Generation of antitumor chimeric antigen receptors incorporating T cell signaling motifs.

Chimeric antigen receptor (CAR) T cells have been used to successfully treat various blood cancers, but adverse effects have limited their potential. Here, we developed chimeric adaptor proteins (CAPs) and CAR tyrosine kinases (CAR-TKs) in which the intracellular ζ T cell receptor (TCRζ) chain was replaced with intracellular protein domains to stimulate signaling downstream of the TCRζ chain. CAPs contain adaptor domains and the kinase domain of ZAP70, whereas CAR-TKs contain only ZAP70 domains.

Metabolic dialogues: regulators of chimeric antigen receptor T cell function in the tumor microenvironment.

Tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) T cells have demonstrated remarkable success in the treatment of relapsed/refractory melanoma and hematological malignancies, respectively. These treatments have marked a pivotal shift in cancer management. However, as "living drugs," their effectiveness is dependent on their ability to proliferate and persist in patients.

CD3ζ ITAMs enable ligand discrimination and antagonism by inhibiting TCR signaling in response to low-affinity peptides.

The T cell antigen receptor (TCR) contains ten immunoreceptor tyrosine-based activation motif (ITAM) signaling sequences distributed within six CD3 subunits; however, the reason for such structural complexity and multiplicity is unclear. Here we evaluated the effect of inactivating the three CD3ζ chain ITAMs on TCR signaling and T cell effector responses using a conditional 'switch' mouse model. Unexpectedly, we found that T cells expressing TCRs containing inactivated (non-signaling) CD3ζ ITAMs (6F-CD3ζ) exhibited reduced ability to discriminate between low- and high-affinity ligands, resulting in enhanced signaling and cytokine responses to low-affinity ligands because of a previously undetected inhibitory function of CD3ζ ITAMs.

Co-op CARs for targeting acute myeloid leukemia.

Chimeric antigen receptor (CAR) T cell therapies are limited by antigen escape and on-target/off-tumor toxicity. In addressing these challenges, Haubner et al. develop an "IF-BETTER" strategy.

Apoptotic contraction drives target cell release by cytotoxic T cells.

Cytotoxic T lymphocytes (CTLs) fight intracellular pathogens and cancer by identifying and destroying infected or transformed target cells. To kill, CTLs form a specialized cytotoxic immune synapse (IS) with a target of interest and then release toxic perforin and granzymes into the interface to elicit programmed cell death. The IS then dissolves, enabling CTLs to search for additional prey and professional phagocytes to clear the corpse.

Universal antigen encoding of T cell activation from high-dimensional cytokine dynamics.

Systems immunology lacks a framework with which to derive theoretical understanding from high-dimensional datasets. We combined a robotic platform with machine learning to experimentally measure and theoretically model CD8 T cell activation. High-dimensional cytokine dynamics could be compressed onto a low-dimensional latent space in an antigen-specific manner (so-called "antigen encoding").

Rejuvenating Effector/Exhausted CAR T Cells to Stem Cell Memory-Like CAR T Cells By Resting Them in the Presence of CXCL12 and the NOTCH Ligand.

Unlabelled: T cells with a stem cell memory (T) phenotype provide long-term and potent antitumor effects for T-cell transfer therapies. Although various methods for the induction of T-like cells have been reported, few methods generate T-like cells from effector/exhausted T cells. We have reported that coculture with the Notch ligand-expressing OP9 stromal cells induces T-like (iT) cells.

Whole-exome sequencing and host cell reactivation assay lead to a diagnosis of xeroderma pigmentosum group D with mild ultraviolet radiation sensitivity.

A case of xeroderma pigmentosum (XP) group D in a 39-year-old Japanese man is reported. The patient had suffered from moderate to severe solar sensitivity and freckle-like pigmented macules in sun-exposed areas since 6 years of age, and developed skin malignancies such as squamous cell carcinoma, actinic keratosis, Bowen's disease and basal cell carcinoma. The minimal erythema dose for ultraviolet (UV) radiation was decreased with a delayed peak reaction.

