Abstract
Abstract: :
Purpose: To culture and expand viable retinal progenitor cells from cadaveric human retina (hRPCs) and evaluate expression of surface markers by these cells. Methods: Retinas were dissected from stillborn premature infants, dissociated, and cultured. Cells were grown as spheres or adherent monolayers in the presence of EGF + bFGF (both 20 ng/ml) and antibiotics. Expanded populations were banked or harvested as a single cell suspension for flow cytometry. Results: Cultured human retinal progenitors expressed Ki67 as well as a range of familiar surface markers including GD2 ganglioside, LeX (CD15), the tetraspanins CD9 and CD81, NCAM (CD56), Fas (CD95), and MHC class I antigens. No expression of MHC class II, CD3 zeta, or CD133 was observed. Conclusions: The surface marker expression profile of human retinal progenitors is similar to that of progenitors from human brain (Klassen, et al., Neurosci. Lett., 2001) as well as analogous cells derived from the retina of neonatal GFP mice (Klassen, et al., ARVO abstract, 2002). Tetraspanins are thought to play a role in proliferation, migration, and differentiation. Non-protein epitopes such as GD2 ganglioside and CD15 may be of interest for prospective selection of retinal progenitors. Pronounced MHC class I expression is a recurring feature of human CNS progenitors. Lack of detectible MHC class II likely confers a degree of immune privilege upon hRPCs, compared to fetal tissue grafts containing microglia.
Keywords: regeneration • retinal culture • flow cytometry