Last month, a team of scientists announced what could prove to be an enormous step forward in the fight against H.I.V.
Scientists at Scripps Research Institute said they had developed an artificial antibody that, once in the blood, grabbed hold of the virus and inactivated it. The molecule can eliminate H.I.V. from infected monkeys and protect them from future infections.
But this treatment is not a vaccine, not in any ordinary sense. By delivering synthetic genes into the muscles of the monkeys, the scientists are essentially re-engineering the animals to resist disease. Researchers are testing this novel approach not just against H.I.V., but also Ebola, malaria, influenza and hepatitis.
“The sky’s the limit,” said Michael Farzan, an immunologist at Scripps and lead author of the new study.
Dr. Farzan and other scientists are increasingly hopeful that this technique may be able to provide long-term protection against diseases for which vaccines have failed. The first human trial based on this strategy — called immunoprophylaxis by gene transfer, or I.G.T. — is underway, and several new ones are planned.
“It could revolutionize the way we immunize against public health threats in the future,” said Dr. Gary J. Nabel, the chief scientific officer of Sanofi, a pharmaceutical company that produces a wide range of vaccines.
Whether I.G.T. will succeed is still an open question. Researchers still need to gauge its safety and effectiveness in humans. And the prospect of genetically engineering people to resist infectious diseases may raise concerns among patients.
“The reality is we are touching third rails, and so it’s going to take some explanation,” said Dr. David Baltimore, a Nobel Prize recipient and virologist at Caltech who is testing I.G.T. against a number of diseases.
Conventional vaccines prompt the immune system to learn how to make antibodies by introducing it to weakened or dead pathogens, or even just their molecular fragments. Our immune cells produce a range of antibodies, some of which can fight these infections.
In some cases, these antibodies provide strong defenses. Vaccinations against diseases such as smallpox and measles can lead to almost complete protection.
But against other diseases, conventional vaccines often fail to produce effective antibodies. H.I.V., for example, comes in so many different strains that a vaccine that can protect against one will not work against others.
I.G.T. is altogether different from traditional vaccination. It is instead a form of gene therapy. Scientists isolate the genes that produce powerful antibodies against certain diseases and then synthesize artificial versions. The genes are placed into viruses and injected into human tissue, usually muscle.
The viruses invade human cells with their DNA payloads, and the synthetic gene is incorporated into the recipient’s own DNA. If all goes well, the new genes instruct the cells to begin manufacturing powerful antibodies.
Scientists at Scripps Research Institute said they had developed an artificial antibody that, once in the blood, grabbed hold of the virus and inactivated it. The molecule can eliminate H.I.V. from infected monkeys and protect them from future infections.
But this treatment is not a vaccine, not in any ordinary sense. By delivering synthetic genes into the muscles of the monkeys, the scientists are essentially re-engineering the animals to resist disease. Researchers are testing this novel approach not just against H.I.V., but also Ebola, malaria, influenza and hepatitis.“The sky’s the limit,” said Michael Farzan, an immunologist at Scripps and lead author of the new study.
Dr. Farzan and other scientists are increasingly hopeful that this technique may be able to provide long-term protection against diseases for which vaccines have failed. The first human trial based on this strategy — called immunoprophylaxis by gene transfer, or I.G.T. — is underway, and several new ones are planned.
“It could revolutionize the way we immunize against public health threats in the future,” said Dr. Gary J. Nabel, the chief scientific officer of Sanofi, a pharmaceutical company that produces a wide range of vaccines.
Whether I.G.T. will succeed is still an open question. Researchers still need to gauge its safety and effectiveness in humans. And the prospect of genetically engineering people to resist infectious diseases may raise concerns among patients.
“The reality is we are touching third rails, and so it’s going to take some explanation,” said Dr. David Baltimore, a Nobel Prize recipient and virologist at Caltech who is testing I.G.T. against a number of diseases.
Conventional vaccines prompt the immune system to learn how to make antibodies by introducing it to weakened or dead pathogens, or even just their molecular fragments. Our immune cells produce a range of antibodies, some of which can fight these infections.
In some cases, these antibodies provide strong defenses. Vaccinations against diseases such as smallpox and measles can lead to almost complete protection.
But against other diseases, conventional vaccines often fail to produce effective antibodies. H.I.V., for example, comes in so many different strains that a vaccine that can protect against one will not work against others.
I.G.T. is altogether different from traditional vaccination. It is instead a form of gene therapy. Scientists isolate the genes that produce powerful antibodies against certain diseases and then synthesize artificial versions. The genes are placed into viruses and injected into human tissue, usually muscle.
The viruses invade human cells with their DNA payloads, and the synthetic gene is incorporated into the recipient’s own DNA. If all goes well, the new genes instruct the cells to begin manufacturing powerful antibodies.
by Carl Zimmer, NY Times | Read more:
Image: John Hersey
