Recombinant retroviral vectors for gene therapy

A recombinant retroviral vector, which is a Split-Intron Self-Inactivating (SIN) vector, comprising:

• a. A viral major splice donor (mSD) consisting of the nucleotide sequence of SEQ ID No:
• 2 or SEQ ID No. 3
• b. A mouse mammary tumor vector long terminal repeat (MMTV-LTR), wherein the MMTV-LTR has at least 90% sequence identity with the nucleotide sequence of SEQ ID NO:
• 6, or a Type B leukemogenic virus long terminal repeat (TBLV-LTR), wherein the TBLV-LTR has at least 90% sequence identity with the nucleotide sequence of SEQ ID NO:
• 7;
• c. A eukaryotic splice acceptor (eSA), wherein the eSA has at least 90% sequence identity with the nucleotide sequence of SEQ ID NO:
• 4;
• and
• d. A eukaryotic splice donor (eSD), wherein the eSD has at least 90% sequence identity with the positions 20-35 of the nucleotide sequence of SEQ ID NO:
• 5;
• and
• e. A constitutive transport element (CTE), wherein the CTE has at least 90% sequence identity with the nucleotide sequence SEQ ID NO:
• 8.