Figure 3.

Exhausted T Cells Infiltrate the Muscle after rAAV1 Administration

Nonhuman primates were injected IM, VLP, or IAPD with an ssAAV1 vector (6e12 vg/kg). Muscles were harvested 21 and 60 days after dosing and were dissociated as described in Materials and Methods. The exhausted T cell population was analyzed by flow cytometry. (A) Gating strategy. RA1683, right quadriceps (injected muscle), 60 days after dosing. T cells are gated as CD3⁺ cells in the lymphocyte subset, CD8 T cells are gated as CD3⁺ CD8⁺ cells in the CD3⁺ subset, and exhausted T cells are gated as PD-1⁺ cells in the CD3⁺ CD8⁺ subset. (B and C) Percentages of CD8 T cells (B) and exhausted T cells (C) in injected muscle or perfused limb at day 21 and day 60 after dosing. nd, not detected. (D) Detection of exhausted T cells by immunohistochemistry in injected muscle after IM delivery (RA0764, day 60 post-injection). Scale bars: 10 μm.