CD4CAR T-cell expansion in tissues following Env boost. (A) Total CD4CAR T-cell frequency (CD45⁺CD3⁺CAR⁺) in tissues before and after Env boosting. Cells from lower gastrointestinal tract (lower GI), upper gastrointestinal tract (upper GI), axillary lymph nodes (Ax LN), spleen, and bronchoalveolar lavage (BAL) were dissociated and measured for each animal (A15104, blue; A15112, green; A15106, purple; A15108, red). CD4 CAR T-cell frequency was also analyzed in CD8^– (B) and CD8⁺ (C) T-cell subsets following Env boost at 2 weeks (light gray bars, circle symbols) and 4 weeks (dark gray bars, square symbols) after CAR T-cell infusion. Bars represent the means of n = 4 animals.