B-cell receptors bind to antigens that are either freely dissolved or present on the surface of invading or foreign cells. T-cell receptors ________.
A) are active only in lymph nodes
B) bind only to antigens present on the surface of the invading or foreign cells
C) bind only to freely dissolved antigens in the plasma
D) bind to antigen fragments presented on major histocompatibility (MHC) complexes by host cells
E) bind to antigens that are either freely dissolved or present on the surface of invading or foreign cells

Question

Quizplus · Accepted Answer

T-cell receptors (TCRs) bind to antigen fragments that are presented on major histocompatibility (MHC) complexes by host cells. This allows T cells to recognize antigens derived from both foreign and host cells. Unlike B-cell receptors, TCRs cannot bind to freely dissolved antigens or antigens present on the surface of invading cells.

B-Cell Receptors Bind to Antigens That Are Either Freely Dissolved