Scientists learn how pathogens hack our immune systems to go undetected

February 27, 2014, Federation of American Societies for Experimental Biology

A new report appearing in the March 2014 issue of The FASEB Journal helps shed light on what drives the evolution of pathogens, as well as how our bodies adapt to ward them off. Specifically, the report shows that our bodies naturally employ a mechanism, called "CD33rSiglecs," that not only dampens unwanted immune responses against one's own cells, but also evolves rapidly to recognize foreign invaders. What's more, the report explains how pathogens exploit this immunological "vulnerability" of "self-recognition" to evade our bodies' defenses. This leads to a seemingly endless "arms race" between constantly evolving pathogens and immune systems. Understanding this phenomenon may become crucial for developing novel drugs against various pathogens that try to take advantage of this system.

"Our data explain why the CD33rSiglec-encoding cluster of genes is undergoing rapid evolution via multiple mechanisms, driven by the need to maintain self-recognition by innate immune cells, even while escaping two distinct mechanisms of subversion by pathogens," said Ajit Varki, M.D., a researcher involved in the work from the Departments of Medicine and Cellular and Molecular Medicine at the University of California in San Diego, CA.

Please note: Non-human samples used for these studies were collected under ethical standards and approval processes similar to those that apply to humans, and that no animals were harmed in these studies.

To make this discovery, Varki and colleagues compared three major CD33rSiglecs from humans, chimpanzees and baboons. While chimpanzees and baboons express two types, Neu5Ac and Neu5Gc, humans express only one, Neu5Ac. They then compared specific binding properties and expression patterns of these CD33rSiglecs and found that while related CD33rSiglecs from humans, chimpanzees and baboons recognize pathogenic bacteria, they do so differently. Additionally, different types of CD33rSiglecs within the same species also showed similar variances.

"Just like malicious computer software programs, these pathogens 'hack' our immune systems with the goal of going undetected," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Now that we understand how these are hacking our immune systems, we can understand how evolution has permitted us to distinguish the 'self' our ignores from the 'non-self' the system evolved to combat."

Explore further: Explainer: What is the immune system?

More information: FASEB J. March 2014 28:1280-1293; DOI: 10.1096/fj.13-241497

Related Stories

Explainer: What is the immune system?

January 8, 2014
The immune system is an integral part of our body, keeping us safe from diseases – from the common cold to more severe illnesses such as cancer.

Studies of cow antibodies help scientists understand how our own bodies work

February 18, 2014
Understanding how antibodies work is important for designing new vaccines to fight infectious diseases and certain types of cancer and for treating disorders of the immune system in animals and humans.

From friend to foe: How benign bacteria evolve to virulent pathogens

December 12, 2013
Bacteria can evolve rapidly to adapt to environmental change. When the "environment" is the immune response of an infected host, this evolution can turn harmless bacteria into life-threatening pathogens. A study published ...

Body's 'safety procedure' could explain autoimmune disease

September 5, 2013
Monash University researchers have found an important safety mechanism in the immune system that may malfunction in people with autoimmune diseases, such as Multiple Sclerosis, potentially paving the way for innovative treatments.

How our immune system backfires and allows bacteria like Salmonella to grow

February 6, 2014
Our immune system wages an internal battle every day to protect us against a broad range of infections. However, researchers have found that our immune response can sometimes make us vulnerable to the very bacteria it is ...

New insights into the immune system of the gastrointestinal tract

December 9, 2013
Lymphotoxin is a cytokine, or intercellular messenger, and plays an important role in the immunological balance of the gastrointestinal tract. It regulates the immune system of the digestive tract, which is made up of immune ...

Recommended for you

Blood-vessel-on-a-chip provides insight into new anti-inflammatory drug candidate

January 15, 2018
One of the most important and fraught processes in the human body is inflammation. Inflammatory responses to injury or disease are crucial for recruiting the immune system to help the body heal, but inflammation can also ...

Molecule produced by fat cells reduces obesity and diabetes in mice

January 15, 2018
UC San Francisco researchers have discovered a new biological pathway in fat cells that could explain why some people with obesity are at high risk for metabolic diseases such as type 2 diabetes. The new findings—demonstrated ...

Obese fat becomes inflamed and scarred, which may make weight loss harder

January 12, 2018
The fat of obese people becomes distressed, scarred and inflamed, which can make weight loss more difficult, research at the University of Exeter has found.

Optimized human peptide found to be an effective antibacterial agent

January 11, 2018
A team of researchers in the Netherlands has developed an effective antibacterial ointment based on an optimized human peptide. In their paper published in the journal Science Translational Medicine, the group describes developing ...

Research discovers possible link between Crohn's and Parkinson's in Jewish population

January 11, 2018
Mount Sinai Researchers have just discovered that patients in the Ashkenazi Jewish population with Crohn's disease (a chronic inflammatory of the digestive system) are more likely to carry the LRRK2 gene mutation. This gene ...

Scientists use gene expression to understand how astrocytes change with age

January 11, 2018
Potentially explaining why even healthy brains don't function well with age, Salk researchers have discovered that genes that are switched on early in brain development to sever connections between neurons as the brain fine-tunes, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.