A group of researchers headed by Dr. Jordan S. Orange at the Children’s Hospital of Philadelphia have gained detailed insight into the immune system by making use of the stimulation emission depletion (STED) microscope.
This microscope provides very small scale images at extremely high resolution. Unlike other microscopes which cannot differentiate objects that are smaller than 200 nm, the STED can differentiate structures which are smaller than 60 nm. The microscope uses a combination of laser and fluorescent lights to view tiny objects.
According to Dr Jordan, the natural killer cells attach themselves to the virus infected cells at the immune synapse and release granules comprising of molecules. These molecules in turn kill the infected cells. However, before the molecules are released from the cells, they should pass through a thick protein network called the F-actin.
It was thought earlier that F-actin was not present in the immune synapse. With the use of the new microscope it has been found out that F-actin permeates the immune synapse and allows just enough space for the molecules to pass. Simultaneously F-actin helps the molecules to move towards the infected cells faster by actively interacting with them.
Dr. Jordan also added that natural killer cells will be studied further to determine how lytic granules move within the immunological synapse. These investigations are expected to aid scientists in formulating better treatments for diseases that affect the immune system by altering immune responses.
Source: www.chop.edu