Cowan, C. | Search bioRxiv

bioRxiv2024

Universal protection of allogeneic cell therapies from natural killer cells via CD300a agonism

Immunogenicity limits the persistence of off-the-shelf, allogeneic cell therapies and transplants. While ablation of human leukocyte antigen (HLA) removes most T cell and humoral alloreactivity, no solution has enabled universal protection against the resulting natural killer (NK) cell response. Here, we engineered Trans Antigen Signaling Receptors (TASR) as a new class of NK inhibitory ligands and discovered CD300a, a previously inaccessible receptor, as a functional target. CD300a TASR outperformed leading alternative strategies in focused screens, including CD47 and HLA-E, and was solely capable of universally protecting allogeneic T cells against a large human cohort (45/45 donors), spanning diverse demographics and NK cell phenotypes. A model allogeneic T cell therapy co-expressing an anti-CD19 Chimeric Antigen Receptor (CAR) and CD300a TASR, produced using multiplexed non-viral integration, exhibited enhanced B cell killing potency under allogeneic immune pressure. CD300 TASR represents a universal solution to NK alloreactivity, broadening the population that could be effectively treated by next-generation allogeneic cell therapies. CategoryImmunobiology and Immunotherapy Key PointsO_LIAn engineered CD300a agonist ligand (CD300a TASR) universally protects HLA-deficient allogeneic T cells from NK-mediated rejection. C_LIO_LICD300a TASR is more protective in CMV seropositive hosts than HLA-E ligand and enhances CAR-T efficacy under allogeneic immune pressure. C_LI

immunology↗

bioRxiv2018

Targeting neuronal and glial cell types with synthetic promoter AAVs in mice, non-human primates, and humans

Targeting genes to specific neuronal or glial cell types is valuable both for understanding and for repairing brain circuits. Adeno-associated viral vectors (AAVs) are frequently used for gene delivery, but targeting expression to specific cell types is a challenge. We created a library of 230 AAVs, each with a different synthetic promoter designed using four independent strategies. We show that ~11% of these AAVs specifically target expression to neuronal and glial cell types in the mouse retina, mouse brain, non-human primate retina in vivo, and in the human retina in vitro. We demonstrate applications for recording, stimulation, and molecular characterization, as well as the intersectional and combinatorial labeling of cell types. These resources and approaches allow economic, fast, and efficient cell-type targeting in a variety of species, both for fundamental science and for gene therapy.

neuroscience↗