Cxcl12

Definition

CXCL12, also known as stromal-derived factor-1 (SDF-1), is a chemokine that plays a crucial role in the migration and homing of immune cells. It is produced by various cells in primary and secondary lymphoid organs and interacts with its receptor, CXCR4, to regulate the movement of lymphocytes and other immune cells during immune responses and development.

5 Must Know Facts For Your Next Test

1. CXCL12 is primarily produced by stromal cells in bone marrow and lymphoid tissues, contributing to the retention and trafficking of lymphocytes.
2. The interaction between CXCL12 and CXCR4 is vital for the homing of B cells to germinal centers within secondary lymphoid organs.
3. CXCL12 not only attracts immune cells but also plays a role in the survival and proliferation of these cells within the lymphoid tissues.
4. Deficiency or dysfunction of CXCL12 can lead to impaired immune responses and has been associated with various immunological disorders.
5. In addition to its role in immune cell trafficking, CXCL12 is implicated in processes like tissue repair and tumor progression.

Review Questions

• How does CXCL12 facilitate the migration of lymphocytes in primary and secondary lymphoid organs?
  • CXCL12 acts as a chemotactic signal that guides lymphocytes towards specific areas within primary and secondary lymphoid organs. By binding to its receptor CXCR4 on lymphocytes, it creates a directional signal that helps them migrate effectively. This process is crucial for the proper localization of B cells in germinal centers and T cells in areas where they can interact with antigen-presenting cells.
• Discuss the implications of CXCL12 signaling in immune cell retention within the bone marrow and its significance in overall immune function.
  • CXCL12 plays a critical role in retaining immune cells, particularly B cells, within the bone marrow. The continuous signaling from CXCL12 ensures that these cells are preserved until they are needed for an immune response. Disruption in this signaling can lead to either excessive egress of lymphocytes from the marrow or inadequate recruitment during an immune response, impacting overall immune function and potentially leading to immunodeficiencies.
• Evaluate how alterations in CXCL12 expression might influence both normal immunity and disease processes such as cancer.
  • Alterations in CXCL12 expression can significantly impact both normal immunity and disease processes like cancer. In a healthy immune system, proper CXCL12 signaling ensures effective trafficking and retention of lymphocytes, maintaining a robust defense against pathogens. However, in cancer, tumor cells may exploit increased levels of CXCL12 to attract regulatory T cells that suppress anti-tumor immunity. Thus, understanding CXCL12's role can provide insights into therapeutic targets for enhancing anti-cancer responses while balancing normal immune function.

Related terms

Chemokine: A type of small signaling protein that guides the movement of immune cells towards sites of inflammation or infection.

CXCR4: The receptor for CXCL12, which is found on the surface of various immune cells, mediating their migration in response to CXCL12 signaling.

Lymphocytes: A subset of white blood cells that are integral to the immune system, including T cells and B cells, which respond to infections and diseases.