Tiny 'executioners' in the human body

Millions of special cells regularly patrol your body to kill cancer cells, viruses and harmful microorganisms.

'Executioner' cells are attacking a cancer cell (black).Photo: med.upenn.edu.

The tiny little objects above are a type of lymphatic cell. They can quickly detect a dangerous cell, cut holes in its outer shell and release poison into the hole to destroy the cell. They also give warning signals to other immune cells to join the attack.

Despite being called by a terrifying name, executioner cells are really dedicated warriors in a battle that never ends with illness. Wayne Yokoyama, an immunologist at the Howard Hughes Medical Institute of the University of Washington (USA), said the executioner's 'license' is a tail that allows them to attack harmful cells. .

Although the butcher cell was discovered more than 30 years ago, so far we have not understood much about them. Scientists continue to conduct many researches to understand the mechanism by which cell cells can detect targets, how they differentiate infected cells from healthy cells and how they attack targets.

'We still don't know where and when the butcher cell was born , ' admits James Di Santo, director of Immunology at the Pasteur Institute (France). Meanwhile, Michael Caligiuri, professor of cancer research at Ihio University (USA, said: 'We only understand part of the way the butcher cell distinguishes another cell from a friend or foe.

Wayne Yokoyama and colleagues conducted a number of experiments on butchery cells in the 80s of the last century. But tests are forced to stop because of side effects. Recently Wayne and some scientists have discovered that butcher cells can remember the location of every infected cell they once destroyed.

The butcher cells are born continuously in the bone marrow. They wandered in the blood and lymph to look for infected cells or cancer. When they find such a cell, they approach and find a way to 'execute' the target.

On the surface of healthy cells there is always a protein called MHC-1. If the butcher cell does not detect MHC-1 on a certain cell, its fate will quickly end. Thus, MHC-1 is what helps cells to distinguish between friends and enemies. Another strength of the butcher cell is the reaction rate and they can attack immediately after detecting the appearance of strange molecules.