Cap-independent multicistronic retroviral vectors

Abstract

Retroviral vectors for producing coordinately expressed polycistronic mRNA in transfected host cells. A representative retroviral construct capable of forming a proviral genome in a host cell contains a first nucleotide coding sequence, a second nucleotide coding sequence, and a third nucleotide sequence capable of hybridizing under stringent conditions to a 5′ nontranslated region (NTR) of a picornavirus RNA or its complementary RNA strand. The first, second, and third nucleotide sequences are operably linked such that transcription of the proviral genome gives rise to a messenger RNA molecule containing transcripts of the first, second, and third nucleotide sequences. The transcript of the third nucleotide sequence in the messenger RNA molecule contains a nucleic acid capable of forming a regulatory stem-loop nucleic acid structure followed by at least one operable AUG start codon. The regulatory stem-loop nucleic acid structure is capable of operably binding a translation initiation complex in a host cell such that the transcripts of the first and second nucleotide sequences in the messenger RNA molecule are coordinately expressed in the host cell.