Beyond CAR T cells: Engineered Vγ9Vδ2 T cells to fight solid tumors

Efficient multiplex non-viral engineering and expansion of polyclonal γδ CAR-T cells for immunotherapy

Gamma delta (γδ) T cells are defined by their unique ability to recognize a limited repertoire of non-peptide, non-MHC-associated antigens on transformed and pathogen-infected cells. In addition to their lack of alloreactivity, γδ T cells exhibit properties distinct from other lymphocyte subsets, prompting significant interest in their development as an off-the-shelf cellular immunotherapeutic. However, their low abundance in circulation, heterogeneity, limited methods for ex vivo expansion, and under-developed methodologies for genetic modification have hindered basic study and clinical application of γδ T cells. Here, we implement a feeder-free, scalable approach for ex vivo manufacture of polyclonal, non-virally modified, gene edited chimeric antigen receptor (CAR)-γδ T cells in support of therapeutic application. Engineered CAR-γδ T cells demonstrate high function in vitro and and in vivo. Longitudinal in vivo pharmacokinetic profiling of adoptively transferred polyclonal CAR-γδ T cells uncover subset-specific responses to IL-15 cytokine armoring and multiplex base editing. Our results present a robust platform for genetic modification of polyclonal CAR-γδ T cells and present unique opportunities to further define synergy and the contribution of discrete, engineered CAR-γδ T cell subsets to therapeutic efficacy in vivo.

Amplifying "eat me signal" by immunogenic cell death for potentiating cancer immunotherapy

Immunogenic cell death (ICD) is a unique mode of cell death, which can release immunogenic damage-associated molecular patterns (DAMPs) and tumor-associated antigens to trigger long-term protective antitumor immune responses. Thus, amplifying "eat me signal" during tumor ICD cascade is critical for cancer immunotherapy. Some therapies (radiotherapy, photodynamic therapy (PDT), photothermal therapy (PTT), etc.) and inducers (chemotherapeutic agents, etc.) have enabled to initiate and/or facilitate ICD and activate antitumor immune responses. Recently, nanostructure-based drug delivery systems have been synthesized for inducing ICD through combining treatment of chemotherapeutic agents, photosensitizers for PDT, photothermal transformation agents for PTT, radiosensitizers for radiotherapy, etc., which can release loaded agents at an appropriate dosage in the designated place at the appropriate time, contributing to higher efficiency and lower toxicity. Also, immunotherapeutic agents in combination with nanostructure-based drug delivery systems can produce synergetic antitumor effects, thus potentiating immunotherapy. Overall, our review outlines the emerging ICD inducers, and nanostructure drug delivery systems loading diverse agents to evoke ICD through chemoradiotherapy, PDT, and PTT or combining immunotherapeutic agents. Moreover, we discuss the prospects and challenges of harnessing ICD induction-based immunotherapy, and highlight the significance of multidisciplinary and interprofessional collaboration to promote the optimal translation of this treatment strategy.

Unlocking the potential of allogeneic Vδ2 T cells for ovarian cancer therapy through CD16 biomarker selection and CAR/IL-15 engineering

Allogeneic Vγ9Vδ2 (Vδ2) T cells have emerged as attractive candidates for developing cancer therapy due to their established safety in allogeneic contexts and inherent tumor-fighting capabilities. Nonetheless, the limited clinical success of Vδ2 T cell-based treatments may be attributed to donor variability, short-lived persistence, and tumor immune evasion. To address these constraints, we engineer Vδ2 T cells with enhanced attributes. By employing CD16 as a donor selection biomarker, we harness Vδ2 T cells characterized by heightened cytotoxicity and potent antibody-dependent cell-mediated cytotoxicity (ADCC) functionality. RNA sequencing analysis supports the augmented effector potential of Vδ2 T cells derived from CD16 high (CD16Hi) donors. Substantial enhancements are further achieved through CAR and IL-15 engineering methodologies. Preclinical investigations in two ovarian cancer models substantiate the effectiveness and safety of engineered CD16Hi Vδ2 T cells. These cells target tumors through multiple mechanisms, exhibit sustained in vivo persistence, and do not elicit graft-versus-host disease. These findings underscore the promise of engineered CD16Hi Vδ2 T cells as a viable therapeutic option for cancer treatment.

Local Ablative Therapy Associated with Immunotherapy in Locally Advanced Pancreatic Cancer: A Solution to Overcome the Double Trouble?-A Comprehensive Review

Pancreatic ductal adenocarcinoma (PDAC) remains a major killer and is a challenging clinical research issue with abysmal survival due to unsatisfactory therapeutic efficacy. Two major issues thwart the treatment of locally advanced nonresectable pancreatic cancer (LAPC): high micrometastasis rate and surgical inaccessibility. Local ablative therapies induce a systemic antitumor response (i.e., abscopal effect) in addition to local effects. Thus, the incorporation of additional therapies could be key to improving immunotherapy's clinical efficacy. In this systematic review, we explore recent applications of local ablative therapies combined with immunotherapy to overcome immune resistance in PDAC and discuss future perspectives and challenges. Particularly, we describe four chemoradiation studies and nine reports on irreversible electroporation (IRE). Clinically, IRE is the ablative therapy of choice, utilized in all but two clinical trials, and may create a favorable microenvironment for immunotherapy. Various immunotherapies have been used in combination with IRE, such as NK cell- or γδ T cell-based therapy, as well as immune checkpoint inhibitors. The results of the clinical trials presented in this review and the advancement potential of these therapies to phase II/III trials remain unknown. A multiple treatment approach involving chemotherapy, local ablation, and immunotherapy holds promise in overcoming the double trouble of LAPC.

