CHICAGO
(Reuters) - News (Updated
September 18, 2011)
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Sun Sep 11, 2011
By Julie Steenhuysen
CHICAGO
(Reuters) -
The study, published on
Sunday in the journal Nature Methods, involved inserting monkey genes that block
the virus into feline eggs, or oocytes, before they are fertilized.
The scientists also
inserted jellyfish genes that make the modified cells glow an eerie green colour
-- making the altered genes easy to spot.
Tests on cells taken from
the cats show they are resistant to feline immunodeficiency virus, or FIV, which
causes AIDS in cats.
"This provides the
unprecedented capability to study the effects of giving AIDS-protection genes
into an AIDS-vulnerable animal," Dr. Eric Poeschla of the Mayo Clinic in
Poeschla said that besides
people, cats and to some extent, chimpanzees, are the only mammals that develop
a naturally occurring virus that causes AIDS.
"Cats suffer from
this all over the world," he said.
Just as the human
immunodeficiency virus, or HIV, does in people, FIV works by wiping out
infection-fighting T-cells.
FIV infects mostly feral
cats, of which there are half billion in the world, Poeschla said. It is
transmitted by biting, largely by males defending their territory, but companion
cats are affected as well.
In both humans and cats,
proteins called restriction factors that normally fight off viral infections are
defenceless against HIV and FIV because the viruses evolved potent
counter-weapons. But certain monkey versions of these restriction factors are
capable of fighting the virus and the team used one such gene from the rhesus
monkey.
For the team, which
included collaborators in
GREEN FLUORESCENT PROTEIN
GENE
To do that, they used a
harmless virus to insert the genes into the eggs, a process that has already
been done in other mammals including mice, pigs, sheep and marmoset monkeys.
To make it easier to check
which cells had the monkey gene, the team also inserted a green fluorescent
protein gene from the jellyfish Aequorea victoria that makes them glow green.
"We did it to mark
cells easily just by looking under the microscope or shining a light on the
animal."
The method worked so well
nearly all offspring from the modified eggs have the restriction factor genes.
And these defence proteins are made throughout the cat's body.
The team has mated two of
the three original green-glowing cats, which have produced litters totalling
eight kittens which make glowing cells as well.
But the point is not to
breed generations of disease-resistant, glowing cats. Rather, the team plans to
study these felines as a new way to develop treatments for HIV and the feline
version of the disease.
Researchers said the work
has several potential uses.
"This technology can
be applied to a wide range of species, for many of which there are clear
applications and potential benefits," Dr. Laurence Tiley of the
"It will be
interesting to see how enthusiastically this capability in cats is received and
adopted by the HIV and neurobiological research communities and what other
research opportunities it offers. A representative non-primate animal model
would be a fantastic new tool for studying HIV pathogenesis."
So far, Poeschla's team
has only tested cells taken from the animals and found they were resistant to
FIV. But eventually they plan to expose the cats to the virus and see if they
are protected.
"If you could show
that you confer protection to these animals, it would give us a lot of
information about protecting humans," Poeschla said.
For cats, this may
eventually lead to gene therapy or new drug treatments for FIV, he said.
(Editing by Eric Beech)
September 15 2011
Kerry Cullinan
Two years ago, an alliance
of Thai and US scientists revealed that a huge trial of an Aids vaccine had for
the first time protected some people from HIV – but they didn’t know why or
how it had worked.
At the International Aids
Vaccine conference in
The one antibody was high
in those who didn’t get HIV and it attached itself to the same parts of the
virus every time, suggesting that it could recognise the virus.
The other antibody had the
opposite effect, being high in those infected and low in those not infected.
Antibodies are special
cells in the body that recognise viruses that invade the body. These antibodies
mobilise other cells in the body (CD8 cells) to kill these invaders.
From outside this tight
scientific community, these findings seem small. But to those who have been
trying to find a vaccine for the past 25 years, they are the cause of great
excitement and optimism.
Dr Bart Haynes, scientific
head of the Thai trial known as RV144, described the findings as “intriguing
clues” that provide direction for future research.
Finding these clues was an
intense process involving 35 scientists based at 20 different institutes, who
sifted through about 4 000 blood samples.
Although the RV144 vaccine
protected only 31 percent of the people involved in the trial after three years,
its protective effect after one year was an impressive 60 percent. Scientists
are now trying to understand how to maintain the protective effect.
The RV144 trial combined
two vaccines. The first aimed to prime people’s immune systems to recognise
HIV, and the other, injected within six months of the first, aimed to boost
their immune systems to fight infection.
By October, scientists
will recruit a group of volunteers involved in the RV144 trial and give them
another booster shot of the vaccine to see whether their immunity against HIV
can be pushed up again.
