Can studying bat’s immunity help stop the epidemics?
Can CoVID-19 be a direct descendant of SARS-CoV-2? Relating fragments with ancestor sequences is difficult
The virus that causes COVID-19 probably shared an ancestor with bat coronaviruses more recently than scientists had thought. Researchers say that it is not possible to find the direct descendant of SARS-CoV-2.
It is a clever approach. “It gives you the purest signal of evolutionary time.” He points out that some fragments were short, which makes them less reliable, as there are only a limited number of nucleotides to compare.
Bats, infectious diseases and their research: a collaborative effort of Lin-fa Wang, a virologist, and an immunologist
Colonies are expensive to establish and maintain; bats have longer pregnancies and fewer pups than the standard laboratory mouse. Only a handful of the more than 1,450 species of bat have been bred in research colonies around the world. The big brown bats are from Germany, Wang’s cave nectar bats are from Colorado, and Egyptian fruit bats are from Germany. The colonies have no horseshoe bats that are coronaviruses-hosting. “People have tried and failed,” to breed those bats, probably because researchers don’t know enough about their roosting preferences, says Aaron Irving, an infectious-diseases researcher at Zhejiang University in Haining, China.
The colony was set up by Lin-fa Wang, a virologist at Duke–NUS Medical School to create a controlled setting for studying bat biology, including the inner workings of their immune system.
Since the emergence of the disease,Wang has become more crowded in his research niche. Attendance at talks and conferences about bats is rising — at one symposium hosted last year in the United States, there were 30% more participants compared with the same event organized before the pandemic — and funders are ploughing money into studies of bats and infectious diseases: in 2021, for instance, both China and the United States announced specific funding pots for research into bats and viruses.
“There are going to be some huge steps forward in the next two or three years in terms of bat virology and bat immunology,” says Tony Schountz, an immunologist at Colorado State University in Fort Collins.
“The colony has given us everything we wanted,” says Wang. His office is adorned with souvenirs collected over the years — a ‘batman’ keychain, a bat-printed mug, resin-encased bat specimens, framed drawings of bats.
Researchers find a lot to puzzle over in bats. They are “super cool animals” says Zwaka. They are the only mammals to have evolved flight, and they use sound waves to locate objects in the dark. They have long lives because of their small size, and have a low incidence of cancer.
In cell experiments, they found that the rhinolophid and hipposiderid versions of the protein lacked an amino acid found in most other mammals. The change seemed to keep it from leaving cells, and probably prevented the protein from triggering an inflammatory response. Such proteins could hold important clues for how bats live with deadly viruses and could inspire therapies in people, says Irving.
Source: https://www.nature.com/articles/d41586-023-00791-x
Viruses and stem cells from a dam in Cádiz, Spain, reveal the origins of coronavirus genomes
Some of these questions took Javier Juste to an abandoned dam in Cádiz, Spain, one night in May 2020. He went to the dam to take two horseshoe bats from their roost.
The researchers now plan to use the stem cells to generate lung, gut and blood tissue, as well as infecting the cells with viruses. Zwaka hopes to use the tissue to better understand bat immunity, and eventually “to develop strategies for human health”. Other researchers are using bat organoids developed using stem cells extracted directly from bats to answer similar questions.
Many of the parts of the original coronavirus genomes were found by Zwaka and other researchers, along with an abundance of sections that were simply viral fragments. The viral gene expression was higher and more diverse in pluripotent cells than in both bat skin cells and in pluripotent cells from mice and humans. What’s more, the pluripotent bat cells actually used the viral fragments to make what appeared to be virus-like particles.
The project was in fact part of a global genome consortium, called Bat1k, co-founded by Teeling and aiming to create high-quality genomes for every bat species. Some 80 bat genomes have been mapped so far due to the surge of interest and funding since the outbreak of the swine flu.
Among the trendiest techniques enabled by high-quality genomes is single-cell RNA sequencing, in which researchers take a cell of interest and analyse its RNA contents to explore the cell’s components and how they work.
Source: https://www.nature.com/articles/d41586-023-00791-x
The hum of a machine and two people talking loudly under the midday Sun: Singapore’s cosmological nuclear power crisis is accelerating to a halt
In Singapore, the weather is warm and humid under a bright midday Sun, but inside it’s cooler. The two people are talking loudly above the hum of a machine.
