Clinical Scale Zinc Finger Nuclease-mediated Gene Editing of PD-1 in Tumor Infiltrating Lymphocytes for the Treatment of Metastatic Melanoma.

Programmed cell death-1 (PD-1) is expressed on activated T cells and represents an attractive target for gene-editing of tumor targeted T cells prior to adoptive cell transfer (ACT). We used zinc finger nucleases (ZFNs) directed against the gene encoding human PD-1 (PDCD-1) to gene-edit melanoma tumor infiltrating lymphocytes (TIL). We show that our clinical scale TIL production process yielded efficient modification of the PD-1 gene locus, with an average modification frequency of 74.

Delayed administration of a bio-engineered zinc-finger VEGF-A gene therapy is neuroprotective and attenuates allodynia following traumatic spinal cord injury.

Following spinal cord injury (SCI) there are drastic changes that occur in the spinal microvasculature, including ischemia, hemorrhage, endothelial cell death and blood-spinal cord barrier disruption. Vascular endothelial growth factor-A (VEGF-A) is a pleiotropic factor recognized for its pro-angiogenic properties; however, VEGF has recently been shown to provide neuroprotection. We hypothesized that delivery of AdV-ZFP-VEGF--an adenovirally delivered bio-engineered zinc-finger transcription factor that promotes endogenous VEGF-A expression--would result in angiogenesis, neuroprotection and functional recovery following SCI.

Gene editing of CCR5 in autologous CD4 T cells of persons infected with HIV.

Background: CCR5 is the major coreceptor for human immunodeficiency virus (HIV). We investigated whether site-specific modification of the gene ("gene editing")--in this case, the infusion of autologous CD4 T cells in which the CCR5 gene was rendered permanently dysfunctional by a zinc-finger nuclease (ZFN)--is safe.

Methods: We enrolled 12 patients in an open-label, nonrandomized, uncontrolled study of a single dose of ZFN-modified autologous CD4 T cells.

A live-attenuated Listeria vaccine (ANZ-100) and a live-attenuated Listeria vaccine expressing mesothelin (CRS-207) for advanced cancers: phase I studies of safety and immune induction.

Purpose: Listeria monocytogenes (Lm)-based vaccines stimulate both innate and adaptive immunity. ANZ-100 is a live-attenuated Lm strain (Lm ΔactA/ΔinlB). Uptake by phagocytes in the liver results in local inflammatory responses and activation and recruitment of natural killer (NK) and T cells, in association with increased survival of mice bearing hepatic metastases.

Priming and activation of human ovarian and breast cancer-specific CD8+ T cells by polyvalent Listeria monocytogenes-based vaccines.

Immunotherapeutic vaccine is potentially an effective strategy to combat cancer. Essential components of an effective vaccine must include antigens that are processed by the major histocompatibility complex class I pathway, presented by the tumor major histocompatibility complex molecules, and an effective antigen delivery platform that is capable of breaking self-tolerance. In this study, we characterized a set of ovarian cancer-specific T-cell epitopes delivered by live-attenuated recombinant Listeria monocytogenes (Lm DeltaactADeltainlB) as a vaccine vector.

Activation of immature hepatic NK cells as immunotherapy for liver metastatic disease.

NK cells can identify and eliminate emerging tumors due to altered expression of activating and inhibitory ligands on aberrant cells, a process that is greatly enhanced following NK cell activation. As a principal site of both tumor metastases and immature NK cells, the liver represents a unique anatomic location in which activation of the innate immune system could provide substantial therapeutic benefit. We describe here the NK cell-dependent destruction of a primary hepatic tumor following infection with an attenuated intracellular bacterium derived from Listeria monocytogenes.

Selective targeting of antitumor immune responses with engineered live-attenuated Listeria monocytogenes.

Improved immunization and ex vivo T-cell culture strategies can generate larger numbers and more potent tumor-specific effector cells than previously possible. Nonetheless, the capacity of these cells to eliminate established tumors is limited by their ability to efficiently enter tumor-bearing organs and mediate their effector function. In the current study, we show that the administration of an engineered organ-homing microbe selectively targets tumor-specific immune responses to metastases within that organ.

Listeria-based cancer vaccines that segregate immunogenicity from toxicity.

The facultative intracellular bacterium Listeria monocytogenes is being developed as a cancer vaccine platform because of its ability to induce potent innate and adaptive immunity. For successful clinical application, it is essential to develop a Listeria platform strain that is safe yet retains the potency of vaccines based on wild-type bacteria. Here, we report the development of a recombinant live-attenuated vaccine platform strain that retains the potency of the fully virulent pathogen, combined with a >1,000-fold reduction in toxicity, as compared with wild-type Listeria.

Listeria monocytogenes as a vaccine vector: virulence attenuation or existing antivector immunity does not diminish therapeutic efficacy.

The bacterium L. monocytogenes is a proposed vaccine carrier based upon the observation that this pathogen replicates within the intracytoplasmic environment facilitating delivery of Ag to the endogenous Ag processing and presentation pathway with subsequent stimulation of peptide specific MHC class I-restricted CD8(+) effector cells. In this report, we evaluate virulence-attenuated strains of Listeria monocytogenes as vaccine vectors and examine whether existing antivector (antilisterial) immunity limits or alters its efficacy as a therapeutic cancer vaccine.

Vesicular stomatitis virus: an exciting new therapeutic oncolytic virus candidate for cancer or just another chapter from Field's Virology?

Selected mutant strains of vesicular stomatitis virus (VSV) are described that are unable to combat endogenous IFN-beta signaling within infected normal cells and as a result are dramatically more selective for productive growth in tumor cells having a defective antiviral response. The VSV mutants may have the potential to be used clinically as a systemic oncolytic agent for the treatment of distal and metastatic cancers.