Allogeneic Cell Research Articles

Gamma/delta T cells as cellular vehicles for anti-tumor immunity.

Adoptive cellular immunotherapy as a new paradigm to treat cancers is exemplified by the FDA approval of six chimeric antigen receptor-T cell therapies targeting hematological malignancies in recent years. Conventional αβ T cells applied in these therapies have proven efficacy but are confined almost exclusively to autologous use. When infused into patients with mismatched human leukocyte antigen, αβ T cells recognize tissues of such patients as foreign and elicit devastating graft-versus-host disease. Therefore, one way to overcome this challenge is to use naturally allogeneic immune cell types, such as γδ T cells. γδ T cells occupy the interface between innate and adaptive immunity and possess the capacity to detect a wide variety of ligands on transformed host cells. In this article, we review the fundamental biology of γδ T cells, including their subtypes, expression of ligands, contrasting roles in and association with cancer prognosis or survival, as well as discuss the gaps in knowledge pertaining to this cell type which we currently endeavor to elucidate. In addition, we propose how to harness the unique properties of γδ T cells for cellular immunotherapy based on lessons gleaned from past clinical trials and provide an update on ongoing trials involving these cells. Lastly, we elaborate strategies that have been tested or can be explored to improve the anti-tumor activity and durability of γδ T cells in vivo.

Upregulation of IDO gene expression reduces the immunogenicity of epidermal cells and strengthens the immune protection of epidermal cells during transplantation treatment of wounds

BackgroundEpidermal cell transplantation is a feasible treatment option for large wounds; however, sources of autologous epidermal cells are often limited. Allogeneic epidermal cells can be cultured conveniently; however, related immune rejection needs to be addressed. Herein, we hypothesized that the immunogenicity of epidermal cells with high indoleamine 2,3-dioxygenase (IDO) expression may be reduced by gene transfection. Methods/ResultsTo test this hypothesis, we obtained stable transfectants by transfecting epidermal stem cells with a lentiviral vector encoding the IDO gene and screening them for puromycin resistance (a marker for successful transfection). The phenotype tested using cell counting kit −8 and Transwell assays confirmed that IDO-transfected epidermal cells maintained their characteristics. Co-culture of IDO-transfected epidermal cells with allogeneic CD4+ T cells in vitro showed that the upregulation of IDO expression in epidermal cells inhibited the proliferation of CD4+ T cells (P < 0.001, P < 0.001, and P < 0.001, respectively) and promoted their apoptosis (P = 0.00028, P = 0.0006, and P = 0.00247, respectively) and transformation into functional regulatory T cells (Tregs) (P = 0.0051, P = 0.0132, and P = 0.0248, respectively) compared with Con, NC, and 1-MT groups. The increased proportion of Tregs may be related to the overexpression of IDO, which promoted the expression of transforming growth factor beta (TGF-β) (P = 0.0001, P = 0.0013, and, P = 0.0009) and interleukin (IL) 10 (IL-10) (P = 0.0062, P = 0.0058, and P = 0.0119) while inhibited the expression of IL-2 (P = 0.0012, P = 0.0126, and P = 0.0066). We further verified these effects in vivo as transplanted IDO-transfected epidermal stem cells were effective in treating wounds in mice. On days 5 and 7, wounds treated with IDO cells healed faster than those in the other groups (day 5: P = 0.012 and P = 0.0136; day 7: P = 0.0242 and P = 0.0187, respectively), whereas this effect was significantly inhibited by 1-methyltryptophan (1-MT) (day 5: P = 0.0303; day 7: P = 0.0105). Immunofluorescence staining detected IDO and CD4+ Foxp3+ Tregs in the transplanted wounds, which may promote Foxp3+ Tregs in the wound tissue (day 5: P < 0.0001, P < 0.0001, and P < 0.0001; day 7: P < 0.0001, P < 0.0001, and P < 0.0001), respectively) and decrease CD4+ T cells (day 5: P < 0.0001, P < 0.0001, and P < 0.0001; day 7: P < 0.0001, P < 0.0001, and P < 0.0001). ConclusionOur results suggest that the upregulation of IDO expression in epidermal stem cells can reduce their immunogenicity by promoting Tregs, thus inducing the immune protection of epidermal stem cells.

