Structural studies of staphylococcal enterotoxin H in complex with T cell receptor and major histocompatibility complex class II

• Superantigens (SAgs) are bacterial toxins capable of cross-linking the immune receptors of the host, the T cell receptor (TCR) and major histocompatibility complex (MHC) class II, and thereby trigger a massive release of cytokines. This could lead to toxic shock syndrome, which can have a fatal outcome. Here, we present the crystal structure of the ternary complex between the superantigen, staphylococcal enterotoxin H (SEH), TCR and MHC, as well as the dimer complex, including only TCR and SEH. It is evident that SEH interacts with the variable α domain (Vα) of TCR, in sharp contrast to previously studied SAgs that interact with the Vβ domain. Due to the high structural conservation of amino acids in SEH that are crucial for the interaction, we propose that in addition to Vβ activation of T cells, there are SAgs, in addition to SEH, which are able to activate T cells through Vα as well. In addition to providing crucial information regarding the nature of TCR-mediated recognition of superantigens, the finding have central implications for future strategies aimed at preventing or modulating the often pathogenic response to superantigens.

Subject headings

NATURVETENSKAP  -- Biologi -- Strukturbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Structural Biology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Immunologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Immunology (hsv//eng)

Publication and Content Type

vet (subject category)

kon (subject category)