Cutaneous nerves anticipate and fight infections: study

Washington DC: A recent discovery revealed that pain-sensitive nerves help fight skin infections and prevent their spread, suggesting a new type of immunity.

"These pain-sensitive nerves can detect pathogens and, for the first time, we have shown that they activate an immune response and also report protective immunity in sites adjacent to the infection." that the immune system and the nervous system work synergistically for the host.These findings could also have important implications for the development of more specific therapies for autoimmune skin conditions such as psoriasis, "said Daniel Kaplan , the lead author of the study published in Cell's journal.

Until about ten years ago, it was thought that the pain had evolved so that your body would tell you to stay away from a particular stimulus or report a problem of functioning, as an injury. More recently, however, researchers have shown that it can play an important role in immunity against certain pathogens.

In this study, Kaplan and lead author Jonathan Cohen collaborated with Pitt's neurobiology professors and pain experts, Kathy Albers, to develop an optogenetic mouse model in which pain-sensitive skin neurons could be activated. by a brilliant blue light.

They first showed that simply activating these neurons released a small protein called CGRP, which recruited different types of immune cells to the site. This has suggested that neurons detecting skin pathogens on their own launcher initiate an immune response even before sentinel immune cells can do so.

Then, in the same mouse model, they infected the animals either with Candida albicans, a fungus responsible for candidiasis, commonly known as thrush, or with Staphylococcus aureus, a common bacterium that can become deadly under certain conditions.

Using optogenetics and chemical nerve inhibitors, the researchers showed through a series of elegant experiments that, when the fungus infected the skin at a particular location, the nerves detected and initiated an immune response to fight the disease. Infection, but they also sent a signal to the spinal cord. . Researchers have called this new nerve-driven protection mechanism "anticipated immunity".

"The advantage of involving the nervous system is that it can communicate information from one space to the other in the space of a few milliseconds, relative to the number hours or days when immune cells perform the same function.It is the difference between sending a warning to the British advance by Paul Revere and sending a telegram to do the same, "said Jonathan Cohen, the first author of the study.

Kaplan said that while it remains to be seen how the results would translate for humans, they have interesting implications for autoimmune diseases of barrier tissues such as skin or intestines.