Characterization of the porcine neonatal Fc receptor--potential use for trans-epithelial protein delivery.
The neonatal Fc receptor transports maternal immunoglobulin across the gut wall and has the potential to deliver genetically engineered proteins bearing immunoglobulin Fc domains across the gut to the mucosal immune system. Here we have characterized the porcine neonatal Fc receptor and tested its utility as a model system to study this kind of protein delivery. The complete DNA sequence obtained from an EST revealed 70-80% homology to mouse and human receptors, respectively, and tyrptophan and di-leucine endocytosis motifs were identified in the cytoplasmic tail. Reverse transcription-polymerase chain reaction analysis showed expression of the receptor mRNA in gut, liver, kidney and spleen tissue, aortic endothelial cells and monocytes. Pig kidney cell lines showed saturable pH-dependent binding and uptake of porcine immunoglobulin G (IgG) and also bovine, mouse and human IgG. Polyclonal antibodies raised against the receptor immunoprecipitated a protein of 40,000 MW when the cDNA was expressed in cells and the receptor required assembly with porcine beta2-microglobulin for transport from the endoplasmic reticulum to recycling and early endosomes. Immunohistochemical analysis showed the receptor expressed in epithelial cells of the gut of young and adult animals. The ability of the receptor to deliver immunoglobulin across the gut was demonstrated by feeding piglets bovine colostrum as a source of bovine IgG. Bovine IgG was delivered into the pig circulation. Pigs express the neonatal Fc receptor and the receptor has the potential to deliver protein antigens to the pig immune system.
Stirling
Catrina M A
CM
Division of Immunology, Institute for Animal Health, Pirbright Laboratory, Pirbright, UK. catrina.stirling@bbsrc.ac.uk
Charleston
Bryan
B
Takamatsu
Haru
H
Claypool
Steven
S
Lencer
Wayne
W
Blumberg
Richard S
RS
Wileman
Thomas E
TE
D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D001692:Biological Transport; D015153:Blotting, Western / Q000379:methods; D002417:Cattle; D018929:Cell Culture Techniques; D002460:Cell Line; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D019084:Fluorescent Antibody Technique, Indirect; D005818:Genetic Engineering; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D047468:Immunoprecipitation; D007413:Intestinal Mucosa / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding; D051381:Rats; D011961:Receptors, Fc / Q000032:analysis* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D012756:Sheep; D013552:Swine; D014709:Vero Cells
D007141:Immunoglobulin Fc Fragments; D011961:Receptors, Fc; D011994:Recombinant Proteins