Sodium Bicarbonate Facilitates Low-dose Oral Tolerance To Peanut In Mice

Abstract

RationaleOral tolerance specifically inhibits production of allergic IgE antibody and is therefore a potential method for suppressing food allergy. We have previously demonstrated that a single oral dose of one mg is sufficient to induce oral tolerance to egg white but not peanut extract in mice. The current study objective was to determine the specific experimental parameters required to achieve oral tolerance to peanut.MethodsFemale C3H/HeJ mice were orally gavaged once with 1 or 2 mg of egg white or peanut extract in Hank's balanced salt solution with or without 0.2M sodium bicarbonate one week prior to intraperitoneal immunization. Serum was collected one week later and assayed for egg or peanut specific antibody responses.ResultsIgE antibody responses were suppressed by prior oral exposure to egg white extract at all doses with or without sodium bicarbonate. Inhibition of IgE responses to peanut was demonstrated at the 2 mg dose but not at the 1 mg dose. However, addition of sodium bicarbonate for oral dosing led to induction of oral tolerance to peanut at both the 1 mg and 2 mg doses.ConclusionsFoods differ in their capacity to induce oral tolerance. In contrast to egg white, 1 mg of peanut given orally does not inhibit IgE production in mice unless it is administered in a 0.2M sodium bicarbonate solution. Results demonstrate that oral tolerance can be facilitated through simple methods, possibly by altering solubility or digestibility of food proteins. (This abstract does not reflect EPA policy.) RationaleOral tolerance specifically inhibits production of allergic IgE antibody and is therefore a potential method for suppressing food allergy. We have previously demonstrated that a single oral dose of one mg is sufficient to induce oral tolerance to egg white but not peanut extract in mice. The current study objective was to determine the specific experimental parameters required to achieve oral tolerance to peanut. Oral tolerance specifically inhibits production of allergic IgE antibody and is therefore a potential method for suppressing food allergy. We have previously demonstrated that a single oral dose of one mg is sufficient to induce oral tolerance to egg white but not peanut extract in mice. The current study objective was to determine the specific experimental parameters required to achieve oral tolerance to peanut. MethodsFemale C3H/HeJ mice were orally gavaged once with 1 or 2 mg of egg white or peanut extract in Hank's balanced salt solution with or without 0.2M sodium bicarbonate one week prior to intraperitoneal immunization. Serum was collected one week later and assayed for egg or peanut specific antibody responses. Female C3H/HeJ mice were orally gavaged once with 1 or 2 mg of egg white or peanut extract in Hank's balanced salt solution with or without 0.2M sodium bicarbonate one week prior to intraperitoneal immunization. Serum was collected one week later and assayed for egg or peanut specific antibody responses. ResultsIgE antibody responses were suppressed by prior oral exposure to egg white extract at all doses with or without sodium bicarbonate. Inhibition of IgE responses to peanut was demonstrated at the 2 mg dose but not at the 1 mg dose. However, addition of sodium bicarbonate for oral dosing led to induction of oral tolerance to peanut at both the 1 mg and 2 mg doses. IgE antibody responses were suppressed by prior oral exposure to egg white extract at all doses with or without sodium bicarbonate. Inhibition of IgE responses to peanut was demonstrated at the 2 mg dose but not at the 1 mg dose. However, addition of sodium bicarbonate for oral dosing led to induction of oral tolerance to peanut at both the 1 mg and 2 mg doses. ConclusionsFoods differ in their capacity to induce oral tolerance. In contrast to egg white, 1 mg of peanut given orally does not inhibit IgE production in mice unless it is administered in a 0.2M sodium bicarbonate solution. Results demonstrate that oral tolerance can be facilitated through simple methods, possibly by altering solubility or digestibility of food proteins. (This abstract does not reflect EPA policy.) Foods differ in their capacity to induce oral tolerance. In contrast to egg white, 1 mg of peanut given orally does not inhibit IgE production in mice unless it is administered in a 0.2M sodium bicarbonate solution. Results demonstrate that oral tolerance can be facilitated through simple methods, possibly by altering solubility or digestibility of food proteins. (This abstract does not reflect EPA policy.)