Scientists have discovered an unexpected way the immune system can attack cancer, a breakthrough that could help researchers develop new cancer treatments in the future. The findings challenge a long-held belief about how the body's immune cells recognise and destroy cancer cells.

The immune system uses special proteins called major histocompatibility complexes (MHC) to identify harmful cells, including cancer cells.

For many years, scientists believed that one type of MHC protein, known as MHC class I, mainly worked with immune cells called CD8+ T cells, often referred to as "killer" T cells because they directly attack and destroy abnormal cells.

Another group of immune cells, known as CD4+ T cells or "helper" T cells, was thought to play a supporting role by coordinating immune responses rather than directly killing cancer cells. However, the new study suggests the immune system may work differently than previously understood.

Researchers found that CD4+ T cells can play a much bigger role in fighting cancer than scientists once believed, especially when cancer cells try to hide from the immune system.

The study, published in journal Nature Immunology, was led by Dr. Pavan Reddy, Director of the Dan L Duncan Comprehensive Cancer Center at Baylor College of Medicine, along with researchers from the University of Michigan Rogel Cancer Center.

Many cancers develop ways to avoid being recognised by the body's natural defenses. One common strategy is reducing the amount of MHC class I on their surface.

By doing this, cancer cells can escape detection by killer T cells, making it harder for the immune system and certain cancer treatments to find and destroy them. To understand what happens when cancer cells lose these proteins, researchers studied both human samples and laboratory models. What they found surprised them

Source:Ndtv