21. The Immune System

Which of the following is a step required for activation of a B cell by a T-dependent antigen?

T-dependent antigens can stimulate B cells to become activated but require _________ assistance.

T-independent antigens:

Lipopolysaccharide (LPS) is an endotoxin found on the surface of gram-negative bacteria. LPS can cause the body to enter septic shock and result in multi-system organ failure. Because of its severe effects, it is important that the immune cells react quickly to LPS. LPS is an antigen that can directly trigger antibody secretion once it comes in contact with a B cell. LPS is what kind of antigen?