibitory receptors on T cells to escape tumor immunity, and targeting such mechanisms has shown remarkable clinical benefit, but in a limited subset of patients. We hypothesized that cancer cells mimic noncanonical mechanisms of early development such as axon guidance pathways to evade T cell immunity. Using gain-of-function genetic screens, we profiled axon guidance proteins on human T cells and their cognate ligands and identified fibronectin leucine-rich transmembrane protein 3 (FLRT3) as a ligand that inhibits T cell activity. We demonstrated that FLRT3 inhibits T cells through UNC5B, an axon guidance receptor that is up-regulated on activated human T cells. FLRT3 expressed in human cancers favored tumor growth and inhibited CAR-T and BiTE + T cell killing and infiltration in humanized cancer models. An FLRT3 monoclonal antibody that blocked FLRT3-UNC5B interactions reversed these effects in an immune-dependent manner. This study supports the concept that axon guidance proteins mimic T cell checkpoints and can be targeted for cancer immunotherapy.

Exploring the role of CRISPR in cell-based cancer immunotherapy

Cancer immunotherapy, particularly CAR-T cells, has transformed the landscape of cancer treatment, offering a paradigm shift in prognosis. To enhance the efficacy of cancer treatment, recent scientific endeavors have concentrated on harnessing the potential of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) technology where they use this technology to cancer treatments and cancer immunotherapy including the engineered CAR-T cell. There have been a lot of advances including correcting genetic mutation, curing genetic disorders, etc. this review paper will cover cancer immunotherapy, CAR-T cell therapy and it;s mechanism, successful clinical trials, ongoing clinical trials, the current limitations as well as the future advantages of this technology.

Targeting Protein Tyrosine Phosphatases to Improve Cancer Immunotherapies.

Advances in immunotherapy have brought significant therapeutic benefits to many cancer patients. Nonetheless, many cancer types are refractory to current immunotherapeutic approaches, meaning that further targets are required to increase the number of patients who benefit from these technologies. Protein tyrosine phosphatases (PTPs) have long been recognised to play a vital role in the regulation of cancer cell biology and the immune response. In this review, we summarize the evidence for both the pro-tumorigenic and tumour-suppressor function of non-receptor PTPs in cancer cells and discuss recent data showing that several of these enzymes act as intracellular immune checkpoints that suppress effective tumour immunity. We highlight new data showing that the deletion of inhibitory PTPs is a rational approach to improve the outcomes of adoptive T cell-based cancer immunotherapies and describe recent progress in the development of PTP inhibitors as anti-cancer drugs.