Oral-antigen delivery by way of a multiple emulsion system enhances oral tolerance

The delivery of diverse antigens by way of this multiple emulsion system enhances the induction of oral tolerance. This has been found with three different antigens, namely with GtfB.1::PhoA, a bacterial protein that is a weak inducer of oral tolerance when given by itself, with BSA, and with OVA. With regard to the last antigen, delivery of OVA in MES in fairly low dose is able to induce tolerance even in a T-cell receptor transgenic mouse. Based on preliminary observations, the MES appears to deliver antigen into the lymphoid follicles or Peyer's patches of the mouse intestine, and not into the epithelial layer. The mechanism of tolerance induction by MES is not yet known. However, addition of small amounts of CT to antigen in MES is able to break tolerance and switch the response to one of strong immunity. Because the components of the MES used in these experiments are biodegradable and nontoxic, this system could potentially be used in humans. Oral tolerance has been formally demonstrated in humans after the feeding of a soluble protein antigen. This result supports the notion that oral tolerance might be exploited for the treatment of autoimmune disorders. To date, the studies of autoantigen feeding for the treatment of multiple sclerosis and rheumatoid arthritis have demonstrated safety, but the efficacy has been unclear. The use of MES in humans has not been tested, but this approach or others like it may increase the effectiveness of this potential therapy.