摘要 |
<p>A DNA sequence corresponding to a non-integrating retrovirus having high protein expression is taught. The DNA sequence corresponds to a retroviral genome that is reverse transcriptase and/or integrase and where the 3'LTR has been replaced by a heterologous polyadenylation sequence. Preferably, a strong heterologous promoter is inserted in the 5'LTR upstream of the viral enhancer and promoter. In preferred embodiments the retroviral genome is a primate lentivirus or HTLV-1 or 2 genome. Changes are also made to enhance expression of the processed envelope protein. With an HIV genome a stop codon is inserted in the gp160 gene after the cleavage site for gp120. The gp41 reading frame can be inserted in the nef reading frame with a nucleotide encoding a secretory sequence at the N-terminal. The DNA sequence can be used to produce an immune reaction or large amounts of viral protein.</p> |