How Do Killer Immune Cells Protect Themselves?

White blood cells, which release a toxic potion of proteins to kill cancerous and virus-infected cells, are protected from any harm by the physical properties of their cell envelopes, find scientists from UCL and the Peter MacCallum Cancer Centre in Melbourne. Until now, it has been a mystery to scientists how these white blood cells – called cytotoxic lymphocytesavoid being killed by their own actions and the discovery could help explain why some tumours are more resistant than others to recently developed cancer immunotherapies.

The research, published in Nature Communications, highlights the role of the physical properties of the white blood cell envelope, namely the molecular order and electric charge, in providing such protection.

Cytotoxic lymphocytes, or white blood cells, rid the body of disease by punching holes in rogue cells and by injecting poisonous enzymes inside. Remarkably, they can do this many times in a row, without harming themselves. We now know what effectively prevents these white blood cells from committing suicide every time they kill one of their targets,” according to Professor Bart Hoogenboom (London Centre for Nanotechnology, UCL Physics & Astronomy and UCL Structural & Molecular Biology), co-author of the study.

The scientists made the discovery by studying perforin, which is the protein responsible for the hole-punching. They found that perforin’s attachment to the cell surface strongly depends on the order and packing of the molecules – so-called lipids – in the membrane that surrounds and protects the white blood cells.

Source: https://www.ucl.ac.uk/