Interleukin-10 Gene Transfer in Rat Limbal Transplantation

ABSTRACT

Purpose: To evaluate the gene transfer of the interleukin (IL)-10 cytokine as a treatment modality for prolonging limbal allograft survival in a rat model.

Materials and methods: Adenoviral (AV) and lentiviral (LV) vectors were produced for ex vivo gene transfer into limbal graft tissue prior to orthotopic transplantation. Experimental groups comprised unmodified isografts, unmodified allografts, allografts transfected with a reporter gene, and allografts transfected with IL-10. The functional effects of the transgenes were determined by clinical assessment and by following donor cell survival in the recipient animal. Group comparisons were made using survival analysis and tested with the log-rank test. Differences in mean rejection times between groups were tested using the Wilcoxon rank-sum test.

Results: Isografts survived during the entire observation period of 56 days. Allografts underwent clinical rejection at a mean of 6.7 days (standard deviation 2.0) postoperatively, irrespective of the presence of transgenes (p < 0.001 for difference in rejection times). For both the AV and LV vector systems, Kaplan–Meier analysis showed a statistically significant difference with respect to time-to-graft failure when comparing allografts transfected with IL-10 with allografts transfected with reporter gene alone (p = 0.011 and p < 0.001, respectively). In the isografts, donor cells could be detected during the complete observation period. In all the allograft groups, however, donor cell detection declined after 1 week and was lost after 4 weeks.

Conclusions: Under the conditions tested in the present model, both the AV and the LV vector systems were able to transfect limbal graft tissue ex vivo with biologically active IL-10, leading to delayed rejection compared to the controls.

KEYWORDS:

• Adenoviral vector
• gene therapy
• interleukin-10
• lentiviral vector
• limbal transplantation

Acknowledgments

The authors thank Mrs Kirsty Kirk and Dr Francisca Angerstein for assistance in following up research animals. CK was supported by the Nachwuchsförderungskredit der Universität Zürich, by the EMDO Stiftung Zürich, and by the Schweizerische Fonds zur Bekämpfung und Verhütung der Blindheit. KAW was supported by the National Health & Medical Research Council (NHMRC) of Australia. The NHMRC, the Ophthalmic Research Institute of Australia, and the Flinders Medical Centre Foundation also provided project grant support.

Declaration of Interests

All authors (CK, LAM, HMB, YDI, DGAP, DSA, LMB, KAW) certify that they have no financial interests or nonfinancial benefits in the subject matter or materials discussed in this manuscript.