TWiV 420: Orthogonal vectors

The TWiV gurus describe how to use an orthogonal translation system to produce infectious but replication-incompetent influenza vaccines.

You can find TWiV #420 at microbe.tv/twiv, or listen below.

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Fake news and fake science

The Cow PockIn a recent editorial, the New York Times wrote about ‘the breakdown of a shared public reality built upon widely accepted facts’. As a scientist, I am appalled by the disdain for facts shown by many in this country, including the President-Elect. Unfortunately, science is not without its share of fake information.

The Times argues that at one time, nearly everyone had a unified source of news – the proverbial Walter Cronkite. Social media and the internet changed all that, allowing people to have their own sources of news, whether they be real or fake. The web developers in Macedonia who are paid $30,000 a month to spew out fake news are just part of the problem.

The goal of science is to discover how our world works. It’s about finding facts, not fake answers. Yet fake science has always been with us. Not long after Edward Jenner demonstrated vaccination against smallpox using pustules from milkmaids with cowpox, skeptics thought that this process would lead to the growth of cow-parts from the inoculated areas (see illustration). To this day anti-vaxers spew fake science which they claim shows that vaccines are not safe, do not work, or cause autism.

Fake science does not stop with anti-vaxers. There are people who deny climate change (including our President-Elect), despite easily accessible data showing that the trend is real. There are people who, bafflingly, claim that HIV does not cause AIDS, or that Zika virus does not cause birth defects, or that genetically modified plants will cause untold harm to people who consume them. The list of fake science goes on and on. The situation is appalling to any scientist who examines the data and finds clear proof that HIV does cause AIDS, and that Zika virus does cause birth defects.

There is also fake science perpetrated by scientists – those who publish fake data to advance their career. There are so many examples of such science fraud that there is a website to document the inevitable retractions – called RetractionWatch, of course. I find the existence of such a site lamentable.

That fake news can play such a large part in the operation of our society was something I only recognized recently. My initial reaction, as a scientist, was outrage that anyone would want to believe in, and adopt, lies. But this is a naive reaction, not only because bad behavior should always be expected of some humans, but because fake science has surrounded me for my entire career.

Nevertheless, I am a scientist who looks for the truth, and I simply cannot tolerate fabrication, whether in science or politics or in any field.

I don’t know how to solve the fake news and fake science problems. But the Times has a suggestion:

Without a Walter Cronkite to guide them, how can Americans find the path back to a culture of commonly accepted facts, the building blocks of democracy? A president and other politicians who care about the truth could certainly help them along. In the absence of leaders like that, media organizations that report fact without regard for partisanship, and citizens who think for themselves, will need to light the way.

I’m not sure that today’s profit-driven media organizations are the answer to the fake news problem. But I’ve always felt that scientists can help counter fake science. We all need to communicate in some way so that the public sees us as a single voice, advocating the huge role that science plays in our lives. That’s why here at virology blog, and over at MicrobeTV, you’ll always find real science.

TWiV 419: The selfless gene

The TWiVrific gang reveal how integration of a virophage into the nuclear genome of a marine protozoan enhances host survival after infection with a giant virus.

You can find TWiV #419 at microbe.tv/twiv, or listen below.

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Altruistic viruses

Cafeteria roenbergensisVirophages (the name means virus eater) were first discovered to replicate only in amoeba infected with the giant mimiviruses or mamaviruses.  They reduce yields of the giant viruses, and also decrease killing of the host cell. Another virophage called mavirus has been found to integrate into the genome of its host and behaves like an inducible antiviral defense system (link to paper).

The host cell of the virophage mavirus is Cafeteria roenbergensis, Cro (pictured), a marine phagotropic flagellate, that is infected with the giant virus CroV (Cafeteria roenbergensis virus). When Cro cells are infected with a mixture of mavirus and CroV, the virophage integrates into the host cell genome. There it remains silent; the cells survive, and no virophage particles are produced. Such cells can be called lysogens, a name applied to bacteria containing integrated bacteriophage genomes, or prophages.

How does the mavirus genome integrate into the Cro cell? The viral genome encodes an integrase, an enzyme that cuts host DNA and inserts a copy of the viral genome. Retroviruses achieve the same feat via an integrase.

