Abstract
Purpose: :
Age related macular degeneration is a major cause of visual morbidity world-wide. Retinal cell transplantation is one possible therapy and in recent years transplants of RPE have been shown to delay photoreceptor degeneration in the RCS Rat. Basic research in this field has been limited by a failure to accurately identify the temporal health and survival of grafted tissue. We have previously determined that only 2-5% of grafted human cells and fewer rat cells survive 5 months post graft. Graft cell survival is crucial to the success of this research before we can answer questions on immune responses and long term function.This project aims to characterise an extended life murine RPE cell line for use in allogeneic subretinal transplant studies. The mouse is a more versatile animal model for use in immunological experiments and allows us to take advantage of transgenic models for later research.
Methods: :
The RPET cell line was obtained from Dr Hiroshi Tomita in TUBERO, Sendai, Japan, they were grown in culture at 33 C on collagen coated flasks and their basic morphology compared to that of the more commonly used human ARPE19 cell line (ATCC) The RPET cell line has been derived from transgenic C57BL/6 mice harbouring temperature sensitive simian virus 40 T-antigen. Immunocytochemistry was used to assess junctional marker ZO-1 (BD Biosciences), adherens junction protein ß-Catenin (BD Biosciences), and cytokeratins 5&8 and 18 (both from Eurodiagnostica).
Results: :
Cell morphology is very similar between the RPET and the ARPE19 cell lines with both showing characteristic RPE expression patterns for ZO-1 and ß-catenin. Cells grew as contact inhibited monolayers with the RPET cells exhibiting a slightly more elongated morphology than the ARPE19. Both cell lines expressed cytokeratins characteristic of epithelial phenotypes (5&8 for all epithelia and 18 for non stratified epithelia).
Conclusions: :
Before using a novel cell line for these experiments it is imperative to assess the characteristics of the cells and how they compare to normal retinal pigment epithelial cells. By confirming that these cells conform to well established markers of RPE cell morphology and function we have shown that they are suitable for use in retinal transplantation studies. These cells will allow future cell survival studies assessing basic immunological responses to allogeneic subretinal transplantation of RPE cells in a murine model.
Keywords: retinal pigment epithelium • transplantation • retinal degenerations: cell biology