97th DOG Annual Meeting 1999

P581

PROPERTIES OF IMMUNE PRIVILEGED TISSUE IN DIFFERENT RETINAL PIGMENT EPITHELIAL CELL POPULATIONS

H. Wenkel1,2, J. W. Streilein1

Fetal retinal pigment epithelial (RPE) cells have shown to possess special characteristics facilitating prolonged survival when transplanted to a non-privileged site. We wanted to evaluate whether adult or cultured RPE cells share the same properties.

Methods: Fetal or adult C57BL-6 RPE cells were harvested and either immediately transplanted or cultured for five passages before grafting into the anterior chamber, the subretinal space, subconjunctivally and underneath the kidney capsule of histoincompatible BALB/c mice. Groups of cultured cells were pretreated with gamma-interferon for 48 hours before transplantation. Recipients were tested for C57BL-6 specific delayed type hypersensitivity (DH) with and without prior challenge with C57BL-6 spleen cells.

Results: All different RPE cell grafts showed a significantly increased survival compared with conjunctival grafts at all evaluated sites. Weak immunization against donor cells by RPE cell grafts was only increased by pretreatment with gamma-interferon. All populations of RPE cells injected intraocularly induced immune deviation in contrast to kidney capsule were strong DH was seen following immunization with spleen cells.

Conclusions: Even adult or cultured RPE cells, or cells pretreated with gamma-interferon demonstrate properties of immune privileged tissues and survive for a prolonged period of time at conventional transplantation sites. All tested populations of RPE cells induce immune deviation when injected intraocularly.

1Schepens Eye Research Institute and Depart. of Ophthalmology, Harvard Medical School, Boston, MA, USA;
2Depart. of Ophthalmology, University Erlangen-N├╝rnberg, Schwabachanlage 6, D-91054 Erlangen, Germany.


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