American Board of Surgery Qualifying Exam (ABS QE) Practice Test

What is the primary purpose of dendritic cells?

1. Production of antibodies

2. Antigen presentation to T cells

3. Phagocytosis of bacteria

4. Promotion of memory cell activation

The correct answer is: Antigen presentation to T cells

The primary purpose of dendritic cells is to present antigens to T cells, making them crucial players in the adaptive immune response. Dendritic cells are specialized antigen-presenting cells that capture, process, and present antigens on their surface using major histocompatibility complex (MHC) molecules. This process is vital for the activation of naïve T cells, which require antigen presentation to become activated and differentiate into effector T cells. When dendritic cells encounter pathogens, they internalize these antigens, and through a series of complex processes including processing the proteins into peptide fragments, they load these peptides onto MHC molecules. Once this occurs, dendritic cells migrate to lymph nodes where they interact with T cells, providing necessary signals for their activation. This interaction is pivotal for generating an effective immune response, including the activation of CD4+ T helper cells and CD8+ cytotoxic T cells, which are essential for attacking infected cells or orchestrating broader immune responses. While other immune cells, like B cells, are responsible for the production of antibodies, and macrophages perform phagocytosis of bacteria, these functions are not the primary role of dendritic cells. Additionally, while memory cell activation is a part of the immune response,