All are true regarding superantigens except? – Microbiology MCQ

All are true regarding superantigens except?
A. Activate very large numbers of B cells
B. Bind outside the antibody binding groove
C. Are medium sized proteins
D. Cause release of cytokines

Correct answer : A. Activate very large numbers of B cells
Streptococcal-superantigen-Spe-H
Streptococcal superantigen Spe-HMolecular structure of Streptococcal superantigen Spe-H

Superantigens activate very large number of T cells.
They are medium sized proteins which bind outside the antibody binding groove.
They have high resistance to proteases.
They cause release of cytokines resulting in massive proliferation of T lymphocytes.

Ref: Ananthanarayan and Paniker’s Textbook of Microbiology, 9th edition, p90.
Image credits: Jawahar Swaminathan and MSD staff at the European Bioinformatics Institute. https://en.wikipedia.org/wiki/File:PDB_1eu4_EBI.jpg