Final answer:
Superantigens harm the body by causing an uncontrolled activation of T cells, leading to a cytokine storm, which results in severe inflammatory responses like high fevers, low blood pressure, multi-organ failure, and potentially, death.
Step-by-step explanation:
Mechanism of Harm by Superantigens
Superantigens cause harm to the body by binding simultaneously to MHC II molecules on antigen-presenting cells (APCs) and the variable region of the T-cell receptor (TCR) ß chain. This abnormal binding, which is characterized by a lack of specific foreign epitope recognition, results in the nonspecific activation of T cells. Such an activation leads to an excessive release of cytokines, typically known as a cytokine storm. This cytokine storm triggers an overwhelming inflammatory response that can have severe consequences, including life-threatening high fevers, low blood pressure, shock, multi-organ failure, and potentially, death.
Bacteria such as Staphylococcus aureus and Streptococcus pyogenes, as well as certain viruses, produce these harmful superantigens. The systemic inflammatory response they provoke can lead to conditions like toxic shock syndrome and scarlet fever, both capable of causing fatalities if not promptly treated.