Transduced T cells expressing human SSTR2 and application thereof
The present invention is directed to transduced T cells expressing at least 100,000 molecules of human somatostatin receptor 2 (SSTR2), which improves PET/CT imaging sensitivity. The present invention is also directed to transduced T cells expressing SSTR2 and chimeric antigen receptor (CAR). In one embodiment, the CAR is specific to human ICAM-1 and the CAR comprises a binding domain that is scFv of anti-human ICAM-1, or an I domain of the αL subunit of human lymphocyte function-associated antigen-1. In another embodiment, the CAR is specific to human CD19, and the CAR comprises a binding domain that is scFv of anti-human CD19. The present invention is further directed to using the above transduced T cells for monitoring T cell distribution in a patient by PET/CT imaging and/or treating cancer.
1. An isolated nucleic acid encoding human SSTR2 and chimeric antigen receptor (CAR) specific to human ICAM-1, wherein the CAR comprises the binding domain to human ICAM-1, and the binding domain is scFv of anti-human ICAM-1, or an I domain of the αL subunit of human lymphocyte function-associated antigen-1.
2. The isolated nucleic sequence according to claim 1 , wherein the binding domain to human ICAM-1 is a wild type I domain having the sequence of 130-310 amino acids of SEQ ID NO: 1, a mutant having 1 to 3 mutations of the wild type, or a sequence having at least 95% identity to the wild type or the mutant.
3. The isolated nucleic acid according to claim 1 , further encoding an amino acid cleavage sequence in between the human SSTR2 or the CAR, wherein the amino acid cleavage sequence comprises a 2A peptide from porcine teschovirus-1 (P2A), equine rhinitis A virus (E2A), thosea asigna virus (T2A), or foot-and-mouth disease virus (F2A).
4. The isolated nucleic acid according to claim 1 , wherein the CAR further comprises a transmembrane domain, at least one co-stimulating domain, and an activating domain.
5. The isolated nucleic acid according to claim 4 , wherein the co-stimulatory domain is selected from the group consisting of CD28, 4-1BB, ICOS-1, CD27, OX-40, GITR, and DAP10.
6. The isolated nucleic acid according to claim 4 , wherein the activating domain is CD3 zeta.
7. The isolated nucleic acid according to claim 1 , which is a lentivirus vector.
8. The isolated nucleic sequence according to claim 2 , wherein the I domain is a wild type I domain having the sequence of 130-310 amino acids of SEQ ID NO: 1.
9. The isolated nucleic sequence according to claim 2 , wherein the I domain is a mutant having 1 to 3 mutations of the wild type I domain having the sequence of 130-310 amino acids of SEQ ID NO: 1.
10. The isolated nucleic sequence according to claim 9 , wherein the I domain mutant has a mutation of I288N, I309T, L295A, F292A, F292S, L289G, F292G, or F265S, of the wild-type I domain.
11. The isolated nucleic sequence according to claim 9 , wherein the I domain mutant has two mutations of F265S and F292G, of the wild-type I domain.
12. The isolated nucleic sequence according to claim 9 , wherein the I domain mutant has three mutations of F265S, F292G, and G311C, of the wild-type I domain.
13. The isolated nucleic sequence according to claim 1 , wherein the binding domain to human ICAM-1 is scFv of anti-human ICAM-1.