This video, we're going to briefly discuss retinoic acid inducible gene like receptors, or for short, RIG like receptors. Now these RIG like receptors are a second type of cytoplasmic PRR in addition to the nod like receptors that we talked about in some of our previous lesson videos. And so once again, these RIG like receptors are cytoplasmic PRRs that are capable of detecting cytoplasmic mAMPS or cytoplasmic microbe-associated molecular patterns. Now, specifically, these RIG like receptors are cytoplasmic proteins or cytoplasmic PRRs that detect viral RNA. And, these RIG like receptors that are capable of detecting viral RNA in the cytoplasm are found in most types of host cells.
Now the RIG like receptors are capable of distinguishing between host cell RNA and viral RNA by two features that we have listed down below. The first feature is that viral RNA can be double-stranded. And double-stranded RNA is quite unique and really only found in some types of viruses. And host RNA is not double-stranded, so that makes it easy to distinguish the host cell's RNA from viral RNA. Now a second important feature that helps distinguish host RNA from viral RNA is that host cell RNA is going to have a 5 prime cap as well as a poly A tail, a 3 prime poly A tail.
However, viral RNA does not have a 5 prime cap or a poly A tail. And so that is another way to distinguish between host cell RNA and viral RNA. And so if we take a look at our image down below over here on the left-hand side, notice we have our map of the lesson on the scanning systems of innate immunity, which serve to detect signs of microbes and host cell damage, and they serve somewhat as these security cameras. And so here in this video, we're focusing specifically on pattern recognition receptors, specifically these RIG like receptors. And so, these RIG like receptors, again are capable of detecting viral RNA.
And so when a virus infects a cell, so here we have an infecting virus, it will uncoat and release its genetic material, and that viral genetic material can be transcribed through the process of transcription to make viral RNA, either viral single-stranded RNA or viral double-stranded RNA. And so regardless if it's viral single-stranded RNA or viral double-stranded RNA, the RIG like receptors, which are down below right here, are capable of distinguishing the host cell's RNA, which notice the host cell's RNA is over here. It is single-stranded, and it has a 5 prime cap and a poly A tail, from the viral RNA. And so, that's because, again, the viral RNA is, not going to have the 5 prime cap or poly A tail, and also viral RNA can be double-stranded. And so these RIG like receptors will detect these viral RNA molecules, and upon detecting the viral RNA molecules, it could initiate some kind of immune response, like, for example, the release of a cytokine, perhaps an interferon, for example, which we'll get to talk about the interferon response in more detail later in our course.
But for now, this here concludes our brief lesson on these RIG like receptors, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video.