Bestas, Burcu3; Moreno, Pedro M D3; Blomberg, K Emelie M3; Mohammad, Dara K3; Saleh, Amer F3; Sutlu, Tolga3; Nordin, Joel Z3; Guterstam, Peter3; Gustafsson, Manuela O3; Kharazi, Shabnam3; Piątosa, Barbara3; Roberts, Thomas C3; Behlke, Mark A3; Wood, Matthew J A3; Gait, Michael J3; Lundin, Karin E3; El Andaloussi, Samir3; Månsson, Robert3; Berglöf, Anna3; Wengel, Jesper4; Smith, C I Edvard3
1 Department of Physics, Chemistry and Pharmacy, Faculty of Science, SDU2 NAC, Institut for Fysik og Kemi, Department of Physics, Chemistry and Pharmacy, Faculty of Science, SDU3 unknown4 Department of Physics, Chemistry and Pharmacy, Faculty of Science, SDU
X-linked agammaglobulinemia (XLA) is an inherited immunodeficiency that results from mutations within the gene encoding Bruton's tyrosine kinase (BTK). Many XLA-associated mutations affect splicing of BTK pre-mRNA and severely impair B cell development. Here, we assessed the potential of antisense, splice-correcting oligonucleotides (SCOs) targeting mutated BTK transcripts for treating XLA. Both the SCO structural design and chemical properties were optimized using 2'-O-methyl, locked nucleic acid, or phosphorodiamidate morpholino backbones. In order to have access to an animal model of XLA, we engineered a transgenic mouse that harbors a BAC with an authentic, mutated, splice-defective human BTK gene. BTK transgenic mice were bred onto a Btk knockout background to avoid interference of the orthologous mouse protein. Using this model, we determined that BTK-specific SCOs are able to correct aberrantly spliced BTK in B lymphocytes, including pro-B cells. Correction of BTK mRNA restored expression of functional protein, as shown both by enhanced lymphocyte survival and reestablished BTK activation upon B cell receptor stimulation. Furthermore, SCO treatment corrected splicing and restored BTK expression in primary cells from patients with XLA. Together, our data demonstrate that SCOs can restore BTK function and that BTK-targeting SCOs have potential as personalized medicine in patients with XLA.
Journal of Clinical Investigation, 2014, Vol 124, Issue 9, p. 4067-4081