New Nano Device Detects Immune System Cell Signaling

ScienceDaily (Sep. 3, 2008) — Scientists have detected previously unnoticed chemical signals that individual cells in the immune system use to communicate with each other over short distances.
The signals the researchers detected originated in dendritic cells – the sentinels of the immune system that do the initial detection of microscopic invaders – and were received by nearby T-cells, which play a number of crucial roles in the immune system, including coordination of attacks on agents that cause disease or infection.

The chemical signals cells exchange when they come into contact have been studied extensively. But it has not been possible to detect chemical messages that travel between cells that are nearby but not in contact – called paracrine signals – because they are highly localized and they are produced in concentrations that have been below detection levels. A new technology, called a multi-trap nanophysiometer, was required to demonstrate the existence of non-contact signaling. This is one of the first microfluidic devices that has been applied successfully to the study of cell-to-cell signaling in the immune system.

A detailed description of the multi-trap nanophysiometer (MTN) and how it enabled the accidental discovery of paracrine signaling has been published online by the Lab on a Chip journal. The new device was developed by a team of researchers at the Vanderbilt Institute for Integrative Biosystems Research and Education headed by John P. Wikswo, the Gordon A. Cain University Professor at Vanderbilt.

“This is an important advance and potentially very useful technology,” says co-author Derya Unutmaz, now an associate professor of microbiology at New York University’s School of Medicine. “The ability to study the behavior of single cells may not be as critical if you are studying the heart or muscles, which are mostly formed by uniform cells, but it is crucial for understanding how the immune system functions. The wide surveillance of the body that it conducts requires extensive communication between dozens of different kinds of immune cells.”

The reason for this is that the dendritic cells, T-cells and B-cells in the immune system, which tend to concentrate in the lymph nodes spread throughout the body, function as individual, unattached cells. If dendritic cells detect invaders in the body, they rapidly migrate to lymph nodes and have to find the appropriate T-cells to alert them. But how dendritic cells attract the right T-cells among millions of cells within the lymph nodes remains an immunological puzzle.

Scientists have been trying to develop systems for single-cell analysis for a number of years. Because of the difficulty of keeping normal cells alive, they have been forced to use cells that have been genetically altered so they can be cultured indefinitely. Although the alteration “immortalizes” the cells, it also significantly limits their usefulness. The MTN is the first system that can monitor biochemical changes (….)
continue reading article: http://www.sciencedaily.com/releases/2008/09/080903172412.htm

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~ by vascoteixeira on September 4, 2008.

 
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