Donor-derived Cells Research Articles

Proteogenomic identification of an immunogenic antigen derived from human endogenous retrovirus in renal cell carcinoma.

CD8+ T cells can recognize tumor antigens displayed by HLA class I molecules and eliminate tumor cells. Despite their low tumor mutation burden, immune checkpoint blockade (ICB) is often beneficial in patients with renal cell carcinoma (RCC). Here, using a proteogenomic approach, we directly and comprehensively explored the HLA class I-presenting peptidome of RCC tissues and demonstrated that the immunopeptidomes contain a small subset of peptides derived from human endogenous retroviruses (hERV). A comparison between tumor and normal kidney tissues revealed tumor-associated hERV antigens, one of which was immunogenic and recognized by host tumor-infiltrating lymphocytes (TIL). Stimulation with the hERV antigen induced reactive CD8+ T cells in healthy donor-derived (HD-derived) peripheral blood mononuclear cells (PBMC). These results highlight the presence of antitumor CD8+ T cell surveillance against hERV3895 antigens, suggesting their clinical applications in patients with RCC.

Local coordination of epithelial planar polarity in the maintenance and regeneration of the adult rat airway.

The maintenance of planar polarity in airway multiciliated cells (MCCs) has been poorly characterized. We recently reported that the direction of ciliary beating in a surgically inverted tracheal segment remained inverted beyond the time required for the turnover of cells, without adjustment to global distal-to-proximal polarity. We hypothesized that the local maintenance of tissue-level polarity occurs via locally reproduced cells. To provide further insight regarding this hypothetical property, we performed allotransplantation of an inverted tracheal segment between wild-type (donor) and tdTomato-expressing (host) rats, with and without scratching the mucosa of the transplants. The origin of cells in the transplants was assessed using tdTomato-specific immunostaining. Ciliary movement and structures were observed by high-speed video and electron microscopy to analyze MCC orientations. Variabilities in the orientations of closely and distantly located MCCs were analyzed to evaluate the local- and broad-scale coordination of polarity, respectively. The epithelium was maintained by donor-derived cells in the non-scratched inverted transplant over 6months, beyond one cycle of turnover. The inverted orientation of MCCs was also maintained throughout the non-scratched transplant. MCCs regenerated in the scratched transplant were derived from the host and exhibited diverse orientations across the transplant. However, the orientations of adjacent regenerated MCCs were often coordinated, indicating that airway MCCs can locally coordinate their orientations. A steady-state airway may maintain MCC orientation by locally reproducing MCCs via the local coordination of polarity. This local coordination enables the formation and maintenance of tissue-level polarity in small regions after mucosal injury.

Donor-derived CAR-T therapy improves the survival of relapsed B-ALL after allogeneic transplantation compared with donor lymphocyte infusion.

Chimeric antigen receptor (CAR)-T cell therapy revolutionized treatment for various hematologic malignances. However, limited studies were reported to compare the efficacy and safety of CAR-T and donor lymphocyte infusion (DLI) for patients with relapsed B-cell acute lymphoblastic leukemia (B-ALL) after hematopoietic stem cell transplantation (HSCT) comprehensively. We conducted a single-center, retrospective comparative study that consisted of 12 patients who were treated with DLI (control group) and 12 patients treated with donor-derived CD19 CAR-T cells (experimental group, 6 patients also received CD22 or CD123 CAR-T cells sequentially) with 3 overlaps. The event-free survival (EFS) of patients in experimental group was superior to that of the control group: 516days versus 98days (p = 0.0415). Compared with 7 of 12 patients treated with DLI suffered grades III-IV acute graft versus host disease (aGVHD), one grade III aGVHD developed in patients treated with CAR-T therapy. No significant difference in the incidence of infection was identified between these two groups. Most patients in the experimental group had only mild cytokine release syndrome and none developed neurotoxicity. The univariate analysis of patients in the experiment group revealed that earlier CAR-T therapy for post-transplantation relapse was associated with better EFS. There was no significant difference in EFS between patients treated with dual-target CAR-T with those with single CD19 CAR-T. In this study, our data supported that donor-derived CAR-T therapy is a safe and potentially effective treatment for relapsed B-ALL after HSCT and may be superior to DLI.

