Tolerosomes are physiologically produced as a response to dietary peptides; it is already known that enterocytes posses the molecular mechanisms for processing peptides in a similar manner to lymphocytes. The fate of tolerosomes is not precisely known, but it seems that they merge with intestinal dendritic cells, conveying to them the information that orally administered peptides must be interpreted as tolerogens. SEA can stimulate this mechanism, find more thus favoring the development of tolerance to peptides/proteins administered subsequently via the oral route. This characteristic of SEA might be useful in therapy for regulating immune responses. The present

paper reviews the current status of research regarding the impact of SEA on the enteric immune system and its potential use in the treatment of allergic and autoimmune diseases. Staphylococcal enterotoxin A belongs to the family of staphylococcal enterotoxins, a group of molecules which have drawn the attention of researchers in the field of immunity for over 30 years. The first SE discovered was SEA, in 1966,

followed by another eight (B-E, G-J). The original observations were connected with the ability of these enterotoxins to induce toxic shock when food contaminated with Staphylococcus aureus strains was ingested (1). From the beginning, it was observed that SEs are active in very small amounts (micrograms), and are very stable. Generally, PD-L1 mutation foods contaminated by them retain their toxicity after boiling or freezing. Even in the digestive tract, these proteins are not degraded by local proteases and can therefore still exert their specific actions (2). In the case of SEA, at approximately 4 hr after the ingestion of less than 1 μg, symptoms such as nausea, vomiting, and abdominal cramps appear (3). This is accompanied

by an inflammatory infiltrate abundant in PMNs in the lamina propria and epithelium of the intestinal wall. PMNs release large quantities of mediators such as histamine, leukotrienes, Unoprostone and intestinal neuropeptides including substance P, all of which contribute to the clinical picture (4). The proof for the inflammatory etiology of the symptom of emesis in toxic shock is that this symptom is reversed by the administration of antihistamines. In some animal models, it has been proved that SEA also induces secretion of monocyte chemo-attractant protein 1 (5), IL-6 and IL-8 by the intestinal myofibroblasts (6). Under the influence of SEA, the serotonin concentration increases in the intestinal wall, stimulating local vagal receptors, an absolutely necessary step in the development of the gastrointestinal symptoms (7). In addition to their toxic activity, SEs stimulate adaptive immunity as SAs, which means that the number of T cells activated by these toxins is much greater than in the case of normal antigens.