Hyperimmunized hens are an effective means of generating large quantities of
antigen specific egg
antibodies that have use as oral supplements. In this study, we attempted to create a
peptide specific antibody that produced outcomes similar to those of the human
pharmaceutical,
sevelamer HCl, used in the treatment of
hyperphosphatemia (a sequela of
chronic renal disease). Egg
antibodies were generated against 8 different human intestinal
sodium-dependent
phosphate cotransporter 2b (NaPi2b)
peptides, and hNaPi2b
peptide egg
antibodies were screened for their ability to inhibit
phosphate transport in human intestinal Caco-2 cell line. Antibody produced against human
peptide sequence TSPSLCWT (anti-h16) was specific for its
peptide sequence, and significantly reduced
phosphate transport in human Caco-2 cells to 25.3±11.5% of control nonspecific antibody, when compared to
nicotinamide, a known inhibitor of
phosphate transport (P≤0.05). Antibody was then produced against the mouse-specific
peptide h16 counterpart (mouse sequence TSPSYCWT, anti-m16) for further analysis in a murine model. When anti-m16 was fed to mice (1% of diet as dried egg yolk
powder), egg yolk
immunoglobulin (
IgY) was detected using immunohistochemical staining in mouse ileum, and egg anti-m16
IgY colocalized with a commercial goat anti-NaPi2b antibody. The effectiveness of anti-m16 egg antibody in reducing serum
phosphate, when compared to
sevelamer HCl, was determined in a mouse feeding study. Serum
phosphate was reduced 18% (P<0.02) in mice fed anti-m16 (1% as dried egg yolk
powder) and 30% (P<0.0001) in mice fed
sevelamer HCl (1% of diet) when compared to mice fed nonspecific egg
immunoglobulin. The methods described and the findings reported show that oral egg
antibodies are useful and easy to prepare
reagents for the study and possible treatment of select diseases.