Donor-derived CD19 CAR-T Cells versus Chemotherapy Plus Donor Lymphocyte Infusion for Treatment of Recurrent CD19-positive B-ALL After Allogeneic Hematopoietic Stem Cell Transplantation.

This study aimed to compare the efficacy of anti-CD19 chimeric antigen receptor T cells (CAR-T cells) versus chemotherapy plus donor lymphocyte infusion (chemo-DLI) for treating relapsed CD19-positive B-cell acute lymphoblastic leukemia (B-ALL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Clinical data of 43 patients with B-ALL who relapsed after allo-HSCT were retrospectively analyzed. Twenty-two patients were treated with CAR-T cells (CAR-T group), and 21 with chemotherapy plus DLI (chemo-DLI group). The complete remission (CR) and minimal residual disease (MRD)-negative CR rates, leukemia-free survival (LFS) rate, overall survival (OS) rate, and incidence of acute graft-versus-host disease (aGVHD), cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were compared between the two groups. The CR and MRD-negative CR rates in the CAR-T group (77.3% and 61.5%) were significantly higher than those in the chemo-DLI group (38.1% and 23.8%) (P=0.008 and P=0.003). The 1- and 2-year LFS rates in the CAR-T group were superior to those in the chemo-DLI group: 54.5% and 50.0% vs. 9.5% and 4.8% (P=0.0001 and P=0.00004). The 1- and 2-year OS rates in the CAR-T versus chemo-DLI group were 59.1% and 54.5% vs. 19% and 9.5% (P=0.011 and P=0.003). Six patients (28.6%) with grade 2-4 aGVHD were identified in the chemo-DLI group. Two patients (9.1%) in the CAR-T group developed grade 1-2 aGVHD. Nineteen patients (86.4%) developed CRS in the CAR-T group, comprising grade 1-2 CRS in 13 patients (59.1%) and grade 3 CRS in 6 patients (27.3%). Two patients (9.1%) developed grade 1-2 ICANS. Donor-derived anti-CD19 CAR-T-cell therapy may be better, safer, and more effective than chemo-DLI for B-ALL patients who relapse after allo-HSCT.

ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION IN ELDERLY PATIENTS IN BRAZIL

The allogeneic hematopoietic stem cell transplant (allo-HCT) represents an important therapeutic strategy for acute leukemias, lymphomas and solid neoplasms, also used in benign diseases, such as aplastic anemia and inborn errors of immunity. This treatment requires myeloablative chemotherapy (conditioning regimen) followed by the infusion of donor-derived hematopoietic stem cells. However, this procedure carries some risks, such as infections, graft versus host disease (GVHD) and conditioning toxicity, which may result in transplant-related mortality. Over the decades, due to the increasing life expectancy and new advances in medicine, the cases of patients > 50 years with hematologic diseases that need allogeneic transplant have grown, requiring a comprehensive geriatric assessment as a mechanism for the best treatment option choice.
 Objective: To apply a clinical frailty score and Karnofsky score in allogeneic hematopoietic stem cell older than 50 years old for three years in Walter Cantídio University Hospital (Fortaleza/Ceará) and in Amaral Carvalho Hospital (Jaú/São Paulo), expecting to recognize the profile of this patients and to demonstrate the relation between the clinical frailty score and overall survived, besides to estimate the contribution of GVHD prophylaxis and relapse in overall survival. Methods: Multicentric, retrospective, descriptive, analytical and quantitative study, acquiring dates by means of exams and medical record from Walter Cantídio University Hospital in Fortaleza/Ceará and Amaral Carvalho Hospital in Jaú/São Paulo. Results: The study selected 252 patients, 147 males and 105 females, sort in gender, disease, HCTCI score, CFS and KPS. In three years, the overall survival in FIT score is 2,46 years, while in FRAILTY score is 1,82 years. About the prophylaxis, the combination of cyclosporine, mycophenolate mofetil, cyclophosphamide had worse results than others prophylaxis. As expected, in case of relapse, there is shorter survival. Conclusion: The elderly population require a geriatric score in order to evaluate the profile of this patients once the allogeneic transplant must happen, then FIT patients has longer survival than FRAILTY patients.

