Bacteria, why do they make me sick?/Current discussions
CHAPTER 5
CURRENT
DISCUSSIONS
Current discussions
GENOME EDITING
For decades, people have been yearning for being able to permanently alter the DNA, by inserting or deleting genes or specific pieces of DNA. The reason is that this process can be applied to agronomy, veterinary and human medicine.
Some tools that are currently used to modify DNA are Zinc finger nucleases (ZFNs), transcription-activator like effector nucleases (TALEN), and the revolutionary technique of nucleases and the clustered regularly interspaced short palindromic repeats (CRISPR/Cas) system.
The first two, are based on proteins conformed by a DNA catalytic domain and a recognition domain of the targeted gene. It is not possible to make multiple changes simultaneously with the first two techniques. However, with the CRISPR/Cas technique, it is possible to modify a DNA sequence easily, quickly and accurately in different domains of the genome of a living organism. This genome editing technique is inspired by the rudimentary immune system with which some bacteria keep virus genome fragments in their genome. This process allows the bacteria to identify the virus and produce enzymes that cut and deactivate the RNA virus.
The CRISPR-Cas technique has already been used to cause and correct mutations in different types of cells, including bacteria and human eukaryotic cells. However, its main inconvenient is the involuntary generation of genetic material errors. This situation decreases the efficacy of the technique, preventing it to be considered as a future gene replacement therapy.
A new CRISPR version developed by Gaudelli et al. reduced the involuntary genomic error rate from 10 to 0.1 percent. The researchers have proved their new technology by correcting genetic errors on blood pathologies (leukemia) which were originated by DNA mutations in the eukaryotic cells.
Chilean scientists in vaccine
development
DR. PABLO VALENZUELA
Dr. Pablo Valenzuela discoveries changed the face of modern medicine. He is a restless scientist (Biochemist of Universidad de Chile. Chemistry Ph.D. of the Northwestern University, and postdoctoral researcher at the University of California), and an entrepreneur by nature (he founded the biotechnology companies Chiron Corporation and BiosChile). Dr. Valenzuela developed the vaccine against Hepatitis B, sequenced the genome of the immunodeficiency virus, and under his direction, the Hepatitis C virus was discovered. He currently works at the Foundation Science and Life, searching for new drugs to treat cancer.
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In an interview with CONICYT, Dr. Kalergis said that “this pioneering initiative is transformed into a phase I clinical study, the first for a vaccine developed by Chilean science and in compliance with all national and international regulations.” |
DR. ALEXIS KALERGIS
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Dr. Alexis Kalergis, professor of the Pontificia Universidad Católica de Chile, developed in Chile a vaccine against the respiratory syncytial virus (RSV). This virus is the main cause of respiratory infectious diseases in children in Chile and the world. The vaccine has passed the pre-clinical and manufacture studies, and there is an agreement with the Health Department to ensure access to the vaccine for the entire population through the National Program of Immunization.
Also, in collaboration with Dr. Susan Bueno, Dr. Kalergis is developing a vaccine against the human metapneumovirus (HMPV), which causes respiratory infectious diseases, especially among children and older adults.