Induced Pluripotent Stem Cell-Derived Mesenchymal Stromal Cells Promote Muscle Regeneration in a Diabetic Mouse Model of Critical Limb Threatening Ischemia

Critical limb threatening ischemia (CLTI), the end stage of peripheral arterial disease (PAD), is diagnosed in 500,000 patients each year, often results in amputation, and has a ~50% 5-year mortality rate. Diabetic CLTI patients experience especially high morbidity and mortality, and no effective non-surgical therapy exists for this population. Our Phase II MOBILE trial demonstrated that autologous bone marrow nucleated cells were unable to prevent amputations in diabetic patients; however, data from a Phase I trial shows that allogeneic bone marrow-derived mesenchymal stromal cells (BMD-MSC) stimulated angiogenesis in ischemic muscle, including diabetics. While allogeneic MSC may be an effective cell preparation to treat diabetic CLTI, passaging-related cell senescence prevents generation of sufficient cell numbers for therapeutic use. The development of induced pluripotent stem cell (iPSC)-derived MSC overcomes cell senescence issues and offers the possibility of genetic modifications to enhance cell function. The current study was designed to determine potential mechanisms by which iPSC-MSC stimulate muscle regeneration in a rodent CLTI model.&#x0D; The CLTI mouse model was created by ligation/excision of the femoral artery in male polygenic diabetic TallyHo mice. Mice with intramuscular administration of iPSC-MSC displayed positive indicators of muscle regeneration compared to vehicle control mice. Real-time PCR performed with gastrocnemius muscle obtained 7- or 30-days post iPSC-MSC injection showed an increase in mRNA expression for MyH3, MyoD1, Mrc1, FoxP3, and VEGF-A vs. vehicle treated muscle, indicating promotion of muscle regeneration, M2-biased macrophage expression, T regulatory cell (Treg) expansion, and vascular proliferation. Downregulation of the NADPHoxidase subunit p47phox indicated a decrease in oxidative stress in the treated mice. The results are consistent with iPSC-MSC promotion of muscle regeneration via a Treg mediated stimulation of the M1-M2 macrophage phenotypic shift. Thus, human iPSC-MSC could be an effective treatment to stimulate muscle regeneration and ameliorate CLTI in diabetic patients.

Trends in cell medicine: from autologous cells to allogeneic universal-use cells for adoptive T-cell therapies.

In currently ongoing adoptive T-cell therapies, T cells collected from patients are given back to them after ex vivo activation and expansion. In some cases, T cells are transduced with chimeric antigen receptor (CAR) or T-cell receptor (TCR) genes during the ex vivo culture period in order to endow T cells with the desired antigen specificity. Although such strategies are effective in some types of cancer, there remain issues to be solved: (i) the limited number of cells, (ii) it is time-consuming, (iii) it is costly, and (iv) the quality can be unstable. Points (ii) and (iv) can be solved by preparing allogeneic T cells and cryopreserving them in advance and methods are being developed using healthy donor-derived T cells or pluripotent stem cells as materials. Whereas it is difficult to solve (i) and (iii) in the former case, all the issues can be cleared in the latter case. However, in either case, a new problem arises: rejection by the patient's immune system. Deletion of human leukocyte antigen (HLA) avoids rejection by recipient T cells, but causes rejection by NK cells, which can recognize loss of HLA class I. Various countermeasures have been developed, but no definitive solution is yet available. Therefore, further research and development are necessary.

