v*****s
发帖数: 20290 | 1 【 以下文字转载自 Joke 讨论区 】
发信人: mutouhui (mutouhui), 信区: Joke
标 题: Re: 麻省科学家发现病毒克星“天龙”
发信站: BBS 未名空间站 (Sun Nov 13 19:08:54 2011, 美东)
http://web.mit.edu/press/2011/antiviral.html
New drug could cure nearly any viral infection
Researchers at MIT’s Lincoln Lab have developed technology that may someday
cure the common cold, influenza and other ailments.
CAMBRIDGE, Mass. — Most bacterial infections can be treated with
antibiotics such as penicillin, discovered decades ago. However, such drugs
are useless against viral infections, including influenza, the common cold,
and deadly hemorrhagic fevers such as Ebola.
Now, in a development that could transform how viral infections are treated,
a team of researchers at MIT’s Lincoln Laboratory has designed a drug that
can identify cells that have been infected by any type of virus, then kill
those cells to terminate the infection.
In a paper published July 27 in the journal PLoS One, the researchers tested
their drug against 15 viruses, and found it was effective against all of
them — including rhinoviruses that cause the common cold, H1N1 influenza, a
stomach virus, a polio virus, dengue fever and several other types of
hemorrhagic fever.
The drug works by targeting a type of RNA produced only in cells that have
been infected by viruses. “In theory, it should work against all viruses,”
says Todd Rider, a senior staff scientist in Lincoln Laboratory’s Chemical
, Biological, and Nanoscale Technologies Group who invented the new
technology.
Because the technology is so broad-spectrum, it could potentially also be
used to combat outbreaks of new viruses, such as the 2003 SARS (severe acute
respiratory syndrome) outbreak, Rider says.
Other members of the research team are Lincoln Lab staff members Scott Wick,
Christina Zook, Tara Boettcher, Jennifer Pancoast and Benjamin Zusman.
Few antivirals available
Rider had the idea to try developing a broad-spectrum antiviral therapy
about 11 years ago, after inventing CANARY (Cellular Analysis and
Notification of Antigen Risks and Yields), a biosensor that can rapidly
identify pathogens. “If you detect a pathogenic bacterium in the
environment, there is probably an antibiotic that could be used to treat
someone exposed to that, but I realized there are very few treatments out
there for viruses,” he says.
There are a handful of drugs that combat specific viruses, such as the
protease inhibitors used to control HIV infection, but these are relatively
few in number and susceptible to viral resistance.
Rider drew inspiration for his therapeutic agents, dubbed DRACOs (Double-
stranded RNA Activated Caspase Oligomerizers), from living cells’ own
defense systems.
When viruses infect a cell, they take over its cellular machinery for their
own purpose — that is, creating more copies of the virus. During this
process, the viruses create long strings of double-stranded RNA (dsRNA),
which is not found in human or other animal cells.
As part of their natural defenses against viral infection, human cells have
proteins that latch onto dsRNA, setting off a cascade of reactions that
prevents the virus from replicating itself. However, many viruses can
outsmart that system by blocking one of the steps further down the cascade.
Rider had the idea to combine a dsRNA-binding protein with another protein
that induces cells to undergo apoptosis (programmed cell suicide) —
launched, for example, when a cell determines it is en route to becoming
cancerous. Therefore, when one end of the DRACO binds to dsRNA, it signals
the other end of the DRACO to initiate cell suicide.
Combining those two elements is a “great idea” and a very novel approach,
says Karla Kirkegaard, professor of microbiology and immunology at Stanford
University. “Viruses are pretty good at developing resistance to things we
try against them, but in this case, it’s hard to think of a simple pathway
to drug resistance,” she says.
Each DRACO also includes a “delivery tag,” taken from naturally occurring
proteins, that allows it to cross cell membranes and enter any human or
animal cell. However, if no dsRNA is present, DRACO leaves the cell unharmed.
Most of the tests reported in this study were done in human and animal cells
cultured in the lab, but the researchers also tested DRACO in mice infected
with the H1N1 influenza virus. When mice were treated with DRACO, they were
completely cured of the infection. The tests also showed that DRACO itself
is not toxic to mice.
The researchers are now testing DRACO against more viruses in mice and
beginning to get promising results. Rider says he hopes to license the
technology for trials in larger animals and for eventual human clinical
trials.
This work is funded by a grant from the National Institute of Allergy and
Infectious Diseases and the New England Regional Center of Excellence for
Biodefense and Emerging Infectious Diseases, with previous funding from the
Defense Advanced Research Projects Agency, Defense Threat Reduction Agency,
and Director of Defense Research & Engineering (now the Assistant Secretary
of Defense for Research and Engineering). | m******i
发帖数: 73 | 2 joke版转回来的, 呵呵
大伙儿议议.
someday
drugs
,
【在 v*****s 的大作中提到】
: 【 以下文字转载自 Joke 讨论区 】
: 发信人: mutouhui (mutouhui), 信区: Joke
: 标 题: Re: 麻省科学家发现病毒克星“天龙”
: 发信站: BBS 未名空间站 (Sun Nov 13 19:08:54 2011, 美东)
: http://web.mit.edu/press/2011/antiviral.html
: New drug could cure nearly any viral infection
: Researchers at MIT’s Lincoln Lab have developed technology that may someday
: cure the common cold, influenza and other ailments.
: CAMBRIDGE, Mass. — Most bacterial infections can be treated with
: antibiotics such as penicillin, discovered decades ago. However, such drugs
| w***a
发帖数: 4361 | 3 看见plos one就没往下看了。。。
【在 m******i 的大作中提到】
: joke版转回来的, 呵呵
: 大伙儿议议.
:
: someday
: drugs
: ,
| x**y
发帖数: 46 | 4 很有创意，只是还不够完善。看看其他的评论：
Broad-spectrum antiviral strategy
Peter Hare
Journal name:
Nature Biotechnology
Volume:
29,
Page:
885
Year published:
(2011)
DOI:
doi:10.1038/nbt.2014
Published online13 October 2011Most antiviral therapies are pathogen-
specific and likely to select for resistance if the virus can mutate the
drug target. Rider et al. couple the ability to detect long double-stranded
RNA (dsRNA)—a telltale indicator of viral infection in mammalian cells—
with procaspase-activated apoptosis for broad-spectrum antiviral activity.
Dubbed DRACOs (double-stranded RNA–activated caspase oligomerizers), these
chimeric constructs each comprise (i) a terminal transduction domain for
cell penetration, (ii) a dsRNA-binding domain to detect viral infection and
(iii) an apoptosis-promoting domain, such as a procaspase-binding domain or
a procaspase, which is activated by dsRNA-dependent oligomerization. When
tested in 11 mammalian cell types, DRACOs are effective against 15 different
viruses. Prophylactic intraperitoneal delivery of DRACOs also reduces the
morbidity of mice following subsequent intranasal challenge with H1N1
influenza virus. The strategy seems best suited to situations when exposure
to a dangerous virus is anticipated; in contrast, once an infection is
established, the treatment may result in potentially dangerous inflammation
and organ damage. Unfortunately, the earliest stages of viral infection are
usually the most difficult to diagnose. Systemic delivery of DRACOs might
also result in nondiscriminate killing of healthy cells infected with
nonpathogenic viruses. (PLoS One 6, e22572, 2011) | g********0
发帖数: 6201 | |
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