Uptake of maternal immunoglobulins in the enterocytes of suckling piglets: improved detection with a streptavidin-biotin bridge gold technique.
In ungulates, intestinal absorption of maternal immunoglobulins from colostrum plays a vital role in the acquisition of passive immunity during early neonatal life. In the present study we used post-embedding colloidal gold labeling to examine the intracellular localization of IgG in the jejunal enterocytes of miniature piglets suckled for 2 hr. Quantitation of the immunolabeling revealed that the most sensitive technique for IgG detection was the streptavidin bridge-gold technique. In this method, the LR White-embedded sections were labeled sequentially with biotinylated anti-porcine IgG, streptavidin, and biotinylated BSA conjugated to 10-nm colloidal gold. With this approach, we found the following sequence of maternal IgG accumulation: passage of IgG from colostrum through the brush border; binding to the apical plasma membrane; uptake in noncoated pits and invaginations; transport in endocytotic vesicles; and accumulation in granules in the apical cytoplasm.
Kömüves
L G
LG
USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX 77030-2600.
Heath
J P
JP
D000818:Animals; D000831:Animals, Newborn / Q000276:immunology*; D001426:Bacterial Proteins; D001710:Biotin; D003126:Colostrum / Q000276:immunology; D006046:Gold; D007112:Immunity, Maternally-Acquired; D007136:Immunoglobulins / Q000378:metabolism*; D007408:Intestinal Absorption; D007583:Jejunum / Q000502:physiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D019809:Streptavidin; D013552:Swine
D001426:Bacterial Proteins; D007136:Immunoglobulins; D001710:Biotin; D006046:Gold; D019809:Streptavidin