Adoptive cell transfer therapy with ex vivo primed peripheral lymphocytes in combination with anti-PDL1 therapy effectively inhibits triple-negative breast cancer growth and metastasis

BackgroundAdoptive cell transfer cancer immunotherapy holds promise for treating disseminated disease, yet generating sufficient numbers of lymphocytes with anti-cancer activity against diverse specificities remains a major challenge. We recently developed a novel procedure (ALECSAT) for selecting, expanding and maturating polyclonal lymphocytes from peripheral blood with the capacity to target malignant cells.MethodsImmunodeficient mice were challenged with triple-negative breast cancer cell lines or patient-derived xenografts (PDX) and treated with allogeneic or autologous ALECSAT cells with and without anti-PDL1 therapy to assess the capacity of ALECSAT cells to inhibit primary tumor growth and metastasis.ResultsALECSAT mono therapy inhibited metastasis, but did not inhibit primary tumor growth or prolong survival of tumor-bearing mice. In contrast, combined ALECSAT and anti-PDL1 therapy significantly inhibited primary tumor growth, nearly completely blocked metastasis, and prolonged survival of tumor-bearing mice.ConclusionsCombined ALECSAT and anti-PDL1 therapy results in favorable anti-cancer responses in both cell line-derived xenograft and autologous PDX models of advanced triple-negative breast cancer.

Acellular scaffold-based approach for in situ genetic engineering of host T-cells in solid tumor immunotherapy

BackgroundTargeted T-cell therapy has emerged as a promising strategy for the treatment of hematological malignancies. However, its application to solid tumors presents significant challenges due to the limited accessibility and heterogeneity. Localized delivery of tumor-specific T-cells using biomaterials has shown promise, however, procedures required for genetic modification and generation of a sufficient number of tumor-specific T-cells ex vivo remain major obstacles due to cost and time constraints.MethodsPolyethylene glycol (PEG)-based three-dimensional (3D) scaffolds were developed and conjugated with positively charged poly-L-lysine (PLL) using carbamide chemistry for efficient loading of lentiviruses (LVs) carrying tumor antigen-specific T-cell receptors (TCRs). The physical and biological properties of the scaffold were extensively characterized. Further, the scaffold loaded with OVA-TCR LVs was implanted in B16F10 cells expressing ovalbumin (B16-OVA) tumor model to evaluate the anti-tumor response and the presence of transduced T-cells.ResultsOur findings demonstrate that the scaffolds do not induce any systemic inflammation upon subcutaneous implantation and effectively recruit T-cells to the site. In B16-OVA melanoma tumor-bearing mice, the scaffolds efficiently transduce host T-cells with OVA-specific TCRs. These genetically modified T-cells exhibit homing capability towards the tumor and secondary lymphoid organs, resulting in a significant reduction of tumor size and systemic increase in anti-tumor cytokines. Immune cell profiling revealed a significantly high percentage of transduced T-cells and a notable reduction in suppressor immune cells within the tumors of mice implanted with these scaffolds.ConclusionOur scaffold-based T-cell therapy presents an innovative in situ localized approach for programming T-cells to target solid tumors. This approach offers a viable alternative to in vitro manipulation of T-cells, circumventing the need for large-scale in vitro generation and culture of tumor-specific T-cells. It offers an off-the-shelf alternative that facilitates the use of host cells instead of allogeneic cells, thereby, overcoming a major hurdle.

PROTO-ADVANCED PERSONALIZED THERAPIES FOR OSTEOARTHRITIS

Osteoarthritis (OA) is the most common joint disease, affecting approximately 16% of the adult population worldwide. The chronic inflammation in the joint leads to the breakdown of cartilage, which leads to permanent pain and limitations in everyday life at an early stage of the disease. To date, there is no therapy that can interrupt the inflammatory state or reverse cartilage damage. The PROTO consortium (funded by the EU Horizon Europe program, Grant 101095635) aims to prevent the development of OA by correcting a pathological biomechanical pattern by a digital training intervention and to treat early stage OA with an innovative allogeneic cell therapy.

