Flowchart of QVQ – Services

For technical details: see our Technology Page

Services include llama immunization, construction of phage-display libraries, custom-tailored selection procedures, production of VHH, plain or equipped with different tags in bacteria and upscaling of production in yeast up to GMP production in collaboration with Orthros TR BV. The knowledge build up within QVQ can be used to optimize the VHH for stability, production levels and humanization.

Immunization and library construction

Immunization and library construction

Immunizations of llamas are done in collaboration with Kaneka Eurogentec and Preclinics and immunization strategies are developed together with the customer.  All immunizations are conducted according to the applicable animal welfare act at place and reviewed by the animal experiment commission of the company.

Phage display selection and screening

QVQ always proposes a phage display-selection strategy that, based on own experience and available tools, should result in the selection of the desired target binders. Such a strategy is carefully designed to include customer’s requests and wishes.

Importantly, the propective final application of the VHHs are already taken into consideration while determining the phage display-selection strategy. The expertise of the QVQ team can be used to select for agonistic, antagonistic VHH, or VHHs targeting preferred epitopes, have high stability or high specificity.

Production and delivery

After phage-display selections, individual VHH clones will be characterized for binding, competition and functionality using available tools . Moreover, sequences of the different VHHs will be determined. QVQ will select a lead panel of 6 VHHs based on a combination of binding data, sequence data and, if available, functional data obtained by the customer. These lead-candidate VHHs will be cloned in a bacterialexpression plasmid and purified from the periplasm of Escherichia coli using IMAC.

QVQ provides a detailed report describing all the above mentioned steps and data, along with purified VHH protein of the 6 lead clones (0,5 mg of each).

Custom VHH labelling

In case labeled VHHs are requested, QVQ aims to deliver VHHs that are exclusively directionally labeled, because this preserves the integrity of the VHH. QVQ offers an C-terminal C-direct tag that is conjugated with a variety of labels using a sulfhydryl-maleimide coupling.

Optimization

QVQ disposes of a large database of VHH sequences, which are used to analyse and predict production yield, stability and protease resistance. Moreover, due to a wealth of mutagenesis information, QVQ is able to manipulate VHH-sequences to improve their production yields and stability.

VHHs are derived from heavy-chain only antibodies found in camelides and are therfore not of human origin. Based on published and proprietary information, QVQ can modify the VHHs sequences to render them more human-like (humanization).

VHH production

QVQ has ample experience with the production of recombinant VHH from bacterial and yeast hosts and can offer productions up to 500 mg. Moreover, QVQ can offer with a myriad tags at the C terminus of the VHHs. Purification of the VHHs is either done by affinity chromatography (IMAC) or IEX-chromatography. In addition, QVQ has gained experience in translating the production knowledge to perform GMP-approved production of VHHs, making them suitable for diagnostic imaging in human.

Fermentation

QVQ has invested in fermentation equipment and can now capitalize on the longstanding knowledge to obtain very high quantities of VHH in a fermentative process. Two standard protocols are available which are tailored for either well-producing VHH (> 1 g/L) or more difficult to produce VHH (50-800 mg/L)