Which of the following is a characteristic of superantigens?

Superantigens are a unique class of antigens that trigger a particularly powerful immune response. Unlike conventional antigens, which typically require processing and presentation by antigen-presenting cells to T cells, superantigens can bind directly to T cell receptors and major histocompatibility complex (MHC) molecules. This leads to the activation of a large number of T cells, far exceeding the normal response to a typical antigen.

When superantigens are present, they cause widespread activation of T cells, resulting in the release of various cytokines. This can lead to a cytokine storm, which is a rapid and excessive immune response that can have both protective effects during infections and contribute to detrimental outcomes such as toxic shock syndrome.

In contrast, other options do not accurately describe the properties of superantigens. While they may influence T cell behavior, they do not specifically induce apoptosis, prevent differentiation in a broad sense, or are exclusive to certain bacteria, as superantigens can be produced by a variety of pathogens, including viruses and some non-pathogenic bacteria. This distinctive immune activation mechanism underscores the role of superantigens in pathogenesis and immune system dysregulation.