THE CHALLENGES OF STEM CELL THERAPY FOR THE TREATMENT OF TENDINOPATHY IN THE CLINIC: LESSONS FROM A LARGE ANIMAL MODEL

Stem cells represent an exciting biological therapy for the management of many musculoskeletal tissues that suffer degenerative disease and/or where the reparative process results in non-functional tissue (‘failed healing’). The original hypothesis was that implanted cells would differentiate into the target tissue cell type and synthesise new matrix. However, this has been little evidence that this happens in live animals compared to the laboratory, and more recent theories have focussed on the immunomodulatory effects via the release of paracrine factors that can still improve the outcome, especially since inflammation is now considered one of the central processes that drive poor tendon healing. Because of the initial ‘soft’ regulatory environment for the use of stem cells in domestic mammals, bone and fat-derived stem cells quickly established themselves as a useful treatment for naturally occurring musculoskeletal diseases in the horse more than 20 years ago (Smith, Korda et al. 2003). Since the tendinopathy in the horse has many similarities to human tendinopathy, we propose that the following challenges and, the lessons learnt, in this journey are highly relevant to the development of stem cells therapies for human tendinopathy:Source – while MSCs can be recovered from many tissues, the predominant sources for autologous MSCs have been bone and fat. Other sources, including blood, amnion, synovium, and dental pulp have also been commercialised for allogenic treatments.Preparation – ex vivo culture requires transport from a licensed laboratory while ‘minimally manipulated’ preparations can be prepared patient-side. Cells also need a vehicle for transport and implantation.Delivery – transport of cells from the laboratory to the clinic for autologous ex vivo culture techniques; implantation technique (usually by ultrasound-guided injection to minimise damage to the cells (or, more rarely, incorporated into a scaffold). They can also be delivered by regional perfusion via venous or arterial routes.Retention – relatively poor although small numbers of cells do survive for at least 5 months. Immediate loss to the lungs if the cells are administered via vascular routes. Synovially administered cells do not engraft into tendon.Adverse effects – very safe although needle tracts often visible (but do not seen to adversely affect the outcome). Allogenic cells require careful characterisation for MHC Class II antigens to avoid anaphylaxis or reduced efficacy.Appropriate injuries to treat – requires a contained lesion when administered via intra-lesional injection. Intrasynovial tendon lesions are more often associated with surface defects and are therefore less appropriate for treatment. Earlier treatment appears to be more effective than delayed, when implantation by injection is more challenging.Efficacy - beneficial effects shown at both tissue and whole animal (clinical outcome) level in naturally-occurring equine tendinopathy using bone marrow-derived autologous MSCs Recent (licenced) allogenic MSC treatment has shown equivalent efficacy while intra-synovial administration of MSCs is ineffective for open intra-synovial tendon lesions.Regulatory hurdles – these have been lighter for veterinary treatments which has facilitated their development. There has been greater regulation of commercial allogenic MSC preparations which have required EMA marketing authorisation.

Current state and future prospects of off-the-shelf allogeneic CAR NK therapy

Chimeric antigen receptor-transduced autologous T (CAR-T) cell therapy targeting CD19 has revolutionized the treatment of CD19-positive hematological tumors, including acute lymphoblastic leukemia and large B-cell lymphoma. However, despite the high response rate, many problems such as exceedingly high cost, complex logistics, insufficient speed, and manufacturing failures have become apparent. One solution for these problems is to use an allogeneic cell as an effector cell for genetic modification with CAR. Allogeneic, or "off-the-shelf", CAR-expressing immune-effector cells include 1) genome-edited, T-cell receptor (TCR) gene-deleted CAR-T cells generated using healthy adult donor T cells, 2) induced pluripotent stem cell-derived CAR-T cells, and 3) CAR NK cells. NK cells are notorious for their poor ex-vivo expansion and low susceptibility to genetic modification. In this article, I will review the current state and future prospects of allogeneic CAR cell therapies, with special reference to CAR NK cells.

Nanoparticles loaded with IL-2 and TGF-β promote transplantation tolerance to alloantigen.

