Multidimensional single-cell analysis identifies a role for CD2-CD58 interactions in clinical antitumor T cell responses.

The in vivo persistence of adoptively transferred T cells is predictive of antitumor response. Identifying functional properties of infused T cells that lead to in vivo persistence and tumor eradication has remained elusive. We profiled CD19-specific chimeric antigen receptor (CAR) T cells as the infusion products used to treat large B cell lymphomas using high-throughput single-cell technologies based on time-lapse imaging microscopy in nanowell grids (TIMING), which integrates killing, cytokine secretion, and transcriptional profiling.

Cytotoxic T lymphocytes targeting a conserved SARS-CoV-2 spike epitope are efficient serial killers.

Understanding immune response to infections and vaccines lags understanding humoral responses. While neutralizing antibody responses wane over time, T cells are instrumental in long-term immunity. We apply machine learning and time-lapse imaging microscopy in nanowell grids (TIMING) to study thousands of videos of T cells with specificity for SARS-CoV-2 eliminating targets bearing spike protein as a surrogate for viral infection.

Adoptive immunotherapy with double-bright (CD56 /CD16 ) expanded natural killer cells in patients with relapsed or refractory acute myeloid leukaemia: a proof-of-concept study.

Patients with acute myeloid leukaemia (AML) have a five-year survival rate of 28·7%. Natural killer (NK)-cell have anti-leukaemic activity. Here, we report on a series of 13 patients with high-risk R/R AML, treated with repeated infusions of double-bright (CD56 /CD16 ) expanded NK cells at an academic centre in Brazil.

Designed improvement to T-cell immunotherapy by multidimensional single cell profiling.

Background: Adoptive cell therapy based on the infusion of chimeric antigen receptor (CAR) T cells has shown remarkable efficacy for the treatment of hematologic malignancies. The primary mechanism of action of these infused T cells is the direct killing of tumor cells expressing the cognate antigen. However, understanding why only some T cells are capable of killing, and identifying mechanisms that can improve killing has remained elusive.

Human LAPGARPFOXP3 regulatory T cells attenuate xenogeneic graft versus host disease.

Adoptive transfer of regulatory T cells (FOXP3 Tregs) has been developed as a potential curative immune therapy to prevent and treat autoimmune and graft-versus-host diseases (GVHD). A major limitation that has hindered the use of Treg immunotherapy in humans is the difficulty of consistently isolating and obtaining highly purified Tregs after expansion. : We isolated Tregs from expansion cultures based on their selective surface expression of latency-associated peptide (LAP).

Infusion of Alloanergized Donor Lymphocytes after CD34-selected Haploidentical Myeloablative Hematopoietic Stem Cell Transplantation.

Allogeneic hematopoietic stem-cell transplantation (HSCT) is a curative treatment for many hematologic cancers. Use of haploidentical (mismatched) donors increases HSCT availability but is limited by severe graft-versus-host disease (GvHD) and delayed immune reconstitution. Alloanergization of donor T cells is a simple approach to rebuild immunity while limiting GvHD after haploidentical HSCT, but the optimal T-cell dose and impact on immune reconstitution remain unknown.

Defining potency of CAR T cells: Fast and furious or slow and steady.

Genetically engineered T cells that express chimeric antigen receptors (CAR) are heterogeneous and thus, understanding the immunotherapeutic efficacy remains a challenge in adoptive cell therapy. We developed a high-throughput single-cell methodology, Timelapse Imaging Microscopy In Nanowell Grids (TIMING) to monitor interactions between immune cells and tumor cells . Using TIMING we demonstrated that CD4 CAR T cells participate in multi-killing and benefit from improved resistance to activation induced cell death in comparison to CD8 CAR+ T cells.

Antitumor activity of CD56-chimeric antigen receptor T cells in neuroblastoma and SCLC models.

The CD56 antigen (NCAM-1) is highly expressed on several malignancies with neuronal or neuroendocrine differentiation, including small-cell lung cancer and neuroblastoma, tumor types for which new therapeutic options are needed. We hypothesized that CD56-specific chimeric antigen receptor (CAR) T cells could target and eliminate CD56-positive malignancies. Sleeping Beauty transposon-generated CD56R-CAR T cells exhibited αβT-cell receptors, released antitumor cytokines upon co-culture with CD56 tumor targets, demonstrated a lack of fratricide, and expression of cytolytic function in the presence of CD56 stimulation.

