Health Flash: 4.25.18
antibiotics hinder immune system
Doctors already recommend against taking antibiotics for viral infections because they are ineffective, and in a new study published in Cell Reports, investigators from Washington University School of Medicine suggest there may be a greater reason to avoid taking the drugs unnecessarily. Researchers found that taking antibiotics increases susceptibility to viral infection in mice. Many viral infections cause mild to severe diseases, and the study wanted to determine whether antibiotic use could explain why some people get sick and others do not. A healthy immune system depends on a healthy gut microbiome, but antibiotics kill off members of the normal bacterial community.
The researchers reasoned that antibiotics compromise the immune system and leave the body unprepared to fight off infection. To test this hypothesis, mice were given a placebo or a cocktail of four antibiotics for two weeks before being infected with West Nile virus. About 80 percent of the mice who received no antibiotics survived the infection, as opposed to 20 percent of the antibiotic-treated ones. The mice given antibiotics were found to have lower numbers of immune cells known as killer T cells, which recognize the invading virus and play a critical role in controlling the infection.
protein structure mapped
According to a recent paper published in Nature Communications, Saint Louis University researchers have determined the structure of a key protein involved in the body’s inflammatory response. The enzyme calcium independent phospholipase A2 beta produces signals after injury to initiate the inflammatory response, and the team wanted to learn how it activates, breaks down substrates and shuts down. According to Dr. Sergey Korolev, the protein has a role in various areas of study such as the cardiovascular system, insulin production and neurodegenerative issues. Since the protein plays different roles in different tissues and parts of the cell, past researchers have had difficulty understanding how it operates. The SLU research team used X-ray crystallography to grow a crystal of the protein and shoot X-ray beams through it. The diffraction pattern was analyzed to detail the three-dimensional structure. The team found that the protein’s structure was different from what previously had been predicted, which could make it easier to develop drugs to inhibit the protein and serve as potential new therapies for cardiovascular disease, diabetes, cancer metastasis and neurodegenerative disease.
new sepsis treatment
Sepsis develops when an infection triggers an overwhelming immune response. Standard treatment involves a high dose of antibiotics that fight the infection but often don’t address the disrupted immune system. Researchers at Washington University School of Medicine have found that a drug that boosts the immune system may treat the condition. Their trial involved 27 sepsis patients. Seventeen were treated with a drug made from interleukin-7 (IL-7), which enhances the proliferation and survival of two types of immune cells that work to recruit other cells to fight severe infections.
The remaining patients received standard sepsis treatment. The researchers showed that IL-7 boosts adaptive immunity and could improve patient survival. “We know that 40 percent of patients die in the 30- to 90-day period after the initial septic infection,” says senior investigator Dr. Richard Hotchkiss. “Their bodies can’t fight secondary infections that develop later on because their immune systems are shot. We think this approach could make a big difference.” Hotchkiss and his team are planning a larger trial to determine if IL-7 can improve sepsis survival rates.