Which of the following statements concerning antigen-presenting cells is true?

• A. Antigen-presenting cells do not interact with T cells.
• B. Antigen-presenting cells are only found in the bloodstream.
• C. Antigen-presenting cells include macrophages, dendritic cells, and B cells.
• D. Antigen-presenting cells can directly destroy pathogens.

Answer: (C)

Verified step by step guidance

1. Understand the role of antigen-presenting cells (APCs) in the immune system. APCs are crucial for initiating the immune response by processing and presenting antigens to T cells.
2. Recognize that APCs interact with T cells. This interaction is essential for the activation of T cells, which are a critical component of the adaptive immune response.
3. Identify the types of cells that function as APCs. These include macrophages, dendritic cells, and B cells, all of which can process and present antigens to T cells.
4. Consider the locations where APCs can be found. While they are present in the bloodstream, they are also located in various tissues throughout the body, especially in areas where pathogens are likely to enter.
5. Clarify the function of APCs in relation to pathogen destruction. APCs do not directly destroy pathogens; instead, they present antigens to T cells, which then coordinate the immune response to eliminate the pathogens.