Biology subjects

Arthofer, E.

Publications and source records attributed to Arthofer, E..

3 recordsLinked to original sources

bioRxiv2021

A Novel CRISPR-Engineered, Stem Cell-Derived Cellular Vaccine

COVID-19 has forced rapid clinical translation of novel vaccine technologies, principally mRNA vaccines, that have resulted in meaningful efficacy and adequate safety in response to the global pandemic. Notwithstanding this success, there remains an opportunity for innovation in vaccine technology to address current limitations and meet the challenges of inevitable future pandemics. We describe a universal vaccine cell (UVC) rationally designed to mimic the natural physiologic immunity induced post viral infection of host cells. Induced pluripotent stem cells were CRISPR engineered to delete MHC-I expression and simultaneously overexpress a NK Ligand adjuvant to increase rapid cellular apoptosis which was hypothesized to enhance viral antigen presentation in the resulting immune microenvironment leading to a protective immune response. Cells were further engineered to express the parental variant WA1/2020 SARS-CoV-2 spike protein as a representative viral antigen prior to irradiation and cryopreservation. The cellular vaccine was then used to immunize non-human primates in a standard 2-dose, IM injected prime + boost vaccination with 1e8 cells per 1 ml dose resulting in robust neutralizing antibody responses (1e3 nAb titers) with decreasing levels at 6 months duration. Similar titers generated in this established NHP model have translated into protective human neutralizing antibody levels in SARS-Cov-2 vaccinated individuals. Animals vaccinated with WA1/2020 spike antigens were subsequently challenged with 1.0 x 105 TCID50 infectious Delta (B.1.617.2) SARS-CoV-2 in a heterologous challenge which resulted in an approximately 3-log order decrease in viral RNA load in the lungs. These heterologous viral challenge results reflect the ongoing real-world experience of original variant WA1/2020 spike antigen vaccinated populations exposed to rapidly emerging variants like Delta and now Omicron. This cellular vaccine is designed to be a rapidly scalable cell line with a modular poly-antigenic payload to allow for practical, large-scale clinical manufacturing and use in an evolving viral variant environment. Human clinical translation of the UVC is being actively explored for this and potential future pandemics.

immunology↗

bioRxiv2021

Genetic editing of CISH enhances T cell effector programs independently of immune checkpoint cell surface ligand expression

PD-1 acts as a negative regulator of T cell-mediated immune responses in the setting of persistent antigen expression, including cancer and chronic pathogen infections. Antibody-mediated blockade of the PD-1/PD-L1 axis benefits a subset of patients with highly immunogenic malignancies; however, many patients fail to respond due to a requirement for expression of the cell surface ligand PD-L1 within the tumor microenvironment. CISH is a member of a new class of intra-cellular immune checkpoint molecules that function downstream of the T cell receptor to regulate antigen-specific effector functions, including reactivity to cancer neoantigens. Herein, we employed multiplex CRISPR editing of primary human T cells to systematically compare the function of CISH deletion relative to PDCD1 (the gene encoding PD-1) and/or VSIG9 (the gene encoding TIGIT) in a model of neoantigen-mediated cancer cell cytolysis. PD-1 and TIGIT disruption enhanced cytolytic activity exclusively in the setting of high PD-L1 expression. In contrast, CISH inactivation enhanced antigen-specific cytolysis of tumor cells regardless of PD-L1 expression, including outperforming PD-1 and TIGIT disruption even in the presence of high PD-L1 tumor cells. Furthermore, we observed a synergistic increase in tumor cell killing when CISH and PD-1 or TIGIT are inactivated in combination, supporting the notion that these immune checkpoints regulate non-redundant pathways of T cell activation. Together, these data demonstrate that the intra-cellular immune checkpoint protein CISH can potentially enhance anti-tumor responses against a broad range of cancer types regardless of PD-L1 biomarker status.

cancer biology↗

bioRxiv2020

A Novel Cell Therapy for COVID-19 and Potential Future Pandemics: Virus Induced Lymphocytes (VIL)

The a priori T cell repertoire and immune response against SARS-CoV-2 viral antigens may explain the varying clinical course and prognosis of patients having a mild COVID-19 infection as opposed to those developing more fulminant multisystem organ failure and associated mortality. Using a novel SARS-Cov-2-specific artificial antigen presenting cell (aAPC), coupled with a rapid expansion protocol (REP) as practiced in tumor infiltrating lymphocytes (TIL) therapy, we generate an immune catalytic quantity of Virus Induced Lymphocytes (VIL). Using T cell receptor (TCR)-specific aAPCs carrying co-stimulatory molecules and major histocompatibility complex (MHC) class-I immunodominant SARS-CoV-2 peptide-pentamer complexes, we expand virus-specific VIL derived from peripheral blood mononuclear cells (PBMC) of convalescent COVID-19 patients up to 1,000-fold. This is achieved in a clinically relevant 7-day vein-to-vein time-course as a potential adoptive cell therapy (ACT) for COVID-19. We also evaluate this approach for other viral pathogens using Cytomegalovirus (CMV)-specific VIL from donors as a control. Rapidly expanded VIL are enriched in virus antigen-specificity and show an activated, polyfunctional cytokine profile and T effector memory phenotype which may contribute to a robust immune response. Virus-specific T cells can also be delivered allogeneically via MHC-typing and patient human leukocyte antigen (HLA)-matching to provide pragmatic treatment in a large-scale therapeutic setting. These data suggest that VIL may represent a novel therapeutic option that warrants further clinical investigation in the armamentarium against COVID-19 and other possible future pandemics.

immunology↗