Which among the following is true about Super antigens?
They bind to the cleft of the MHC
Needs to processed before presentation
They are presented by APC' S to T cells
Directly attached to lateral aspect of TCR B chain
A group of antigens have been termed superantigens because they stimulate a much larger number of T cells than would be predicted based on the specificity of combining site diversity. This causes a massive cytokine release. The action of superantigens is based on their ability to bind directly to MHC proteins and to paicular V regions of the TCR without involving the antigen combining site. Individual superantigens recognize exposed poions defined by framework residues that are common to the structure of one or more V regions. Any T cells bearing those V sites may be directly stimulated. Ref: Ray C.G., Ryan K.J. (2010). Chapter 2. Immune Response to Infection. In C.G. Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.