Table of Contents
What receptor does influenza bind to?
Sialic acids (SAs) of cell surface glycoproteins and glycolipids are the receptors for the influenza virus, recognized by the viral glycoprotein hemagglutinin (HA; Figure 1). The site on HA at which the cellular receptors are bound is at the distal end of the molecule.
How does the immune system response to the influenza virus?
The initial immune response involves cells of the body’s innate immune system, such as macrophages and neutrophils. These cells express receptors that are able to sense the presence of the virus. They then sound the alarm by producing small hormone-like molecules called cytokines and chemokines.
How does influenza evade the immune system?
Antigenic drift and shift to escape immunity. The gradual accumulation of mutations, mainly in the highly variable globular head region of HA, causes the influenza virus to escape recognition by virus neutralizing antibodies and allows it to cause seasonal epidemic outbreaks. This phenomenon is called antigenic drift.
Why does influenza lack the ability to repair those errors?
Like all living things, influenza makes small errors—mutations—when it copies its genetic code during reproduction. But influenza lacks the ability to repair those errors, because it is an RNA virus; RNA, unlike DNA, lacks a self-correcting mechanism. As a result, influenza is not genetically stable.
How does influenza bind to cell?
Influenza A virus (IAV) binds its host cell using the major viral surface protein hemagglutinin (HA). HA recognizes sialic acid, a plasma membrane glycan that functions as the specific primary attachment factor (AF).
Where does influenza bind to?
The viruses attach to cells within the nasal passages and throat (i.e., the respiratory tract). The influenza virus’s hemagglutinin (HA) surface proteins then bind to the sialic acid receptors on the surface of a human respiratory tract cell.
Which antigens are most important in the immune response to the influenza virus?
The humoral immune system produces antibodies against different influenza antigens, of which the HA-specific antibody is the most important for neutralization of the virus and thus prevention of illness.
How do RNA viruses evade the immune system?
DNA and RNA viruses use complex methods to evade immune cell detection through disruption of the Interferon Signaling Pathway, remodeling of cellular architecture, targeted gene silencing, and recognition protein cleavage.
What is flu antigen?
The HA and NA surface proteins of influenza viruses are “antigens,” which means they are recognized by the immune system and are capable of triggering an immune response, including production of antibodies that can block infection.
Why are RNA viruses and retroviruses more error prone in their replication than DNA viruses?
These differences have several mechanistic bases. First, the polymerases of the vast majority of RNA viruses lack 3′ exonuclease proofreading activity and hence are more error-prone than those of DNA viruses [9, 10].
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