Figure 7.

T Cell Responses Directed against AAV2 Capsid or the RPE65 Protein as a Function of Time after Ipsilateral Subretinal Readministration of AAV2-hRPE65v2

IFN-γ secretion by PBMCs after stimulation with the AAV2 capsid or RPE65 protein at baseline and post-injection time points showed variable increases at the 4 week time point as measured by IFN-γ ELISpot assay with PMA+ION, positive control. The different test antigens for each of the panels are indicated in (E). The pre-injection samples (baseline and baseline for the first injection) are shown in (A) and (B), respectively. The results at 2, 4, and 6 weeks post injection 2 are shown in (C), (D), and (E), respectively. One animal showed a cell-mediated response to the AAV capsid at the 4 week time point (D) and that response then subsided (E). There were also cell-mediated responses to the RPE65 protein at 4 weeks (D) and those resolved thereafter (E). Response to an antigen was considered positive when the number of SFUs per 200,000 PBMCs was higher than 50 SFUs (dotted line) per 200,000 PBMCs and three or more times the SFU per 200,000 PBMCs measured for the medium control. Error bars indicate SEM, calculated as the SD of the readings divided by the square root of the number of readings.