CONVENTIONAL ANTIGENS 

                   SUPERANTIGENS 

·       Stimulate only one in 10⁵ to 10⁶ T cells [27].

·       Processing to oligopeptide of 8 to 20 amino acids is required [28].

·       Bind within the antigen-binding groove of MHC class-I or II molecules, as a result, T cell recognition is MHC-restricted {figure 1}.

·       Presentation to CD4+ or CD8+T cells.

·       Strong response by immune system requires prior exposure.

·       Exposure to conventional antigen leads to up-regulation of subsequent responses.

·       Induce memory responses.

·       Conventional antigen/hapten-induced maturation of dendritic cells is resistant to effects of cyclosporine.

·       Stimulate about 10 to 20% of total T cells [1-3, 27]

·       Not processed and not presented as oligopeptides, they undergo limited cleavage during functional maturation and no extensive degradation during processing [28].

·        Bind outside the antigen-binding groove.  As a result, T cell recognition of superantigen is not MHC-restricted [28, 29].

·       Bacterial superantigens stimulate both CD4+ and CD8+T cells, but viral superantigens stimulate only CD4+ T cells [6].

·       Response does not require prior exposure [6].

·       Downregulation of subsequent responsiveness due to the apoptosis of the stimulated T cells [6, 30].

·       Do not induce memory responses [6].

·       Superantigen-induced maturation of dendritic cells is suppressed by cyclosporine [24].