ContribUted by Guest Blogger: A. Parayannilam ’13
The cold sores many of us see on our mouths or faces at one point in our lifetimes are caused by the prevalent Herpes simplex virus Type 1(HSV1). More serious symptoms can develop if the virus infects the Central Nervous System, causing herpes encephalitis and damage to the brain. A recent study has shown how interferon delta (IFN-λ), a member of a group of proteins known as interferons (IFNs), can reduce infectivity of the virus in the Central Nervous System. The results of the study are promising: perhaps by recruiting the body’s own defenses, we can avoid the use of potentially unsafe antiviral drugs in treatment for the disease.
Researchers observed IFN-λ to significantly reduce the quantity of the virus found in infected cells of the central nervous system, specifically astrocytes and neurons. Researchers investigated the mechanism behind IFN-λ’s anti-HSV-1 effect and found that IFN-λ activated several Type 1 IFNs. Type 1 IFNs play critical roles in our innate immunity and defense against viruses. To test the significance of Type 1 IFNs, researchers treated astrocytes and neurons with Type 1 IFN antibodies, essentially preventing IFN- λ from activating Type 1 IFNs in these cells. The antibody-treated cells became highly susceptible to infection, highlighting the importance of Type 1 IFNs in the virulence of the disease.
Another method by which IFN- λ reduces infectivity of the virus is by promoting cytokine signaling. Cytokine signaling is a method of intercellular communication cells use to warn each other of infection. Because HSV-1 suppresses cytokine signaling, uninfected cells aren’t able to prepare themselves for possible infection, making these cells more susceptible to infection.
The study raises a number of questions. The researchers discuss the interplay between HSV-1 and interferon delta, but how about the interplay between HSV-2 and interferon delta? The study examines how interferon delta can reduce infectivity in astrocytes and neurons– can interferon delta similarly reduce infectivity in cells outside the Central Nervous System? Is this a fix to the annoying, chronic cold sores that affect the majority of us?
The problem here is that large pharmaceutical companies will find ways to profit if there is a cure for cold sores. What I would like to see is the low incidence of side effects. If it is possible, natural ingredients would be the most ideal way to prepare the formulation. Hopefully, the government would provide more funds for the non-profitable research. This may prevent the commercialization of the cure so that most victims who are in the lower income bracket can benefit from it.
Though it would be great if this study led to a cure for HSV-1,from what Professor Esteban said, it may not be worth it to risk toxic side effects for something so minor. Its interesting that such a study was done however because, as was noted in the post, the researchers have found a connection between HSV-1 and interferon delta which could potentially be used to find the correlation between HSV-2 and interferon delta. Since HSV-2 is considered a bigger threat to its hosts, this could have a much greater impact. Either way it seems there is a need for more studies to monitor the effects of this treatment.
I also find this study very interesting considering how prevalent herpes is amongst society. However i feel like the herpes virus would likely evolve if interferon delta were to become mainstream drug used to reduce the infectivity because it reduces the quantity of virus found but does not completely eliminate it. Those few virus particles left will probably be able to evolve and become resistant to the effectiveness of the IFN treatment.
It’ll be interesting to see how this works in animals. People have tried using cytokines to control infections before and the idea is always promising but has problems in practice. Interferons are used in the treatment of hepatitis B, and its one of the best available treatments if the patient can handle the toxic side effects – this is a case of the cure sometimes being worse than the disease. We might not be so willing to accept toxic side effects to treat something annoying rather than life threatening, but we can still hope that toxicity won’t be a problem in this particular case.
This study is of great interest to me. I was unaware that there was even a possible cure for herpes, let alone one that looks promising. The fact that this interferon is so effective in the central nervous system is very exciting, since it could improve the lives of so many infected people. If the interferon could prevent cold sores from forming, the contagion of the virus would significantly decrease, causing a large decrease in the number of people infected with the virus. The question is, would the virus quickly notice this change and mutate?