Mapping of Staphylococcal Enterotoxin A Functional Binding Sites and Presentation by Monoclonal Antibodies and Fusion Proteins
AUTOR(ES)
Mahana, Wahib
FONTE
American Society for Microbiology
RESUMO
Staphylococal enterotoxins (SE) bind with high affinity to major histocompatibility complex (MHC) class II proteins and stimulate large number of T cells via the Vβ region of the T-cell receptor (TCR). To map the epitopes of SE type A (SEA) involved in MHC binding and cell proliferation, 20 specific anti-SEA monoclonal antibodies (MAbs) and two large glutathione S-transferase fusion proteins corresponding to the amino and carboxy termini, respectively, of SEA were used. The functionality of these antibodies was tested, by MHC binding inhibition, interleukin-2 production, and T-cell proliferation assays. Moreover, I studied the ability of the MAbs to present SEA in vitro to human and murine cells and their reactivity with the two fusion proteins. This study showed that all of the MAbs have a defined effect on one or both immunological properties of SEA and were able to present SEA to human and murine cells. However, one MAb (4H8) recognized SEA but without any interference with its biological activities. When the MAbs were tested to react with the two fusion proteins representing the SEA molecule, all of the MAbs were negative except for two. These results confirmed the presence of two functionally different binding sites of SEA with MHC class II molecules and the importance of the disulfide loop for the mitogenic activity of SEA. I further demonstrated that MAbs can present SEA to immune cells independent of the site recognized by the antibody and that the integrity of the SEA molecule is very important for its functions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=96543Documentos Relacionados
- Nature and reactivity of staphylococcal enterotoxin A monoclonal antibodies.
- Production of monoclonal antibodies to staphylococcal enterotoxin A.
- Specificity and cross-reactivity of staphylococcal enterotoxin A monoclonal antibodies with enterotoxins B, C1, D, and E.
- Quantitative determination of staphylococcal enterotoxin A by an enzyme-linked immunosorbent assay using a combination of polyclonal and monoclonal antibodies and biotin-streptavidin interaction.
- T-cell antigen receptor binding sites for the microbial superantigen staphylococcal enterotoxin A.