Advertisement

Piggyback Pathogen

Editor’s Choice in Immunology

By | September 1, 2011

CORBIS, DENNIS KUNKEL MICROSCOPY, INC.

The paper

A. Ives et al., “Leishmania RNA virus controls the severity of mucocutaneous leishmaniasis,” Science, 331:775-78, 2011. Free F1000 Evaluation

The finding

The parasite Leishmania—which forms large, slow-healing sores when it attacks the skin (cutaneous leishmaniasis, CL)—can become more aggressive, metastasizing to the nasal passages and throat, a condition called mucocutaneous leishmaniasis, or MCL. Researchers knew that several Leishmania species harbor a double-stranded RNA virus called LRV1, but they didn’t know if it contributed to MCL. Nicolas Fasel from the University of Lausanne, Switzerland, and colleagues showed that the MCL parasite is more heavily infected with the virus, and that the resulting pathology is caused by overstimulation of the host immune system.

The contributor

The researchers isolated metastatic strains of Leishmania and noticed that they induced sustained production of chemokines and cytokines in macrophages in vitro. But blocking phagocytosis prevented the hyperinflammatory response associated with MCL.

The trigger

The researchers hypothesize that when the parasites were lysed within the cells, they released their viral hitchhikers. The virus’s double-stranded RNA would bind to intracellular Toll-like receptors, triggering inflammatory pathways. Indeed, when the team tested macrophages functionally deficient in Toll-like receptors, the reaction was hampered.

The treatment

If doctors could parse patients into MCL and CL groups, using the level of virus in their parasites as a marker, they could avoid unnecessary treatment of the 90 percent of infected patients whose CL clears on its own, said Phillip Scott, professor of immunology at the University of Pennsylvania, who was not involved with the research.

 

Advertisement

Add a Comment

Avatar of: You

You

Processing...
Processing...

Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo
Advertisement

Popular Now

  1. Staying Active in the Lab
    Careers Staying Active in the Lab

    Retiring as a professor, and even shutting down your own lab, doesn’t necessarily mean quitting research.

  2. When Does a Smart Mouse Become Human?
  3. The Lies That Scars Tell
    Notebook The Lies That Scars Tell

    Macaque trainers in Bangladesh are often bitten by their monkeys, but rarely infected by a particular simian retrovirus.

  4. Antibiotic Resistance Can Boost Bacterial Fitness
Advertisement
NeuroScientistNews
NeuroScientistNews
Advertisement
The Scientist