Rotavirus, a major cause of early childhood diarrhea, could have a lot to tell drug developers about how to deliver their products into cells.
Rotavirus doesn’t have an outer membrane, so it’s had to evolve a special system to infect cells. “Viruses with a membrane, like flu or HIV, can simply fuse that membrane with the membrane of the target cell and dump their contents inside the cell,” says Stephen Harrison, PhD, chief of the Laboratory of Molecular Medicine at Boston Children’s Hospital.
Rotavirus does something different, Harrison’s lab has found. First, each virion attaches itself to the cell membrane and wraps itself inside it. Next, its outer proteins, VP4 (the red spikes above) and VP7 (in yellow), disrupt that membrane — and are stripped off in a matter of seconds.
“If you will, they’re the booster the rocket has to shed so the payload can continue,” says Harrison. …
Today, stories of polio may seem like echoes from far-away history to those born after 1979, the year that polio was eradicated in the U.S. Since then, it has been customary for children to receive four doses of the polio vaccine to protect them from ever contracting the terrifying disease also known as “infantile paralysis.”
Polio, however, still afflicts people in some areas of the world today. It causes muscle wasting and — in the most severe cases — can completely rob a person of his or her ability to move or breathe, resulting in death.
In the U.S., research efforts to create a polio vaccine lasted much of the 20th century. Although the virus was thriving and spreading among people, researchers repeatedly failed at getting poliovirus to survive in culture.
Then, one of the most crucial breaks in the fight against polio occurred in a Boston Children’s Hospital laboratory in 1949, during the heyday of polio outbreaks. …
Residents of Arkansas have been under siege by a viral threat that is typically preventable through vaccination. Since August 2016, more than 2,000 people have been stricken with mumps, an infection of the major salivary glands that causes uncomfortable facial swelling.
The disease is highly contagious but can usually be prevented by making sure that children (or adults) have had two doses of the measles-mumps-rubella (MMR) vaccine. But strangely, about 70 percent of people in Arkansas who got sick with mumps reported that they had received their two doses of the MMR vaccine.
As you may have heard, Brazil is facing a startling outbreak of microcephaly, a rare condition in which a child is born with a head and brain that are much smaller than normal. Microcephaly is almost always associated with neurologic impairment and can be life-threatening.
The epidemic has been linked to an influx of the mosquito-borne virus Zika, first detected in Brazil last April. This past Friday, January 16, the Centers for Disease Control and Prevention issued travel warnings advising pregnant women to avoid visiting El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela and Puerto Rico. And over the weekend, the first U.S. case of microcephaly linked to Zika reportedly surfaced in Hawaii.
If you follow cancer biology, then you’ve probably heard of ubiquitin before. Ubiquitin tags a cell’s damaged or used proteins and guides them to a cellular machine called the proteasome, which breaks them down and recycles their amino acids. Proteasome-blocking drugs like Velcade® that go after that recycling pathway in cancer cells have been very successful at treating two blood cancers—multiple myeloma and mantle cell lymphoma—and may hold promise for other cancers as well.
Less well known, however, is the fact that ubiquitin helps normal, healthy cells raise an alarm when viruses attack. Ubiquitin works with a protein called RIG-I, part of a complex signaling pathway that detects viral RNA and triggers an innate antiviral immune response.
Our immune system has immense powers of observation. It needs to in order to fend off the millions of bacteria, viruses, fungi, you name it, that we get exposed to every day.
I’m not talking about antibodies and T cells—parts of the immune system’s adaptive arm, which is fine-tuned to recognize a specific virus or bacterium. Rather, I’m talking about pattern recognition proteins—biological sensors capable of recognizing features and structures that only bacteria or viruses have. These make up the immune system’s innate arm, which essentially primes the body to attack anything that looks remotely like it doesn’t belong.
For instance, our cells carry sensors that can detect double-stranded RNA (dsRNA), which certain kinds of viruses use to encode their genome—like the rotavirus, which causes severe diarrhea in infants and small children. Our genome, by contrast, is encoded in DNA, and the RNA we make is single-stranded; if there’s dsRNA present, it means there’s a virus around.