Question

Which of the following cell types belong to stromal compartment of lymph nodes? a. Fibroblastic reticular cells b. Sinus endothelial cells c. High endothelial cells d. T cells e. B cells f. DCs

Short answer

Answer: The cell types that belong to the stromal compartment of lymph nodes are fibroblastic reticular cells, sinus endothelial cells, and high endothelial cells.

Step-by-step solution

Identify the cell types involved in the lymphatic system

Lymph nodes are an important part of the immune system, providing a site for activation and differentiation of lymphocytes, which are key cells for adaptive immunity. The lymphatic system contains different cell types, including lymphocytes (B cells, T cells), dendritic cells (DCs), fibroblastic reticular cells, sinus endothelial cells, and high endothelial cells.

Understanding the stromal compartment

The stromal compartment of a lymph node consists of structural, non-immune cells that help create a scaffold or support system for the immune cells within the lymph node. The cells in the stromal compartment can be characterized by their ability to produce extracellular matrix proteins, collagen, and growth factors, which contribute to the overall structure and function of the lymph node.

Assess whether fibroblastic reticular cells belong to the stromal compartment

Fibroblastic reticular cells (FRCs) are specialized cells that provide a structural framework and produce extracellular matrix components, such as collagen, for the lymphoid tissue. By providing the scaffold for the immune cells, FRCs play a crucial role in the structure of the lymph node. Therefore, fibroblastic reticular cells (option a) are part of the stromal compartment.

Assess whether sinus endothelial cells belong to the stromal compartment

Sinus endothelial cells are flat, thin cells lining the luminal surface of lymphatic sinuses, the channels that help transport immune cells within the lymph node. By regulating lymphatic fluid flow and immune cell trafficking, sinus endothelial cells contribute to the overall organization and function of the lymph node. Therefore, sinus endothelial cells (option b) are part of the stromal compartment.

Assess whether high endothelial cells belong to the stromal compartment

High endothelial cells (HECs) are specialized, tall, and oval-shaped endothelial cells that form the high endothelial venules, the sites where immune cells enter the lymph node. Since they provide structural support and regulate immune cell entry into the lymph node, high endothelial cells (option c) are also part of the stromal compartment.

Assess whether T cells, B cells, and DCs belong to the stromal compartment

T cells (option d), B cells (option e), and dendritic cells (option f) are immune cells that participate directly in the immune response. They do not provide structural support or produce extracellular matrix components like the stromal cells do. Therefore, T cells, B cells, and DCs are not part of the stromal compartment.

Provide the final answer

Based on the analysis, the cell types that belong to the stromal compartment of lymph nodes are: a. Fibroblastic reticular cells b. Sinus endothelial cells c. High endothelial cells