Clinical-grade natural killer cells expanded from donor peripheral blood and anti-leukemia effect against myeloid leukemia.

e19018 Background: Natural killer (NK) cells play a crucial role in immune surveillance and tumor clearance. It has been reported that allogeneic NK cell therapy has good safety and curative effect in patients with refractory and relapsed acute myeloid leukemia (AML). However, the clinical application of adoptive NK infusion is limited due to the lower number of human NK cells. We established a feeder-free NK cell expansion system from peripheral blood (PB) and explore the anti-leukemia potential in preclinical and clinical studies. Methods: The killing capacity of ex vivo-expanded NK cells were detected by Flow cytometry. The in vivo expansion, survival and anti-leukemia activity of the expanded NK cells were detected in K562-bearing NSG mice. Six AML patients with hematological/extra medullary relapsed (n = 3) or persistent positive minimal residual disease (n = 3) after consolidation and maintenance therapy were enrolled in Peking University Institute of Hematology from 2021 to 2022. The patients were treated with high-dose cyclophosphamide and fludarabine, then combined with adoptive infusion of donor-derived expanded NK cells. The chimerism, the number and function of NK cells were analyzed, and the safety and clinical efficacy were evaluated. Results: The ex vivo-expanded NK cells exhibit highly anti-leukemia activity. NK cells proliferate in mice and the CD56+ cells to reach the peak time in each organ is 3-7 days and drop to the level before infusion after 14 days. NK cell infusion significantly improve the survival of leukemia mice, and the anti-leukemia effect is NK cell dose-dependent. In the clinical trial, six patients received a total of 7 cases of NK cell infusion, including 3 cases in low-dose group and 4 cases in middle-dose group, among which 1 patient received 2 dose (1 low-dose and 1 middle-dose). In the low-dose group, 1 patient got response (1/3), with the minimal residual disease turned negative. In the middle-dose group, 3 patients responded (3/4), of which 1 patient had the fusion gene CBFB /ABL decreased from 0.99% to 0.13%, 1 case of extramedullary recurrence of AML turned negative, and NK cells could be detected in cerebrospinal fluid, 1 case of hematological recurrence got hematological remission after treatment. The survival time of NK cells in vivo was 7d-30d, with longer time in middle dose group than those in low dose group. The proportion and number of NK cells in responding cases were significantly higher than those in non-responsive group. Conclusions: Clinical grade expanded NK cells has strong anti-leukemia activity in patients with relapse or minimal residual positive AML patients. NK cells can survive for 2 weeks and can enter the central nervous system without obvious adverse reactions. The response rate in middle-dose group is higher than that in low-dose group. However, the efficacy of NK cells still needs to be further confirmed in a large sample size. Clinical trial information: NCT04221971 .

The ELiPSE-1 study: A phase 1, multicenter, open-label study of CNTY-101 in subjects with relapsed or refractory CD19-positive B-cell malignancies.

