Sequence-specific 2'-O-methoxyethyl antisense oligonucleotides activate human platelets through glycoprotein VI, triggering formation of platelet-leukocyte aggregates
Martina H. Lundberg Slingsby,
Prakrith Vijey,
I-Ting Tsai,
Harvey Roweth,
Genevieve Couldwell,
Adrian R. Wilkie,
Hans Gaus,
Jazana M. Goolsby,
Ross Okazaki,
Brooke E. Terkovich,
John W. Semple,
Jonathan N. Thon,
Scott P. Henry,
Padmakumar Narayanan,
Joseph E. Italiano Jr.
Affiliations
Martina H. Lundberg Slingsby
Vascular Biology Program, Department of Surgery, Boston Children’s Hospital, Boston, MA, USA; Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Prakrith Vijey
Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
I-Ting Tsai
Vascular Biology Program, Department of Surgery, Boston Children’s Hospital, Boston, MA, USA; Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Harvey Roweth
Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Genevieve Couldwell
Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Adrian R. Wilkie
Vascular Biology Program, Department of Surgery, Boston Children’s Hospital, Boston, MA, USA; Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Hans Gaus
Nonclinical Development, Ionis Pharmaceuticals Inc., Carlsbad, CA
Jazana M. Goolsby
Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Ross Okazaki
Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Brooke E. Terkovich
Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
John W. Semple
Departments of Pharmacology and Medicine, University of Toronto, Toronto, Canada; Division of Hematology and Transfusion Medicine, Lund University, Lund
Jonathan N. Thon
Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Scott P. Henry
Nonclinical Development, Ionis Pharmaceuticals Inc., Carlsbad, CA
Padmakumar Narayanan
Nonclinical Development, Ionis Pharmaceuticals Inc., Carlsbad, CA
Joseph E. Italiano Jr.
Vascular Biology Program, Department of Surgery, Boston Children’s Hospital, Boston, MA, USA; Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Antisense oligonucleotides (ASO) are DNA-based, disease-modifying drugs. Clinical trials with 2'-O-methoxyethyl (2’MOE) ASO have shown dose- and sequence-specific lowering of platelet counts according to two phenotypes. Phenotype 1 is a moderate (but not clinically severe) drop in platelet count. Phenotype 2 is rare, severe thrombocytopenia. This article focuses on the underlying cause of the more common phenotype 1, investigating the effects of ASO on platelet production and platelet function. Five phosphorothioate ASO were studied: three 2’MOE sequences; 487660 (no effects on platelet count), 104838 (associated with phenotype 1), and 501861 (effects unknown) and two CpG sequences; 120704 and ODN 2395 (known to activate platelets). Human cord bloodderived megakaryocytes were treated with these ASO to study their effects on proplatelet production. Platelet activation (determined by surface P-selectin) and platelet-leukocyte aggregates were analyzed in ASO-treated blood from healthy human volunteers. None of the ASO inhibited proplatelet production by human megakaryocytes. All the ASO were shown to bind to the platelet receptor glycoprotein VI (KD ~0.2-1.5 μM). CpG ASO had the highest affinity to glycoprotein VI, the most potent platelet-activating effects and led to the greatest formation of platelet-leukocyte aggregates. 2’MOE ASO 487660 had no detectable platelet effects, while 2’MOE ASOs 104838 and 501861 triggered moderate platelet activation and SYKdependent formation of platelet-leukocyte aggregates. Donors with higher platelet glycoprotein VI levels had greater ASO-induced platelet activation. Sequence-dependent ASO-induced platelet activation and platelet-leukocyte aggregates may explain phenotype 1 (moderate drops in platelet count). Platelet glycoprotein VI levels could be useful as a screening tool to identify patients at higher risk of ASO-induced platelet side effects.
