SUNDAY, JUNE 24, 2018

Researchers discover a key to understanding the human immune system

A team of Whitehead Institute researchers recently discovered how T follicular helper cells function in the body, a key to understanding the human immune system.

The human immune system is composed of many different processes, all of which scientists still do not entirely understand. What scientists knew previously was that if a foreign virus or bacteria invaded the body, germinal centers in the lymph nodes produced B-cell antibodies, hopefully a perfect match for fighting the infection.

The body has multiple GCs in a single lymph node, with each GC containing an exclusive batch of B cells. As the infection progresses, some of the B cells fail to make an effective antibody and are eliminated. Very few GCs make an effective antibody to fight off infection, but those that do release the antibody and it goes to work to fight off the foreign pathogen.

Scientists previously observed that Tfh cells select which antibodies made the cut and which ones did not, but they did not know how the cells worked. This knowledge is a key component of understanding the immune system and developing effective vaccines.

Whitehead Fellow Gabriel Victoria and his team, for the first time, were able to capture the process by which the Tfh cells function. The finding was published in the August 9 issue of Science.

The team of researchers used fluorescence microscopy to follow the Tfh cells and noticed that the cells move from GC to GC, unlike the B cells that remain stationary. The process gives scientists clues to understand how the body deals with mutating infections and how to design more effective vaccines to fight off disease.

"We are slowly deciphering the rules governing antibody evolution in the germinal center," Victoria said. "This will help inform vaccine design, especially for rapidly mutating viruses like HIV. It may be that manipulating the germinal center will be necessary to produce effective vaccines."