Development, characterization and in vitro hematopoeitic differentiation of griscelli syndrome i̇nduced pluripotent stem cells

GÜNEY ESKEN, G. Development, Characterization and in vitro Hematopoietic Differentiation of Griscelli Syndrome İnduced Pluripotent Stem Cells. Hacettepe University Institute of Health Sciences Stem Cell Doctor of Philosophy Thesis, Ankara, 2018. Griscelli type 2 Syndrome (GS-2) is a rare, autosomal recessive immune deficiency syndrome. The RAB27A gene mutation in GS-2 patients results in the loss of function of T and NK cells. Induced pluripotent stem cells (iPSC) express pluripotency genes, have the capacity for infinite expansion and can differentiate into cells from all three germ layers. They can be induced using integrative and non-integrative systems by the use of the Oct-4, Sox-2, Klf-4, c-Myc (OSKM) transcription factors. To better understand GS-2 disease and to test novel treatment options, there is a need for an in vitro GS-2 model. For this reason, in this thesis, iPSC clones were made from 3 GS-2 patients and thoroughly characterized. GS-2 iPSCs were stained for SSEA1, SSEA4, TRA-1-60, TRA-1-81 and Oct4 via immunofluorescent staining's. They also expressed SOX2, NANOG and OCT4, as confirmed by RT-PCR. They were differentiated in vitro into hematopoietic lineage and in vivo in a teratoma assay into cells from all three germ layers. In addition, all GS-2 iPSCs displayed a normal karyotype (46,XX or 46,XY) and were shown to express the RAB27A gene mutation that was present in the original somatic donor cells. In conclusion, using lentiviral transfer of OSKM, we were able to create bona fide iPSCs from 3 GS-2 patients and characterized the cells. These cells can be used in future studies for the development of novel treatment options and to study the pathophysiology of GS-2 disease.