The immune system protects from infections by detecting and eliminating invading pathogens. These two strategies form the basis of conventional clinical approaches in the fight against infectious diseases.
In the latest issue of the journal Science, Miguel Soares from the Instituto Gulbenkian de Ciência (Portugal) together with Ruslan Medzhitov from Yale University School of Medicine and David Schneider from Stanford University propose that a third strategy needs to be considered: tolerance to infection, whereby the infected host protects itself from infection by reducing tissue damage and other negative effects caused by the pathogen or the immune response against the invader. The authors argue that identifying the mechanisms underlying this largely overlooked phenomenon may pave the way to new strategies to treat many human infectious diseases.
Upon invasion by pathogens (bacteria, viruses or parasites), the immune system kicks into action, by detecting, destroying and ultimately eliminating the pathogen. This so-called "resistance to infection" is crucial in protecting the host from infection, but is often accompanied by collateral damage to some of the host's vital tissues (liver, kidney, heart, brain).
If uncontrolled tissue damage may have lethal consequences, as often happens, for example, in severe malaria, severe sepsis and possibly other infectious diseases. Tolerance reduces the harmful impact of infection and of the ensuing immune response on the host.
Although a well-studied phenomenon in plant immunity, tolerance to infection has been largely overlooked in mammals, including humans. While there is still much to be learnt about how and under which circumstances tolerance to infection is employed by the host, most of what is currently known about the molecular mechanisms underlying this host defense strategy comes from work carried out at the Instituto Gulbenkian de Ciência by the group led by Miguel Soares.
The team is particularly interested in identifying disease-specific tolerance mechanisms, on the one hand, and also general strategies of tolerance, that may, possibly, be employed protectively, to precondition the host to future infections.
Because resistance is, generally, the only mechanism considered in animal and human studies, when the host capitulates to infection it is often attributed to failure of the immune system.
The authors argue that this is not always the case, and underscore the importance of distinguishing between failed resistance and failed tolerance as the cause for morbidity and mortality by infectious diseases. This distinction will dictate the choice of therapeutic approaches.
When the primary problem is failed tolerance, then boosting the immune system, or administering antibiotics, may be ineffective. In this case, enhancing tolerance would possibly be much more effective in fighting infectious, inflammatory and auto-immune diseases.
Ana Godinho | EurekAlert!
Spanish scientists create a 3-D bioprinter to print human skin
24.01.2017 | Carlos III University of Madrid
Tracking movement of immune cells identifies key first steps in inflammatory arthritis
23.01.2017 | Massachusetts General Hospital
A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
24.01.2017 | Physics and Astronomy
24.01.2017 | Life Sciences
24.01.2017 | Health and Medicine