Stickycell’s advanced Leukocyte Adhesive Function Assay (LAFA) is a new way to measure inflammation, a primary determinant of autoimmune diseases.
Previously we’ve shown how circulating leukocytes in our blood become stickier and cause Multiple Sclerosis (MS) (Sticky Cell Series Article 4). In this article we will show how LAFA is applied in a clinical setting and used to detect “stickier” leukocytes as an early warning sign of MS.
When leukocytes are circulating in the blood they interact with and adhere to the blood vessel wall endothelial cells. The stronger the interaction, the more inflamed and activated the immune system becomes (Sticky Cell Series Article 2). StickyCell’s LAFA technology mimics this process and provides us with a tool to assess leukocyte “stickiness”.
This is roughly how it works; imagine rolling a ball across a smooth surface like a carpet. The ball rolls easily unobstructed. If you wrap the ball with double-sided adhesive tape and roll it again, the ball may roll, but it will do so more slowly. Leukocytes in people with MS are stickier and move more slowly along the blood vessel endothelial cells and they are more likely to be recruited into the surrounding tissue to cause inflammation. Based on the same principle, the stickier MS leukocytes can easily be singled-out using the LAFA assays.
To prove this, we took blood samples from a healthy volunteer and an MS patient to compare. VCAM-1 was used as an adhesive substrate to promote leukocyte recruitment (Sticky Cell Series Article 6). VCAM-1 is a protein expressed by the blood vessel endothelial cells and it plays a crucial role in regulating leukocyte recruitment.
After being analysed by LAFA, the results are best demonstrated by these videos.
The videos compare VCAM-1 dependent leukocyte recruitment between a healthy person and an MS patient. The green and red dots represent CD4 (Green) and CD8 (Red) cells, which were fluorescently labelled using complementary colours to distinguish between them. CD4 and CD8 are two important leukocyte subsets with slightly different roles in our immune system.
In the video on the right (MS patient’s blood) there are more green, interacting CD4 cells compared with the video on the left (healthy person’s blood). This indicates more activated CD4 cells and more inflammation in the MS patient compared with the healthy person. More importantly, the CD4 and CD8 cells in the MS patient’s blood roll more slowly than the cells in the healthy blood, again suggesting pronounced inflammation in the MS patient.
The videos show clearly that the MS patient’s blood is more activated and the leukocytes are “stickier”.
An activated immune system is a red flag for disease. LAFA detects immune system activation and gives an early warning for Multiple Sclerosis well before clinical symptoms may become obvious.
Our R&D team at StickyCell are working hard to bring real benefits to people who have a high risk of immune disorders.
Blood samples from a healthy volunteer and an MS patient were analysed by LAFA technology and the results were recorded by these videos.
More interacting cells were observed in the MS patient and these cells are “stickier” than healthy cells.
These videos show clearly how LAFA technology can detect early signs of disease, not only in MS but also in other immune disorders.