Brussels, 01 Feb 2006
Researchers in the UK and Belgium have developed a new dye technique that has the potential to throw new light on the progression of many common cancers, HIV infection and what we can learn about the human body.
The lymphocyte (white blood cell) is the body's front-line defence against infection, and a better knowledge of the workings of the lymphocyte will give us a better understanding of the aetiology of various diseases, including cancer, and especially HIV - which targets the lymphocyte specifically - and leukaemia.
The team from the department of immunology, Imperial College London, has published its findings in the Proceeding of the Royal Society. In sheep experiments, the researchers were able to stain B lymphocytes using a dye known as carboxyfluorescein diacetata succinimidyl ester (or more succinctly, CFSE). This dye stains all the host's lymphocytes. The researchers than tested the blood regularly over the following 11 weeks to see what had happened to those lymphocytes.
In the past, labels such as BrdU and deuterated glucose have been used in the lab to monitor the progress of lymphocytes in diseases such as HIV and leukaemia. The problem with those older labels is that they attach themselves to live DNA, and typically only show up when the cell is dividing. This has left the majority of the lymphocyte life-cycle hidden.
To accurately measure the rate of cell death, as well as division and proliferation throughout the human body, another technique has been sought for some time. This new CFSE method stains all the cells it comes into contact with, and when a cell divides, the stain is divided between the two new cells.
The majority of the results will be published at a later date, but already a new discovery has been made: 'During the first few days post-labelling the majority of labelled cell loss in not due to cell death as is often assumed but the exit of unlabelled cells from the spleen,' reads the paper.
The researchers believe that a combination of CFSE and some of the older forms of labelling will enable researchers to learn a little more about the life of the lymphocyte. CFSE labelling appears to favour poorly circulating lymphocytes, while the older forms of labelling favour cells in lymphoid tissue. 'This work opens the way for utilising CFSE in the physiological setting to estimate lymphocyte kinetics in situ,' claim the researchers.