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Winter the Llama – Can She Save Humanity?

By Shlomo Maital

Winter the Llama

 OK, so I can see how an MIT scientist can save the world.

   But a llama? Winter the llama?

   So here’s the story, by Jillian Kramer, writing in the New York Times today:

   “Winter is a 4-year-old chocolate-colored llama with spindly legs, ever-so-slightly askew ears and envy-inducing eyelashes. Some scientists hope she might be an important figure in the fight against the novel coronavirus.   She is not a superpowered camelid. Winter was simply the lucky llama chosen by researchers in Belgium, where she lives, to participate in a series of virus studies involving both SARS and MERS. Finding that her antibodies staved off those infections, the scientists posited that those same antibodies could also neutralize the new virus that causes Covid-19. They were right, and published their results Tuesday in the journal Cell.

       “Scientists have long turned to llamas for antibody research. In the last decade, for example, scientists have used llamas’ antibodies in H.I.V. and influenza research, finding promising therapies for both viruses.   Humans produce only one kind of antibody, made of two types of protein chains — heavy and light — that together form a Y shape. Heavy-chain proteins span the entire Y, while light-chain proteins touch only the Y’s arms. Llamas, on the other hand, produce two types of antibodies. One of those antibodies is similar in size and constitution to human antibodies. But the other is much smaller; it’s only about 25 percent the size of human antibodies. The llama’s antibody still forms a Y, but its arms are much shorter because it doesn’t have any light-chain proteins.”

“This more diminutive antibody can access tinier pockets and crevices on spike proteins — the proteins that allow viruses like the novel coronavirus to break into host cells and infect us — that human antibodies cannot. That can make it more effective in neutralizing viruses.”

How an Overnight COVID-19 Test Took 35 Years to Invent

By Shlomo Maital

Dr. Fang  Zhang

   As Darwin observed, when he was praised for his breakthrough: Scientists stand on the shoulders of giants. Now, a new genetic test for COVID-19 may be as quick, simple and cheap as a self-administered pregnancy test, with two lines on a slip of paper.

     Here is the story. Let’s begin by noting that the hero is ethnic Chinese, Fang Zhang, a researcher at MIT’s Broad Institute. With massive anti-Asian and anti-Semitic hatred filling the Internet, it is fitting the hero should be named Zheng.

     Chapter One. Some 35 years ago, a biologist named Kary Mullis invented PCR. Polymerase chain reaction (PCR) is a method used in molecular biology to rapidly make millions to billions of copies of a specific DNA sample. This allows scientists to take a very small sample of DNA and amplify it to a large enough amount to study in detail. For example, suppose you are looking for the presence of the genetic material of a virus. You take a swab, use PCR, make millions of copies of the stuff, and then it becomes easy to detect it in a test tube.   Mullis won the Nobel Prize for this discovery, in 1993.

     Chapter Two. CRISPR: Clustered Regularly Interspaced Short Palindromic Repeats. (A palindrome is a word or phrase that reads the same forwards and backwards, e.g. a man a plan acanal panama. ) The discovery of clustered DNA repeats occurred independently in three parts of the world. The first description of what would later be called CRISPR is from Osaka University researcher Yoshizumi Ishino and his colleagues in 1987.

     Say you want to modify a specific gene – snip it out, replace it, test it, etc. First, you ‘tag’ it with a molecule (like putting a big road sign, “HERE I AM!”, on it). Second, you attach an enzyme to the tag. The enzyme cuts the CAN right at that spot!   You can then replace the faulty or offending gene with a different improved one.

     Chapter Three. MIT. Dr. Zhang and other researchers have retooled CRISP-R. They use it not to snip out a gene, but to give a signal that the enzyme has reached its target – a piece of genetic material that is unique to COVID-19. When this happens, a screaming signal is emitted, say, figuratively, a bright Day-Glo sign saying, Yikes, it’s the novel coronavirus!  

       Chapter Four. Translate the complex lab procedure to a simple cheap test. Take samples from a person’s throat and nose. Put it into a test tube with chemicals that tear open viruses.   Use an eye dropper to put some of the liquid into a second test tube containing CRISPR. Put the test tube in hot water, at 140 degrees F. (80 C.). Stick a piece of paper into the tube. If two lines appear: COVID-19 is present.

     The test worked on 12 patients, and can be simplified greatly and produced at $6 per test. This may enable massive population-wide testing, that can help open societies and economies without a massive second-wave of plague.

       Classic scientific breakthrough: 35 years, and an overnight breakthrough!




Blog entries written by Prof. Shlomo Maital

Shlomo Maital
May 2020