Perforin-deficient CAR T cells recapitulate late-onset inflammatory toxicities observed in patients.

Late-onset inflammatory toxicities resembling hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS) occur after chimeric antigen receptor T cell (CAR T cell) infusion and represent a therapeutic challenge. Given the established link between perforin deficiency and primary HLH, we investigated the role of perforin in anti-CD19 CAR T cell efficacy and HLH-like toxicities in a syngeneic murine model. Perforin contributed to both CD8+ and CD4+ CAR T cell cytotoxicity but was not required for in vitro or in vivo leukemia clearance.

Phosphate Transporter Profiles in Murine and Human Thymi Identify Thymocytes at Distinct Stages of Differentiation.

Thymocyte differentiation is dependent on the availability and transport of metabolites in the thymus niche. As expression of metabolite transporters is a rate-limiting step in nutrient utilization, cell surface transporter levels generally reflect the cell's metabolic state. The GLUT1 glucose transporter is upregulated on actively dividing thymocytes, identifying thymocytes with an increased metabolism.

CD19-targeted CAR regulatory T cells suppress B cell pathology without GvHD.

Regulatory T cells (Tregs) play essential roles in maintaining immunological self-tolerance and preventing autoimmunity. The adoptive transfer of antigen-specific Tregs has been expected to be a potent therapeutic method for autoimmune diseases, severe allergy, and rejection in organ transplantation. However, effective Treg therapy has not yet been established because of the difficulty in preparing a limited number of antigen-specific Tregs.

In Vitro Generation of Stem Cell Memory-Like T Cells from Activated T Cells.

Adoptive T-cell therapy is an attractive strategy for cancer immunotherapy. The transfer of in vitro expanded tumor-associated antigen (TAA)-specific T cells from patients may effectively fight against the original tumor cells. The chimeric antigen receptor-engineered T (CAR-T) cells are also shown to be a promising therapy for hematologic malignancies.

Memory T cell, exhaustion, and tumor immunity.

CD8T cells are important in protective immunity against intracellular pathogens and tumors. In chronic infections or cancer, CD8T cells are constantly exposed to antigens and inflammatory signals. Such excessive and constitutive signals lead to the deterioration of T cell function, called 'exhaustion'.

The NOTCH-FOXM1 Axis Plays a Key Role in Mitochondrial Biogenesis in the Induction of Human Stem Cell Memory-like CAR-T Cells.

Recent studies have shown that stem cell memory T (T) cell-like properties are important for successful adoptive immunotherapy by the chimeric antigen receptor-engineered-T (CAR-T) cells. We previously reported that both human and murine-activated T cells are converted into stem cell memory-like T (iT) cells by coculture with stromal OP9 cells expressing the NOTCH ligand. However, the mechanism of NOTCH-mediated iT reprogramming remains to be elucidated.

In Vitro Conversion of Activated T Cells into Stem Cell Memory-Like T Cells.

Adoptive T cell therapy is an attractive strategy in tumor immunotherapy. The transfer of in vitro expanded tumor-associated antigen (TAA)-specific T cells from patients may effectively destroy the original tumor cells. One of the limitations is a rapid acquisition of tolerant (anergy, deletion, dysfunctional, and/or exhausted) phenotypes.

Brain regulatory T cells suppress astrogliosis and potentiate neurological recovery.

In addition to maintaining immune tolerance, FOXP3 regulatory T (T) cells perform specialized functions in tissue homeostasis and remodelling. However, the characteristics and functions of brain T cells are not well understood because there is a low number of T cells in the brain under normal conditions. Here we show that there is massive accumulation of T cells in the mouse brain after ischaemic stroke, and this potentiates neurological recovery during the chronic phase of ischaemic brain injury.

