Affinity Maturated T-Cell Receptor (No. T4-1662)
Lead Researcher: Lea Eisenbach
Immunotherapy, that is the use of the immune system to treat cancer, is currently a leading candidate in the combat against cancer. Unlike the toxic effects of both chemotherapy and radiation, immunotherapy is considered to have mild side effects due to its ability to differentiate between healthy and cancerous cells. Also, the therapeutic role of the immune system is an essential element in the healing process due to bone marrow transplantation for hematologic malignancies.
However, a more efficacious and less toxic T cells based treatment is required. Effective therapy depends on the functional avidity between T cell receptors (TCRs) and peptide-MHC complex (pMHC). However, the natural affinity of TCR is low and they do not naturally undergo the processes that improve antibody affinity, such as somatic hypermutation (SHM). Currently there is no method of increasing the affinity of a TCR to its ligand. Moreover, there is no knowledge on how use affinity maturated TCRs for creating anti-tumor reactive cells
This technology presents a method of increasing the affinity of a TCR to its ligand. This is done by subjecting TCR genes to SHM via the enzyme Activation Induced cytidine Deaminase (AID). The technology further provides affinity maturated TCRs (in cell- bound or in soluble form) and their pharmaceutical potential for immunotherapy.
• Generating anti-tumor T cells
• Generating T cells reactive against a selected antigen
This novel technology reveals that the affinity of a TCR to its ligand may be increased remarkably by subjecting TCR genes to SHM, directed by AID. First a nucleic acid construct encoding a TCR gene is expressed in a host cell. Next SHM is used to introduce mutations to the TCR gene. Last, the cells expressing the TCR with a high affinity to the ligand are selected.
There are three parallel approaches to perform affinity maturation for the TCR: (1) Ex-vivo affinity maturation system, using Tet-regulated expression of AID (2) Ex-vivo affinity maturation system, using controlled expression of AID by mRNA electrophoresis (3) In-vitro affinity maturation system, using extracts from cells that are in SHM and recombinant AID.