We have previously reported that nanoparticles (NPs) loaded with IL-2 and TGF-β and targeted to T cells induced polyclonal T regulatory cells (Tregs) that protected mice from graft-versus-host disease (GvHD). Here, we evaluated whether administration of these NPs during alloantigen immunization could prevent allograft rejection by converting immunogenic responses to tolerogenic ones. Using C57BL/6 mice and BALB/c mice as either donors or recipients of allogeneic splenocytes, we found that treatment with the tolerogenic NPs in both strains of mice resulted in a marked inhibition of mixed lymphocyte reaction (MLR) to donor cell alloantigen but not to third-party control mouse cells after transfer of the allogeneic cells. The decreased alloreactivity associated with a four- to fivefold increase in the number of CD4+ and CD8+ T regulatory cells (Tregs) and the acquisition of a tolerogenic phenotype by recipient dendritic cells (DCs) in NP-treated mice. As allogeneic cells persisted in NP-treated mice, these findings suggest that tolerogenic NPs can induce alloantigen-specific Tregs and tolerogenic DCs promoting tolerogenic responses to alloantigen. By inhibiting reactivity to allotransplant, this approach could help reduce the need for immune suppression for the maintenance of allografts.

Effect of the transplantation type on the neuroprotective properties of mesenchymal stromal cells

Many preclinical studies using adult Mesenchymal Stromal Cells (MSCs) for neurodegenerative diseases show promising results. However, there is a lack of concordance between the extensive research on MSC neuroprotection and clinical translation as evidenced by the few clinical trials currently using this strategy. A major discordance between animal models and patients is the type of transplant. Commonly, human cells are tested in animal models but this is a xenotransplant. As a rule, though, patients are either treated with autologous (syngeneic) or allogeneic cells. However, the crosstalk between the grafted cells and the host tissue is something that, despite its importance, is not being systematically investigated. We will show here that the therapeutic outcome, host homeostasis and immune response to intravitreal administered bone‐marrow MSCs radically changes depending on the type of transplantation. As expected, xenografts are the more damaging, followed by allografts with or without immunosuppression. Syngrafts are not completely innocuous, but they do not alter neuronal functionality, making them the safest and the best ones to neuroprotect and to induce axonal regeneration. In conclusion, the transplantation modality should be taken into consideration when conducting preclinical studies if we intend a more realistic translation into clinical practice.

Effects of ferric derisomaltose on postoperative anaemia in adult spinal deformity surgery: a study protocol for a randomised controlled trial

IntroductionPostoperative anaemia is prevalent in adult spinal deformity (ASD) surgery in association with unfavourable outcomes. Ferric derisomaltose, a novel iron supplement, offers a promising solution in rapidly treating postoperative anaemia....

Interleukin-2 is required for NKp30-dependent NK cell cytotoxicity by preferentially regulating NKp30 expression.

Natural killer (NK) cells are key effectors in cancer immunosurveillance, eliminating a broad spectrum of cancer cells without major histocompatibility complex (MHC) specificity and graft-versus-host diseases (GvHD) risk. The use of allogeneic NK cell therapies from healthy donors has demonstrated favorable clinical efficacies in treating diverse cancers, particularly hematologic malignancies, but it requires cytokines such as IL-2 to primarily support NK cell persistence and expansion. However, the role of IL-2 in the regulation of activating receptors and the function of NK cells expanded for clinical trials is poorly understood and needs clarification for the full engagement of NK cells in cancer immunotherapy. Here, we demonstrated that IL-2 deprivation significantly impaired the cytotoxicity of primary expanded NK cells by preferentially downregulating NKp30 but not NKp46 despite their common adaptor requirement for expression and function. Using NK92 and IL-2-producing NK92MI cells, we observed that NKp30-mediated cytotoxicity against myeloid leukemia cells such as K562 and THP-1 cells expressing B7-H6, a ligand for NKp30, was severely impaired by IL-2 deprivation. Furthermore, IL-2 deficiency-mediated NK cell dysfunction was overcome by the ectopic overexpression of an immunostimulatory NKp30 isoform such as NKp30a or NKp30b. In particular, NKp30a overexpression in NK92 cells improved the clearance of THP-1 cells in vivo without IL-2 supplementation. Collectively, our results highlight the distinct role of IL-2 in the regulation of NKp30 compared to that of NKp46 and suggest NKp30 upregulation, as shown here by ectopic overexpression, as a viable modality to harness NK cells in cancer immunotherapy, possibly in combination with IL-2 immunocytokines.

