Graft-host integration following retinal transplantation to dystrophic RCS rats
Field:	Disorders of the nervous system
Authors:	Zhang, Yiqin Perez, Maria-Thereza
Address of presenting author:	Wallenberg Retina Center Department of Ophthalmology Lund University Hospital S-221 85 Lund Sweden
E-mail:	yiqin.zhang@oft.lu.se
Phone:	+46 46 17 27 91
Fax:	+46 46 17 27 21
Text of abstract:	We have examined the degree of graft-host integration when transplanting embryonic retinal tissue to the subretinal space of RCS rats. In this animal model of recessively inherited retinal degeneration, photoreceptor cells are lost between 1 and 3 months of age. RCS rats were 32 and 73-days old at the time of transplantation. After various survival times (1-6 mo), the retinas were processed for immunocytochemistry using antibodies against calbindin, protein kinase C (PKC), and the neuronal form of nitric oxide synthase (NOS). In transplantation to 32-day old hosts, no labeled graft-host connecting fibers were seen with any of the markers following short survival times. With time, and only in areas where host photoreceptors were lost, some PKC, calbindin, and NOS-labeled processes originating in the grafts were seen to cross the graft-host interface and terminate in the host plexiform layers. In transplantation to 73-day old hosts (most photoreceptors are lost already at the time of transplantation), labeled fibers were seen to cross the graft-host interface at all survival times. However, their number was still relatively low. Our results indicate that graft-host integration does occur following transplantation to RCS rats, but may be limited by photoreceptor-associated factor(s) if transplanting at a stage when host photoreceptors still remain. On the other hand, when transplanting at a later stage, other barriers may be created as a result of the extensive cell loss. We are currently looking at the expression of various molecules present within the graft and host retina that may play a role in limiting integration. We are also testing means of overcoming potential barriers. Supported by MFR, KMA, Crafoord and Wallenberg Foundations, and Foundation Fighting Blindness
Keywords:	retinal degeneration, transplantation, graft-host integration

Created 2000-03-15