Hit intracellular targets with genetic delivery
With shorter gene lengths, VHH antibodies are perfect for constructing new genetic therapies and targeted protein degraders like bioPROTACs.
Scientific & Therapeutic Context
About Intracellular VHHs
Until recently, intracellular therapeutic targets had only been accessible to small molecule drugs, since traditional mAbs are too large and complex to access these spaces. Now that genetic delivery vectors are more advanced, it is possible to deliver small-format antibodies like VHHs to be expressed directly inside cells, unlocking the intracellular target space.
Why consider VHH antibodies for intracellular and TPD applications?
VHHs are small, so they are encoded by shorter genes (~350 bp). Shorter genes are advantageous in genetic delivery applications because:
- Genetic delivery vectors have limited capacity. Shorter genes create more space to add additional co-expressed elements to build even more innovative therapies.
- VHH antibodies are small enough to build bi- or multi-specific intracellular therapies.
- Smaller vectors tend to have better transduction efficiencies.
Advantages of VHH antibodies for intracellular targeting
In addition to being small, VHH antibodies are simple and stable. Conventional antibodies are manufactured and tested before dosing. In contrast, genetically delivered antibodies are produced inside patient cells after DNA delivery. This requires reliable folding and good solubility in the cytoplasmic environment. VHH antibodies meet these requirements. They are highly soluble and fold consistently during intracellular expression. Isogenica’s VHH antibodies contain a single disulphide bond as standard, which reduces the risk of misfolding.
Combined with emerging viral or nucleic acid delivery technologies, VHH intrabodies present a unique opportunity to expand the pharmacological toolbox.
De Genst et al (2022), AstraZeneca
Intracellular targets and targeted protein degraders with VHHs
In early-stage studies, AstraZeneca used Isogenica’s LlamdA® library to identify two types of genetic therapy with very different mechanisms:
‘Intrabodies’ binding to highly specific states of the cardiac protein phospholamban:
– Lead VHHs could discriminate between target phosphorylation and multimerization states – In vivo expression under a cardiac-specific promoter had positive effects on cardiac function
Trim-Away targeted protein degradation
– VHHs targeting human antigen R were expressed as genetic fusions to the TRIM21 ubiquitin ligase domain – The target of the VHH was degraded effectively in vivo leading to reduced tumour growth
Interested in exploring VHHs for intracellular targets? Let's talk.
Explore the science behind our antibody discovery platforms
Access our latest white papers and application notes to see how Isogenica’s synthetic VHH technologies are accelerating innovation in CAR-T, bispecifics, and immuno-oncology.
White Paper “Data-Driven Validation of Synthetic VHHs”
This white paper provides a data-driven validation of Isogenica’s synthetic VHH libraries, powered by Colibra® technology. Designed for biotech and pharmaceutical scientists, it demonstrates how these libraries enhance and accelerate drug discovery, particularly in oncology and immunotherapy. DownloadExtending half-lives of VHH antibodies
Because VHHs are small, they can be cleared quickly from the bloodstream. This can be a useful feature for some applications, but often a longer plasma half-life is desirable. DOWNLOADAdvantages of VHH in bi-specifics
To learn more about the application of VHHs in bi-specifics, we have condensed our expertise into a downloadable Application Note. DOWNLOADOptimizing CAR-T and T-cell antibody engagers: a role for VHH single domain antibodies
This whitepaper summarises the clinical and research landscape for CAR-T and T-cell engaging antibody therapies and show how single domain VHH antibodies can be applied to optimise the next generation of these important new therapeutic modalities. DOWNLOADIsogenica’s PD-L1 VHH as Functional Antagonists
PD-1 is an immune checkpoint protein expressed on the surface of multiple types of immune cells, including antigen-stimulated T-cells and tumour specific T-cells1. Interaction between PD-1 and its ligands (PD-L1 or PD-L2), is responsible for the regulation of T-cell activation, apoptosis, proliferation and cytokine production. DOWNLOADAnti-LRP5/6 VHH inhibits WNT pathway and prevents tumour growth
VHH are the variable domain of heavy chain only antibodies. They are small in size (~15 kD) and biophysically robust. With tunable half-lives, these antibodies are ideal for targeting inaccessible epitopes, achieving enhanced tissue penetration, multi-target binding and formatting for payload delivery… DOWNLOAD