TPS7580 Background: Century Therapeutics’ foundational technology is built on induced pluripotent stem cells, differentiated from allogeneic approaches that utilize non-renewable donor-derived cells. This approach allows production of a clonal cell bank of precisely edited cells that can be expanded and differentiated to supply large amounts of homogeneous allogeneic therapeutic products for off-the-shelf use. CNTY-101 is an allogeneic Chimeric Antigen Receptor NK (CAR-NK) cell product with genetic modifications designed to specifically target CD19-expressing B-cell malignancies, reduce allorejection in the recipient allowing for repeat dosing, increase persistence, and enable cell elimination in the event of unexpected adverse events. CNTY-101, as a CAR-NK product, has the potential for improved safety over T-cell based cellular therapies. Methods: This first-in-human study will determine the MTD and recommended Phase 2 regimen (RP2R) of CNTY-101 in combination with subcutaneous (SC) IL-2 in patients with R/R aggressive and indolent CD19-positive B-cell Non-Hodgkin lymphomas including diffuse large B-cell lymphoma, mantle cell lymphoma, primary mediastinal large B-cell lymphoma, follicular lymphoma and marginal zone lymphoma, who are without other treatment options. Part 1 of the study (dose escalation using the BOIN design) will start with a dose of CNTY-101 cells without IL-2 (1 to 3 subjects), followed by dose escalation up to four dose cohorts administering a single dose of CNTY-101 cells in combination with IL-2 daily for 8 days (Sched A). After the single-dose MTD (or the maximal single dose) has been reached, a fractionated schedule of 3 doses per 28-day cycle, administered on Days 1, 8, and 15 (Sched B), will also be explored, starting with approximately one-third the maximum single dose level of CNTY-101, followed by escalation/de-escalation. Subjects in whom CNTY-101 shows signs of clinical benefit (i.e. stable disease or better per Lugano 2014 criteria) may receive additional cycles of CNTY-101 if the Investigator, Sponsor, and appropriate regulatory authorities, as required, concur that the benefit-risk is positive. One overall CNTY-101 RP2R will be declared in Part 1. Part 2, expansion, will further evaluate the safety, pharmacokinetics (PK), and efficacy of the CNTY-101 regimen, treating up to an additional 12 subjects to reach a total of approximately 20 subjects treated at the RP2R. In addition to safety and efficacy endpoints, the trial will evaluate exploratory PK, immunogenicity and pharmacodynamic endpoints including evaluations of tumor cfDNA, iNK tumor trafficking and serum cytokines. Clinical trial information: NCT05336409 .

Cellular activation pathways and interaction networks in vascularized composite allotransplantation.

Vascularized composite allotransplantation (VCA) is an evolving field of reconstructive surgery that has revolutionized the treatment of patients with devastating injuries, including those with limb losses or facial disfigurement. The transplanted units are typically comprised of different tissue types, including skin, mucosa, blood and lymphatic vasculature, muscle, and bone. It is widely accepted that the antigenicity of some VCA components, such as skin, is particularly potent in eliciting a strong recipient rejection response following transplantation. The fine line between tolerance and rejection of the graft is orchestrated by different cell types, including both donor and recipient-derived lymphocytes, macrophages, and other immune and donor-derived tissue cells (e.g., endothelium). Here, we delineate the role of different cell and tissue types during VCA rejection. Rejection of VCA grafts and the necessity of life-long multidrug immunosuppression remains one of the major challenges in this field. This review sheds light on recent developments in decoding the cellular signature of graft rejection in VCA and how these may, ultimately, influence the clinical management of VCA patients by way of novel therapies that target specific cellular processes.

Detection of mutant antigen-specific T cell receptors against multiple myeloma for T cell engineering

Multiple myeloma (MM) remains an incurable hematological neoplasm. Neoantigen-specific Tcell receptor (TCR)-engineered T(TCR-T) cell therapy is a potential alternative treatment. Particularly, TCRs derived from a third-party donor may cover broad ranges of neoantigens, whereas TCRs in patients suffering from immune disorders are limited. However, the efficacy and feasibility of treating MM have not been evaluated thoroughly. In this study, we established a system for identifying immunogenic mutant antigens on MM cells and their corresponding TCRs using healthy donor-derived peripheral blood mononuclear cells (PBMCs). Initially, the immune responses to 35 candidate peptides predicted by the immunogenomic analysis were investigated. Peptide-reactive T lymphocytes were enriched, and subsequently, TCR repertoires were determined by single-cell TCR sequencing. Eleven reconstituted TCRs showed mutation-specific responses against 4 peptides. Particularly, we verified the HLA-A∗24:02-binding QYSPVQATF peptide derived from COASY S55Y as the naturally processed epitope across MM cells, making it a promising immune target. Corresponding TCRs specifically recognized COASY S55Y+HLA-A∗24:02+ MM cells and augmented tumoricidal activity. Finally, adoptive cell transfer of TCR-T cells showed objective responses in the xenograft model. We initiatively proposed the utility of tumor mutated antigen-specific TCR genes to suppress MM. Our unique strategy will facilitate further identification of neoantigen-specific TCRs.