Generation and application of human induced-stem cell memory T cells for adoptive immunotherapy.

Adoptive T-cell therapy is an effective strategy for cancer immunotherapy. However, infused T cells frequently become functionally exhausted, and consequently offer a poor prognosis after transplantation into patients. Adoptive transfer of tumor antigen-specific stem cell memory T (T ) cells is expected to overcome this shortcoming as T cells are close to naïve T cells, but are also highly proliferative, long-lived, and produce a large number of effector T cells in response to antigen stimulation.

Inhibition of Nr4a Receptors Enhances Antitumor Immunity by Breaking Treg-Mediated Immune Tolerance.

Enhanced infiltration of regulatory T cells (Treg) into tumor tissue is detrimental to patients with cancer and is closely associated with poor prognosis as they create an immunosuppressive state that suppresses antitumor immune responses. Therefore, breaking Treg-mediated immune tolerance is important when considering cancer immunotherapy. Here, we show that the Nr4a nuclear receptors, key transcription factors maintaining Treg genetic programs, contribute to Treg-mediated suppression of antitumor immunity in the tumor microenvironment.

Generation of allo-antigen-specific induced Treg stabilized by vitamin C treatment and its application for prevention of acute graft versus host disease model.

Antigen-specific regulatory T cells (Tregs) possess the potential to reduce excess immune responses in autoimmune diseases, allergy, rejection after organ transplantation and graft-versus-host disease (GVHD) following hematopoietic stem cell transplantation. Although in vitro-expanded antigen-specific induced Tregs (iTregs) have been considered to be a promising therapeutic agent against such excessive immune reactions, the instability of iTregs after transfer is a fundamental problem in their clinical application. In this study, we searched for the optimal way to generate stable iTregs for the prevention of the murine GVHD model, in which conventional iTregs are reported to be inefficient.

Improvement of Foxp3 stability through CNS2 demethylation by TET enzyme induction and activation.

Since induced regulatory T cells (iTregs) can be produced in a large quantity in vitro, these cells are expected to be clinically useful to induce immunological tolerance in various immunological diseases. Foxp3 (Forkhead box P3) expression in iTregs is, however, unstable due to the lack of demethylation of the CpG island in the conserved non-coding sequence 2 (CNS2) of the Foxp3 locus. To facilitate the demethylation of CNS2, we over-expressed the catalytic domain (CD) of the ten-eleven translocation (TET) protein, which catalyzes the steps of the iterative demethylation of 5-methylcytosine.

Blockage of Core Fucosylation Reduces Cell-Surface Expression of PD-1 and Promotes Anti-tumor Immune Responses of T Cells.

Programmed cell death 1 (PD-1) is highly expressed on exhausted T cells and inhibits T cell activation. Antibodies that block the interaction between PD-1 and its ligand prevent this inhibitory signal and reverse T cell dysfunction, providing beneficial anti-tumor responses in a substantial number of patients. Mechanisms for the induction and maintenance of high PD-1 expression on exhausted T cells have not been fully understood.

Notch-mediated conversion of activated T cells into stem cell memory-like T cells for adoptive immunotherapy.

Adoptive T-cell immunotherapy is a promising approach to cancer therapy. Stem cell memory T (T) cells have been proposed as a class of long-lived and highly proliferative memory T cells. CD8 T cells can be generated in vitro from naive CD8 T cells via Wnt signalling; however, methods do not yet exist for inducing T cells from activated or memory T cells.

Suppression of Th2 and Tfh immune reactions by Nr4a receptors in mature T reg cells.

Regulatory T (T reg) cells are central mediators of immune suppression. As such, T reg cells are characterized by a distinct pattern of gene expression, which includes up-regulation of immunosuppressive genes and silencing of inflammatory cytokine genes. Although an increasing number of transcription factors that regulate T reg cells have been identified, the mechanisms by which the T reg cell-specific transcriptional program is maintained and executed remain largely unknown.