Peripheral Blood Lymphocytes
Encyclopedia
Peripheral blood lymphocytes (PBL) are mature lymphocyte
s that circulate in the blood
, rather than localising to organs (such as the spleen
or lymph nodes). They comprise T cells, NK cells and B cells.
Lymphocyte
A lymphocyte is a type of white blood cell in the vertebrate immune system.Under the microscope, lymphocytes can be divided into large lymphocytes and small lymphocytes. Large granular lymphocytes include natural killer cells...
s that circulate in the blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
, rather than localising to organs (such as the spleen
Spleen
The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...
or lymph nodes). They comprise T cells, NK cells and B cells.