Safety and Efficacy of Intratumoral Injections of Chimeric Antigen Receptor (CAR) T Cells in Metastatic Breast Cancer.

Chimeric antigen receptors (CAR) are synthetic molecules that provide new specificities to T cells. Although successful in treatment of hematologic malignancies, CAR T cells are ineffective for solid tumors to date. We found that the cell-surface molecule c-Met was expressed in ∼50% of breast tumors, prompting the construction of a CAR T cell specific for c-Met, which halted tumor growth in immune-incompetent mice with tumor xenografts.

Outcomes of children, adolescents, and young adults following allogeneic stem cell transplantation for secondary acute myeloid leukemia and myelodysplastic syndromes-The MD Anderson Cancer Center experience.

We conducted a retrospective analysis of outcomes for children and young adults with sAML/sMDS who underwent HSCT at our institution. Thirty-two patients (median age 20 years) with sAML (n=24) and sMDS (n=8) received HSCT between 1990 and 2013. The median time from sAML/sMDS diagnosis to HSCT was 4.

Targeting B-cell malignancies through human B-cell receptor specific CD4 T cells.

The B-cell receptor (BCR) expressed by a clonal B cell tumor is a tumor specific antigen (idiotype). However, the T-cell epitopes within human BCRs which stimulate protective immunity still lack detailed characterization. In this study, we identified 17 BCR peptide-specific CD4 T-cell epitopes derived from BCR heavy and light chain variable region sequences.

Tethered IL-15 augments antitumor activity and promotes a stem-cell memory subset in tumor-specific T cells.

Adoptive immunotherapy retargeting T cells to CD19 via a chimeric antigen receptor (CAR) is an investigational treatment capable of inducing complete tumor regression of B-cell malignancies when there is sustained survival of infused cells. T-memory stem cells (T) retain superior potential for long-lived persistence, but challenges exist in manufacturing this T-cell subset because they are rare among circulating lymphocytes. We report a clinically relevant approach to generating CAR T cells with preserved T potential using the Sleeping Beauty platform.

Imaging of Sleeping Beauty-Modified CD19-Specific T Cells Expressing HSV1-Thymidine Kinase by Positron Emission Tomography.

Purpose: We have incorporated a positron emission tomography (PET) functionality in T cells expressing a CD19-specific chimeric antigen receptor (CAR) to non-invasively monitor the adoptively transferred cells.

Procedures: We engineered T cells to express CD19-specific CAR, firefly luciferase (ffLuc), and herpes simplex virus type-1 thymidine kinase (TK) using the non-viral-based Sleeping Beauty (SB) transposon/transposase system adapted for human application. Electroporated primary T cells were propagated on CD19 artificial antigen-presenting cells.

Improving vascular maturation using noncoding RNAs increases antitumor effect of chemotherapy.

Current antiangiogenesis therapy relies on inhibiting newly developed immature tumor blood vessels and starving tumor cells. This strategy has shown transient and modest efficacy. Here, we report a better approach to target cancer-associated endothelial cells (ECs), reverse permeability and leakiness of tumor blood vessels, and improve delivery of chemotherapeutic agents to the tumor.

Redirecting Specificity of T cells Using the Sleeping Beauty System to Express Chimeric Antigen Receptors by Mix-and-Matching of VL and VH Domains Targeting CD123+ Tumors.

Adoptive immunotherapy infusing T cells with engineered specificity for CD19 expressed on B- cell malignancies is generating enthusiasm to extend this approach to other hematological malignancies, such as acute myelogenous leukemia (AML). CD123, or interleukin 3 receptor alpha, is overexpressed on most AML and some lymphoid malignancies, such as acute lymphocytic leukemia (ALL), and has been an effective target for T cells expressing chimeric antigen receptors (CARs). The prototypical CAR encodes a VH and VL from one monoclonal antibody (mAb), coupled to a transmembrane domain and one or more cytoplasmic signaling domains.

Phase I trials using Sleeping Beauty to generate CD19-specific CAR T cells.

Background: T cells expressing antigen-specific chimeric antigen receptors (CARs) improve outcomes for CD19-expressing B cell malignancies. We evaluated a human application of T cells that were genetically modified using the Sleeping Beauty (SB) transposon/transposase system to express a CD19-specific CAR.

