close

Adenovirus: receptors, trafficking, immunogenicity & vectorology

Eric J Kremer

Research projects

EKL coordinates project iAds – “Intelligent design of adenovirus vectors”

 

For the last 20 years, the Kremer lab has had a broad interest in adenovirus biology. Adenoviruses are nonenveloped, double-stranded DNA pathogens with a genome size of 28 – 42 kb. To date, ~70 human and > 150 nonhuman adenovirus types have been described. We focus on human and canine adenoviruses (CAV-2) vectors.

OUR PRINCIPLE AREAS OF INTEREST ARE:

1.Understanding the function of CAR, the coxsackievirus adenovirus receptor, in the healthy and disease brain, and during adenovirus trafficking.

As the name suggests, CAR was originally identified as an attachment molecule for coxsackie B viruses and some adenoviruses, including canine adenovirus type 2 (CAV-2) vectors, whose transduction efficacy is CAR dependent. CAR is a single-pass transmembrane protein belonging to the CTX subfamily of the Ig-super family. CAR function is best characterized in epithelial cells where it participates to the maintenance of tight junctions. Although a role for CAR in brain development has been hypothesized and a function in regulating axonal growth reported, its role in the adult brain is largely uncharacterized. In this context, understanding CAR’s biological function, as well as the impact of its loss of function and distribution in the CNS is indispensable for both fundamental and applied neurobiology studies.

Figure 1. Mouse hippocampal neurons at day in vitro 15 (DIV 15). Cells were labelled for mouse coxsackie- and adenovirus receptor using a goat anti-mCXADR (R&D systems) detected with a donkey anti-goat Alexa 488 and a rabbit anti-CAR (gift from Joseph Zabner) detected with an donkey anti-rabbit Alexa 647. Nucleus were stained using DAPI (blue). Images were acquired using Leica SP5 confocal microscope with 40X 1.4 oil objectives. Serial Z-plan were recorded and images represent z-projection of all 34 plan acquire. (yellow image)

Images represent mouse hippocampal neurons at day in vitro 7 (DIV 7). Cells were labelled for mouse coxsackie- and adenovirus receptor using a rabbit anti-mCAR (Bethyl) detected with a donkey anti-mouse Alexa 555 and a mouse anti-RNA Pol II H5 (Abcam) detected with an donkey anti-mouse Alexa 488. Nucleus were stained using DAPI (blue). Images were acquired using Leica SP5 confocal microscope with 40X 1.4 oil objectives. Serial Z-plan were recorded and images represent overlay from different plan. Images were pseudo-colored CAR in magenta, RNA pol in cyan and DAPI in yellow.

2.Understanding how mononuclear phagocytes, in particular dendritic cells, process and respond to immune-complexed adenoviruses (IC-Ad)

The nearly ubiquitous presence of anti-adenovirus antibodies and memory T cells is due to recurrent and cross-reacting adenovirus infections during childhood. Thus, when Ad-based vectors are used in a host with memory immunity this creates an environment close to a secondary infection in the clinic.

How do IC-Ads and other host factors impact the maturation of antigen-presenting cells (APC)? Our underlying questions encompass the entry and signaling pathways and how the IC-Ads traffic in APC. In our studies we use human dendritic cells to study the interaction of IC-HAd5 and innate immune sensors. Dendritic cells are the major APC in blood and tissue and play a pivotal role in the sensing of infection and activation and re-activation of the adaptive immune response.

IC-Ads triggers several innate immune sensors and induce DC maturation (the virus alone is far less potent). Our aim is to understand the interactions of the IC-Ads during the initial activation and death of DC. Our studies contribute to both fundamental and applied questions in adenovirus biology, vaccination and gene therapy.

Figure 2. IC-HAdV trafficking and cellular events leading to pyroptotic dendritic cell death.

IC-HAdV are taken up via FcγR-mediated endocytosis and fuse with TLR9+ endolysosomal vesicles because of NAb-dependent capsid stabilization at endosomal pH. At the more acidic pH in lysosome-like vesicles, IC-HAdV begin to disassemble and to release viral DNA, membrane lytic protein VI, and cellular components. TLR9 engagement induces MyD88-NF-κB-dependent de novo expression of TNF and pro-IL-1β. During vesicular DNA sensing, protein VI release from the capsid leads to endolysosomal membrane lysis and IC-HAdV gain access to the cytosol. The cytosolic inflammasome sensor AIM2 interacts with the HAdV-C5 genome and induces inflammasome assembly and activation of caspase 1, and downstream cleavage of pro-IL-1 and GSDMD. Together this leads to pyroptosis of MoDCs.

3.Optimizing CAV-2 vector for gene transfer to the CNS

The Kremer labs created replication-defective and helper-dependent CAV-2 vectors. CAV-2 vectors allow preferential gene transfer to neurons and widespread distribution after injection into the brain. We and others have used them to explore, treat and understand the healthy and diseased CNS.

To respond to the increasing number of requests for CAV-2 vectors, the CNRS BioCampus created a non-profit vector core that provides vectors at cost to colleagues. Please address your questions to cav.2@biocampus.cnrs.fr or see https://www.pvm.cnrs.fr/

Figure 3. Neurons infected with CAV-2 vectors expressing GFP and Cherry.

Composition of the sub-group: Florence Rage, Johann Soret, Pauline Duc et Audrey Moisan.

Understanding the molecular mechanisms of Spinal Muscular Atrophy (SMA)

Spinal Muscular Atrophy (SMA), a hereditary disease, results from degeneration of motor neurons leading to severe muscular atrophy. This disease is caused by the deletion and/or mutation of the SMN1 gene. Due to its crucial role in the biogenesis of spliceosome components, SMN deficiency is correlated to numerous splicing alterations. At the cytoplasmic level, given the high polarity of motor neurons, multiple other molecular mechanisms are impaired in this disease, including mRNA transport along axons of motor neurons and the formation and the maintenance of neuromuscular junctions (NMJs).