Charting new paradigms for CAR-T cell therapy beyond current Achilles heels.

Chimeric antigen receptor-T (CAR-T) cell therapy has made remarkable strides in treating hematological malignancies. However, the widespread adoption of CAR-T cell therapy is hindered by several challenges. These include concerns about the long-term and complex manufacturing process, as well as efficacy factors such as tumor antigen escape, CAR-T cell exhaustion, and the immunosuppressive tumor microenvironment. Additionally, safety issues like the risk of secondary cancers post-treatment, on-target off-tumor toxicity, and immune effector responses triggered by CAR-T cells are significant considerations. To address these obstacles, researchers have explored various strategies, including allogeneic universal CAR-T cell development, infusion of non-activated quiescent T cells within a 24-hour period, and in vivo induction of CAR-T cells. This review comprehensively examines the clinical challenges of CAR-T cell therapy and outlines strategies to overcome them, aiming to chart pathways beyond its current Achilles heels.

The Progress and Prospects of Immune Cell Therapy for the Treatment of Cancer.

Immune cell therapy as a revolutionary treatment modality, significantly transformed cancer care. It is a specialized form of immunotherapy that utilizes living immune cells as therapeutic reagents for the treatment of cancer. Unlike traditional drugs, cell therapies are considered "living drugs," and these products are currently customized and require advanced manufacturing techniques. Although chimeric antigen receptor (CAR)-T cell therapies have received tremendous attention in the industry regarding the treatment of hematologic malignancies, their effectiveness in treating solid tumors is often restricted, leading to the emergence of alternative immune cell therapies. Tumor-infiltrating lymphocytes (TIL) cell therapy, cytokine-induced killer (CIK) cell therapy, dendritic cell (DC) vaccines, and DC/CIK cell therapy are designed to use the body's natural defense mechanisms to target and eliminate cancer cells, and usually have fewer side effects or risks. On the other hand, cell therapies, such as chimeric antigen receptor-T (CAR-T) cell, T cell receptor (TCR)-T, chimeric antigen receptor-natural killer (CAR-NK), or CAR-macrophages (CAR-M) typically utilize either autologous stem cells, allogeneic or xenogeneic cells, or genetically modified cells, which require higher levels of manipulation and are considered high risk. These high-risk cell therapies typically hold special characteristics in tumor targeting and signal transduction, triggering new anti-tumor immune responses. Recently, significant advances have been achieved in both basic and clinical researches on anti-tumor mechanisms, cell therapy product designs, and technological innovations. With swift technological integration and a high innovation landscape, key future development directions have emerged. To meet the demands of cell therapy technological advancements in treating cancer, we comprehensively and systematically investigate the technological innovation and clinical progress of immune cell therapies in this study. Based on the therapeutic mechanisms and methodological features of immune cell therapies, we analyzed the main technical advantages and clinical transformation risks associated with these therapies. We also analyzed and forecasted the application prospects, providing references for relevant enterprises with the necessary information to make informed decisions regarding their R&D direction selection.

Allogeneic CAR-T cells with of HLA-A/B and TRAC disruption exhibit promising antitumor capacity against B cell malignancies

