The ups and downs of T cells The role of costimulatory molecules in the modulation of T cell responses
T cell activation requires the combination of antigen in the context of MHC and costimulatory molecules to induce a functional immune response. For our studies, we primarily utilized superantigens (SAg) that bind MHC class II molecules as first signal. Mutations in the SAg MHC class II a-chain binding site reduced the number of responding T cells expressing particular TCR Vb chains, whereas mutati
