Figure 1.

Adeno‐associated virus serotype 8 (AAV8)‐factor IX (FIX) gene therapy elicits robust anti‐AAV8 T‐cell and antibody responses, preventing redosing. Mice were immunized with AAV8‐FIX (FIXR338L) or buffer and killed on day 28 for analysis of FIX expression and anti‐AAV8 immunity. A, FIX expression on day 28. B, Anti‐AAV8 binding and neutralizing antibody titer at day 28 after AAV8 challenge. C, T‐cell response was characterized after in vitro restimulation with AAV8 peptide pools by IFN‐γ ELISpot. AAV8‐specific CD4⁺ T‐cell responses were analyzed by fluorescence‐activated cell sorting (D, E). Ctrl, Control; PBS, phosphate‐buffered saline (significant P > .005; n.s. = not significant)