CD24 is a protein on the surface of many cells in the human body, where it is involved in cellular communication and identification. Anchored to the cell membrane, its presence influences how cells interact with their environment. The protein participates in processes ranging from cell growth to immune system regulation.
What CD24 Does in the Body
CD24 contributes to several routine cellular functions, including cell adhesion and cell migration. Cell adhesion is the process of how cells bind to form tissues, while migration is necessary for development and tissue repair. These actions are important for maintaining the body’s structural integrity and its overall ability to heal.
CD24 is commonly found on various immune cells, including B and T lymphocytes, where it participates in their development and activation. Its presence on these cells helps modulate the immune response. Additionally, CD24 is expressed on certain types of stem cells, contributing to their capacity for self-renewal and tissue regeneration.
CD24’s Role in Disease
The function of CD24 can be altered in various disease states, particularly in cancer and inflammatory conditions. In these scenarios, the protein’s normal signaling activities are dysregulated, which contributes to disease progression.
Cancer
Many types of cancer cells exhibit high levels of CD24 on their surface. This overexpression helps tumors thrive by promoting growth and metastasis, the process by which cancer spreads. The CD24 protein interacts with a receptor on immune cells called Siglec-10, sending a “don’t eat me” signal. This interaction allows cancer cells to evade destruction by macrophages, which are immune cells that normally engulf abnormal cells. This mechanism of immune evasion is a significant factor in the progression of several cancers, including breast, ovarian, and pancreatic cancer.
Inflammation and Autoimmune Conditions
CD24 also has a role in regulating inflammation by controlling the body’s response to tissue damage and infection. In severe conditions like sepsis, an excessive inflammatory response known as a “cytokine storm” can occur, causing widespread damage. Research suggests CD24 helps dampen this overreaction by interacting with Siglec-10 to suppress inflammatory signals. In autoimmune diseases like multiple sclerosis, where the immune system mistakenly attacks the body’s own tissues, the regulatory functions of CD24 are also implicated.
Targeting CD24 for Medical Treatment
Given its role in both cancer and inflammation, CD24 has become a target for developing new medical treatments. Scientists are exploring two primary strategies: one aimed at blocking CD24’s function in cancer and another that uses CD24 itself as a therapeutic agent to control inflammation.
Blocking CD24 in Cancer
For cancer treatment, the goal is to counteract the “don’t eat me” signal that CD24 sends. Researchers are creating therapeutic antibodies that bind to the CD24 protein on cancer cells. By attaching to CD24, these antibodies block its interaction with the Siglec-10 receptor on macrophages. This action unmasks the cancer cells, allowing the immune system to recognize and destroy them. This is a form of immunotherapy, a strategy designed to enhance the body’s natural anti-tumor response.
Using CD24 as a Therapy
A different approach involves administering a soluble or engineered form of the CD24 protein to patients. This strategy is being investigated for conditions with excessive inflammation, such as severe COVID-19 or graft-versus-host disease. The administered CD24 protein, often as CD24Fc, can circulate and bind to molecules that trigger dangerous inflammatory responses. This helps calm the overactive immune system and prevent tissue damage associated with a cytokine storm.
Current Research and Future Directions
The development of therapies targeting CD24 is an active area of medical research. Potential treatments for both cancer and inflammatory diseases are in various stages of clinical trials to evaluate their safety and effectiveness. The results from early trials have been encouraging, but more research is needed to confirm the benefits and identify which patients are most likely to respond.
The potential applications for CD24-based therapies may extend beyond their current focus. Scientists are exploring its role in other conditions, including metabolic disorders and neurological diseases. As understanding of this protein’s functions grows, new opportunities for therapeutic intervention may emerge. Ongoing research aims to bring current experimental drugs to the clinic and uncover new ways to use this molecule.