Competitive sgRNA Screen Identifies p38 MAPK as a Druggable Target to Improve HSPC Engraftment.
Previous gene therapy trials for X-linked chronic granulomatous disease (X-CGD) lacked long-term engraftment of corrected hematopoietic stem and progenitor cells (HSPCs). Chronic inflammation and high levels of interleukin-1 beta (IL1B) might have caused aberrant cell cycling in X-CGD HSPCs with a concurrent loss of their long-term repopulating potential. Thus, we performed a targeted CRISPR-Cas9-based sgRNA screen to identify candidate genes that counteract the decreased repopulating capacity of HSPCs during gene therapy. The candidates were validated in a competitive transplantation assay and tested in a disease context using IL1B-challenged or X-CGD HSPCs. The sgRNA screen identified Mapk14 (p38) as a potential target to increase HSPC engraftment. Knockout of p38 prior to transplantation was sufficient to induce a selective advantage. Inhibition of p38 increased expression of the HSC homing factor CXCR4 and reduced apoptosis and proliferation in HSPCs. For potential clinical translation, treatment of IL1B-challenged or X-CGD HSPCs with a p38 inhibitor led to a 1.5-fold increase of donor cell engraftment. In summary, our findings demonstrate that p38 may serve as a potential druggable target to restore engraftment of HSPCs in the context of X-CGD gene therapy.
['Klatt|Denise|D|', 'Ha|Teng-Cheong|TC|', 'Schinke|Maximilian|M|0000-0002-0442-2185', 'Selich|Anton|A|', 'Lieske|Anna|A|', 'Dahlke|Julia|J|', 'Morgan|Michael|M|', 'Maetzig|Tobias|T|', 'Schambach|Axel|A|']
D000818:Animals D064113:CRISPR-Cas Systems D002478:Cells, Cultured D004195:Disease Models, Animal D040181:Genetic Diseases, X-Linked D015316:Genetic Therapy D006105:Granulomatous Disease, Chronic D018380:Hematopoietic Stem Cell Transplantation D006412:Hematopoietic Stem Cells D006801:Humans D007249:Inflammation D053583:Interleukin-1beta D051379:Mice D012313:RNA D019718:Receptors, CXCR4 D015398:Signal Transduction D048051:p38 Mitogen-Activated Protein Kinases
p38 MAPK HSPCs X-linked chronic granulomatous disease (X-CGD) interleukin-1 beta CRISPR-Cas9 bone marrow transplantation