One-Stop Solution for Neutralizing VHH Development

Neutralizing VHH presents a crucial therapeutic opportunity against virus or toxin infections. Creative Biolabs has years' of experience in VHH development. Our scientists can provide the best-quality one-stop solution for the development of neutralizing VHH to offer the best support to help advance our clients' programs.

Virus or toxin neutralization by antibodies predominantly relies on the ability to block the interaction between the virion and a specific cellular receptor, thereby blocking viral entry and release. Such blocking may occur due to direct binding to a viral epitope involved with receptor interaction. To treat or prevent infectious diseases or poisoning by protein toxins, VHH with blocking effect and neutralizing capacity could be a small potential drug/inhibitor candidate for prophylactic and therapeutic treatment.

Neutralizing VHH

The current limitations in diagnosis and therapeutic applications have forced us to think of a new antibody format with better stability, faster tissue distribution, higher binding affinity, and neutralizing capacities of toxins and viruses. VHH is the smallest natural single-antigen-binding fragment (~ 15 kDa), which possesses many attractive features such as the ability to identify and bind a wide variety of epitopes, especially hidden viral epitopes. The capacity to refold following thermal or chemical denaturation; ease of cloning and large-scale production. A large degree of homology with the human VH, and rapid tissue penetration as well as rapid clearance. The convex conformations formed by VHHs can target unique and cryptic epitopes and confer unique binding specificities by blocking the concave epitopes of antigens. Moreover, their small size makes them ideal building blocks for the generation of multivalent or multispecific constructs to increase both affinity and neutralizing potency and prevent the appearance of viral escape mutants. More importantly, VHHs can be easily administered via the inhalation or oral route, directly to the site of viral infection, because of their small size and favorable biophysical characteristics, making them considerable advantages for the treatment, such as the fast onset of action, low systemic exposure, and high concentration at the site of disease.

Some neutralizing VHHs specifically recognize toxins or viruses without cross-reactivity with closely related structures of the members of the family. In contrast, there is a group of broad neutralizing VHHs that can bind to the functionally conserved epitopes of a series of related targets. Based on our advanced technology platforms and extensive experience, Creative Biolabs has set up a one-stop procedure to develop not only the specific neutralizing VHH but also the broad neutralizing VHH with the highest efficiency and the best quality for any targets. These VHHs can also be easily engineered to further increase neutralization activity by increasing binding moieties, such as multivalent constructs. The VHH-mediated neutralization against viruses or toxins is significant to improve neutralizing VHH-based diagnostics, engineered vaccines, and new small molecule therapeutic strategies to prevent recurrent infections.

Typical Pathway for Neutralizing VHH Development

Features of One-Stop Neutralizing VHH Development

The potent neutralizing VHH has shown promise for future diagnostic, prophylactic, or therapeutic applications. With our well-established platform and rich experience, Creative Biolabs can offer the best one-stop service and high-quality neutralizing VHHs to contribute to the success of your projects significantly. Please feel free to contact us for more information and a detailed quote.

Published Data

Fig. 1 TB493-011 exhibits adequate neutralization against rVSV-SARS-CoV-2 (Omicron BA.1.7418017) and rVSV-SARS-CoV-2 (Omicron BA.4/5).^{1, 2}

In this study, a rapid, high-throughput process was developed for the discovery of monospecific VHH antibodies against the SARS-CoV-2 variant and the iterative development of VHH-Fc-VHH bispecific antibodies capable of neutralizing the emerging SARS-CoV-2 variant. Screening VHH single-domain phage libraries resulted in the discovery of high-affinity VHH antibodies with unique target epitopes. TB202-3 was a newfound VHH that binds tightly to all of the variants tested, and TB618-065 demonstrated high-affinity binding profiles to SARS-CoV-2 Omicron variants and unique epitopes in recent studies. Combining the two VHHs into a conjugate named TB493-011 that can interact with various multiple epitopes on the viral S protein, the tetravalent bispecific construct exerted enhanced neutralizing efficacy against a range of Omicron sublineage variants and exhibited increased resistance to antigen escape compared to the monospecific antibody. Due to the small size and high stability of the VHH single-domain antibody, TB493-011 shows a rapid iterative capacity to promptly adjust the antibody portfolio in response to mutations in viral variants.

FAQ

1. What makes VHH antibodies suitable for neutralizing pathogens?

VHH antibodies have several properties that make them particularly effective for neutralizing pathogens. Firstly, they often have smaller sizes compared to conventional antibodies. This allows them to penetrate tissues more effectively and bind to hidden or cryptic epitopes that are not accessible to larger antibodies. Secondly, VHHs are engineered with high affinity and specificity against specific viral or bacterial antigens. Finally, they are highly stable at a broad range of temperatures and pH levels, making them suitable for various environments and storage conditions.

2. What advantages do neutralizing VHHs offer over conventional neutralizing antibodies for therapeutic applications?

Neutralizing VHHs offers several advantages over conventional neutralizing antibodies. Their small size allows better tissue and cellular penetration, and their simplistic structure enables easy engineering to create bispecific or multispecific antibodies. Due to their small size and the possibility of humanization, they can reduce the risk of immunogenic responses and enable efficient and cost-effective production.

3. What techniques are used to enhance the neutralizing potency of VHH antibodies?

Several techniques, like Fc fusion, PEGylation, and specific format engineering, can be used to enhance the neutralizing potency of VHHs. Improving the Fc fusion of VHH enables longer half-life and enhanced effector functions, and PEGylation optimizes pharmacokinetics by increasing its size and stability. VHHs can be designed for bispecific or multispecific formats to target multiple epitopes on a pathogen or different pathogens simultaneously as well.

4. How do researchers identify the neutralizing epitopes targeted by VHHs?

Researchers identify neutralizing epitopes using methods such as epitope mapping, mutagenesis studies, and competition assays. By using techniques like X-ray crystallography and cryo-electron microscopy, it is easy to visualize VHH-antigen interactions. Introducing mutations and assessing the impact on binding can be used to determine critical residues. Besides, competition assays can be utilized to see if VHHs block the binding of other neutralizing antibodies or the natural ligand.

5. Are there any notable examples of VHHs being used in neutralizing viral infections?

A noteworthy example is the use of VHHs to target the spike protein of SARS-CoV-2. These VHHs have demonstrated efficacy in neutralizing the virus by preventing its binding to the ACE2 receptor on host cells, thereby inhibiting viral entry. Additionally, VHHs have been explored for the neutralization of other viruses, including HIV, RSV, and influenza.

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