Making the immune system work for you: The story of CAMPATH-1H

Harnessing the human immune system, for our own ends, has been a goal of medics and researchers for decades. The immune system is one of evolutions most impressive creations. Given limited genetic resources it’s capable of producing billions of unique antibodies and receptors to recognise pathogens. Given this diversity, this power for recognising many different proteins, there is a problem: stopping the immune system from attacking its own body. Fortunately a system exists. Immune cells are tested on their ability to react to the various bumps, crannies, and crevices of proteins from the body’s own cells. If they react, they are ordered to commit suicide, and the threat of an immune system attacking its own body is thwarted. Obviously, it’s not a perfect system. Sometimes things go wrong and people get autoimmune diseases, with varying degrees of severity. But on the whole, it’s pretty good. But this pruning of self-reactive ...(Read More)

Flying Mammals and a New Jumping Gene

Within our DNA are the remains of thousands, maybe millions, of genetic nomads. They once roamed free through the landscape of our genomes; now most are silenced and still, unable to move. These are the ‘jumping genes’, or ‘transposable elements’ to give them their proper name; curious stretches of mobile DNA. Almost 50% of our DNA is made of these remnants. We see them in virtually all organisms, from bacteria, insects and fish all the way through to us humans. In mammals the only active jumping genes we’ve seen are a type called retro-transposons, which scatter copies of themselves throughout genomes. Now a new DNA sequence for a different type of jumping gene, the first active example of its kind ever to be seen in a mammal, has been spotted jumping around in the genome of the brown bat.

Fighting fat with… fat?

What do explosives and weight loss have in common?* To find out we need to go back to World War One, to a munitions factory in France. People working with explosives were running high temperatures and losing weight. Some dangerously so. This was no fever, due to some viral or bacterial infection. It was due to a chemical they were using, similar in structure to TNT: dinitrophenol (DNP). Later, in the 1930s, DNP popped up again, this time marketed as a treatment for obesity. It failed due to its high toxicity. We now know how DNP causes these bizarre effects; it short-circuits a key process used by cells to store energy in chemical form, releasing it as heat instead. We’ve since discovered that this is a trick mammals are born to do to. A type of fat, called ‘brown adipose tissue’, or BAT, does the same trick as DNP, only ...(Read More)

My enemy’s enemy is my… enemy?

Like a kind of Russian doll infection, a prolific human parasite—responsible for almost 250 million infections annually—can itself harbour a parasite, a virus. You might reasonably feel a sense of something akin to schadenfreude; glad it’s getting a dose of its own medicine, so to speak… But you may be too hasty. The very presence of this virus—though it doesn’t infect human cells—in its parasite host could be making infections worse, or even stymying our attempts at  relieving the infection. The parasite in question, with around 3.7 million people infected in the US alone, is the most common protozoan infection in the industrialised world: Trichomonas vaginalis (TrV). It infects the human genitourinary tract of both men and women causing Trichomoniasis; in fact, it can only live in the human genitourinary tract (an ‘obligate human parasite’). Women are more likely to experience symptoms than men, and while generally mild,  it can be bad. Its ...(Read More)

Waking the (Tiny) giant…

Nestled safely away within your cells, among your DNA, lies something…foreign. An invader. Something you weren’t born with, hidden, evading your immune system and waiting to make its next strike: a ‘latent’ virus. In all probability, there are armies of different viruses performing this same trick throughout your body. Remaining silent; some of their own mysterious accord, others kept in check by your immune system or by random mutations, rendering them useless. Now researchers at The Ohio State University and the University of Oxford have worked out how some of these viruses can reactivate in healthy people, and once again go about their nefarious mindless deeds: hijacking our cells machinery, producing more of their own kind, and causing disease. An inefficient virus kills its host. A clever virus stays with it. — James Lovelock In healthy people latent viruses aren’t generally a problem, occasionally annoying, but rarely life threatening. However, ...(Read More)

Finding the un-natural in the lab…

Taming the power of the immune system in the lab wasn’t easy. For a start, it was a mystery how we have so many different antibodies, millions at any one time. But if it’s one gene per protein, and we only had something like 30,000 genes, how could we have millions of different antibodies? Understanding this problem was the key that unlocked one way to make antibodies against targets that we select. We can use them as tools in the lab, or to treat disease—therapeutic antibodies. Chances are you may know someone who has, or is, using them; if they have Crohn’s disease for example. Just finding antibodies that stick to a target—some unique bump, crevice or corner on a virus, for example—isn’t enough. The next step is to find out if they do something useful. They may stick but not prevent infection, or not activate some receptor on a ...(Read More)

The “Dirty Little Secret”* About Vaccines

Note: This originally appeared on the SciBox section of the Oxford SciBar. Check out the site, there’s a host of podcasts of talks and other articles there.   In some ways, the immune system’s like a brain: it can learn, it can adapt and, so it’s ready for the next time, it can remember. This is, perhaps, its single most important feature. The immune system has the chance to learn a unique signature on the surface of an invader every time we’re infected by something, be it virus, bacteria or even a parasite. Once it learns these signatures the body produces antibodies or ’killer cells’ to fight it. When the infection has been defeated, special cells – B-cells – remember it, for as long as a life time. If the invader returns it won’t have such an easy time: the immune system will be ready. Like most things that learn, the ...(Read More)