Johns Hopkins Researchers Use Primary Immunodeficiencies to Discover New Info About Immune System Cells

 

The COVID era emphasized the importance of maintaining a strong immune system. But what about people who are less fortunate?

Johns Hopkins researchers recently announced some good news for those who have an immune system disease. According to an article in Science Daily, a team of Johns Hopkins researchers has new information about the response of immune system cells to bacteria and viruses that cause disease.

The researchers concentrated on three inherited primary immunodeficiency syndromes that are linked to mutations in the CARD11 gene.

These syndromes prevent the body’s defense against pathogens and put people at risk for upper respiratory infections, fungal infections, and pneumonia. Environmental and food allergies are also a concern.

On the Attack

Antibodies are produced by B cells that attack viruses, bacteria, and toxins. When the body’s cells become cancerous or overcome with viruses, T cells go on the attack.

The researchers have now discovered the critical step in the B and T cells’ molecular circuitry that prompts a defense against foreign invaders.

They believe that their discovery will eventually explain why there are different reactions to infections between individuals or even between populations.

The CARD11 Gene

CARD11 sends out instructions that produce a protein cluster called an oligomer. The cluster is associated with the functioning of cells in the immune system such as B cells and T cells (lymphocytes).

Mutations in the CARD11 gene cause the oligomer to override the protective response. One bad copy can cause a disruption in the entire cluster.

The team used engineered T cells grown in the laboratory that were functioning and also used CARD11 genes that were mutated. The focus was on protein levels. It was also of interest to see if cells became activated and could send signals to other immune cells.

The researchers discovered that CARD11 mutations affect the way protein clusters open and then bind to other proteins. This occurs as a chain reaction that informs T cells of nearby pathogens.

On the other hand, if a mutated CARD11 gene is closed, a favorable immune response is unlikely to occur because the cluster cannot signal the other proteins.

Another experiment found that even if the T cells were open, the CARD11 mutation could still obstruct the pathway.

Dr. Joel Pomerantz at Johns Hopkins Medical School commented that these findings provide insight into various immune responses. He believes that eventually, they will fully understand immune cell fundamentals and why some people are at higher risk than others when exposed to pathogens.