According to surprising new research, some strains of the HPV virus may inadvertently help us protect against skin cancer.
The much malignant family of viruses also causes STDs and cancers of the cervix, head and neck and more.
Some scientists have wondered if HPV can also cause skin cancer – but the new Massachusetts General Hospital study suggests the exact opposite.
The scientists discovered that the presence of these viruses that live on the skin of some people actually activates the immune system in a way that indirectly helps against skin cancer.
When harmless HPV colonizes skin cancer at an early stage (see photo), the immune system thinks the combination is a wart and sends T cells to fight it, but in fact it unintentionally helps to fight scquamous cell carcinoma (red)
More than 100 HPV strains exist – shortly before human papillomavirus – and can affect humans.
Almost everyone who is sexually active will, at some point in the course of their life, contract one or more strains of the virus.
In the US, about 79 million Americans have the virus and about 14 million people are expected to contract the virus every year.
In most symptomatic cases it causes genital warts that can be removed or treated, but can return.
HPV was once considered almost unavoidable incidental damage to sexual activity, rarely tested for unless someone had warts and was considered fairly harmless.
But in the 1950s and 1960s, scientists began to notice links between HPV and cervical cancer.
By the 1980s, a German scientist studying viruses had demonstrated the link between three HPV strains and cervical cancer. He received a Nobel Prize for his work.
Since then, scientists have discovered that about 12 strains out of 100 or so cause cervical cancer and, according to more recent discoveries, are likely to cause head, neck, vulva, penis, anus and throat cancer.
Now the HPV vaccine, Gardasil, protects against four HPV strains, including HPV-16 and -18, which together account for approximately 70 percent of all cervical cancers.
After the latest discovery, and in a biological irony, people can soon get other strains of the virus themselves as a vaccine against other cancers.
It's not surprising that people with a suppressed immune system are more vulnerable to viral infections – such as HPV – and skin cancer, so scientists thought there might have been a link between the two, but couldn't find one.
Although dangerous sexually transmitted forms of the virus hide in the genitals, many low-risk variants can camp harmlessly on human skin.
Using & # 39; experimental models & # 39 ;, samples of human skin cancer and mice, the Massachusetts General team discovered that when harmless HPV was present, the immune system was activated.
The immune system recognized the virus – although it did not cause any negative effects – and sent T cells to defend itself against it.
Accidentally, those T cells also have anti-cancer effects that protect against the common disease, squamous cell carcinoma.
& # 39; This is the first proof that this & # 39; human & # 39; or symbiotic & # 39; Viruses can have beneficial health effects, both in experimental models and in humans, and it appears that this beneficial effect has to do with cancer protection, ”said study co-author Dr. Shawn Dmehri.
& # 39; The role of these commensal viruses, in this case papillomaviruses, is to induce immunity that subsequently protects patients against skin cancer. & # 39;
From that finding it was tested how mice with the virus on their heir developed skin cancer at different speeds than their counterparts without.
Their findings suggested that the virus could be used to stimulate T cell activity and thereby help prevent skin cancer.
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