Tissue-specific expression of functionally rearranged lambda 1 Ig gene through a retrovirus vector.

To explore the potential use of retrovirus vectors for the transfer of genomic DNA sequences into mammalian cells, recombinant retroviral genomes were constructed that encode a functionally rearranged murine lambda 1 immunoglobulin gene. Several of these genomes could be transmitted intact to recipient cells by viral infection, although successful transmission depended both on the orientation of the lambda 1 sequences and on their specific placement within vector sequences. The lambda 1 gene transduced by viral infection was expressed in a cell lineage-specific manner, albeit at lower levels than endogenous lambda 1 gene expression in cells from the B-lymphocyte lineage. Vectors yielding integrated proviruses that lacked viral transcriptional enhancer sequences were used to show that neither viral transcription nor the viral transcriptional sequences themselves had any effect on the tissue specificity of lambda 1 gene expression or the absolute amount of lambda 1 transcription. Vector transcription did, however, dramatically decrease the amount of lambda 1 protein that could be detected in tranduced cells. These results suggest that retrovirus vectors may be useful reagents not only for the expression of complementary DNA sequences but also for studies of tissue-specific transcription in mammalian cells.