In our projects, we are using human induced pluripotent stem cells (hIPSCs) from healthy and SMA individuals to obtain motor neurons and study :             

  • The splicing defects of mRNAs in SMN deficient cells.
  • The localization and local translation of mRNAs along axons of motor neurons using the MS2 and SunTag systems, integrated in target genes by the CRISPR-Cas9 technology.
  • The SMN-interacting protein network in control and SMA MNs and myoblasts derived from iPSCs by combining CRISPR-Cas9 technology and biotin proximity-dependent labeling (BioID).
  • The formation, development and maintenance of mature and functional human NMJs using microfluidic devices coupled with microelectrode array (MEA) in an interdisciplinary collaboration with Benoît Charlot (IES) and Gilles Carnac (Phymedexp) (Duc et al., 2021 Lab Chip, doi 10.1039/d1lc00497b).
  • Finally, in collaboration with Eran Perlson (Tel Aviv University, Israel), we are also developing 24-well plate devices, combined with MEA, in order to recapitulate NMJs from SMA and ALS patients and to perform drug assays with personalized medicine approach.
a-Schematic view of the microfluidic device developed by the team to reconstitute human neuromuscular junctions and assess their electrical activity (Duc et al., 2021, Lab Chip), b- Schematic view of splicing efficiency in a mouse model depending on U12-U2 score.

Members

Team leader

Eric KREMER

Chercheur DR1

(+33) 04 34 35 96 72

217

Bertrand BEUCHER

IR-Recherche

+33 (0)4 34 35 96 74

Mohamed BOUSLIM

Stagiaire

+33 (0)4 34 35 96 82

225

Thomas BUFFENOIR

IE-Recherche

+33 (0)4 34 35 96 74

217

Pauline DUC

Post-Doc

+33 (0)4 34 35 96 98

225

Elina GERBER-TICHET

Doctorant

+33 (0)4 34 35 96 74

217

Iria GONZALEZ-DOPESO-REYES

IR-Recherche

+33 (0)4 34 35 96 75

218

Caroline ISMEURT

Post-Doc

+33 (0)4 34 35 96 74

217

Marina LAVIGNE

IE-Recherche

+33 (0)4 34 35 96 75

217

Audrey MOISAN

IE-Recherche

+33 (0)4 34 35 96 84

225

Veronika PECIAROVA

IE-Administratif

+33 (0)4 34 35 96 74

217

Florence RAGE

Chercheur DR2

(+33) 04 34 35 96 98

225

Fatimat SHIDI

IE-Recherche

+33 (0)4 34 35 96 74

217

Johann SORET

Chercheur DR2

(+33) 04 34 35 96 98

225

Previous lab members
Scientists

Vasiliki Kalatzis, Harry Wodrich, Sara Salinas

Assistant Professors

Franck Mennechet

PhD students

Matthieu Perreau, Nicolas Serratrice, Claire Hippert, Nadia Skander, Daniel Henaff, Sophie Creysells, Aurelie Cubizolle, Phuong Tran, Fabien Loustalot, Karsten Eichholz, Amani Wehbi, Océane Paris, Aline Raissa Ouoba

Post-docs

Olivier Billet, Karsten Eichholz, Charleine Zussy, Felix Junyent, Neus Bayo-Puxan, Thierry Bru, Khalil MAZOUNI, Hanna Dreja, Dominique Mercier, Anne Keriel, Kalpana Shrivastava, Hiep Tran, Danila del Rio, Coraline Chéneau, Phuong Tran, Océane Paris

Engineers

Aurelie Gennetier, Sandy Ibanes, Greg Conductier

Selected Publications

More information

Funding

EKL coordinates project iAds – “Intelligent design of adenovirus vectors”.

iAds is a European Innovation Council (EIC) Pathfinder project that aims to maximise the potential of adenovirus vector for vaccines and gene transfer.

The consortium of 6 partners from 5 European countries will dedicate 4 years to develop an intelligent design of adenovirus vectors (iAds). The project aims to maximise the potential of adenovirus vectors for vaccines and gene transfer. The objective is to revolutionise gene transfer and generate solutions in areas of unmet medical need via a platform that exploits the full potential of viral vectors. iAds aims to target specific cell types in the heart and brain to improve gene therapy efficacy and safety.

Gene therapy is a highly promising approach for treating certain diseases. Viral vectors have been developed stripped of their ability to cause disease and are instead used to deliver genetic material into cells for therapeutic purposes. Adenoviruses are particularly attractive because they can efficiently deliver DNA into both dividing and non-dividing cells. Funded by the European Innovation Council, the iAds project aims to overcome the limitations of adenoviral vectors, such as host immune responses and imperfect targeting. The consortium will create an in-silico platform for the design of intelligent adenovirus vectors with a focus on heart- and brain-specific targeting, addressing areas of unmet medical need.

For more information: www.intelligentadenoviruses.eu

View all research teams

Team Overview
Model organism studied
nonhuman primates, dogs, rats, mice, primary human mononuclear phagocytes / Human cells (iPSC-derived MNs from healthy and SMA individuals)
Biological process
immunology, intracellular trafficking, adult neurogenesis / RNA splicing, transport and local translation, synaptic activity of NMJs
Biological techniques
cell biology, biochemistry, virology, immunology, gene transfer, gene therap / Molecular biology, cell cultures, 2D in vitro neuro-muscular junctions on Chip