Month: May 2018

The word “chikungunya” (chik-en-gun-ye) comes from Kimakonde, the language spoken by the Makonde people in southeast Tanzania and northern Mozambique. It means “to become contorted,” because that’s what happens to people who get infected. The contortion is a result of severe and debilitating joint pain. Chikungunya was first identified in Tanzania in 1952, but by now cases have been reported around the globe. There is no cure; the CDC recommends that “travelers can protect themselves by preventing mosquito bites.”

Chikungunya is only one of a family of viruses transmitted through mosquitoes for which we have no targeted treatment. This may partially be due to the fact that we didn’t know how they get into our cells. But for chikungunya, we’ve just found one of the proteins responsible.

Identification via deletion

Researchers used the CRISPR-Cas9 DNA editing system to delete more than twenty-thousand mouse genes—a different one in each cell in a dish. Then they added chikungunya to the dish, isolated the cells that didn’t get infected, and looked to see which gene they lacked. This gene would encode a protein required for viral infection, since infection didn’t happen in its absence.

In this way they found a gene encoding an adhesion molecule that was required for chikungunya to infect these cells. Similar genes are found in other mammals, birds, and amphibians, and they are homologous to an adhesion molecule used as an entry receptor for another class of viruses. This particular gene goes by the catchy name of Mxra8. Interestingly, no similar protein is found in mosquitoes.

Since the scientists were using a special “cell-culture-adapted vaccine strain” of chikungunya, they repeated their experiment with an Asian strain and a West African strain of the virus. Neither could infect cells lacking Mxra8. Nor could some other viruses in the same family (called arthritogenic alphaviruses): Ross River virus, Mayaro virus, Barmah Forest virus, and O’nyong nyong virus. However, an East/Central/South African strain of chikungunya and a few others in the same family did not seem to be quite as dependent on Mxra8.

In human cells, too

Results were not limited to mouse cells in petri dishes. They also held true in human cells of the various types infected by chikungunya, like fibroblasts, osteoblasts, chondrocytes, and skeletal muscle cells. Humans have four versions of Mxra8, and knocking out each of them diminished the ability of chikungunya to infect the cells. Mice treated with antibodies to Mxra8 had reduced levels of infection—the antibodies bind to the Mxra8 molecules on the surface of the mouse cells, so the virus can’t access it to get in.

Mxra8 doesn’t seem to be required for viral replication, only for viral entry into cells. Further experiments that home in on exactly where the virus binds to it could hopefully lead to the development or identification of small molecules that block the interaction, barring the virus from getting into the cells and preventing infection and disease.

Nature, 2018. DOI: 10.1038/s41586-018-0121-3 (About DOIs).

Hackers, possibly working for an advanced nation, have infected more than 500,000 home and small-office routers around the world with malware that can be used to collect communications, launch attacks on others, and permanently destroy the devices with a single command, researchers at Cisco warned Wednesday.

VPNFilter—as the modular, multi-stage malware has been dubbed—works on consumer-grade routers made by Linksys, MikroTik, Netgear, TP-Link, and on network-attached storage devices from QNAP, Cisco researchers said in an advisory. It’s one of the few pieces of Internet-of-things malware that can survive a reboot. Infections in at least 54 countries have been slowly building since at least 2016, and Cisco researchers have been monitoring them for several months. The attacks drastically ramped up during the past three weeks, including two major assaults on devices located in Ukraine. The spike, combined with the advanced capabilities of the malware, prompted Cisco to release Wednesday’s report before the research is completed.

Expansive platform serving multiple needs

“We assess with high confidence that this malware is used to create an expansive, hard-to-attribute infrastructure that can be used to serve multiple operational needs of the threat actor,” Cisco researcher William Largent wrote. “Since the affected devices are legitimately owned by businesses or individuals, malicious activity conducted from infected devices could be mistakenly attributed to those who were actually victims of the actor. The capabilities built into the various stages and plugins of the malware are extremely versatile and would enable the actor to take advantage of devices in multiple ways.”

Sniffers included with VPNFilter collect login credentials and possibly supervisory control and data acquisition traffic. The malware also makes it possible for the attackers to obfuscate themselves by using the devices as nondescript points for connecting to final targets. The researchers also said they uncovered evidence that at least some of the malware includes a command to permanently disable the device, a capability that would allow the attackers to disable Internet access for hundreds of thousands of people worldwide or in a focused region, depending on a particular objective.

“In most cases, this action is unrecoverable by most victims, requiring technical capabilities, know-how, or tools that no consumer should be expected to have,” Cisco’s report stated. “We are deeply concerned about this capability, and it is one of the driving reasons we have been quietly researching this threat over the past few months.”

Comcast today said it is preparing an offer to buy major portions of 21st Century Fox, which would give it majority control of Hulu and other media properties.

Walt Disney Company already has a $52.4 billion all-stock deal to buy the 21st Century Fox properties. But Comcast was rumored to be lining up $60 billion in financing in order to make a hostile bid for the Fox assets, and Comcast’s announcement today confirms it.

Comcast “is considering, and is in advanced stages of preparing, an offer for the businesses that Fox has agreed to sell to Disney,” Comcast’s announcement said. Comcast is working on the offer in preparation for shareholder meetings in which the Disney/Fox deal will be considered.

The Fox properties for sale do not include assets such as the Fox News Channel, Fox Business Network, and Fox Broadcasting Company. Those properties would be spun off into a company being referred to as “New Fox,” and Comcast would acquire 21st Century Fox after the spinoff.

The Fox sale to either Disney or Comcast would include 21st Century Fox’s film and television studios; cable entertainment networks; the Fox Sports Regional Networks; and international properties including Star in India and Fox’s 39-percent ownership of Sky across Europe.

Comcast seeks control of Hulu

The sale would also include Fox’s 30-percent stake in Hulu, the popular online video streaming service. Comcast already owns 30 percent of Hulu, so a deal with Fox would give the nation’s largest cable company majority control over the online video provider.

Comcast said its offer for Fox “would be at least as favorable to Fox shareholders as the Disney offer.”

“While no final decision has been made, at this point the work to finance the all-cash offer and make the key regulatory filings is well advanced,” Comcast also said.

Separately, Comcast is trying to buy Sky, the British pay-TV company. After an initial review, a British government official said the government is unlikely to challenge a Comcast/Sky merger.

In the US, a Comcast/Fox deal would face scrutiny from the Department of Justice, which is trying to stop AT&T from buying Time Warner Inc. A judge is expected to rule on the AT&T/Time Warner merger by June 12, and Comcast was reportedly waiting for the outcome of that trial before proceeding with a bid for Fox assets.

“Comcast made the announcement Wednesday about its preparations because its executives were worried that Fox and Disney might rush a shareholder vote before the decision on the AT&T/Time Warner deal came down, according to people close to Comcast,” The Wall Street Journal reported today.

Comcast already owns NBCUniversal thanks to a 2011 acquisition; it was the NBC purchase that gave Comcast its minority stake in Hulu. US regulators imposed merger conditions that prevent Comcast from exercising operational control over Hulu, but those conditions will expire on September 1 of this year.