A team of researchers from the Institute for Infectious Diseases (IFIK) at the University of Bern and the Federal Institute of Virology and Immunology (IVI) have assessed virus growth and activation of the cellular defense mechanisms in the respiratory tract. They have shown that natural temperature differences that exist in the upper and lower respiratory tract have a profound influence on SARS-CoV-2 replication and subsequent innate immune activation in human cells. The findings can help to develop antiviral drugs and preventive measures.
“SARS-CoV-2 and SARS-CoV are highly similar genetically, generate a homologous repertoire of viral proteins, and use the same receptor to infect human cells. However, despite these similarities, there are also important differences between the two viruses,” says Ronald Dijkman from the Institute for Infectious Diseases (IFIK) at the University of Bern. For example, SARS-CoV infection is characterized by severe disease and inflammation in the lower respiratory tract and infected individuals are only contagious after the onset of symptoms, making it easier to identify and interrupt infection chains.
In contrast, SARS-CoV-2 preferentially replicates in the upper airways (nasal cavity, pharynx, trachea) and can be efficiently transmitted from one individual to another before the appearance of disease symptoms. Moreover, the outcome of SARS-CoV-2 infection varies widely from person to person, and can manifest as asymptomatic, mild, or severe disease. Older people as well as individuals with certain underlying medical conditions (heart conditions, diabetes, cancer) are at greater risk of developing severe illness, which is often associated with infection of lower respiratory tissues, high levels of inflammation, and lung failure.
Temperature is key
To better understand why infections with SARS-CoV and SARS-CoV-2 result in such different clinical outcomes, researchers from the University of Bern used specialized human airway cell cultures to investigate the impact of respiratory tract temperatures on SARS-CoV and SARS-CoV-2 replication. The cells originate from human samples and mimic the complexity of the cells found in the respiratory tract. They grow in special containers, are nourished from the bottom side and are exposed to air on the top side, just like the cells in the human trachea. The cultures also make mucus and have cilia that beat very quickly. “Because the organization of these cells greatly resembles the cells found in human tissues, they are a relevant system that can be used in a laboratory to study respiratory viruses,” Dijkman explains.
The researchers have now used this existing model for the first time to study the effects of respiratory temperatures on SARS-CoV and SARS-CoV-2 replication. They found that temperature plays an important role as SARS-CoV-2 preferred to replicate at temperatures typically found in the upper airways (33°C). Colder incubation temperatures allowed the virus to replicate faster and to a higher extent than when infections were carried out at 37°C to mimic the lower lung environment. Unlike SARS-CoV-2, replication of SARS-CoV was not impacted by different incubation temperatures. The experiments were conducted both in the high security laboratory of the IVI in Mittelhäusern and in the biosafety laboratory of the Institute for Infectious Diseases (IFIK) at the University of Bern in the building of sitem-insel, the Swiss Institute for Translational Medicine and Entrepreneurship.
Image Credit: Uni. of Bern
Post by Amanda Scott, NA CEO. Follow her on twitter @tantriclens
Thanks to Heinz V. Hoenen. Follow him on twitter: @HeinzVHoenen
News
RNA Recycling Extends Lifespan
Summary: Researchers discovered a biological “trash disposal” mechanism that directly controls how fast we age. While circular RNA has long been known to accumulate in cells as we get older, this study proves for the [...]
Cancer’s Deadly Paradox: How Tumors Break Their Own DNA To Keep Growing
Cancer’s strongest gene switches push DNA into damaging overdrive, creating repeated breaks and repairs that may fuel tumor evolution while exposing possible therapeutic weak spots. A new study indicates that cancer can harm its own genetic [...]
NanoMedical Brain/Cloud Interface – Explorations and Implications. A new book from Frank Boehm
New book from Frank Boehm, NanoappsMedical Inc Founder: This book explores the future hypothetical possibility that the cerebral cortex of the human brain might be seamlessly, safely, and securely connected with the Cloud via [...]
Our books now available worldwide!
Online Sellers other than Amazon, Routledge, and IOPP Indigo Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artifcial Intelligence Global Health Care Equivalency In The Age Of Nanotechnology, Nanomedicine And Artificial [...]
Ryugu asteroid samples contain all DNA and RNA building blocks, bolstering origin-of-life theories
All the essential ingredients to make the DNA and RNA underpinning life on Earth have been discovered in samples collected from the asteroid Ryugu, scientists said Monday. The discovery comes after these building blocks [...]
Is Berberine Really a “Natural Ozempic”?
Often labeled a “natural Ozempic,” berberine is widely discussed as a metabolic aid. Yet research suggests its influence may lie deeper. In recent years, berberine has gained significant attention as a supposed “natural way” [...]
Viagra Ingredient Shows Promise for Rare Childhood Brain Disease in Surprising Study
A rare childhood disease with no approved treatment may have an unexpected new therapeutic candidate. Sildenafil, the active ingredient also sold under the brand name Viagra, may help reduce symptoms in people with Leigh [...]
In a first for China, Neuracle’s implantable brain-computer interface wins approval
In a landmark development, Neuracle Medical Technology has secured the country’s first-ever approval for an implantable brain-computer interface (BCI) system designed to restore hand motor function in patients with spinal cord injuries, in a [...]
A Cambridge Lab Mistake Reveals a Powerful New Way to Modify Drug Molecules
A surprising lab discovery reveals a light-powered way to tweak complex drugs faster, cleaner, and later in development. Researchers at the University of Cambridge have created a new technique for altering complex drug molecules [...]
New book from NanoappsMedical Inc – Molecular Manufacturing: The Future of Nanomedicine
This book explores the revolutionary potential of atomically precise manufacturing technologies to transform global healthcare, as well as practically every other sector across society. This forward-thinking volume examines how envisaged Factory@Home systems might enable the cost-effective [...]
Scientists Discover Simple Saliva Test That Reveals Hidden Diabetes Risk
Researchers have identified a potential new way to assess metabolic health using saliva instead of blood. High insulin levels in the blood, known as hyperinsulinemia, can reveal metabolic problems long before obvious symptoms appear. It is [...]
One Nasal Spray Could Protect Against COVID, Flu, Pneumonia, and More
A single nasal spray vaccine may one day protect against viruses, pneumonia, and even allergies. For decades, scientists have dreamed of creating a universal vaccine capable of protecting against many different pathogens. The idea [...]
New AI Model Predicts Cancer Spread With Incredible Accuracy
Scientists have developed an AI system that analyzes complex gene-expression signatures to estimate the likelihood that a tumor will spread. Why do some tumors spread throughout the body while others remain confined to their [...]
Scientists Discover DNA “Flips” That Supercharge Evolution
In Lake Malawi, hundreds of species of cichlid fish have evolved with astonishing speed, offering scientists a rare opportunity to study how biodiversity arises. Researchers have identified segments of “flipped” DNA that may allow fish to adapt rapidly [...]
Scientists Discover Why Some COVID Survivors Still Can’t Taste Food Years Later
A new study provides the first direct biological evidence explaining why some people continue to experience taste loss long after recovering from COVID-19. Researchers have uncovered specific biological changes in taste buds that could help [...]
Catching COVID significantly raises the risk of developing kidney disease, researchers find
Catching Covid significantly raises the risk of developing deadly kidney disease, research has shown. The virus was found to increase the chances that patients will develop the incurable condition by around 50 per cent. [...]
