in this video, we're going to begin our introduction to the interferon response. And so first we need to recall from some of our previous lesson videos that interfere ons are commonly abbreviated as I. F. N. And these interference are one of many different types of cytokines or chemical signals used to communicate between cells. And so these interference are specifically cytokines that provide anti viral effects or in other words it helps to provide defense against viruses and it will provide these antiviral effects to neighboring cells. And so we'll be able to talk more details about the steps of the interferon response in our very next lesson video. But for now if we take a look at our image down below notice we're showing you our map of the lesson on innate immunity. And right now here in this video we're focusing in specifically on the second line of defense on the innate defector actions, specifically the interferon response. And so once again in our next lesson video we'll get to talk a lot more details about this interferon response in order to understand how it allows for antiviral effects. And so I'll see you all in our next video
Steps of the Interferon Response
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in this video, we're going to talk more details about the steps of the interfere on response, which recall from our last lesson, video provides antiviral effects or defense against viruses in neighboring cells. Now, before we begin, I want to first mention that the text that you see up above uh corresponds with the image that you see down below on the interfere on responds. And so one thing that we're going to do as we break this up is we're going to go from the text up above down to the image down below so you can see how it corresponds. And so here what we're saying is that when the P. R. R. S. Or the pattern recognition receptors of an infected cell detect viral RNA. A sometimes that infect itself can produce and secrete interfere ons which recall interference are commonly abbreviated as I. F. Ens. And so if we take a look at our image down below on the left hand side over here, uh notice that we're showing you our first cell and this first cell is being infected by a virus and so notice that this is our virus. And notice that the virus here is infecting this uh cell that we have right here. And so the virus is infecting the cell. However this infected cell uh is sometimes able to create interference and so notice that this cell, although it is being infected it is producing and secreting these interfere on molecules. And the interfere on molecules can again be produced by the first cell and diffuse over towards neighboring cells. And so again what we're saying here is that the infected cell can produce and secrete interference and those interference can go on to diffuse to a neighboring cell and bind to that neighboring cell in order to warn that neighboring cell of the presence of the virus. And so notice here in the image we have these little interfere on molecules diffusing over to a neighboring cell here that has not yet been infected by the virus. Now notice this little bubble speech that's being said here by the first cell that is infected. Notice that because this cell here is being infected by the virus. Uh it's saying I'm doomed. And so this first cell that although it is being infected by the virus and it is ultimately going to be killed by the virus. Um it's saying here that maybe I can save my neighbors if I release interference. And so the first cell, although it knows it is going to die by the virus, it can release these interference again to warn neighboring cells of the presence of the virus before the virus actually gets over to it. And so again here, what we're saying is that these interfere ons that have been released by the first infected cell, they can diffuse over towards neighboring cells and bind to those neighboring cells that have not yet been infected and when the interference bind to those neighboring cells that have not yet been infected, it can actually lead to the production of inactive antiviral proteins or I A VPs in those neighboring cells that have not yet been infected. And so if we take a look at our image down below, notice that these interfere arms that have diffused over to the neighboring cell over here allow for the production of I. A VPs in active antiviral proteins. And so notice it says here that the neighboring cell receives the interference. It detects the interference and the detection of the interference allows the neighboring cell to produce those I A VPs in active antiviral proteins. Now these inactive antiviral proteins as their name implies, they are inactive And so because they are in active they are not going to do anything until they become activated. However they are being expressed. So they are ready to take action and become activated when the scenario presents itself. And so notice that this bubble speech over here by the neighboring cell is saying, oh I just got a message and the message is referring to the interference that my neighbor was infected by a virus. So I better make these antiviral proteins or I A VPs. Now if this neighboring cell down the line is ever infected by that virus, then the detection of that viral double stranded RNA or just any type of viral RNA that is detected that can actually activate that neighboring cells inactive antiviral proteins and the activation of an active antiviral proteins will form a VPs active viral active antiviral proteins and these active uh antiviral proteins or a VPs, they have the ability to stop translation of the sell by degrading the cells M R N. A. And ultimately this will trigger a popped Asus. And although a popped Asus is programmed cell death, that will kill the cell, it is also going to prevent, it will also prevent the virus from using the cell as a host to replicate. And so ultimately it will prevent the virus replication. And so if we take a look at our image down below, notice that the first cell over here that is infected by the virus again, it releases those interference so that the neighboring cell can respond to those interference. However, the first cell again, the infected cell is going to ultimately die. It will produce new viruses, so more viruses will be produced. And again the infected cell here is going to lice so it is going to die. However, by releasing the interference, the first infected cell is making an effort to help uh control the replication of the virus by um allowing for antiviral proteins to be produced. And so notice that later down the line, if this virus ever tries to make an attempt to infect this neighboring cell, this neighboring cell has these inactive antiviral proteins and the neighboring cell if it is ever infected by the virus, the the inactive antiviral proteins, the I a VPs are able to activate into a VPs. And so notice that the bubble speech here in the neighboring cell is saying, hey uh sorry virus um that I know you're trying to infect me but you're not going to use me to replicate. I'm going to sacrifice myself by performing a popped Asus so that your replication cycle ends here. And so notice that saying I. Veeps or inactive apps activate into A VPs and so you can see the I. A. VPs here are activating into a VPs and the A VPs can trigger apoptosis. And so notice that the cell here is performing apoptosis and notice it's saying I might be dead. But so are you virus. And so because this cell performs a popped Asus, it prevents the replication of the virus. And so whereas the first cell over here produced many uh copies of the virus, the second cell did not produce any copies of the virus. And so this helps to prevent um the replication of the virus. And to limit the replication of the virus. And so notice down below what we're saying is thanks to this interfere on response. The virus is unable to replicate in the neighboring cell because the neighboring cell was prompted to produce antiviral proteins. And so by preventing the replication of the virus. This is a great step in preventing the spread of the virus and is going to allow for the buying of more time to ultimately eliminate the virus from our bodies and to again get rid of the virus. And so this interfere on response again is an antiviral response that helps protect neighboring cells from viruses and ultimately help limit the replication of a virus. And so notice here in summary, the interference function is to prevent or limit viral replication by warning neighboring cells to build antiviral proteins. And so this year concludes our lesson on the steps of the interferon response and its antiviral effects, and we'll be able to get some practice applying these concepts as we move forward in our course. And so I'll see you all in our next video.
How does the interferon response provide anti-viral protection?
Interferons bind to the virus neutralizing it.
Interferons stimulate neighboring cells to produce anti-viral proteins.
Interferons prevent the virus from entering the cell.
Interferons prevent the virus from leaving the infected cell and infecting neighboring cells.
If a cell produces antiviral proteins (AVPs) what occurs when that cell encounters dsRNA?
The antiviral proteins trigger the production of iAVPs.
The antiviral proteins cease protein translation in the cell so no viral proteins can be made.
The antiviral proteins become activated and the cell undergoes apoptosis to stop the viral spread.
The antiviral proteins trigger the production of interferon proteins to warn neighboring cells of viral infection.
How does the interferon response to an invading virus result in the infected cell undergoing apoptosis?
Detection of viral RNA triggers the degradation of host RNA and stops translation which results in cell death.
Detection of viral proteins inactivates the AVPs which triggers cells death.
Detect of viral RNA ceases all functions of the cell and results in cell lysis and release of newly made viruses.
Detection of viral proteins causes pores to form in the surface of the cell resulting in apoptosis.
Which of the following cells can induce viral-infected cells to undergo apoptosis?
Red blood cells.
Which of the following statements about interferon is incorrect?
a) It only works on a few specific types of virus.