Nanobody Discovery

Backgrounds:

Antibodies isolated from alpacas and camels naturally lack the light chain and heavy chain CH1 regions, but retain the VH, CH2 and CH3 regions. They are one or the smallest units with antigen binding capacity, also called as nanobodies or VHH antibodies. Compared with conventional antibodies, nanobodies possess many unique advantages in expression and purification, stability, immunogenicity, and humanization, and have manifested great value and developmental potential in disease diagnosis and treatment. 

Procedure: 

ABLINK has its own alpaca breeding base. Imported alpacas are strictly raised and managed according to regulations. To construct immune phage antibody library, the peripheral blood is collected after 4-6 rounds of antigen immunization to isolate lymphocytes, following by RNA extraction, cDNA synthesis, PCR amplification and phage display. High-affinity antibodies are selected and tested after 3-5 rounds of panning. 

Service Advantages and Features:

1. Standard alpaca breeding management system:

ABLINK has its own alpaca breeding base, adhering to strict and high-quality management and imported traceability. All alpacas are only used for single project to ensure the clear background of each alpaca and the quality of the immune antibody library.

2. Multiple immune methods, library construction, and panning strategies to meet different customer needs:

ABLINK provides antigen immune schemes for proteins, cells, DNA, and peptides, as well as a fast immune scheme completed within 28 days on top of the conventional 70-day immune scheme.  In addition to the conventional VHH3 nanobody library, ABLINK has developed a unique strategy for constructing VHH4 nanobody libraries. Compared to VHH3, the FW2 homology between camelid VHH4 and human VH4 is higher, making it easier to humanize.

Cases:

Development of anti-CD19 nanobody:

CD19 antigen is a transmembrane glycoprotein that is specifically expressed in normal B lymphocytes, tumor B lymphocytes, and follicular dendritic cells, playing an important role in the activation and expansion of B cells. CD19 has been found to be expressed in patients with leukemia and B cell lymphoma. In the development of anti-CD19 nanobody, ABLINK discovered the differences between CD19 recombinant protein and cell surface protein in epitopes and designed targeted immunological strategies.