Allogeneic, donor-derived, second-generation, CD19-directed CAR-T cells for the treatment of pediatric relapsed/refractory BCP-ALL

AbstractAutologous CD19-directed chimeric antigen receptor (CAR)-T cells have shown unprecedented efficacy in children with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, patients either relapsing after allogeneic hematopoietic stem cell transplantation (allo-HSCT) or displaying profound lymphopenia and/or rapidly progressing disease often cannot access autologous products. These hurdles may be overcome by allogeneic, donor-derived CAR-T cells. We tested donor-derived T cells transduced with a second-generation (4.1BB) CD19-directed CAR for treatment of patients with BCP-ALL in a hospital-exemption setting. Two constructs were tested: a retroviral construct incorporating the suicide gene inducible caspase-9 (CD19-CAR–Retro_ALLO) first and then a lentiviral construct and an automated, Prodigy-based manufacturing process (CD19-CAR–Lenti_ALLO). Thirteen children/young adults received ALLO–CAR-T cells between March 2021 and October 2022. Doses ranged between 1.0 × 106 and 3.0 × 106 CAR-T cells per kg. The toxicity profile was comparable with that of autologous CAR-T cells, characterized mainly by cytopenia, cytokine release syndrome (maximum grade 1), and grade 2 immune-effector cell–associated neurotoxicity syndrome. One case of acute graft-versus-host disease (GVHD) occurred and was rapidly controlled with steroids and ruxolitinib. None of the other patients, including 3 given ALLO–CAR-T cells from an HLA-haploidentical donor, experienced GVHD. Two patients received ALLO–CAR-T cells before HSCT and showed a significant expansion of CAR-T cells without any sign of GVHD. All patients obtained complete remission (CR) with absence of minimal residual disease in the bone marrow. With a median follow-up of 12 months (range, 5-21), 8 of 13 patients maintained CR. Allogeneic anti-CD19 CAR-T cells can effectively treat highly refractory BCP-ALL relapsing after allo-HSCT without showing increased toxicity as compared with autologous CAR-T cells.

Intraperitoneal transfer of wild-type bone marrow repopulates tissue macrophages in the Csf1r knockout rat without contributing to monocytopoiesis.

Homozygous null mutation of the Csf1r gene (Csf1rko) in rats leads to the loss of most tissue macrophage populations and pleiotropic impacts on postnatal growth and organ maturation, leading to early mortality. The phenotype can be reversed by intraperitoneal transfer of WT BM cells (BMT) at weaning. Here, we used a Csf1r-mApple transgenic reporter to track the fate of donor-derived cells. Following BMT into Csf1rko recipients, mApple+ve cells restored IBA1+ tissue macrophage populations in every tissue. However, monocytes, neutrophils, and B cells in the BM, blood, and lymphoid tissues remained of recipient (mApple-ve ) origin. An mApple+ve cell population expanded in the peritoneal cavity and invaded locally in the mesentery, fat pads, omentum, and diaphragm. One week after BMT, distal organs contained foci of mApple+ve , IBA1-ve immature progenitors that appeared to proliferate, migrate, and differentiate locally. We conclude that rat BM contains progenitor cells that are able to restore, replace, and maintain all tissue macrophage populations in a Csf1rko rat directly without contributing to the BM progenitor or blood monocyte populations.

