Contribution of Serum Immunoglobulin Transudate to the Antibody Immune Status of Murine Intestinal Secretions: Influence of Different Sampling Procedures

Serum immunoglobulin transudation into the murine gut after intragastric immunization with the model antigen ovalbumin and cholera toxin adjuvant was investigated with regard to the mucosal sampling technique applied. The levels of serum-derived immunoglobulin A (IgA) turned out to be lowest in feces, intermediate in gut lavage fluid specimens, and highest in filter wick-collected samples. However, these levels did not exceed 2% of total and specific IgA in any mucosal sample type, except after the administration of very high antigen doses (≥1 mg of antigen per g of body weight), when transudation rates of up to 31% could be measured in filter wick-collected samples from individual animals. Luminal IgG was plasma transudate and/or bile borne and appeared to be reabsorbed at the mucosa to some extent.