Question

In spite of their low affinity for binding to their antigen, IgM antibodies can

be quite effective at promoting the elimination of extracellular bacterial infections. This is
due to:

A. The ability of IgM antibodies to traffic across epithelial surfaces
B. Multivalent binding of IgM pentamers to repetitive epitopes on bacterial surfaces
C. The high concentration of IgM antibodies in the serum and in all tissues
D. The early production of IgM antibodies during an immune response
E. The high rate of somatic hypermutation in the genes encoding IgM antibodies

Answer 1

IgM antibodies are effective at eliminating extracellular bacterial infections due to their ability to bind to multiple bacterial surfaces simultaneously and activate the complement cascade.

Step-by-step explanation:

IgM antibodies are quite effective at promoting the elimination of extracellular bacterial infections due to the multivalent binding of IgM pentamers to repetitive epitopes on bacterial surfaces.

This allows IgM antibodies to agglutinate bacteria by binding to epitopes on two or more bacteria simultaneously, promoting the clearance of pathogens.

In addition, IgM antibodies can activate the complement cascade, enhancing phagocytosis by opsonization and promoting rapid clearing of pathogens.