Tissue protective effect of hAAT gene therapy in CIA mouse model. DBA/1 mice were intraperitoneally injected with rAAV8-CB-hAAT vector (2 × 1011 particles/mouse, n = 6) or saline (n = 4) two weeks before immunization with CII. Control group received saline. (A) Arthritis development was evaluated based on arthritis score (mean + SD). Open circle represent rAAV8-CB-hAAT vector injected group, open triangle represent control group. Mice were sacrificed on day 28 after CII immunization, hind limbs were harvested and processed for histological assessment. *p < 0.05 by Mann-Whitney U-test. (B) Histopathological evaluation of arthritis development. Mice in gene therapy group (black bars) or control group (empty bars) were evaluated according to histopathological changes by two blinded pathologists. Each hind paw was evaluated based on a scale ranging from 0-3. (mean+SD). *p < 0.05, **p < 0.01 by Mann-Whitney U-test. (INF: Infiltration of Immune Cells, HYP: Hyperplasia, P.F.: Pannus Formation, B.D.: Bone Destruction) (C,D) Representative joint section from mice receiving hAAT gene therapy. (E,F) Representative joint section from mice in control group (saline injection). Magnification: C,E: 100x; D,F: 200x.