The ambitious quest to map every cell in our body

So to tackle the issue, a consortium of scientists (as part of the Human Cell Atlas project) analyzed around 70,000 cells from the placenta and lining of the womb from women who had terminated their pregnancy at between six and 14 weeks.

The placenta is the organ where nutrients and gases pass back and forth between the mother and developing baby. It was once thought the mother’s immune system must be switched off in the lining of the womb where the placenta embeds, so that the placenta and fetus weren’t attacked for being “alien” (like an unmatched transplant) on account of half the fetus’s genes coming from the father. But this view turned out to be wrong – or too simple at the very least.

We now know, from a variety of experiments including this analysis, that in the womb, the activity of the mother’s immune cells is somewhat lessened, presumably to prevent an adverse reaction against cells from the fetus, but the immune system is not switched off. Instead, the immune cells we met earlier, natural killer cells, well known for killing infected cells or cancer cells, take on a completely different, more constructive job in the womb: helping build the placenta.

Furthermore, the scientists’ analysis of 70,000 cells has highlighted that all sorts of other immune cells are also important in the construction of a placenta. What they all do, though, isn’t yet clear – this is at the edge of our knowledge.

Muzlifah Haniffa, a professor in dermatology and immunology at the Wellcome Sanger Institute and Newcastle University Biosciences Institute in the UK is one of the three women who led this analysis. Haniffa sees the body from two perspectives on an almost daily basis: as a computational analysis of cells on a screen, and as patients who walk through the door. Both as stones and the arch they make.

Right now, these two views don’t easily mesh. But in time, they will. In the future, Haniffa thinks the tools doctors use on a daily basis – such as a stethoscope to listen to a person’s lungs, or a simple blood count – will be replaced by instruments that profile our body’s cells. Algorithms will analyze the results, clarify the underlying problem, and predict the best treatment. Other physicians agree with her – this has to be what is coming in the future of healthcare.

What this could mean for you

Babies are now routinely born by IVF, organ transplants have become common, and cancer survival rates in the UK have roughly doubled in recent years – but all these achievements are nothing to what’s coming.

As I’ve written about in The Secret Body, progress in human biology is accelerating at an unprecedented rate – not only through the Human Cell Atlas project but in many other areas too. Analysis of our genes presents a new understanding of how we differ – the actions of brain cells give clues to how our minds work; new structures found inside our cells lead to new ideas for medicine; proteins and other molecules found to be circulating in our blood change our view of mental health.

Of course, all science has an ever-increasing impact on our lives, but nothing affects us as deeply or directly as new revelations about the human body. On the horizon now, from all this research, are entirely new ways of defining, screening and manipulating health.


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