Fig. 4

Topically applied nebulized IgG can reach the conducting airways and the alveoli in rats and remain functional over time. Lung tissue from IgG- and vehicle-treated animals were fixed and embedded in paraffin. Time points represented are 1 h and 24 h post-inhalation. Tissue sections were analyzed using a pan-Ig secondary antibody coupled to HRP. a Section of lung tissue obtained from a vehicle-treated animal is shown. It represents the level of background of the detection antibody. b Staining with detection antibody of sections obtained from tissues of animal treated with nebulized IgG is shown, legend for the red letters appearing in the sections is as follows; a: alveoli, aM: alveolar macrophage, B: bronchi, Tb: terminal bronchi. c-f Assessment of binding activity of nebulized IgG and IgA recovered from broncho-alveolar lavages was performed using ELISA. Tetanus toxoid antigen (c, d) was used to evaluate IgG from broncho-alveolar lavages obtained from rats (c) and non-human primates (d). Pneumococci polysaccharides were also used to evaluate IgG (e) for broncho-alveolar lavages obtained from non-human primates