When Cro-mavirus lysogens are infected with CroV, the integrated mavirus genome is transcribed to RNA, the viral DNA replicates, and new virus particles are formed. These virophages inhibit the replication of CroV by 100-1000 fold. As a consequence, the host cell population survives.

These findings suggest that the virophage mavirus is altruistic: induction of the integrated genome leads to killing of the host cell, but other members of the cell population are protected. Altruism is not unknown in Nature, but how it evolved is an intriguing question.

All this work was done in a laboratory. It will be necessary to determine if integration of mavirus into Cro cells in the wild has any influence on the ecology of these organisms.

TWiV 418: Of mice and MERS

The TWiVsters describe a new animal model for MERS coronavirus-induced acute respiratory distress syndrome, produced by CRISPR/Cas9 editing of the mouse gene encoding an ortholog of the virus receptor.

You can find TWiV #418 at microbe.tv/twiv, or listen below.

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TWiM 140: Small town, big science

At the Hamilton, Montana Performing Arts Center, Vincent speaks with three local high school graduates and two high school teachers about how Rocky Mountain Laboratories influenced school science programs and opened up career opportunities.

You can find TWiM #140 at microbe.tv/twim, or listen and watch here.

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TWiV Special: Gary Nabel on World AIDS Day 2016

For World AIDS Day 2016, Vincent speaks with Gary Nabel, Chief Scientific Officer at Sanofi and former Director of the Vaccine Research Institute of NIAID, about his career and his work on HIV vaccines.

You can find this TWiV Special at microbe.tv/twiv, or listen and watch here.

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TWiV 417: O is the loneliest letter

The Fellowship of the Virus trace the early history of HIV in North America, based on genome sequences obtained from late 1970s archival sera, which also reveal that Gaetan Dugas was not Patient Zero.

You can find TWiV #417 at microbe.tv/twiv, or listen below.

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TWiV 416: Scattered seeds dormant

The multi-dimensional TWiV-brane brings you the entries in the haiku/limerick contest, and explain how a giant virus infects a host within another host (it has to do with predators!).

You can find TWiV #416 at microbe.tv/twiv, or listen below.

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Dugas was not AIDS Patient Zero

aids_index_case_graphThe popular history of HIV/AIDS describes a man known as Patient Zero, a sexually active flight attendant who traveled the globe and initiated the AIDS epidemic in North America. A new analysis of the viral genome recovered from his serum and that of other patients in the 1970s proves beyond a doubt that he was not Patient Zero (link to paper).

In a heroic effort, thousands of archived serum samples originally collected from cohorts of men who have sex with men in the 1970s in New York and San Francisco, were examined for the presence of HIV by western blot analysis. A total of 83 samples were found to be HIV positive and subjected to deep sequencing, but the viral RNA was degraded and present only in short pieces. To overcome this problem, many DNA primers were used to amplify short RNA fragments by PCR in a procedure colorfully called ‘jackhammering’. The impressive result is that complete HIV-1 coding sequences were obtained from 8 samples: 3 from San Francisco and 5 from New York City.

Analysis of the HIV genome sequences, and comparison with earlier and later data revealed that the virus likely traveled from Africa to the Caribbean around 1967, and from there to New York City in 1971. These results disprove previous ideas that HIV arrived in the Caribbean from the US.

Sequence analysis also reveals that New York City was a hub of early diversification of HIV, and that the epidemic was already mature and genetically diverse by the late 1970s. There appears to have been a single introduction of HIV into San Francisco from New York City in 1976. From those two cities the virus spread elsewhere in the US and overseas.

It has been suggested that a sexually active flight attendant, identified as Gaetan Dugas by Randy Shilts in his book And the Band Played On, was the source of the North American AIDS epidemic. Although at least one study years ago concluded that he was not the first case, this belief persists. Sequencing of HIV from this patient’s serum revealed that he was certainly not the first person in North America infected with this line of HIV-1 (Group M, subtype B) .

A historical reconstruction of the early days of AIDS in the US reveals how Dugas earned the label ‘Patient Zero’. CDC investigators who were studying a sexual network of 40 gay men placed one man at its center, whom they called ‘Patient O’, standing for ‘outside of California’ because he was Canadian (pictured; image credit). Upon publication of this work, the ‘O’ was misinterpreted as a zero and so began the belief that he was the origin of the AIDS outbreak in North America.