A CD123-specific chimeric antigen receptor augments anti-acute myeloid leukemia activity of Vγ9Vδ2 T cells

Aim: To investigate whether anti-CD123 chimeric antigen receptor (CAR)-expressing Vγ9Vδ2 T cells could be an alternative for acute myeloid leukemia (AML) treatment. Materials & methods: Ex vivo expanded Vγ9Vδ2 T cells were electroporated with anti-CD123 CAR-encoding mRNA. The effector function and specificity of the modified Vγ9Vδ2 T cells were examined by in vitro cytotoxicity, degranulation and cytokine release level. The in vivo function was analyzed using the xenograft KG1-luc model with NOD-SCID-γc-/- mice. Results: The modified Vγ9Vδ2 T cells exhibited significantly improved effector activities against both AML cell lines and primary AML cells in vitro. In the xenograft mouse model, the modified Vγ9Vδ2 cells displayed an enhanced tumor control potency. Conclusion: Anti-CD123 CAR-expressing Vγ9Vδ2 T cells may serve as an alternative way to target AML.

Payload Delivery: Engineering Immune Cells to Disrupt the Tumour Microenvironment

Although chimeric antigen receptor (CAR) T cells have shown impressive clinical success against haematological malignancies such as B cell lymphoma and acute lymphoblastic leukaemia, their efficacy against non-haematological solid malignancies has been largely disappointing. Solid tumours pose many additional challenges for CAR T cells that have severely blunted their potency, including homing to the sites of disease, survival and persistence within the adverse conditions of the tumour microenvironment, and above all, the highly immunosuppressive nature of the tumour milieu. Gene engineering approaches for generating immune cells capable of overcoming these hurdles remain an unmet therapeutic need and ongoing area of research. Recent advances have involved gene constructs for membrane-bound and/or secretable proteins that provide added effector cell function over and above the benefits of classical CAR-mediated cytotoxicity, rendering immune cells not only as direct cytotoxic effectors against tumours, but also as vessels for payload delivery capable of both modulating the tumour microenvironment and orchestrating innate and adaptive anti-tumour immunity. We discuss here the novel concept of engineered immune cells as vessels for payload delivery into the tumour microenvironment, how these cells are better adapted to overcome the challenges faced in a solid tumour, and importantly, the novel gene engineering approaches required to deliver these more complex polycistronic gene constructs.

Dysfunctional BTN3A together with deregulated immune checkpoints and type I/II IFN dictate defective interplay between pDCs and γδ T cells in melanoma patients, which impacts clinical outcomes

Objectives

pDCs and γδ T cells emerge as potent immune players participating in the pathophysiology of cancers, yet still remaining enigmatic while harbouring a promising potential for clinical translations. Despite strategic and closed missions, crosstalk between pDCs and γδ T cells has not been deciphered yet in cancers, especially in melanoma where the long‐term control of the tumor still remains a challenge.

Methods

This prompted us to explore the interplay between pDCs and γδ T cells in the context of melanoma, investigating the reciprocal features of pDCs or γδ T cells, the underlying molecular mechanisms and its impact on clinical outcomes.

Results

TLRL‐activated pDCs from the blood and tumor infiltrate of melanoma patients displayed an impaired ability to activate, to modulate immune checkpoints and trigger the functionality of γδ T cells. Conversely, γδ T cells from the blood or tumor infiltrate of melanoma patients activated by PAg were defective in triggering pDCs’ activation and modulation of immune checkpoints, and failed to elicit the functionality of pDCs. Reversion of the dysfunctional cross‐talks could be achieved by specific cytokine administration and immune checkpoint targeting. Strikingly, we revealed an increased expression of BTN3A on circulating and tumor‐infiltrating pDCs and γδ T cells from melanoma patients, but stressed out the potential impairment of this molecule.

Conclusion

Our study uncovered that melanoma hijacked the bidirectional interplay between pDCs and γδ T cells to escape from immune control, and revealed BTN3A dysfunction. Such understanding will help harness and synergise the power of these potent immune cells to design new therapeutic approaches exploiting their antitumor potential while counteracting their skewing by tumors to improve patient outcomes.

An update on B-cell maturation antigen-targeted therapies in Multiple Myeloma

Introduction: B-cell maturation antigen (BCMA) targeted therapy (BCMA-TT) has emerged as a promising treatment for Multiple Myeloma (MM). the three most common treatment modalities for targeting BCMA are antibody-drug conjugates (ADCs), bispecific antibody constructs, including BiTE (bispecific T-cell engager) immuno-oncology therapies, and chimeric antigen receptor (CAR)-modified T-cell therapy.Areas covered: The review provides an overview of the main published studies on clinical and pre-clinical data from trials using BCMA-TT.Expert opinion: Despite progresses in survival outcomes and the availability of new drugs, MM remains an incurable disease. ADC is a promising antibody-based treatment and Belantamab mafodotin showed an anti-myeloma effect alone or in combination with other drugs. The major issue of ADC is the occurrence of events interfering with the efficacy and the off-target cytotoxicity. Bispecific antibody constructs are off-the-shelf therapies characterized by a potential rapid availability. The most critical limitation of bispecific antibody constructs is their short half-life necessitating prolonged intravenous infusion. CAR-T cells produced unprecedented results in heavily pretreated RRMM. The most common toxicities include neurologic toxicity and cytokine release syndrome, B-cell aplasia, cytopenias, and hypogammaglobulinemia. Further studies are needed to detect which are the eligible patients who could benefit from one treatment more than another.