Cellular response in rabbit eyes after human fetal RPE cell transplantation.

Area of Science:

• Ophthalmology
• Cell Biology
• Immunology

Background:

• Investigating cellular responses in rabbit eyes following subretinal transplantation of human fetal retinal pigment epithelial (HFRPE) cells.
• Understanding the inflammatory and proliferative reactions in xenogeneic transplantation models.

Purpose of the Study:

• To evaluate the inflammatory and proliferative cellular responses in rabbit eyes after subretinal transplantation of human fetal retinal pigment epithelial (HFRPE) cells.
• To assess the impact of HFRPE cell density on these responses and potential graft survival.

Main Methods:

• Subretinal injection of 5-Bromo-2-deoxyuridine (BrdU)-labeled HFRPE cells at varying concentrations into rabbit eyes.
• Immunohistochemistry and light microscopy were used to analyze macrophage, glial, and proliferative responses at different time points post-surgery.

Main Results:

• HFRPE cells showed irregular distribution; high-density injections led to retinal breaks, unlike low-density ones.
• Peak inflammatory response occurred between 4-14 days, with higher intensity in high-density groups.
• Host response involved macrophage and glial infiltration, followed by choroidal thickening; donor cell numbers declined after day 14.

Conclusions:

• Xenogeneic HFRPE cell transplantation elicited initial retinal cell responses, followed by choroidal involvement.
• Donor cell decline post-transplantation suggests possible immune rejection.
• The initial concentration of transplanted cells critically influences the intensity of immune and inflammatory responses.