Understanding the Humoral Immune Response

The humoral immune response begins when a macrophage engulfs an antigen, processes it, and presents it on its surface using MHC proteins. A helper T-cell with a matching receptor binds to the antigen, becoming activated by cytokines like interleukin-1 and interleukin-2. This activation leads to the proliferation of helper T-cells. In the effector phase, these activated T-cells help B-cells, which have encountered the same antigen, to become plasma cells that produce specific antibodies. The immune system uses this process to respond to various antigens, requiring specific T-cells and B-cells for different antigenic determinants.

What is the role of Class 2 MHC proteins in the humoral immune response?

• They produce antibodies.

• They bind antigen fragments and display them on the cell surface.

• They destroy antigens directly.

• They activate B-cells.

What is the initial step in the humoral immune response?

• Release of interleukin-2.

• Production of antibodies by plasma cells.

• Engulfing and processing of an antigen by a macrophage.

• Activation of B-cells.

What happens when a helper T-cell binds to a displayed antigen?

• The T-cell becomes inactive.

• The T-cell engulfs the antigen.

• The T-cell releases antibodies.

• The antigen-presenting cell releases interleukin-1.

What is the function of interleukin-2 in the immune response?

• It triggers helper T-cells to divide.

• It destroys antigens.

• It binds to antigens.

• It deactivates B-cells.

What happens to the daughter cells produced by helper T-cells?

• They become macrophages.

• They produce a clone identical to the first T-cell.

• They attack antigens directly.

• They deactivate B-cells.

During the effector phase, what role do activated helper T-cells play?

• They help B-cells develop into plasma cells.

• They directly attack pathogens.

• They produce interleukin-1.

• They become antigen-presenting cells.

How do B-cells become antigen-presenting cells?

• By producing antibodies.

• By engulfing antigens directly.

• By releasing interleukin-2.

• By processing antigens and displaying them with Class 2 MHC proteins.

What triggers B-cells to divide and differentiate into plasma cells?

• Direct contact with antigens.

• Cytokines released by helper T-cells.

• Interleukin-1 from macrophages.

• Binding to Class 1 MHC proteins.

What is the primary function of plasma cells in the immune response?

• To activate helper T-cells.

• To produce antibodies specific to the antigenic determinant.

• To release interleukin-1.

• To engulf antigens.

What is the significance of antigenic determinant specificity in the immune response?

• It ensures that all T-cells can bind to any antigen.

• It allows for a targeted immune response by specific helper T-cells and B-cells.

• It causes the immune system to attack its own cells.

• It prevents the immune system from recognizing antigens.