Absorption, Migration and Kinetics in Peripheral Blood of Orally Administered Ovalbumin in a Mouse Model

Abstract

Intestinal absorption of food proteins is well known, whereas its physiological significance remains to be investigated. Various amounts (1, 10 and 50 mg) of ovalbumin were orally administered to mice and the blood kinetics were subsequently analyzed by two-site ELISA. The blood ovalbumin concentration consistently reached its maximum (7-90 ng/ml) about 20 min after the oral administration and then gradually decreased in a dose-dependent manner. Only intact (45 kDa) and truncated (40 kDa) ovalbumins were always detected in the blood independently of the administration site, intra-stomach or intra-intestine, while various fragments of the protein were observed in the gastrointestinal lumen after the oral administration. Recognition by a specific monoclonal antibody and an acidic shift of its pI value suggested that the 40-kDa truncated ovalbumin was produced by intracellular limited proteolysis at its C-terminus. Such stable absorption and blood kinetics of undigested ovalbumin in normal mice suggest some sort of physiological significance for the intestinal uptake of intact food proteins.

Intracellular Retention and Subsequent Release of Bovine Milk Lactoferrin Taken Up by Human Enterocyte-Like Cell Lines, Caco-2, C2BBe1 and HT-29

“…13,26) However, a collective contribution to the LF uptake by some other mechanisms could not be ruled out, because a certain level of uptake by the enterocytes was also apparent for some proteins other than LF in the present and previous studies. 21,22,27) About 60 ng of LF per well of the Caco-2 cells was taken up by the 3-h loading, while about 120 ng (after subtracting the value of 80 ng for the 1-min incubation) of LF was subsequently released into the culture medium during the 3-h culture. Although the reason for these apparently contradictory results between the LF uptake and subsequent release remains unknown at this moment, the association of LF with its receptor, as speculated by the immunocytological analysis (see Fig.…”

“…Tel: +81-52-789-4129; Fax: +81-52-789-4128; E-mail: tmatsuda@agr.nagoya-u.ac.jp Abbreviations: DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; IntL, intelectin-1; LF, lactoferrin; LY, lysozyme; OA, ovalbumin; OM, ovomucoid; PBS, phosphate-buffered saline; POD, peroxidase ovalbumin (OA), which was taken up from the intestinal lumen, migrated to peripheral blood at a ng/mL level in adult mice 21) and that OA was taken up by the Caco-2 monolayers, degraded within the cells, and partly released in an intact form. 22) In contrast, LF was almost undetectable in the peripheral blood of rats to which LF had been intragastrically administered, 16) and the subcellular localization and dynamics of LF taken up by intestinal epithelial cells have not been well investigated.…”

Binding of Norovirus Virus-Like Particles (VLPs) to Human Intestinal Caco-2 Cells and the Suppressive Effect of Pasteurized Bovine Colostrum on This VLP Binding

“…Some food proteins have been reported to remain intact, at least at immunologically detectable levels, in the lumen of the mouse small intestine. 21,28) It would be of interest to investigate the digestibility or resistance of bovine colostrum IgG in vitro and in vivo using animal models.…”

“…IgG antibodies specific for NoV and SaV VLPs in bovine colostrums were measured by ELISA, as described previously. 21) Briefly, 96-well plates (Nunc, Roskilde) were coated with 1 mg per well of VLPs in PBS. After washing and blocking, the plates were incubated with colostrums diluted to a 1-20 mg protein concentration with PBS/ Tween/BSA, washed with PBS/Tween, and incubated with PODconjugated anti-bovine IgG (H and L chains) antibody (Abcam, Cambridge).…”

Development of Oral Immunotherapy Model Using B10.A Mice and Egg White Lysozyme

“…However, in most cases, foods are cooked and processed with other foods and undergo significant changes in such qualities as digestibility, absorbability and allergenicity. Some studies of the intestinal absorption of food protein have shown that the concentration of protein in the blood increases in a dose-dependent manner and that co-administration with other food components such as protein or corn oil markedly affects the intestinal absorption of allergen (11,12). Furthermore, allergenicity is altered by denaturation and modification (13)(14)(15), such as that occurring through processing or cooking.…”