Viruses: chameleon beings, from villains to good guys
With the arrival of winter, concerns about the transmission of several viruses, especially the flu, increase. When people think of viruses, they quickly associate them with diseases or chemical weapons. However, for us, biotechnologists, they can also be important tools, as we can use their ability to infiltrate and exploit living systems in favor of society. Calm down, I’ll explain to you how this is possible!
Well, initially it is necessary for you to understand that viruses are basically composed of a genetic material inside a protein capsule, thus, they are not considered living beings, as they cannot replicate by themselves. Once they infect cells that allow them to replicate, they lose their identity of origin and act under viral command.
Now that you know how viruses replicate, it’s important to know that even bacteria are targets for these smarties: phages (or bacteriophages) are viruses that only infect bacteria. This is exactly where biotechnology comes in, and we think: Now, if phages are capable of killing bacteria, it can become an advantage for humans, who can use them to kill unwanted bacteria.
Since then, they have been extensively researched for complementary use in antibiotic therapy, since they are immune to the resistance mechanism and specific to their host (each phage only infects one strain of bacteria). This feature prevents the “beneficial” bacteria from being destroyed. However, in order to use this treatment it is necessary to carry out laboratory tests to identify precisely which species of bacteria caused the infection. Studies are also needed to monitor, in the long run, whether bacteria can evolve into phage resistance. However, when bacteria become resistant to one phage, they become susceptible to another. In this way there is almost an endless supply of possible new treatments.
Until recently, there was no way to kill cancer cells without harming healthy cells in the rest of the body, due to the difficulty of targeting a treatment that affected only those affected. However, biotechnology has revolutionized this scenario by developing viruses that selectively destroy tumors. Amgen’s T-VEC is a herpes oncolytic virus, genetically modified to treat melanoma, killing cancer cells in the skin without affecting healthy cells. This is possible because the modified herpes virus can only replicate within cancer cells. They are injected directly into the tumor until the cancer subsides, for approximately four months.
In Germany, ParvOryxo was developed, which selectively kills tumor cells from a wide variety of tumors including glioblastoma and pancreatic cancer. It is able to pass the blood-brain barrier, which protects the brain, directly killing tumor cells, in addition to altering the tumor’s microenvironment, making it more visible to the immune system and increasing its vulnerability to immuno-oncology approaches.
“Pigeons carrier” of genetic material (viral vectors)
When removing the pathogenic components of the virus genome, they can be used as true “pigeons”, delivering genes of interest in genetic therapies. Luxturna, for example, is a viral vector that carries a functional copy of the RPE65 gene in retinal cells, restoring the vision of patients with progressive vision loss due to a mutation.
Although its sinister reputation can never be completely erased, there is no denying that viruses are far from just carrying disease and death. They can act as fantastic biotechnological tools, capable of providing powerful treatments that would be impossible without your help.