Posted on May 1, 2017

Finding the ‘fountain of youth’ has been a topic that has captured the hearts and minds of mankind throughout history. While we credit the current miracles of modern medicine with extending the average lifespan, it has also given witness to the breakdown of the body and mind as people age. The eternal question that has baffled and confounded researchers has been what actually causes this decline. Scientists from all over the globe have been delving into this quandary and it seems that a group at the European Bioinformatics Institute (EMBL-EBI), University of Cambridge, the Wellcome Trust Sanger Institute and the Cancer Research UK-Cambridge Institute (CRUK-CI) may have found a few answers.

Published in Science, the groups researched has shown that older tissue immune cells lack coordination and when compared to younger cells, are more variable in gene expression. This is a key discovery as it assists in settling the debate that scientists have had concerning two separate hypotheses regarding functional degradation. They believed that it was caused either by loss of coordination among the cells or the loss of cellular performance itself.

Researchers and the medical community know that the immune systems is an incredibly coordinated system with many cell types and subtypes that all work together to fight infections. As an individual ages, the immune system also seems to age and there is a weakened response to infection. It has always been a question as to why this occurs.

This initial study took the assumption that either of the debate sides could be correct. They studied a variety of cell types, with an analysis of the gene expression profiles of the ‘average’ gene. Making use of technology involving high-resolution single-cell sequencing, they created a variety of new insights as to the method that cell-to-cell variabilities are associated with aging. In research involving mice, the scientists sequenced the RNA of naïve and memory CD4+ T cells in old and young mice, in both unstimulated and stimulated states. The results that they found indicated that the loss of coordination was the key component of the immune performance impairment caused by T cell aging.

In a article, Group Leader at EMBL-EBI and CRUK-CI, John Marioni stated,

“You could think of DNA sequencing as a fruit smoothie. Traditional sequencing technology is a bit like taking a sip of the smoothie, then trying to guess what the ingredients are. Single-cell genomics now lets us study the ingredients individually, so we get direct insight into the constituent parts. Extrapolating, this means that single-cell sequencing allows researchers to individually look at thousands of genes at any given time.”

So where does this study take us? It has opened the doors to offering a more direct approach for cellular age studies, potentially redirecting the previous debate and now offering an option that illustrates the potential for sequencing single-cells in understanding cell activity and development.