Wellcome-funded researchers have identified four new types of blood cells in human body. These new type of blood cells white blood cells called dendritic cells and monocytes. The cells play a vital role in the body’s immune system and help our bodies to fight off invaders.

To do so, scientists used a new genetic technique to analyze gene expression patterns in individual human blood cells. But the exact functions of the newly discovered units remain a mystery.

Previously scientists found the new type of blood cells analyzing the protein markings on the surface of cells. But, this new technique frequently overlooks hard to identify or rare types of blood cells. In addition, it is much more powerful and can reveal previously unrecognized and rare cell types that would be otherwise difficult to find.

Dr. Divya Shah, from Wellcome Trust, said, “Two important white blood cell types in our bodies help defend us from infection – dendritic cells and monocytes.”

“In this study, scientists have used cutting-edge technologies to find that there are much more types of cells than we originally thought.”

“The next step is to find out what each of these cell types does in our immune system, both when we’re healthy and during disease.”

The subtypes of dendritic cells are the units that raise the alarm during an infection. When these cells come across an invader, it takes in a fragment of that invader and displays it on its cell surface.

Another type of blood cell Monocytes, that is the largest of all white blood cells. Monocytes typically turn into macrophages, the cells that surround and engulf invading particles. The cells eat invaders and digest them to stop them from multiplying and causing harm in the body.