Ebola: How does the virus attack human cells?
Oct 02, · The Ebola outbreak in West Africa is the deadliest occurrence of the disease since its discovery in This graphic explains how it attacks human cells. Embedded within the host-derived lipid envelope of Ebola virus are glycoprotein spikes that bind to cells and mediate fusion between the viral envelope and the host cell membrane, enabling the Cited by:
Behind the unprecedented Ebola outbreak in West Africa lies a species with an incredible power to overtake its host. Zaire ebolavirus and the family of filoviruses to which it belongs owe their virulence to mechanisms that first disarm the immune response and then dismantle the vascular system.
The virus progresses so quickly that researchers what cells does ebola attack struggled to tease out the precise sequence of events, particularly in the midst of an outbreak.
Once the virus enters the body, it targets several types of immune cells that represent the first line of ebopa against invasion. It infects dendritic cells, which normally display signals of an infection on their surfaces to activate T lymphocytes—the white blood cells that could destroy other infected cells before the virus replicates hwat. The virus can start replicating immediately and very quickly. Ebola, like many viruses, works in part by inhibiting interferon—a type of molecule that cells use to hinder further viral reproduction.
As the virus travels in the blood to new sites, other immune cells called macrophages eat it up. Once infected, they release proteins that trigger coagulation, forming small clots throughout the blood vessels and reducing blood supply to organs. They also produce other inflammatory signaling proteins and nitric oxide, which damage the lining of blood how to crochet a doiley, causing them to leak. Although this damage is one of the main symptoms of infection, not all patients exhibit external hemorrhaging—bleeding from the eyes, nose, or other orifices.
Ebola triggers a system-wide doee and fever and can also damage many types of tissues in the body, either by prompting immune cells such as macrophages to release inflammatory molecules or by direct damage: invading the cells and consuming them from within. But the consequences are especially profound wttack the liver, where Ebola wipes out cells required to produce coagulation proteins and other important components of plasma. Damaged cells in the gastrointestinal tract lead to diarrhea that often puts patients dhat risk of dehydration.
And in the adrenal gland, the virus cripples the cells that make steroids to regulate blood pressure and causes circulatory failure that can starve organs of oxygen. Damage to blood vessels leads eboka a drop in blood how to make an image, and patients die from shock and multiple organ failure. Attzck fare better with supportive care, including oral or intravenous rehydration that can buy time for the aytack to fight off infection.
But studies on blood samples from patients during the outbreak of a different Ebola strain in Uganda have also identified genes and other markers that seem to be predictive of survival. Patients who recovered had higher levels of activated T cells in their blood and had certain variants of a gene that codes for surface proteins that white blood cells use to communicate.
The authors note that markers like sCD40L could suggest how to plan a party with a budget therapies that augment the repair mechanisms most important for survival.
By Sofia Moutinho Apr. By Sofia Moutinho Mar. All rights Reserved. The Ebola virus. Dies are some of the basic things we wuat about how Ebola and humans interact.
What does Ebola do to the immune system? How does Ebola cause hemorrhaging? Does the virus target certain organs? What ultimately kills Ebola patients? Why do some people survive infection? Got a tip? How to contact the news team. Latest News. Tropical forest destruction increases, despite the pandemic By Ceols Moutinho Mar. Pesticide-blocking gene transferred from plants to animals By Sofia Moutinho Mar. Scientists have been underestimating the power of tornadoes By Attxck Moutinho Mar.
Abstract. Ebola hemorrhagic fever is a severe viral infection characterized by fever, shock and coagulation defects. Recent studies in macaques show that major features of illness are caused by effects of viral replication on macrophages and dendritic cells. Infected macrophages produce proinflammatory cytokines, chemokines and tissue factor, attracting additional target cells and Cited by: Ebola virus is an enveloped virus with filamentous structure and causes a severe hemorrhagic fever in human and nonhuman primates. Host cell entry is the first essential step in the viral life cycle, which has been extensively studied as one of the therapeutic targets. A virus factor of cell entry is a surface glycoprotein (GP), which is an only essential viral protein in the step, as well as the unique particle Cited by: 4. Aug 13, · It infects dendritic cells, which normally display signals of an infection on their surfaces to activate T lymphocytes—the white blood cells that could destroy other infected cells before the.
