Sugary bugs subvert antibodies

Sugary bugs subvert antibodies
Researchers show how the body's antibody response can protect—not destroy—the bacterium Pseudomonas aeruginosa (pictured). Credit: ©Kierbel, A., et al. 2007. J. Cell Biol. doi:10.1083/jcb.200605142

A lung-damaging bacterium turns the body's antibody response in its favor, according to a study published in The Journal of Experimental Medicine.

Pathogenic bacteria are normally destroyed by antibodies, that coat the outer surface of the bug, laying a foundation for the deposition of pore-forming "complement" proteins that poke lethal holes in the . But despite having plenty of antibodies and complement proteins in their bloodstream, some people can't fight off infections with the respiratory bacterium Pseudomonas aeruginosa. And chronic infection can lead to a condition called bronchiectasis, characterized by persistent cough, shortness of breath, and chest pain.

A group of researchers at the University of Birmingham, England, now find that the antibody response to Pseudomonas can get in its own way. In a subset of infected bronchiectasis patients with particularly poor lung function, they noticed an abundance of one specific type of antibody, called IgG2, which stripped the blood of its normal bug-killing capacity. The IgG2 proteins bound to extra-long sugars on the , a feature unique to the bugs infecting these patients. When these sugar-specific antibodies were removed, the blood's antibacterial prowess was restored.

Exactly how these IgG2 molecules protect the bug is unclear, but they may lure away from more vulnerable parts of the bacterial surface. The discovery of antibodies that protect the bug instead of the person may help to explain why two vaccines based on these extra-long sugars resulted in worse disease in immunized individuals.

More information: Wells, T.J., et al. 2014. J. Exp. Med. DOI: 10.1084/jem.20132444

add to favorites email to friend print save as pdf

Related Stories

(Antibody) orientation matters

Dec 10, 2012

The orientation of antibody binding to bacteria can mean life or death to the bug, according to a study published in The Journal of Experimental Medicine on December 10th. These findings may help explain why these bacter ...

Improving human immunity to malaria

Aug 01, 2012

The deadliest form of malaria is caused the protozoan Plasmodium falciparum. During its life-cycle in human blood, the parasite P. falciparum expresses unique proteins on the surface on infected blood cells. ...

Recommended for you

A new way to prevent the spread of devastating diseases

5 hours ago

For decades, researchers have tried to develop broadly effective vaccines to prevent the spread of illnesses such as HIV, malaria, and tuberculosis. While limited progress has been made along these lines, ...

New molecule allows for increase in stem cell transplants

6 hours ago

Investigators from the Institute for Research in Immunology and Cancer (IRIC) at the Université de Montréal have just published, in the prestigious magazine Science, the announcement of the discovery of a new molecule, the fi ...

Team explores STXBP5 gene and its role in blood clotting

8 hours ago

Two independent groups of researchers led by Sidney (Wally) Whiteheart, PhD, of the University of Kentucky, and Charles Lowenstein, MD, of the University of Rochester, have published important studies exploring the role that ...

User comments