A new way to stimulate the immune system and fight infection

These new data are an essential step towards understanding the operation of these key cells in the immune system, and they could provide a new therapeutic approach to fighting infection. They also suggest that the operation of NK cells must be precisely regulated to guarantee an optimum immune reaction. Details of this work are published in the 20 January 2012 issue of the journal Science.

Our bodies are subject to attack by many different infectious particles (bacteria, viruses, etc.), which surround us in our everyday environment. Various immune cells are activated to fight off these attacks: the first response is from the innate immune cells1, which gradually give way to the memory B and T lymphocytes of the adaptive immune system. The Natural Killer (NK) cells are a part of this first line of defence of the organism. They can selectively kill tumour cells or cells infected by microbes whilst secreting chemical messengers known as cytokines, which stimulate and direct the response of the B and T lymphocytes.

Following the launch of a major genetics programme a few years ago, scientists succeeded in revealing a gene whose deactivation causes heightened functioning of the NK cells (see figure below). This gene, called Ncr1, contributes to the manufacture of the receptor NKp46, which is present on the surface of NK cells. Surprisingly, its role in activating the NK cells has been known for several years.

'NK cells go through various stages of development before combating microorganisms or tumour cells,' explains Sophie Ugolini, joint author of the paper. 'Without this receptor, the NK cells are more reactive and therefore more effective when they encounter the attackers of the organism."

To test the therapeutic potential of their discovery, the scientists blocked the NKp46 receptor using a drug (in this case, a monoclonal antibody). As in the genetics experiments, this treatment that blocks NKp46 makes the NK cells much more effective.

Potential therapeutic approach to fighting infection found Scientists have discovered a new type of treatment to stimulate the function of immune system and fight infection.

Our bodies are subject to attack by many different infectious particles (bacteria, viruses, etc.), which surround us in our everyday environment.

Various immune cells are activated to fight off these attacks: the first response is from the innate immune cells1, which gradually give way to the memory B and T lymphocytes of the adaptive immune system.

The Natural Killer (NK) cells are a part of this first line of defence of the organism. They can selectively kill tumour cells or cells infected by microbes whilst secreting chemical messengers known as cytokines, which stimulate and direct the response of the B and T lymphocytes.

Following the launch of a major genetics programme a few years ago, scientists succeeded in revealing a gene whose deactivation causes heightened functioning of the NK cells. This gene, called Ncr1, contributes to the manufacture of the receptor NKp46, which is present on the surface of NK cells. Surprisingly, its role in activating the NK cells has been known for several years.