BackgroundAlthough chimeric antigen receptor T (CAR-T) cells have been proven to be an effective way of treating B cell malignancies, a lot of patients could not benefit from it because of failure in CAR-T cell manufacturing, disease progression, and unaffordable price. The study aimed to explore universal CAR-T cell products to extend the clinical accessibility.MethodsThe antitumor activity of CRISPR/Cas9-edited allogeneic anti-CD19 CAR-T (CAR-T19) cells was assessed in vitro, in animal models, and in patients with relapsed/refractory (R/R) acute B cell lymphoblastic leukemia (B-ALL) or diffuse large B cell lymphoma.ResultsB2M−/TRAC− universal CAR-T19 (U-CAR-T19) cells exhibited powerful anti-leukemia abilities both in vitro and in animal models, as did primary CD19+ leukemia cells from leukemia patients. However, expansion, antitumor efficacy, or graft-versus-host-disease (GvHD) was not observed in six patients with R/R B cell malignancies after U-CAR-T19 cell infusion. Accordingly, significant activation of natural killer (NK) cells by U-CAR-T19 cells was proven both clinically and in vitro. HLA-A−/B−/TRAC− novel CAR-T19 (nU-CAR-T19) cells were constructed with similar tumoricidal capacity but resistance to NK cells in vitro. Surprisingly, robust expansion of nU-CAR-T19 cells, along with rapid eradication of CD19+ abnormal B cells, was observed in the peripheral blood and bone marrow of another three patients with R/R B-ALL. The patients achieved complete remission with no detectable minimal residual disease 14 days after the infusion of nU-CAR-T19 cells. Two of the three patients had grade 2 cytokine release syndrome, which were managed using an IL-6 receptor blocker. Most importantly, GvHD was not observed in any patient, suggesting the safety of TRAC-disrupted CAR-T cells generated using the CRISPR/Cas9 method for clinical application.ConclusionsThe nU-CAR-T19 cells showed a strong response in R/R B-ALL. nU-CAR-T19 cells have the potential to be a promising new approach for treating R/R B cell malignancies.

Comparative assessment of autologous and allogeneic iNKT cell transfer in iNKT cell-based immunotherapy.

Invariant natural killer T (iNKT) cells are a small subset of T lymphocytes that release large amounts of cytokines such as IFN-γ and exhibit cytotoxic activity upon activation, inducing strong anti-tumor effects. Harnessing the anti-tumor properties of iNKT cells, iNKT cell-based immunotherapy has been developed to treat cancer patients. In one of the iNKT cell-based immunotherapies, two approaches are utilized, namely, active immunotherapy or adoptive immunotherapy, the latter involving the ex vivo expansion and subsequent administration of iNKT cells. There are two sources of iNKT cells for adoptive transfer, autologous and allogeneic, each with its own advantages and disadvantages. Here, we assess clinical trials conducted over the last decade that have utilized iNKT cell adoptive transfer as iNKT cell-based immunotherapy, categorizing them into two groups based on the use of autologous iNKT cells or allogeneic iNKT cells.

CAR-T Cell Therapy in B-Cell Acute Lymphoblastic Leukemia.

Treatment of refractory and relapsed (R/R) B acute lymphoblastic leukemia (B-ALL) is an unmet medical need in both children and adults. Studies carried out in the last two decades have shown that autologous T cells engineered to express a chimeric antigen receptor (CAR-T) represent an effective technique for treating these patients. Antigens expressed on B-cells, such as CD19, CD20, and CD22, represent targets suitable for treating patients with R/R B-ALL. CD19 CAR-T cells induce a high rate (80-90%) of complete remissions in both pediatric and adult R/R B-ALL patients. However, despite this impressive rate of responses, about half of responding patients relapse within 1-2 years after CAR-T cell therapy. Allo-HSCT after CAR-T cell therapy might consolidate the therapeutic efficacy of CAR-T and increase long-term outcomes; however, not all the studies that have adopted allo-HSCT as a consolidative treatment strategy have shown a benefit deriving from transplantation. For B-ALL patients who relapse early after allo-HSCT or those with insufficient T-cell numbers for an autologous approach, using T cells from the original stem cell donor offers the opportunity for the successful generation of CAR-T cells and for an effective therapeutic approach. Finally, recent studies have introduced allogeneic CAR-T cells generated from healthy donors or unmatched, which are opportunely manipulated with gene editing to reduce the risk of immunological incompatibility, with promising therapeutic effects.

