Selective Targeting of Gene Products with the Megakaryocyte Platelet Factor 4 Promoter

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 88; no. 4; pp. 1521 - 1525
• Main Authors: Ravid, Katya, Beeler, David L., Rabin, Michael S., Ruley, H. Earl, Rosenberg, Robert D.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 15-02-1991; National Acad Sciences
• Subjects: Adrenal glands; Animals; beta-Galactosidase - genetics; beta-Galactosidase - metabolism; Biological and medical sciences; Blood cells; Blood Platelets - physiology; Bone marrow cells; DNA - analysis; DNA - genetics; Enzymes; Fundamental and applied biological sciences. Psychology; Gene expression; Genes; Hematopoietic Stem Cells - cytology; Megakaryocytes; Megakaryocytes - cytology; Megakaryocytes - physiology; Mice; Mice, Transgenic; Molecular and cellular biology; Molecular genetics; Organ Specificity; Plasmids; Platelet Factor 4 - genetics; Platelets; Promoter Regions, Genetic; Rats; Recombinant Fusion Proteins - metabolism; Restriction Mapping; Transgenes; Transgenic animals; 5' terminal-Sequence; Transcription promoter; Rodentia; Transgenic animal; Molecular hybrid; Megakaryocyte; Tissue specificity; Gene expression; Platelet factor 4; Vertebrata; Platelet; Mammalia; Reporter gene; Transfection; Gene; Mouse; Coagulation factor; Vector
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.88.4.1521

We have used the 1.1 kilobases of the 5' upstream region of the platelet factor four (PF4) gene coupled to the prokaryotic β-galactosidase gene to generate two lines of transgenic mice that express this construct. Studies of blood, bone marrow, spleen, and thymus reveal that platelets are the only circulating blood cells and megakaryocytes are the only hematopoietic precursor cells that possess the prokaryotic enzyme. The lack of transgene expression in brain, heart, intestine, kidney, liver, lung, and skeletal muscle was established by in situ staining of tissue sections as well as kinetic assay of tissue homogenates. These data suggest that this domain of the PF4 promoter contains most, if not all, of the tissue-specific region of the gene. Unexpectedly, the adrenal gland exhibits ≈2% of the levels of β-galactosidase possessed by megakaryocytes and the distribution of the prokaryotic enzyme corresponds to the location of mineralocorticoid-secreting cells. This result implies that either the PF4 gene is transcribed at low levels in specialized adrenal cells or that these specialized endocrine cells possess trans-acting factors similar to those that control the megakaryocyte promoter. The selective high-level expression of transgenes linked to the PF4 promoter should allow us to augment or suppress the in vivo levels of critical components in megakaryocytes and platelets and subsequently ascertain the effects of these modifications.