Allogenic and autologous anti-CD7 CAR-T cell therapies in relapsed or refractory T-cell malignancies

Chimeric antigen receptor-T (CAR-T) therapy remains to be investigated in T-cell malignancies. CD7 is an ideal target for T-cell malignancies but is also expressed on normal T cells, which may cause CAR-T cell fratricide. Donor-derived anti-CD7 CAR-T cells using endoplasmic reticulum retention have shown efficacy in patients with T-cell acute lymphoblastic leukemia (ALL). Here we launched a phase I trial to explore differences between autologous and allogeneic anti-CD7 CAR-T therapies in T-cell ALL and lymphoma. Ten patients were treated and 5 received autologous CAR-T therapies. No dose-limiting toxicity or neurotoxicity was observed. Grade 1–2 cytokine release syndrome occurred in 7 patients, and grade 3 in 1 patient. Grade 1–2 graft-versus-host diseases were observed in 2 patients. Seven patients had bone marrow infiltration, and 100% of them achieved complete remission with negative minimal residual disease within one month. Two-fifths of patients achieved extramedullary or extranodular remission. The median follow-up was 6 (range, 2.7–14) months and bridging transplantation was not administrated. Patients treated with allogeneic CAR-T cells had higher remission rate, less recurrence and more durable CAR-T survival than those receiving autologous products. Allogeneic CAR-T cells appeared to be a better option for patients with T-cell malignancies.

Successful transplantation of cryopreserved spermatogonia in Sebastes schlegelii: A simple and suitable alternative approach for conservation of viviparous fish

Black rockfish (Sebastes schlegelii) is one of the most important marine economic viviparous fishes. Recently, germplasm degradation and genetic diversity reduction have occurred due to overfishing and long-term artificial breeding. Germ cell transplantation combined with cryopreservation may be an alternative way to protect genetic resources. However, in viviparous fish that undertake fertilization and embryo development in vivo, transplantation is more difficult than in oviparous fish, including selection of transplantation stage, isolation of germ stem cells, and preparation of sterile recipients. This seriously restricts the development of viviparous transplantation. Therefore, in this study, we aimed to explore a transplantation method suitable for these species. Donor cells were isolated from cryopreserved whole testes of 300–400 ​g male Sebastes schlegelii in May, labeled by PKH26, and intra-peritoneally transplanted into allogeneic larvae at 5–10 days post-birth. Subsequently, the development of donor-derived cells in recipients were continuously detected by fluorescence labeling, histology, microsatellite markers, and fecundity tests. The results showed that donors were rich in spermatogonia (75%) and recipients maintained a high survival rate after transplantation, with a rate of >20% at sexual maturity. Further, donor-derived cells successfully migrated (100%), colonized, and incorporated into the developing recipient gonad (93.33%). Finally, transplanted recipients could normally develop and differentiate into male and female individuals, with donor-derived gametes found in 65.38% of mature recipients. In the present study, we first establish a simple and suitable transplantation method for Sebastes schlegelii using immature males and specific larvae, which will serve as a promising tool in the protection of germplasm resources for this transplantation-restricted marine viviparous species.

Maximizing colonization and proliferation of blue catfish (Ictalurus furcatus) donor stem cells for the creation of xenogenic catfish: Identifying the best host age of triploid channel catfish (I. punctatus)

Xenogenesis is an innovative technology for hybrid catfish (♀ channel catfish, Ictalurus punctatus, × ♂ blue catfish, I. furcatus) embryo production. The xenogeneic process can be accomplished by transplanting undifferentiated diploid germline stem cells derived from donor fish into sterile recipients. This methodology enables recipients to produce donor-derived gametes. Until recently, the timing of transplantation of donor cells into hosts was done with limited knowledge of the best age to inject cells. The age of the host could critically affect the success of germ cell transplantation. The present study aimed to identify the best age of the triploid channel catfish to transplant blue catfish stem cells for production of xenogeneic catfish. Triploid channel catfish fry were injected with blue catfish stem cells labeled with PKH26 dye from 0 to 18 days post-hatch (DPH). Then at 50 DPH (1st time interval) and 90 DPH (2nd time interval), total length (TL), weight (BW), and survival of recipients were evaluated. Colonization of donor cells was evaluated in recipients using PKH26 dye fluorescence to calculate percent cell (<150 μm2) and cluster areas (>150 μm2). PCR determined the percentage of xenogens from gonads. Day of stem cell injection had no impact on TL and BW of recipient fish when evaluated at both sampling intervals. Survival of recipients injected with blue catfish stem cells increased from 0 to 5.4 DPH. After 5.4 DPH, survival remained high (≥82%) for fry injected until 18 DPH. At the 1st time interval, cell and cluster area increased as recipients fish injected from 0 to 5.4 DPH and 0 to 5.6 DPH, respectively. Thereafter, fluorescent cell and cluster area in the host declined with no further decrease after 11.3 and 10.4 DPH, respectively. At the 2nd time interval, cell and cluster area increased as recipients were injected from 0 to 5.8 DPH and 0 to 5.7 DPH and significantly declined with no further decrease after 10.2 and 11.3 DPH, respectively. At the 1st time interval, the highest percentage of xenogens were detected when recipients were injected from 3 to 5 DPH (83.3%), while at the 2nd time interval, the highest percentage of xenogens was detected from 4 to 6 DPH (83.3%). Our results show that 4 to 6 DPH is a suitable timespan to inject donor-derived stem cells into recipients. These findings will enhance the efficiency of germ cell transplantation for commercial-scale hybrid catfish production.

