Other animal studies have indicated that parenteral inoculation of SEA promotes the generation and function of regulatory lymphocytes (56, 57). SEA is less well absorbed from

the gut lumen through facilitated transcytosis than are other staphylococcal SAs such as SEB and TSST-1 (58), and is probably AT9283 molecular weight less prone to produce systemic effects when orally administered.). SEA is less well absorbed from the gut lumen through facilitated transcytosis than are other staphylococcal SAs such as SEB and TSST-1 (58), and is probably less prone to produce systemic effects when orally administered.[T1] Also, SEA seems to be more efficient at induction of regulatory-type immune responses than TSST-1 (59). For these reasons, SEA might be a better choice for therapeutic studies of oral tolerance. Three main molecules are affected by autoimmunity in multiple sclerosis, the disease mimicked by EAE: myelin basic protein, proteolipid protein, and myelin oligodendrocyte Selleckchem Wnt inhibitor glycoprotein. There have been attempts at inducing

oral tolerance to these proteins in animal models of EAE (60–64) and also in humans (65–67). The history of the use of staphylococcal enterotoxins in EAE has some aspects in common with oral administration of antigenic myelin proteins. Experiments on animals were first conducted with SEB, and only later with SEA, although SEA is more potent in regard to its effects on T cells. So far, there are no studies of SEA or SEB administration in humans with MS. Also, there are no studies in humans or animals of associations between SEA and any of the myelin antigenic proteins, MBP, PLP or MOG. In general, previous Org 27569 studies using SEA or SEB in animals were focused on parenteral (intravenous or intraperitoneal) administration.

The reason for this is connected to the discovery that in mice which develop EAE, especially the PL/J species, which were massively used in the 1990s, there is TCR restriction of the myelin-reactive cells (68). A significant proportion of these lymphocytes have a TCR that contains the Vβ8 chain (69). SEB is a molecule with tropism for this chain (70). With high doses, lymphocyte stimulation by SAs leads to their deletion (71). The first experiments with SEB on mice actually tried to produce deletion of autoreactive lymphocytes. When given before immunization with MBP, SEB has a protective effect to the development of EAE, because those T cells which might have become autoreactive are eliminated. When SEB is given after immunization, EAE aggravates, because there is supplementary stimulation of the effector cells by the SA (72). Unlike MBP, PLP is not recognized by Vβ8+ T cells (73), accordingly PLP-induced EAE is differently influenced by administration of SEB.