Peter Mac researchers have developed a new sugar-sensing single cell sequencing technology, which has allowed them to better observe T cells and understand more about how they function.

T cells are an important part of our adaptive immune system.

"In the context of cancer, they're the ones you want to harness to try and get rid of the tumour," says cancer immunologist Dr Conor Kearney.

For example, immunotherapy is about making a patient's T cells work better, so they are better at going into a tumour and killing the cancer cells.

However, there are a variety of types of T cells and they all look slightly different.

Previous bulk sequencing techniques made it impossible to unravel which types of T cells were the most effective at destroying cancer.

"A big breakthrough recently has been single cell sequencing has allowed us to pinpoint the T cells that look like they are the really important ones," Dr Kearney says.

Now Dr Kearney and his colleagues have developed a new single cell sequencing technology that can simultaneously detect what genes are expressed, what proteins are produced, and for the first time also what sugars or glycans are attached to those proteins, within a single cell.

The new method has been dubbed SUGAR-seq, which stands for SUrface-protein Glycan And RNA-seq or sequencing, and was described in a paper published in Science Advances last week.

And intriguingly it has revealed something about T cells we didn't know before.

The researchers observed interesting changes in the glycosylation status of T cells, or changes in the sugars connected to the proteins on the surface of the T cells.

"We've identified interesting sugar patterns on the T cells that look like they're responsible for the way the T cells are functioning against the cancer, but we don't exactly know how yet or why," Dr Kearney says.

Could it be that the sugars on the surface of the T cells influence their function, or are merely a marker of their function?

While that's an answer we don't have yet, Dr Kearney says, it’s probably a bit of both.

"What started off as a real cool technology-driven project then led us to some fascinating biology," says Executive Director Cancer Research Professor Ricky Johnstone, who also directed and oversaw the work.

"The thing I really love about the paper is you can be a technocrat and interested in the technology and really get something out of it, or you can be interested in T cell biology and cancer immunology, and get something out of that," he says.

"But if you read the whole paper there's enough in it for everyone."

And knowing more about the sugars connected to the proteins on the surface of cells isn't just of interest to cancer researchers.

"Aberrant glycosylation has been associated with other diseases too, including obesity and autoimmune diseases," Dr Kearney says.

"Our new technology will accelerate our understanding of the role of glycosylation in human diseases, and uncover new ways of treating them."