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This post will not strictly be about immunology, but given that it’s January 2015, I felt like talking about the Science Breakthrough of 2014.
Since 1996, the editors and writers at a journal called Science choose one scientific finding as the breakthrough of the year. Last year they chose Immunotherapy in cancer. Big deal for immunologists.
This year they shook things up a little bit and went onto social media. In addition to selecting their own favourite, they published a short list of 19 great scientific findings from 2014 and let us, the public, vote. OK, I have to admit it’s likely that the majority of people voting were scientist as they had a better chance of hearing about the voting. You can check out the articles for the winner and runner ups here.
Out in space
Interestingly, the choice of the editors (Rosetta’s rendezvous with a comet) only came in third place in the public vote. I wonder why this is.
The landing of space lander Philae was widely covered by the media, but people may have been disappointed that the space craft missed its landing point, fell over and turned off after only 57 hours. And this was before it was capable of performing its most important task – drilling a hole and analysing the composition of the comet.
Don’t be mistaken, though, the mission was far from a failure.
Philae striking a pose
For one, this is only the 7th place outside earth mankind has landed on- so this is a big deal! Secondly, Philae is powered by solar energy and might well wake up again once the comet (its snappy name is 67P/Churyumov-Gerasimenko) gets closer to the sun and Philae is exposed to more sunlight. So this story may not be over just yet. You can follow Philae on twitter (@Philae2014) to find out when and if Philae awakes.
Most importantly, Philaes “mother ship” Rosetta is orbiting the comet since august, following its approach to the sun from only 10 km distance. It’s the first time we can monitor a comet at such close range over such a long period of time! On the way, Rosetta has provided information about how the comet changes on the journey – not only taking pictures but also “smelling” what gases come from the comet. By knowing how orbiting the sun changes the comet, scientist may be able to look back in time and model how comets develop. And that’s of utter importance as there is a theory stating that molecules from comets (water and organic molecules) may started life on earth!
What the public (and I) thought was cool
Now lets get to the public vote. We may even find some immunology!
First place went to adding more information into the DNA of bacteria
DNA stores the information needed to build a cell as well as the whole human body. Normally DNA consists of four different components called nucleotides (A: adenine, T: thymine, C: cytosine and G: guanine) lined up in a long strand. In the normal DNA, which consists of the same four nucleotides in bacteria, plants and animals, A pairs with T and C pairs with G to form the double helix structure between two DNA strands. Any given sequence of A T C G codes for so called peptides, which are the building blocks for life.
Researchers now managed to introduce a new pair of nucleotides (d5SICS and dNaM) to the DNA of a living organism. But not just that, the new pair of nucleotides is also copied within the bacteria and given from one cell to the daughter cell during cell division. So far the new pair of nucleotides does not code for any additional information. But in the future we may be able to create designer molecules, which could find use as medicine.
But don’t fear – there won’t be killer mutated bacteria on the loose any time soon. The bacteria used in this study were feed the foreign nucleotides, but once this diet stopped the bacteria filled their DNA up with natural nucleotides. Basically a safety switch!
Secondly place went to the youth serum
Runner up in the public vote went to my personal favourite. In this study researchers showed that components of young blood could have a rejuvenating effect on old mice! Pretty cool right?
There have been two publications from the same group of researchers around Dr. Saul Villeda about this now, one in 2014 and one in 2011. Worth a read but not free access I am afraid. But that’s what we are here for – a good summary.
It has been known for a while, that with age the number and function of neural stem cells declines in the brain, which leads to decreased cognitive function (that included memory, judgment, decision making and more) in elder people. These studies aimed to see how factors in the periphery, so outside the brain, can affect the brain as it has been previously shown that for example exercise can help cognitive function.
Connecting the blood streams of young and old mice, researchers showed that young animals exposed to old blood had worse memory and learning capacities compared to normal young mice. Trying to identify which cell or molecule is responsible for this effect, the researchers identified an immune messenger molecule called CCL11 as one possible mediator of cognitive decline with age. Injecting CCL11 into young mice not only caused decline in stem cell numbers but CCL11 levels were also found to be increased in elder people.
This finding is striking as the blood-brain-barrier is thought to keep blood-born factors such as immune cells out of the brain. But clearly small immune mediators can pass and have a great effect on the brain during aging. This also fits in with a study showing that illnesses such as the flu can cause decline in Alzheimer patients, demonstrating that peripheral events can have an impact on the brain.
In the publication from 2014, it was shown that the exposure to young blood can rejuvenate old animals. So, again connecting the blood stream of young and old mice, but this time analysing the effect on the older mice, the researchers found that older mice exposed to young blood improved their memory and learning abilities. This is due to the activation of a transcription factor called Creb. Transcription factors can change the expression of a large number of genes in a cell and thereby activate cellular processes. In this case Creb allows neuronal cells to form or strengthens connections (synapses) between the cells leading to improved function of the brain in old mice.
So does that mean we will all soon be young forever? Unlikely, I think, but it may have implications in age-related diseases such as Alzheimer’s disease. In fact there is a clinical trial ongoing in which Alzheimer patients are injected with plasma from young donors to see if this can help stop the cognitive decline caused by the disease.
These were my highlights from the science breakthrough of 2014 – but please check out the whole list of runner ups. They are all worth a read! And please ask if you have any questions about this blog.
Here are the links to the original publications:
New information in bacterial DNA: Malyshev et al 2014
Effect of infections on Alzheimer’s: Holmes et al 2009