How does the immune system recognize and react to the flu?
Following influenza infection or receipt of a flu vaccine, the body’s immune system develops antibodies that recognize and bind to “antigenic sites,” which are regions found on an influenza virus’ surface proteins.
How does the body response to the flu?
How Does It Work? Your body makes proteins called antibodies that destroy abnormal or foreign cells. They help fend off common ailments like the flu or a cold. You also have another response known as the “cell-mediated immune system,” which also attacks pathogens like bacteria and virus-infected cells.
What is the role of neuraminidase in influenza?
Influenza A viruses generally mediate binding to cell surface sialic acid receptors via the hemagglutinin (HA) glycoprotein, with the neuraminidase (NA) glycoprotein being responsible for cleaving the receptor to allow virus release.
How does antigenic variation occur?
Antigenic variation can occur by altering a variety of surface molecules including proteins and carbohydrates. Antigenic variation can result from gene conversion, site-specific DNA inversions, hypermutation, or recombination of sequence cassettes.
What immune systems are involved in fighting the flu?
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.
Why is the capsid important?
The primary role of the capsid is to protect the genome. Additionally, particularly in the non-enveloped viruses, the capsid facilitates the attachment and penetration of the virus to the host cell.
What is antigenic shift in flu?
Another type of change is called “antigenic shift.” Shift is an abrupt, major change in a flu A virus, resulting in new HA and/or new HA and NA proteins in flu viruses that infect humans. Antigenic shift can result in a new flu A subtype.
Does antigenic shift caused pandemic?
Antigenic shift results in a new influenza A subtype that is so different from previous subtypes in humans that most people do not have immunity to the new virus. An antigenic shift can lead to a worldwide pandemic if the virus is efficiently transmitted from person to person.
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