Single-Cell Transcriptomics Reveals Immune Reconstitution in Patients with R/R T-ALL/LBL Treated with Donor-Derived CD7 CAR-T Therapy.

CD7 chimeric antigen receptor T (CAR-T) therapy has potent antitumor activity against relapsed/refractory (R/R) T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL), however, immune reconstitution after CAR-T remains largely unknown. An open-label phase I clinical trial (ChiCTR2200058969) was initiated to evaluate safety and efficacy of donor-derived CD7 CAR-T cells in 7 R/R T-ALL/LBL patients. CAR-T cells were detected by flow cytometry and PCR. Cytokine levels were quantified by cytometric bead arrays. Single-cell RNA sequencing (scRNA-seq) was adopted to profile immune reconstitution. Optimal complete remission (CR) was 100% on day 28, and median followed-up time was 4 months. Leukopenia, thrombocytopenia, and neutropenia were observed in 6 patients, and infections occurred in 5 patients. Two patients died of serious infection and one died of a brain hemorrhage. CAR-T cells expanded efficiently in all patients. CD7+ T cells were eliminated in peripheral blood on day 11 after infusion, and CD7- T cells dramatically expanded in all patients. scRNA-seq suggested that immunologic activities of CD7- T cells were stronger than those of T cells before infusion due to higher expression levels of T-cell function-related pathways, and major characters of such CD7- T cells were activation of autoimmune-related pathways. Monocyte loss was found in 2 patients who died of serious infections, indicating the main cause of the infections after infusion. S100A8 and S100A9 were identified as potential relapse markers due to their notable upregulation in leukocyte lineage in relapsed patients versus non-relapse controls. Our data revealed cellular level dynamics of immune homeostasis of CD7 CAR-T therapy, which is valuable for optimizing the treatment of R/R T-ALL/LBL.

Driving the Chimeric Antigen Receptor: The Road Ahead for Cell Therapy

Driving the Chimeric Antigen Receptor: The Road Ahead for Cell Therapy

Local delivery of tacrolimus using electrospun poly-ϵ-caprolactone nanofibres suppresses the T-cell response to peripheral nerve allografts

Objective. Repair of nerve gap injuries can be achieved through nerve autografting, but this approach is restricted by limited tissue supply and donor site morbidity. The use of living nerve allografts would provide an abundant tissue source, improving outcomes following peripheral nerve injury. Currently this approach is not used due to the requirement for systemic immunosuppression, to prevent donor-derived cells within the transplanted nerve causing an immune response, which is associated with severe adverse effects. The aim of this study was to develop a method for delivering immunosuppression locally, then to test its effectiveness in reducing the immune response to transplanted tissue in a rat model of nerve allograft repair. Approach. A coaxial electrospinning approach was used to produce poly-ϵ-caprolactone fibre sheets loaded with the immunosuppressant tacrolimus. The material was characterised in terms of structure and tacrolimus release, then tested in vivo through implantation in a rat sciatic nerve allograft model with immunologically mismatched host and donor tissue. Main results. Following successful drug encapsulation, the fibre sheets showed nanofibrous structure and controlled release of tacrolimus over several weeks. Materials containing tacrolimus (and blank material controls) were implanted around the nerve graft at the time of allograft or autograft repair. The fibre sheets were well tolerated by the animals and tacrolimus release resulted in a significant reduction in lymphocyte infiltration at 3 weeks post-transplantation. Significance. These findings demonstrate proof of concept for a novel nanofibrous biomaterial-based targeted drug delivery strategy for immunosuppression in peripheral nerve allografting.

