The SHREAD gene therapy platform for paracrine delivery improves tumor localization and intratumoral effects of a clinical antibody

Abstract

The goal of cancer-drug delivery is to achieve high levels of therapeutics within tumors with minimal systemic exposure that could cause toxicity. Producing biologics directly in situ where they diffuse and act locally is an attractive alternative to direct administration of recombinant therapeutics, as secretion by the tumor itself provides high local concentrations that act in a paracrine fashion continuously over an extended duration (paracrine delivery). We have engineered a SHielded, REtargeted ADenovirus (SHREAD) gene therapy platform that targets specific cells based on chosen surface markers and converts them into biofactories secreting therapeutics. In a proof of concept, a clinically approved antibody is delivered to orthotopic tumors in a model system in which precise biodistribution can be determined using tissue clearing with passive CLARITY technique (PACT) with high-resolution three-dimensional imaging and feature quantification within the tumors made transparent. We demonstrate high levels of tumor cell–specific transduction and significant and durable antibody production. PACT gives a localized quantification of the secreted therapeutic and allows us to directly observe enhanced pore formation in the tumor and destruction of the intact vasculature. In situ production of the antibody led to an 1,800-fold enhanced tumor-to-serum antibody concentration ratio compared to direct administration. Our detailed biochemical and microscopic analyses thus show that paracrine delivery with SHREAD could enable the use of highly potent therapeutic combinations, including those with systemic toxicity, to reach adequate therapeutic windows.

NK cells with tissue-resident traits shape response to immunotherapy by inducing adaptive antitumor immunity

“…The multiple cloning site (MCS) of the pShuttle vector was replaced with synthetic MCS modules, called MCS1 or MCS2, by Gibson Assembly (New England Biolabs). The synthetic MCS1 module contained, from 5′ to 3′, the CMV promoter, Nhe I restriction site, Xho I restriction site, and polyadenylate [poly(A)] site from bovine growth hormone as previously described ( 20 ). The MCS2 module contained, from 5′ to 3′, the SV40 promoter, Spe I restriction site, Sal I restriction site, and poly(A) site from SV40.…”

“…To define a model system for local IL-12 therapy that reflects these clinical findings, we used a nonreplicative, shielded, and retargeted AdV5 vector previously established in our laboratory (20)(21)(22). For this study, human epidermal growth factor receptor 2 (HER2) was used as a model antigen to target the HER2-overexpressing syngeneic tumor cell lines B16-HER2 and EMT6-HER2.…”

“…Here, we sought to gain a deeper understanding of how IL-12mediated tumor control is achieved and whether this knowledge ultimately allows to design improved treatment strategies for efficient tumor control. To this end, we used a tumor-targeted adenovirus serotype 5 delivery platform as a tool for intratumoral IL-12 immunotherapy (AdV5-IL-12) (20)(21)(22). In tumor models and patientderived model systems, we demonstrate that the efficacy of IL-12 depends on the intratumoral abundance of a population of CD49a + NK cells with tissue-resident traits and their ability to prime the immune microenvironment by producing the chemokine CCL5.…”

Modular Adapters Utilizing Binders of Different Molecular Types Expand Cell-Targeting Options for Adenovirus Gene Delivery

“…Here, we have focused our work on in vitro applications and shown their usefulness for cell culture assays. As the next step, future studies should be conducted focusing on an in-depth analysis of in vivo approaches ,, of the new modular adapters.…”

An analysis modality for vascular structures combining tissue-clearing technology and topological data analysis

“…Moreover, 3D imaging with the CUBIC system is suitable for analysis of complex vascular structures in vivo. Indeed, some studies recently reported the use of tissue-clearing methods for visualizing blood and lymphatic capillaries in mouse [16][17][18][19][20][21][22][23] .…”