Antisense oligonucleotide complementary to endogenous retroviral MCF env gene inhibits both BFU-E and CFU-S colony formation in mice.

A possible biologic activity of endogenously expressed env sequence of retroviral mink cell focus-forming virus (MCF) genome for hematopoietic colony formation was studied in mice. Antisense 20-mer complementary to MCF env sequence was used to detect the result of blockage of this gene translation on the potency of marrow cells to form colonies of erythroid (BFU-E), myeloid granulocyte-macrophage (CFU-GM), and stem cell (day 11 CFU-S) hematopoietic compartments. A large relative decrease in BFU-E number was found in bone marrow cell cultures preincubated with antisense oligonucleotide during 4 h, whereas CFU-GM colonies remained unaffected. A marked reduction of CFU-S colony formation was also registered under antisense oligomer influence. Following a decreased proliferation of erythroid progenitors, we suggest the mechanism by which antisense oligonucleotide could cause the loss of colony formation. Taken together, these data allow to propose that the expression of this gene is naturally significant for hematopoietic progenitor activity exerting some property of env gene products to regulate the growth of erythroid and multilineage hematopoietic precursors.