Microbiology Practice Exam

Monocytes and macrophages bind to which part of an antibody?

1. The Fab region

2. The Fc region

3. The hinge region

4. The variable region

The correct answer is: The Fc region

Monocytes and macrophages interact with the Fc region of antibodies. This region is the tail part of the antibody that does not bind to the antigen but instead serves as a recognition site for immune cells. When an antibody binds to its specific antigen, the Fc region is exposed and can then bind to Fc receptors on the surface of monocytes and macrophages. This interaction is crucial for the opsonization process, where antibodies coat pathogens and promote their uptake and destruction by phagocytic cells. The Fc region plays a vital role in linking the adaptive and innate immune systems. By facilitating the attachment of phagocytes to antibodies, it enhances the immune response, allowing for the effective clearing of pathogens from the body. Understanding this mechanism is important in the context of various immune responses and therapeutic applications, such as monoclonal antibody therapy.