Antitumor activity of genetically engineered NK-cells in non-hematological solid tumor: a comprehensive review.

Recent advancements in genetic engineering have made it possible to modify Natural Killer (NK) cells to enhance their ability to fight against various cancers, including solid tumors. This comprehensive overview discusses the current status of genetically engineered chimeric antigen receptor NK-cell therapies and their potential for treating solid tumors. We explore the inherent characteristics of NK cells and their role in immune regulation and tumor surveillance. Moreover, we examine the strategies used to genetically engineer NK cells in terms of efficacy, safety profile, and potential clinical applications. Our investigation suggests CAR-NK cells can effectively target and regress non-hematological malignancies, demonstrating enhanced antitumor efficacy. This implies excellent promise for treating tumors using genetically modified NK cells. Notably, NK cells exhibit low graft versus host disease (GvHD) potential and rarely induce significant toxicities, making them an ideal platform for CAR engineering. The adoptive transfer of allogeneic NK cells into patients further emphasizes the versatility of NK cells for various applications. We also address challenges and limitations associated with the clinical translation of genetically engineered NK-cell therapies, such as off-target effects, immune escape mechanisms, and manufacturing scalability. We provide strategies to overcome these obstacles through combination therapies and delivery optimization. Overall, we believe this review contributes to advancing NK-cell-based immunotherapy as a promising approach for cancer treatment by elucidating the underlying mechanisms, evaluating preclinical and clinical evidence, and addressing remaining challenges.

TNF‐a/IL‐1B cytokine licensing enhances immunomodulatory potential of allogeneic mesenchymal stromal cells

Aims/Purpose: Mesenchymal stromal cells (MSCs) have shown great potential for therapeutic treatment of inflammatory diseases; however, their immunomodulatory potential can be further enhanced by cytokine licensing. The aim of this work was to assess changes in MSC surface characterization profile and immunomodulatory function following licensing with TNF‐α/IL‐1β pro‐inflammatory cytokines.Methods: MSCs were isolated from the bone marrow of FVB mice (H2kq) and licensed with a combination of 50 ng/mL TNF‐α and 50 ng/mL IL‐1β or cultured in growth medium alone. MSCs were harvested following 72‐h cytokine stimulation and added to immune cell potency assays. Characterization of MSC surface marker expression was assessed by flow cytometry. The immunology potential of FVB MSCs as an allogeneic cell therapy was assessed in vitro through co‐culture with Balb/c (H2kd) αCD3/CD28 activated T lymphocytes or Balb/c IFN‐γ/LPS‐stimulated macrophages.Results: TNF‐α/IL‐1β licensing was found to induce surface marker phenotype alterations compared with unlicenced MSCs, with increased expression of CD73, CD44, Sca‐1, CD29 and PD‐L1 observed. TNF‐α/IL‐1β licensed MSCs also secreted significantly higher quantities of nitric oxide compared with their untreated counterparts at two separate timepoints, 24‐h and 42‐h post‐stimulation. TNF‐α/IL‐1β MSCs significantly suppressed both CD4+ and CD8+ T cell proliferation at three different rations (1:5, 1:10, 1:50 MSCs: T cells) and significantly increased expansion of CD4+CD25++FoxP3+ regulatory T cells following co‐culture. TNF‐α/IL‐1β MSCs were found to significantly decrease levels of IFN‐γ from proliferating T cells. TNF‐α/IL‐1β MSCs were positive for CD80 expression had significantly reduced MHC I expression and could increase expansion of CD206 on M1‐like macrophages. Both T cell and macrophage co‐cultures with TNF‐α/IL‐1β MSCs showed a significant increase in IL‐6.Conclusions: Our results show the potential to enhance the therapeutic effects of MSC through cytokine licensing. Currently, TNF‐α/IL‐1β MSCs are being tested in ocular surface injury models for therapeutic efficacy.Keywords: Mesenchymal Stromal Cells, Cytokine Licensing, Immunomodulation, TNF‐α/IL‐1β.