Figure 4
Ovalbumin (OVA) and OVA–IgG immune complexes in breast milk. Sensitized and non-sensitized mothers were exposed or not exposed to OVA and breast milk was collected 6 h later. (a) OVA levels in breast milk. The milk from the indicated mice was analyzed for OVA content by enzyme-linked immunosorbent assay (ELISA) (left panel) or western blot (right panel). For ELISA, data show mean±s.e.m. of six independent experiments. For western blot, the result from one representative experiment of three is shown. OVA was used as a control (left lane). (b) OVA–IgG immune complexes in milk. The milk from the indicated mice was analyzed for OVA–IgG1 content by ELISA (left panel), and for OVA content by western blot directly or after removal of protein G-bound material (right panel). For ELISA, data show the mean±s.e.m. of values obtained in six independent experiments. For western blot, the milk from unexposed (lanes 1, 3, and 5) and from OVA-exposed (lanes 2, 4, and 6) sensitized mothers was analyzed directly (lanes 1 and 2) or after removal of protein G-bound material (lanes 3 and 4). Protein G-bound material was eluted and analyzed (lanes 5 and 6). OVA in phosphate-buffered saline (PBS) was used as a control (left lane). One representative experiment out of two is shown. **P<0.01. (c) Levels of OVA–IgG immune complexes and OVA-specific IgG in FPLC fractionated milk. The milk from OVA-exposed sensitized mice was fractionated on FPLC and the fractions corresponding to proteins of the indicated MW were collected and analyzed by ELISA for the presence of OVA-specific IgG1 (dashed line) and OVA–IgG1 immune complexes (solid line). Data show the results of one representative experiment out of four for the milk of OVA-exposed sensitized mice. When the milk of naive mice was analyzed, none of the fractions gave a positive signal.
