Infections in the lower urinary tract rarely migrate to the kidneys, but the precise mechanism that the human body employs to keep the twin organs disease-free has remained a medical mystery—until now.
Earlier reasearch showed that the kidney can sense infections in the bladder and protect itself from bladder infections by flooding the bladder with an antibacterial protein. Also it is well known that the kidney continually releases antimicrobial substances that help prevent the growth of bacteria in the urinary tract, less is known about how the kidney responds after an infection takes hold.
Now, a multidisciplinary team at Cambridge University in England solved the conundrum in an elegant series of experiments. Dr. Andrew P. Stewart and colleagues found that highly specialized biological structures called neutrophil extracellular traps—NETs—are pivotal in protecting the kidneys from infection.
NETs are sticky webs of wispy strands that quite literally serve as traps. They ensnare bacteria that attempt to migrate northward to the kidneys from the lower urinary tract. NETs add to an array of antimicrobial activities mounted by the body to beat back infection.
"These findings highlight the role of NETosis in preventing ascending infections in the urinary tract," Stewart, the study's lead author, wrote. He underscored that NETosis refers to the formation of NETs, which prevent any of the various species of bacteria—E. coli, Enterococcal faecalis, Proteus mirabilis, among others—from migrating upward from the bladder to the kidneys. The study focused on E. coli, the most common bacterial cause of UTIs.
The process of NETosis is another wonder of human biology. It reveals how the body, and more specifically, the immune system, creates structures to ensnare pathogens. The key entity in NETosis is the neutrophil, an immune cell, which is signaled to undergo a unique form of cell death.
To get a mental image of a NET, picture a spider's web—not the lacy geometric kind ornamented with dew drops, but the thicker, more heavily woven type found in attics. NETs are created from neutrophils, critically important cells of the immune system. The main difference between a spider's web and a NET is scale. The arachnids' webs are large and visible to the naked eye; a NET is infinitesimal and requires powerful microscopy.
To be clear, NETs don't stop UTIs from occurring, but they do stop them from spreading and wreaking havoc elsewhere in the urinary tract, the Cambridge team's research demonstrated.
Once infected, the kidneys are susceptible to a serious complication. But the rarity of it, the Cambridge team found, demonstrates that the body has antimicrobial strategies, NETosis being key, which helps confine bacteria to the bladder, keeping the kidneys infection free.
Earlier reasearch showed that the kidney can sense infections in the bladder and protect itself from bladder infections by flooding the bladder with an antibacterial protein. Also it is well known that the kidney continually releases antimicrobial substances that help prevent the growth of bacteria in the urinary tract, less is known about how the kidney responds after an infection takes hold.
Now, a multidisciplinary team at Cambridge University in England solved the conundrum in an elegant series of experiments. Dr. Andrew P. Stewart and colleagues found that highly specialized biological structures called neutrophil extracellular traps—NETs—are pivotal in protecting the kidneys from infection.
NETs are sticky webs of wispy strands that quite literally serve as traps. They ensnare bacteria that attempt to migrate northward to the kidneys from the lower urinary tract. NETs add to an array of antimicrobial activities mounted by the body to beat back infection.
"These findings highlight the role of NETosis in preventing ascending infections in the urinary tract," Stewart, the study's lead author, wrote. He underscored that NETosis refers to the formation of NETs, which prevent any of the various species of bacteria—E. coli, Enterococcal faecalis, Proteus mirabilis, among others—from migrating upward from the bladder to the kidneys. The study focused on E. coli, the most common bacterial cause of UTIs.
The process of NETosis is another wonder of human biology. It reveals how the body, and more specifically, the immune system, creates structures to ensnare pathogens. The key entity in NETosis is the neutrophil, an immune cell, which is signaled to undergo a unique form of cell death.
To get a mental image of a NET, picture a spider's web—not the lacy geometric kind ornamented with dew drops, but the thicker, more heavily woven type found in attics. NETs are created from neutrophils, critically important cells of the immune system. The main difference between a spider's web and a NET is scale. The arachnids' webs are large and visible to the naked eye; a NET is infinitesimal and requires powerful microscopy.
To be clear, NETs don't stop UTIs from occurring, but they do stop them from spreading and wreaking havoc elsewhere in the urinary tract, the Cambridge team's research demonstrated.
Once infected, the kidneys are susceptible to a serious complication. But the rarity of it, the Cambridge team found, demonstrates that the body has antimicrobial strategies, NETosis being key, which helps confine bacteria to the bladder, keeping the kidneys infection free.
