THE HUMAN IMMUNE SYSTEM
IMMUNE RESPONSE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Superantigen
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Supertoxin
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Superantibody
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Superbug
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Detailed explanation-1: -Superantigens are defined by their ability to stimulate a large fraction of T cells via interaction with the TCR V domain (Fig. 5-7). Superantigens are predominantly bacterial in origin, such as staphylococcal enterotoxin and toxin-1 responsible for toxic shock syndrome.
Detailed explanation-2: -Moreover, T-cell activation by superantigens requires their direct binding to CD28 (12), the second signaling molecule mandatory for T-cell activation, which results in massive induction of inflammatory cytokines that mediate toxic shock, including IL-2, IFN-, and TNF.
Detailed explanation-3: -There are six characterized staphylococcal enterotoxins based on serological groups: staphylococcal enterotoxin types A, B, C, D, E, and H (referred to as SEA, SEB, etc.) (3, 60, 65). Ren et al. (60) first identified the nucleotide sequence and protein product designated SEH.
Detailed explanation-4: -Most known superantigens are produced by streptococci and staphylococci. Superantigens are thought to play important roles in the pathophysiology of some forms of bacterial food poisoning, toxic shock syndrome, Kawasaki’s disease, psoriasis, and possibly some autoimmune conditions.