Oral-antigen delivery via a water-in-oil emulsion system modulates the balance of the Th1/Th2 type response in oral tolerance.
OBJECTIVE
To evaluate the ability of a water-in-oil (W/O) emulsion containing ovalbumin (OVA), a model antigen, to induce oral tolerance and to elucidate the mechanism for the induction of oral tolerance by the emulsion system.


METHODS
A W/O emulsion containing OVA was prepared and evaluated its ability to induce oral tolerance in mice. Also, the Th1/Th2 balance in the mice tolerized was investigated in terms of the ratios of anti-OVA IgG2a titer to anti-OVA IgG1 titer (IgG2a/IgG1 ratios) and cytokine profiles.


RESULTS
Anti-OVA total IgG antibody titer of mice administered OVA in saline was approximately 3.5-fold higher than that of the mice administered OVA in W/O emulsion at a dose of 0.1 mg/mouse/day. Similar total IgG responses were observed between the above two at a dose of 1 mg/mouse/day. The IgG2a/IgG1 ratios decreased as the dose of OVA in W/O emulsion, but not in saline, increased at doses of 0, 0.1, and 1 mg/mouse/day. Interferon-gamma secretion of PLN cells from the mice administered OVA in W/O emulsion decreased, whereas their interleukin-4 secretion remained high. Although interferon-gamma secretion for the mice administered OVA in saline decreased, interleukin-4 secretion did not change.


CONCLUSIONS
The present study suggests that oral delivery of OVA via the W/O emulsion system may more efficiently enhance the induction of Th2-dominated imbalance than that of OVA in saline.
Masuda
Kazuyoshi
K
Shionogi Research Laboratories, Shionogi & Co., Ltd., 5-124, Sagisu, Fukushima-ku, Osaka 553-0002, Japan. kazuyoshi.masuda@shionogi.co.jp
Horie
Kazutoshi
K
Suzuki
Ryuji
R
Yoshikawa
Takayoshi
T
Hirano
Koichiro
K
D000284:Administration, Oral; D000818:Animals; D000941:Antigens / Q000008:administration & dosage*; D016503:Drug Delivery Systems / Q000379:methods*; D004361:Drug Tolerance / Q000502:physiology; D004655:Emulsions / Q000008:administration & dosage*; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D008198:Lymph Nodes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009821:Oils / Q000008:administration & dosage; D010047:Ovalbumin / Q000008:administration & dosage; D018417:Th1 Cells / Q000187:drug effects* / Q000378:metabolism*; D018418:Th2 Cells / Q000187:drug effects* / Q000378:metabolism*; D014867:Water / Q000008:administration & dosage
D000941:Antigens; D004655:Emulsions; D007074:Immunoglobulin G; D009821:Oils; D014867:Water; D015847:Interleukin-4; D007371:Interferon-gamma; D010047:Ovalbumin