Co-transducing B7H3 CAR-NK cells with the DNR preserves their cytolytic function against GBM in the presence of exogenous TGF-ß.

Cord blood (CB)-derived natural killer (NK) cells that are genetically engineered to express a chimeric antigen receptor (CAR) are an attractive off-the-shelf therapy for the treatment of cancer, demonstrating a robust safety profile in vivo. For poor prognosis brain tumors such as glioblastoma multiforme (GBM), novel therapies are urgently needed. Although CAR-T cells demonstrate efficacy in preclinical GBM models, an off-the-shelf product may exhibit unwanted side effects like graft-versus-host disease. Hence, we developed an off-the-shelf CAR-NK cell approach using a B7H3 CAR and showed that CAR-transduced NK cells have robust cytolytic activity against GBM cells in vitro. However, transforming growth factor (TGF)-ß within the tumor microenvironment has devastating effects on the cytolytic activity of both unmodified and CAR-transduced NK cells. To overcome this potent immune suppression, we demonstrated that co-transducing NK cells with a B7H3 CAR and a TGF-ß dominant negative receptor (DNR) preserves cytolytic function in the presence of exogenous TGF-ß. This study demonstrates that a novel DNR and CAR co-expression strategy may be a promising therapeutic for recalcitrant CNS tumors like GBM.

The generation and application of antigen-specific T cell therapies for cancer and viral-associated disease.

Immunotherapy with antigen-specific T cells is a promising, targeted therapeutic option for patients with cancer as well as for immunocompromised patients with virus infections. In this review, we characterize and compare current manufacturing protocols for the generation of T cells specific to viral and non-viral tumor-associated antigens. Specifically, we discuss: (1) the different methodologies to expand virus-specific T cell and non-viral tumor-associated antigen-specific T cell products, (2) an overview of the immunological principles involved when developing such manufacturing protocols, and (3) proposed standardized methodologies for the generation of polyclonal, polyfunctional antigen-specific T cells irrespective of donor source. Ex vivo expanded cells have been safely administered to treat numerous patients with virus-associated malignancies, hematologic malignancies, and solid tumors. Hence, we have performed a comprehensive review of the clinical trial results evaluating the safety, feasibility, and efficacy of these products in the clinic. In summary, this review seeks to provide new insights regarding antigen-specific T cell technology to benefit a rapidly expanding T cell therapy field.

Spike-directed vaccination elicits robust spike-specific T-cell response, including to mutant strains.

Although most studies describing coronavirus disease 2019 vaccine responses have focused on antibodies, there is increasing evidence that T cells play a critical role. Here the authors evaluated T-cell responses in seronegative donors before and after vaccination to define responses to the severe acute respiratory syndrome coronavirus 2 reference strain as well as to mutations in the variant strains Alpha/B.1.1.7 and Beta/B.1.351. The authors observed enhanced T-cell responses to reference and variant spike strains post-vaccination.

Mitochondrial Enzymes of the Urea Cycle Cluster at the Inner Mitochondrial Membrane.

Mitochondrial enzymes involved in energy transformation are organized into multiprotein complexes that channel the reaction intermediates for efficient ATP production. Three of the mammalian urea cycle enzymes: N-acetylglutamate synthase (NAGS), carbamylphosphate synthetase 1 (CPS1), and ornithine transcarbamylase (OTC) reside in the mitochondria. Urea cycle is required to convert ammonia into urea and protect the brain from ammonia toxicity. Urea cycle intermediates are tightly channeled in and out of mitochondria, indicating that efficient activity of these enzymes relies upon their coordinated interaction with each other, perhaps in a cluster. This view is supported by mutations in surface residues of the urea cycle proteins that impair ureagenesis in the patients, but do not affect protein stability or catalytic activity. We find the NAGS, CPS1, and OTC proteins in liver mitochondria can associate with the inner mitochondrial membrane (IMM) and can be co-immunoprecipitated. Our in-silico analysis of vertebrate NAGS proteins, the least abundant of the urea cycle enzymes, identified a protein-protein interaction region present only in the mammalian NAGS protein-"variable segment," which mediates the interaction of NAGS with CPS1. Use of super resolution microscopy showed that NAGS, CPS1 and OTC are organized into clusters in the hepatocyte mitochondria. These results indicate that mitochondrial urea cycle proteins cluster, instead of functioning either independently or in a rigid multienzyme complex.