Scientists have uncovered the mechanism by which our innate immunity encapsulates bacteria. The protein GBP1 is an essential element of our body’s natural defense system against harmful microorganisms. This protein can surround bacteria and parasites with a protective coat, but the exact process behind this has been a mystery until recently. Researchers from Delft University of Technology have now shed light on how GBP1 functions, and their findings could pave the way for new treatments for individuals with compromised immune systems, as revealed in a study published in Nature Structural & Molecular Biology.
The protein GBP1 is an essential element of our body’s natural defense system against harmful microorganisms. This protein can surround bacteria and parasites with a protective coat, but the exact process behind this has been a mystery until recently. Researchers from Delft University of Technology have now shed light on how GBP1 functions, and their findings could pave the way for new treatments for individuals with compromised immune systems, as revealed in a study published in Nature Structural & Molecular Biology.
Guanylate Binding Proteins (GBPs) are crucial to our body’s innate immune response, according to biophysicist Arjen Jakobi. “GBPs act as the body’s first line of defense against various infectious illnesses caused by bacteria and parasites. These include dysentery, typhoid fever from Salmonella, and tuberculosis. Additionally, the protein is significantly involved in the sexually transmitted infection chlamydia and toxoplasmosis, which can pose serious risks during pregnancy and to unborn babies.”
Encasing Bacteria
In their study, Jakobi and his team explain for the first time how the innate immune system combats bacteria using GBP1 proteins. “The protein encapsulates bacteria, forming a kind of protective coat around them,” explains Tanja Kuhm, a PhD candidate in Jakobi’s group and the main author of the study. “As this coat tightens, it ruptures the bacteria’s membrane—the essential barrier that protects the invader—allowing immune cells to eliminate the infection.”
Understanding the Defense Mechanism
To decipher the defense mechanism of GBPs, the researchers investigated how GBP1 proteins interact with bacterial membranes using a cryogenic electron microscope. This high-resolution imaging allowed them to observe the process at a molecular level. Jakobi states: “We were able to capture a detailed three-dimensional representation of how the protein coat develops. Combining this with biophysical experiments from Sander Tans’ research group at AMOLF, which allowed for precise manipulation of the system, we successfully decoded the antibacterial function’s mechanism.”
Implications for Treatments
Jakobi believes this research advances our understanding of how the body can fight off bacterial infections. “If we can gain a deeper understanding of this process, we may be able to specifically activate or inhibit the involved proteins using medications, which could lead to faster eradication of certain infections.”
