Binding of Antisense Phosphorothioate Oligonucleotides to Murine Lymphocytes Is Lineage Specific and Inducible

A phosphorothioate oligonucleotide that has been employed to inhibit HIV-1 viral expression in chronically infected H9 cells was examined for its ability to associate with murine lymphoid cells. The relationship between cellular oligonucleotide concentration and the lymphoid target tissues is important to the selection of an animal model, evaluation of potential side effects, and understanding the actions of a therapeutically useful antisense oligonucleotide. Lymphoid cells were harvested from murine peripheral blood, bone marrow, thymus, lymph node, and spleen. Cell subpopulations that bind the oligonucleotide were distinguished by two-color flow cytometry employing a fluoresceinlabeled anti-rev oligonucleotide and phycoerythrin-labeled antibodies to selected cell surface molecules associated with unique subpopulations of cells. Very little oligonucleotide binding was observed in peripheral blood mononuclear cells or thymic T cells, but substantial numbers of cells, primarily B cells from bone marrow and...