SARS-CoV-2 viral entry and replication is impaired in Cystic Fibrosis airways due to ACE2 downregulation

As an inherited disorder characterized by severe pulmonary disease, cystic fibrosis could be considered a comorbidity for coronavirus disease 2019. Instead, current clinical evidence seems to be heading in the opposite direction. To clarify whether host factors expressed by the Cystic Fibrosis epithelia may influence coronavirus disease 2019 progression, here we describe the expression of SARS-CoV-2 receptors in primary airway epithelial cells. We show that angiotensin converting enzyme 2 (ACE2) expression and localization are regulated by Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) channel. Consistently, our results indicate that dysfunctional CFTR channels alter susceptibility to SARS-CoV-2 infection, resulting in reduced viral entry and replication in Cystic Fibrosis cells. Depending on the pattern of ACE2 expression, the SARS-CoV-2 spike (S) protein induced high levels of Interleukin 6 in healthy donor-derived primary airway epithelial cells, but a very weak response in primary Cystic Fibrosis cells. Collectively, these data support that Cystic Fibrosis condition may be at least partially protecting from SARS-CoV-2 infection.

CD7 CAR-T therapy for an AML patient with CD7 expression

To date, no ideal CAR-T product is available for treating acute myeloid leukemia (AML). Recently, CD7 CAR-T therapy has shown promising efficiency in treating T-cell acute lymphoblastic leukemia. Because the CD7 antigen is also expressed on the myeloid blasts of some patients with AML, it might serve as a target for immunotherapy in AML. Herein, we administered CD7-specific CAR-T cells into a 20-year-old woman with AML with CD7 expression. She had a history of multiple relapses (with extramedullary disease, EMD) and treatments (radiation and allogeneic hematopoietic cell transplantation). The most recent relapse indicated a high disease burden with multifocal EMD. After a combination regimen of azacytidine, venetoclax and ruxolitinib, she showed minimal residual disease-positive remission in the bone marrow (BM), and EMD remained present. Subsequently, donor-derived CD7 CAR-T cells infused at a dose of 5.5×105/kg completely eliminated all disease in the BM and extramedullary areas. Grade I cytokine release syndrome occurred with no neurotoxicity. CD7 CAR-T cells were detectable in the peripheral blood and BM. Fifty-five days after T-cell infusion, she underwent a second allogeneic hematopoietic cell transplantation and has survived in disease-free remission for more than 7 months.

Bone Marrow Mesenchymal Stromal/Stem Cell-Derived Extracellular Vesicles Promote Corneal Wound Repair by Regulating Inflammation and Angiogenesis

Severe corneal damage leads to complete vision loss, thereby affecting life quality and impinging heavily on the healthcare system. Current clinical approaches to manage corneal wounds suffer from severe drawbacks, thus requiring the development of alternative strategies. Of late, mesenchymal stromal/stem cell (MSC)-derived extracellular vesicles (EVs) have become a promising tool in the ophthalmic field. In the present study, we topically delivered bone-marrow-derived MSC-EVs (BMSC-EVs), embedded in methylcellulose, in a murine model of alkali-burn-induced corneal damage in order to evaluate their role in corneal repair through histological and molecular analyses, with the support of magnetic resonance imaging. Our data show that BMSC-EVs, used for the first time in this specific formulation on the damaged cornea, modulate cell death, inflammation and angiogenetic programs in the injured tissue, thus leading to a faster recovery of corneal damage. These results were confirmed on cadaveric donor-derived human corneal epithelial cells in vitro. Thus, BMSC-EVs modulate corneal repair dynamics and are promising as a new cell-free approach for intervening on burn wounds, especially in the avascularized region of the eye.