Human single-chain T cell receptors
A soluble human single-chain T cell receptor (TCR) having the structure: Vα2-L-Vβ or Vβ-L-Vα2, wherein L is a linker peptide that links Vβ with Vα, Vβ is a TCR variable β region, and Vα2 is a TCR variable α region of the family 2 is provided. The provided scTCR is useful for many purposes, including the treatment of cancer, viral diseases and autoimmune diseases.
1. A soluble human single-chain T cell receptor (TCR) having the structure:
Vα2-L-Vβ or Vβ-L-Vα2, wherein L is a linker peptide that links Vβ with Vα, Vβ is a TCR variable β region, and Vα2 is a TCR variable α region of family 2, wherein the single-chain TCR does not contain a TCR constant domain, wherein the Vα2 comprises a serine mutation at the position corresponding to position 49 of SEQ ID NO: 43 and wherein the Vα2 comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO. 43.
2. The TCR of claim 1 , wherein the serine mutation at position 49 is a phenylalanine to a serine.
3. The TCR of claim 1 , further comprising one or more mutations in CDR2β or CDR3α.
4. The TCR of claim 1 , wherein the linker peptide contains more than 5 lysine residues.
5. The TCR of claim 1 , wherein the linker peptide contains between 10 and 30 amino acids.
6. The TCR of claim 1 , wherein the linker peptide is GSADDAKKDAAKKDGKS (SEQ ID NO: 4).
7. The TCR of claim 1 , wherein the TCR specifically binds a ligand comprising a peptide known as SL9 (SEQ ID NO: 2) from the HIV Gag protein.
8. The TCR of claim 7 that has the sequence of the Vα (SEQ ID NO: 59) and Vβ (SEQ ID NO:53) regions from the scTCR known as 868-Z11.
9. The TCR of claim 1 , further comprising a biologically active group.
10. The TCR of claim 9 , wherein the biologically active group is selected from: an anti-inflammatory group, an anti-tumor agent, a cytokine, a radioisotope, a toxin, or an antibody such as a single-chain Fv.
11. The TCR of claim 9 , wherein the biologically active group is a cytotoxic molecule.
12. The TCR of claim 1 , further comprising a detectable group.
13. The TCR of claim 12 , wherein the detectable group can be detected by spectroscopic or enzyme-based methods.
14. The TCR of claim 12 , wherein the detectable group is a fluorescent group, a radiolabeled group, an absorbing group, or an enzyme with properties that generate detectable products.
15. The TCR of claim 9 , wherein the biologically active group is bound to the single-chain TCR through a linker.
16. A method for producing single-chain T cell receptors comprising expressing a single-chain TCR of claim 1 in E. coli.
17. A pharmaceutical composition comprising the TCR of claim 1 and a pharmaceutically acceptable carrier.
18. The TCR of claim 1 which has been linked to signaling domains that yields an active TCR on the surface of a T cell.