Methods: T cells were genetically modified using DNA plasmids from the SB platform to stably express a second-generation CD19-specific CAR and selectively propagated ex vivo with activating and propagating cells (AaPCs) and cytokines.

Immunotherapy of acute leukemia by chimeric antigen receptor-modified lymphocytes using an improved Sleeping Beauty transposon platform.

Chimeric antigen receptor (CAR)-modified T-cell adoptive immunotherapy is a remarkable therapeutic option proven effective in the treatment of hematological malignancies. In order to optimize cell manufacturing, we sought to develop a novel clinical-grade protocol to obtain CAR-modified cytokine-induced killer cells (CIKs) using the Sleeping Beauty (SB) transposon system. Administration of irradiated PBMCs overcame cell death of stimulating cells induced by non-viral transfection, enabling robust gene transfer together with efficient T-cell expansion.

T cells expressing CD19-specific Engager Molecules for the Immunotherapy of CD19-positive Malignancies.

T cells expressing chimeric antigen receptors (CARs) or the infusion of bispecific T-cell engagers (BITEs) have shown antitumor activity in humans for CD19-positive malignancies. While BITEs redirect the large reservoir of resident T cells to tumors, CAR T cells rely on significant in vivo expansion to exert antitumor activity. We have shown that it is feasible to modify T cells to secrete solid tumor antigen-specific BITEs, enabling T cells to redirect resident T cells to tumor cells.

Translational Implications for Off-the-shelf Immune Cells Expressing Chimeric Antigen Receptors.

Chimeric antigen receptor (CAR) endows specificity to T-cells independent of human leukocyte antigen (HLA). This enables one immunoreceptor to directly target the same surface antigen on different subsets of tumor cells from multiple HLA-disparate recipients. Most approaches manufacture individualized CAR(+)T-cells from the recipient or HLA-compatible donor, which are revealing promising clinical results.

CD62L+ NKT cells have prolonged persistence and antitumor activity in vivo.

Vα24-invariant natural killer T cells (NKTs) localize to tumors and have inherent antitumor properties, making them attractive chimeric antigen receptor (CAR) carriers for redirected cancer immunotherapy. However, clinical application of CAR-NKTs has been impeded, as mechanisms responsible for NKT expansion and the in vivo persistence of these cells are unknown. Here, we demonstrated that antigen-induced expansion of primary NKTs in vitro associates with the accumulation of a CD62L+ subset and exhaustion of CD62L- cells.

Redirecting T-Cell Specificity to EGFR Using mRNA to Self-limit Expression of Chimeric Antigen Receptor.

Potential for on-target, but off-tissue toxicity limits therapeutic application of genetically modified T cells constitutively expressing chimeric antigen receptors (CARs) from tumor-associated antigens expressed in normal tissue, such as epidermal growth factor receptor (EGFR). Curtailing expression of CAR through modification of T cells by in vitro-transcribed mRNA species is one strategy to mitigate such toxicity. We evaluated expression of an EGFR-specific CAR coded from introduced mRNA in human T cells numerically expanded ex vivo to clinically significant numbers through coculture with activating and propagating cells (AaPC) derived from K562 preloaded with anti-CD3 antibody.

Phase 1 studies of central memory-derived CD19 CAR T-cell therapy following autologous HSCT in patients with B-cell NHL.

Myeloablative autologous hematopoietic stem cell transplantation (HSCT) is a mainstay of therapy for relapsed intermediate-grade B-cell non-Hodgkin lymphoma (NHL); however, relapse rates are high. In phase 1 studies designed to improve long-term remission rates, we administered adoptive T-cell immunotherapy after HSCT, using ex vivo-expanded autologous central memory-enriched T cells (TCM) transduced with lentivirus expressing CD19-specific chimeric antigen receptors (CARs). We present results from 2 safety/feasibility studies, NHL1 and NHL2, investigating different T-cell populations and CAR constructs.

The beneficial effects of a gas-permeable flask for expansion of Tumor-Infiltrating lymphocytes as reflected in their mitochondrial function and respiration capacity.

Adoptive transfer of autologous expanded tumor-infiltrating lymphocytes (TIL) is a highly successful cell therapy approach in the treatment of late-stage melanoma. Notwithstanding the success of this therapy, only very few centers worldwide can provide it. To make this therapy broadly available, one of the major obstacles to overcome is the complexity of culturing the TIL.