Ebola virus mutations may help it evade drug treatment

[cronus]

http://www.eurekalert.org/pub_releases/ ... 091115.php

Ebola virus mutations may help it evade drug treatment

Genetic mutations called "escape variants" in the deadly Ebola virus appear to block the ability of antibody-based treatments to ward off infection, according to a team of U.S. Army scientists and collaborators. Their findings, published online this week in the journal Cell Reports, have implications for the continued development of therapeutics to treat Ebola virus disease, which has claimed the lives of over 11,000 people in West Africa since last year.

Ebola virus overruns the immune system, thus overwhelming the host's ability to fight off the infection. One strategy for treatment is based on the administration of a "cocktail" of antibodies that have the ability to neutralize the virus and allow the host to mount an effective immune response. One such cocktail, known as MB-003, has demonstrated efficacy in nonhuman primates infected with the virus. MB-003 and ZMAb were early formulations used in proof-of-principle trials that led to the more advanced formulation, ZMapp, currently in development and authorized for compassionate use in the West African Ebola outbreak response.

To understand the reasons for the improvement, investigators at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) Center for Genome Sciences (CGS) examined nonhuman primates that succumbed to Ebola virus despite being treated with MB-003 one or two days post-infection. Viral nucleic acids were isolated from blood samples drawn at multiple time points and were sequenced to provide a description of the viral population. This approach is routinely utilized at USAMRIID to study the development of viral therapeutic resistance against antiviral countermeasures, according to Dr. Gustavo Palacios, director of the center and senior author of the study.

Two clusters of changes in the viral genome were observed in one of the animals that succumbed. Several of those changes corresponded with the viral target sites of two of the cocktail's antibodies, triggering an in-depth molecular analysis of the development and impact of those changes.

"The molecular analysis allowed us to see where the cocktails were inducing changes in the genome, and to link those changes to the treatment failure," said co-first author CPT Jeffrey Kugelman, Ph.D., of USAMRIID. Based on these findings, tissues at selected time-points were used for viral isolation, which finally allowed the "rescue" of the mutated virus.

"When this rescued virus was sequenced, we observed that the clusters of changes had progressed from affecting a small portion of the viral population to becoming mutations--permanent changes in the genome--without disrupting any major viral functions, including the ability to cause infection."

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[Rum]

Happine.jpg (56.46 KiB) Viewed 142 times

[cronus]

Don't take it hard. You'll be completely safe Rum so long as you avoid sex and masturbation.

[laklak]

What do you mean, sex AND masturbation? Aren't they the same thing?

[cronus]

What do you mean, sex AND masturbation? Aren't they the same thing?

According to Bill Clinton maybe not...