SBA — Single Best Answer · Review
Question 615
Immunology → General
Classification
Question
SSBAQuestion Header
Which statement best distinguishes a superantigen from conventional antigen recognition?
Question Stem
Select the single best answer.
Options
A
It can stimulate an immune response only after previous exposure
B
It must be a large carbohydrate
C
It acts only after digestion in the gastrointestinal tract
D
It cannot interact with antigen-presenting cells
E
It is a bacterial protein that interacts nonspecifically with antigen-presenting cells and T cells
Explanation
Superantigens are bacterial proteins that interact nonspecifically with antigen-presenting cells and T cells and can provoke a drastic immune response. Antigens more generally stimulate immune responses through specific interaction with effector molecules or lymphocytes.
Option Validity
A) Recognition of foreign antigen is not dependent on previous exposure.
B) Antigens are usually proteins or polypeptides, although large carbohydrates can also be antigenic; this does not define a superantigen.
C) Proteins and carbohydrates are normally digested in the gut, but this does not define superantigen action.
D) Superantigens interact with antigen-presenting cells as well as T cells.
Further Reading
Saxena MRCOG-1 Basic Sciences — Immunology: Immunogenetics and Principles of Antigen Recognition, printed page 212 before Immunoglobulins.