Vectored antibody gene delivery restores host B and T cell control of persistent viral infection

Abstract

Passive antibody therapy and vectored antibody gene delivery (VAGD) in particular offer an innovative approach to combat persistent viral diseases. Here, we exploit a small animal model to investigate synergies of VAGD with the host's endogenous immune defense for treating chronic viral infection. An adeno-associated virus (AAV) vector delivering the lymphocytic choriomeningitis virus (LCMV)-neutralizing antibody KL25 (AAV-KL25) establishes protective antibody titers for >200 days. When therapeutically administered to chronically infected immunocompetent wild-type mice, AAV-KL25 affords sustained viral load control. In contrast, viral mutational escape thwarts therapeutic AAV-KL25 effects when mice are unable to mount LCMV-specific antibody responses or lack CD8 + T cells. VAGD augments antiviral germinal center B cell and antibody-secreting cell responses and reduces inhibitory receptor expression on antiviral CD8 + T cells. These results indicate that VAGD fortifies host immune defense and synergizes with B cell and CD8 T cell responses to restore immune control of chronic viral infection.

Permanent lymphocyte subset elimination upon a single dose of AAV-delivered depletion antibody dissects immune control of chronic viral infection

“…AAVs allow for long-term expression of their encoded transgenes including antibodies 53,54 . Thus, we hypothesized that depletion-AAVs would allow for the permanent elimination of lymphocyte subsets in mice without a need for vector re-administration (Fig.…”

“…The AAV-ST2-Fc construct was designed as follows: a signal peptide preceded the extracellular domain of ST2 (NCBI, Genbank: M24843.1), and the latter was coupled C-terminally to the mouse IgG1a constant domain. We used either one of two AAV vectors expressing antibodies of LCMV-unrelated, irrelevant specificity as controls, one encoding the VSVG-specific antibody VI10 54,91 and the other encoding the mycobacterium-specific antibody E4H3 113 .The nucleotide sequences of the antibody variable regions of the E4H3 hybridoma (generously provided by Camille Locht, Institut Pasteur de Lille, France) as well as of the NK1.1-specific NK cell depletion antibodyproducing hybridoma PK136 (generously provided by Ondrej Stepanek, Institute of Molecular Genetics of the Czech Academy of Sciences, Czech Republic) were determined by whole transcriptome shotgun sequencing (Absolute Antibody, UK). VH and VL of the aCD20-targeting antibody 18B12 and of the aCD8a-targeting antibody YTS169.4 were extracted from patents US 2007/0136826 A1 and WO2014025828 A1, respectively 114,115 .…”

“…Here we develop adeno-associated viral vectors (AAVs) [52][53][54] delivering depletion antibodies (depletion-AAVs) as a novel approach for the permanent depletion of lymphocyte subsets in mice. Depletion-AAVs combine the versatility of classical antibody depletion strategies with the permanent nature of GEMMs.…”

Interleukin-33 from oligodendrocytes sustains effector differentiation of tissue-resident CD8+ T cells and is a druggable target in CNS autoimmune disease

“…The ST2-Fc was cloned into the pENN.AAV.CB7.CI AAV expression plasmid, which contains a CAG-promoter-driven expression cassette flanked by AAV2 inverted terminal repeats (ITRs), obtained from the PENN Vector Core (Perelman School of Medicine, University of Pennsylvania, PA, USA) under MTA. As control, we used an AAV vector expressing the antibody VI10 (Kalinke et al, 1996;Ertuna et al, 2021). AAV vector production (in an AAV8 capsid format) and titration were performed by the Viral Vector Facility (VVF) of the Neuroscience Center Zurich (ZNZ), Switzerland.…”

Functional cure of a chronic virus infection by shifting the virus - host equilibrium state

“…If the virus outcompetes the CTL response, a high virus load state is established that is characterised by T cell exhaustion and maintained through the interaction of inhibitory receptors on T cells with their ligands on antigen-presenting cells (APCs) ( 5 ). However, this harmful equilibrium can be shifted in favour of the host by inducing a virus-specific neutralising antibody response or by providing antibodies as a therapeutic intervention ( 37 , 39 ). Since the cooperativity of remaining CTLs and the newly induced antibody response can be considered as multiplicative rather than just additive, the demand for both specific immune response components is less stringent in absolute numbers ( 40 ).…”