In addition, they have
grown a lot of the protective antibodies – called IgG – and plan to insert
them into monkeys to see whether these can protect the monkeys from the monkey
version of HIV. – Health-e News Service
14 Sep 2011 12:41
Source: Content partner //
IRIN
The six-year clinical
trial was the first to produce evidence of an HIV vaccine that had shown some
protective effect against HIV infection. Volunteers who received a vaccine
combination were 31 percent less likely to be infected than those who did not,
according to findings reported in 2009.
Barton Haynes, from
Blood analyses from 286
RV144 participants showed people with high levels of the antibody immunoglobulin
G were less likely to be infected, while those with high levels of
immunoglobulin A were more likely to be infected.
Presenting the team�s
findings to almost 800 researchers gathered at the ongoing 2011 AIDS Vaccine
conference in
Jim Mullins from the
Next steps
Haynes said analysis was
ongoing as scientists combed data for more �clues� to see how they are
related to immunity. �How can we anticipate what might help in another
clinical trial?�
Some of the vaccinated
volunteers from the RV144 study are soon to be given a booster vaccine to
discover if this can extend and increase immunity to HIV, in a study known as
RV305.
Thai and US researchers
are also designing a study, RV306, in
Also in the pipeline
� the earliest would be 2014, according to the US Military HIV Research
Program (MHRP) � are plans to test an HIV vaccine in
Sanjay Gurunathan from
Sanofi Pasteur, manufacturer of one of the vaccines used in RV144, said a new
partnership of the US National Institute of Allergy and Infectious Diseases, The
Bill & Melinda Gates Foundation, HIV Vaccine Trials Network, MHRP, and
Sanofi Pasteur � known as the Pox Protein Public Private Partnership, or P5
� will aim to increase vaccine efficacy from the 31.2 percent of the RV144
trial to 50 percent.
In addition to the
proposed study with MSM in
There are 23 ongoing
preventative HIV vaccine trials [ http://www.avac.org/ht/a/GetDocumentAction/i/3436
] as of May 2011, according to the US-based NGO Global Advocacy for HIV
Prevention.
pt/kn/mw
(AFP) – 15 September,
2011
The study was initially
planned to study the safety and immune response of the vaccine, known by the
name MSP3.
"However, as malaria
attacks were documented as part of the safety follow-up, the investigators
decided to explore the protective effect of the vaccine," said report
appearing in Thursday's New England Journal of Medicine.
"Results indicate a
high level of efficacy."
In the study, 45 children
aged 12-24 months were randomized into three groups receiving doses of either 15
or 30 micrograms of the experimental malaria vaccine, or the control vaccine
against Hepatitis B.
"Comparing the
groups, they found a striking difference," the study said.
It found children who
received the new vaccine at either dose had incidence rates three to four times
lower than children who did not, "yielding efficacy rates of 64 and 77
percent protection against clinical malaria," the journal article said.
"I found the results
of this preliminary study in
"Larger efficacy
trials in diverse epidemiological settings will be required to confirm these
results."
The study was led by
scientists from the
The researchers found
those receiving the vaccine at either dose had more antibodies protecting
against malaria.
"Despite the
limitations of the design and small sample size, these results strongly suggest
a significant protective effect over the follow-up period," the study said.
Malaria claimed 781,000
lives in 2009, according to the UN's World Health Organization (WHO). About 90
percent of malaria deaths each year occur in
Scientists say fighting
the disease is complicated because the parasite, Plasmodium falciparum, is
several hundred times larger than viruses like measles or polio, but is also as
variable as viruses like influenza and HIV.
"In addition to
demonstrating safety, the vaccine induced the desired type of immune responses
in all vaccinated children: those associated with natural protection observed in
adults," the study concluded.
"This provides hope
that the above approach may provide an artificial way to shortcut the 10-20
years of malaria exposure needed to acquire that highly desirable immune state
seen in adults."
The only malaria vaccine
in advanced clinical trials is the RTS,S vaccine being developed by British
drugmaker GlaxoSmithKline, which could become available in 2015. A 2008 study
showed the RTS,S vaccine with an efficacy of 53 percent for young children and
65 percent for infants.
Copyright © 2011 AFP.
(AFP) – 16 September,
2011
The finance ministry had
awarded a contract to a firm called Siqamba Medical, which planned to buy the
Phoenurse condoms from
A rival firm, Sekunjalo
Investments Corporation, turned to the High Court in
Judge Sulet Potterill
blocked the deal with Siqamba, ruling that the female condoms were too small,
made from the wrong material, and were not approved by the World Health
Organisation, the paper said.