It was recently reported that the number of Ebola cases in the Democratic Republic of Congo has surpassed 1,, making it the second-worst outbreak in history after the outbreak in West Africa in which 29, people were infected and more than 11, died.
This latest milestone is a stark reminder of the urgent need to develop effective prevention and treatment agents for this frequently deadly disease.
Those infected with the Ebola virus experience severe illness, including hemorrhagic fever, which can lead to internal bleeding.
According to the U. Key to developing treatments for the disease is understanding the mechanisms of the infection process. Scientists know that to enter a human cell, Ebola takes advantage of a natural process called macropinocytosis, through which the cell "cleans up" its surroundings by internalizing the dead cell debris that surrounds it.
Proteins on a cell's surface serve as receptors, allowing immune cells to recognize the dead cell debris and internalize it. The virus interacts with these proteins, called T-cell immunoglobulin and mucin domain TIM proteins and uses them to hijack its way into the cell. Once inside, the Ebola virus membrane fuses to the endosome that has formed around it and releases its genetic content into the cell.
Then they bud off the membrane to form a new virus while the healthy host cell dies," says Frank Zhang, associate professor of bioengineering and of mechanical engineering at Lehigh University. Zhang and Jagota have teamed up to try to better understand the biomechanics of Ebola virus-host cell adhesion. The project pairs Jagota's expertise in computational molecular adhesion mechanics with Zhang's focus in mechanosensing, or how cells sense and respond to mechanical stimuli.
The duo, working with colleagues Sven Moller-Tank and Wendy Maury from the University of Iowa, have developed a simple model that characterizes the biomechanics of Ebola virus-host cell adhesion? They have published their findings in Scientific Reports in an article titled: "Biomechanical characterization of TIM protein-mediated Ebola virus- host cell adhesion.
In addition to illuminating the biomechanical parameters important for Ebola attachment to a host cell, the team also demonstrated experimentally that TIM-Ebola virus interactions are mechanically comparable to adhesion molecule e. Through a simple mechanical model, they further demonstrate how molecular binding parameters determine whether they are sufficient for viral adhesion. The purpose of the model is to show how single molecule measurements can be combined with other physical properties of the system, such as density of ligand-receptor pairs and membrane stiffness, to predict whether and to what extent a viral particle will adhere to the cell membrane.
The team models attachment as being driven by adhesion between TIM proteins and phosphatidylserine on the surface of the virus believed to mediate the virus-host cell attachment and resisted by membrane bending.
Zhang uses single molecule force spectroscopy to monitor, manipulate and measure mechanical forces. For example, in the study, Zhang would bring a virus-like particle to a cell with its TIM receptor expressed, observe their interaction, and pull them apart to determine the mechanical strength of the interaction, or how much force is required to pull them apart.
Jagota uses mathematical models to understand the interaction between Ebola and the cell, what properties represent the Ebola virus -- its stiffness, its shape -- and what properties represent the cell -- the components it presents on its surface -- in this interaction. Materials provided by Lehigh University. Note: Content may be edited for style and length. Science News. Story Source: Materials provided by Lehigh University. Journal Reference : Matthew A. Frank Zhang. Biomechanical characterization of TIM protein—mediated Ebola virus—host cell adhesion.
Scientific Reports , ; 9 1 DOI: ScienceDaily, 26 March Lehigh University. Biomechanics of how the Ebola virus attaches to its host cell.
Retrieved April 24, from www. This study helps understand how the virus uses the host to Researchers are using supercomputers to simulate the inner workings of Ebola as well as COVID , looking at how molecules The findings provide the basis for launching a Located outside the cell, these receptors play a decisive role in transmitting information to the inside of the cell. ScienceDaily shares links with sites in the TrendMD network and earns revenue from third-party advertisers, where indicated.
Print Email Share. Boy or Girl? Flushing a Public Toilet? Living Well. View all the latest top news in the environmental sciences, or browse the topics below:. Keyword: Search.