CXCR4

Definition

CXCR4 is a chemokine receptor that plays a crucial role in the entry of the human immunodeficiency virus (HIV) into host cells, making it a key target in the treatment and understanding of HIV/AIDS. This receptor is expressed on the surface of various cell types, including T cells, and serves as a co-receptor for HIV-1 entry, alongside the primary CD4 receptor.

5 Must Know Facts For Your Next Test

1. CXCR4 is a G-protein-coupled receptor that binds to the chemokine CXCL12, also known as stromal cell-derived factor-1 (SDF-1), and mediates various cellular functions, including cell migration and survival.
2. The interaction between CXCR4 and the HIV-1 envelope protein gp120 is a crucial step in the viral entry process, allowing the virus to fuse with the host cell membrane and deliver its genetic material.
3. CXCR4 is expressed on a variety of cell types, including T cells, hematopoietic stem cells, and certain cancer cells, making it an important target for both HIV/AIDS treatment and cancer therapy.
4. Antagonists of CXCR4, such as AMD3100 (Plerixafor), have been developed as therapeutic agents to block HIV-1 entry and mobilize hematopoietic stem cells for transplantation.
5. Genetic variations in the CXCR4 gene have been associated with altered susceptibility to HIV-1 infection and disease progression, highlighting the importance of this receptor in the pathogenesis of HIV/AIDS.

Review Questions

• Explain the role of CXCR4 in the entry of HIV-1 into host cells.
  • CXCR4 serves as a co-receptor, alongside the primary CD4 receptor, for the entry of HIV-1 into host cells. The interaction between the HIV-1 envelope protein gp120 and CXCR4 is a crucial step in the viral entry process, allowing the virus to fuse with the host cell membrane and deliver its genetic material. This makes CXCR4 a key target for the development of HIV/AIDS treatment strategies aimed at blocking viral entry and preventing the progression of the disease.
• Describe the broader biological functions of CXCR4 beyond its role in HIV-1 entry.
  • CXCR4 is a chemokine receptor that binds to the chemokine CXCL12, also known as stromal cell-derived factor-1 (SDF-1). This interaction mediates various cellular functions, including cell migration and survival. CXCR4 is expressed on a variety of cell types, including T cells, hematopoietic stem cells, and certain cancer cells, making it an important target not only for HIV/AIDS treatment but also for cancer therapy. Genetic variations in the CXCR4 gene have been associated with altered susceptibility to HIV-1 infection and disease progression, highlighting the broader significance of this receptor in human health and disease.
• Evaluate the potential therapeutic strategies that target CXCR4 in the context of HIV/AIDS and other diseases.
  • Antagonists of CXCR4, such as AMD3100 (Plerixafor), have been developed as therapeutic agents to block HIV-1 entry and mobilize hematopoietic stem cells for transplantation. By targeting CXCR4, these therapies aim to disrupt the crucial interaction between the HIV-1 envelope protein gp120 and the co-receptor, preventing the virus from entering and infecting host cells. Additionally, the broader biological functions of CXCR4 in cell migration and survival make it a potential target for the treatment of various cancers and other diseases. The development and clinical evaluation of CXCR4-targeted therapies continue to be an active area of research, with the potential to significantly impact the management of HIV/AIDS and other complex diseases.

Related terms

Chemokine: Small signaling proteins that regulate the migration and activation of immune cells, such as T cells and monocytes, by binding to specific cell surface receptors like CXCR4.

CD4: A glycoprotein expressed on the surface of T helper cells, monocytes, macrophages, and dendritic cells, which serves as the primary receptor for HIV-1 entry into host cells.

HIV-1: The most common and virulent strain of the human immunodeficiency virus, which causes acquired immunodeficiency syndrome (AIDS) by targeting and destroying CD4+ T cells, leading to a weakened immune system.