3075 – COMPARATIVE CLASSIFICATION OF HSCS SUBSETS IN HUMAN CORD BLOOD AND BONE MARROW SAMPLES:IMPLICATIONS FOR CELL THERAPY

• Published in: Experimental hematology Vol. 88; p. S61
• Main Authors: Gaafar, Ameera, Alaiya, Ayodele, Yousif, Rama, Shinwar, Zakia Shinwar, Subramanian, Pulicat, Al-Mazrou, Amer, Al-Humaidan, Hind, Alhussein, Khalid
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.08.2020
• ISSN: 0301-472X; 1873-2399
• DOI: 10.1016/j.exphem.2020.09.091

Around 500 BMT are conducted annually in the Kingdom of Saudi Arabia in different specialized centers. Understanding the biology and the molecular signature of the different subsets of primitive HSCs and their development is crucial and has important implications for clinical transplantation and basic research. This study was executed to explore the biology of primitive HSC/HPCs subsets CD34+ and CD34- in cord blood and bone marrow samples by analyzing their cellular and molecular profiling. The study was conducted applying combined surface markers, ALDH, global gene expression, and proteomics analysis. Molecular profiling was explored by morphological, gene expression profile, and proteomics analysis. Likewise, their functional multi differential abilities were assessed up by colony forming unit (CFU). Our results showed that Lin−CD34+CD38Low (+/-) and Lin−CD34−CD38Low/− (-/-) HSC/HPCs subsets were presented in cord blood and BM samples in variable proportions and their ratios estimated to be 1:2. Furthermore, colorogenic ability as demonstrated by CFU assay was found to be reduced in (-/-) compared to (+/-) HSC/HPC subsets. Additionally, both HSC/HPC subsets expressed pluripotency/stemness genes i.e. SOX2, Nanong, OCT4. Protein profiling showed that the two subsets shared more similarity than differences and around 304 proteins have been identified in the CD34+ and CD34- subsets. Only 44 of the 304 identified proteins (approx. 14.4 %) were significantly differentially expressed (≥2- fold change & p < 0.05) between the CD34+ and CD34- fractions, while the majority of the proteins shares similar expression profiles. This is indicative that the two cell sub populations are fairly similar at protein level and there is a small marked difference between them. Distinct biological characteristics of CD34− compared to CD34+ HSC segment were observed, and hopefully further analysis will facilitate in the discovery of a novel marker(s) that will help in their selection for medical applications.