Macrophages exhibit an antiinflammatory response and a reduced maturation profile in the presence of circulating pEF-hAAT-derived hAAT. (A) RAW 264.7 cells were stimulated with LPS (1 ng/mL) in the presence of mouse serum (33% volume) from the following sources: nonstimulated and CT (serum from noninjected mice, n = 8); serum + hAAT (serum from noninjected mice plus 160 µg/mL hAAT, n = 8); serum pEF-hAAT (serum from plasmid-injected mice expressing 500 µg/mL hAAT, n = 8); and serum PBS (serum from PBS-injected mice, n = 8). The 48-h supernatant cytokine levels were analyzed. (B) Surface levels of CD40 and MHCII in peritoneal cell populations directly obtained from islet-grafted mice. The peritoneal cell population (1 × 106 cells per sample) from CT nongrafted mice (black dashed line, n = 6) or islet-grafted mice that were administered PBS (gray solid line, n = 6) or pEF-hAAT (thick black solid line, n = 6) via HD tail-vein injection was assessed for the expression of CD40 (upper panels) and MHCII (lower panels) in total cells (left) and CD11bHI peritoneal cells (middle) by FACS (representative images are shown). Bar graphs depict events from CD11bHI peritoneal cells, presented as fold from CT. Mean ± SEM; *P > 0.05, **P > 0.01.