Scientists discover a new method by which dynamics of cell-cell interactions can be monitored
A new study led by The Rockefeller University assistant professor Gabriel Victora discovered a new method by which dynamics of cell-cell interactions can be monitored as well as the receptors and ligands involved can also be identified.
A new method was discovered called as LIPSTIC (‘Labelling Immune Partnerships by SorTagging Intercellular Contacts’) by which ‘kiss-and-run’ interactions between immune cells can be labeled. This finding is much more than a cosmetic improvement over existing techniques and provides a new tool to study the biologically complex events in a live animal.
“Virtually all of the immunology is based on cell-to-cell contact,” says Victora. “Most immune phenomena require that cells physically meet each other and exchange signals so that the response gets kick-started. That is how the system decides whether or not it wants to react to a stimulus like an invasion by a pathogen, and if it is going to act, what exactly it should do.”
In this new study published in journal Nature author says that in the population of cells, all the cells look same and interaction encountered between the cells could not be identified as individual ones will occasionally engage in talking to another cell, then move away. The author called these encounters between immune cells as “kiss-and-run:” Victora and his team, including postdoctoral associate and first author Giulia Pasqual, created a system for labeling the cellular structures that actually make physical contact when two cells meet.
When these modified cells interact they tag or mark each other the biological equivalent of a smear of lipstick. Because of this tagging, cells which are actively participating in immune function can be recognized and identified by their labeling and counted with flow cytometry, a standard lab technology.
“This enables us to figure out which exact cells within a population are interacting,” says Victora. “We can also monitor how the number and quality of the interacting cells changes over time.” This trove of information, unavailable until now, can help researchers better understand how the immune system functions in the presence of a foreign body.
During their research, the scientists used two type of cell T-cell and dendritic cell. Dendritic-cell alerts the T cell on encounter of antigen and presents them to T-cell through cell to cell contact while T-cell act as an executive director of immune response.
They tested it in mice After approving the working of labelling system. For those experiments, Victora picked a classic model of the immune response in which they used a dendritic cell loaded with antigen so that t cell can recognize it through the receptors present on the surfaces of T cell and then injecting these primed dendritic cells into a mouse’s foot.
After carrying out all this process researchers analysed the lymph nodes from these mice using flow cytometry. They found that immune cells which were labelled in the mice have marked each other on interaction in lymph node and then these cells were identified and counted.
“Now we can measure things that we couldn’t measure before,” Victora says, describing, in his succinct, understated way, exactly the sort of landmark achievement that drives all science.