Virology Lectures 2019 #13: Intrinsic and Innate Defenses

Hosts have many effective defenses to prevent virus infections. These include chemical and physical defenses such as skin and mucus. Viruses that penetrate these barriers encounter intrinsic defenses (always present in the cell), and then innate defenses (which must be induced by infection). Both are highly effective antiviral systems, but are antagonized by many different viral proteins - one reason why viruses are successful at being maintained in populations.

[quagapp]

A few years ago (I used to sell second hand books in NZ or online) I got a book on cell biology which I was interested in, among many other things: and I was fascinated by two things at the start. 1 How people in some places can become drunk without drinking alcohol. 2 apoptosis. Now although I am of English* descent to me that was a great word and it HAS to be a-POP-tosis ...how else to remember that! It seemed an amazing thing. The book hadn't got to viruses but here was a great thing I knew that I knew so many people wouldn't know (as well as the getting drunk thing). Great to be able to drop into the conversation. Once at my ex-wife's place I mentioned this self-suicide, or hari kari of cells (which I think it said was a general defensive strategy): but this was angrily denied. She had studied some of these books but this was wiped aside (she is a nurse): what did I know? But in anycase it is one of the amazing things. And how complex it all is, it all started about 2300 billion years ago when I think primitive cells were using sulfur, then another type of cell or life form started converting the C02 into more Oxygen. By this time photosynthesis was already established. Anyway the exploding cells caught my interest. It seems that the immunune response is like a war, sometimes a wins sometimes b, depending whether strategy of a or b can or cant trick strategy a or b, like the British etc going one more than the Germans in developement of submarine detection, the Germans making a counter...and the same with the code system, then in wars errors are made for all kinds of reasons (living things make errors). Error (mutation etc) is the basis of life. There's a lot going on....But my vote for A - POP! toe - sis !! (Ptosis is like those words I think e.g. Ptomac or ptomic poisoning is a word. Or like Ptolomy. There remain good reasons why Greek and Latin words are in there. They always sound impressive and make the language, scientific and other, interesting. Richard T. NZ, Auck. *There are not really any British people, as to be accurate the "British" language has disappeared almost entirely as Briton was conquered by so many various users of other languages. The remnants are perhaps in the Gaelic languages of Wales etc

[dorasmith]

I learned in high school biology that immune response check to see if cells have both self receptors, like, the HLA antigen complex, and non-self receptors. Wehre did that all go to? HLA antigens don't serve no purpose!

[CompBioQuest]

the classification of innate and adaptive are blurring with the pass of time.

[amirghorbani]

Hi Dr. Racaniello, at 23:18 TLR3 ligand is indicated as ssRNA. As far as I know, TLR3 sences dsRNA.

[ShahidHussain-bhpk]

viruses reside in cells,

do anybody know how a T-cell recognizes virus infected cell and orders it to commit suicide...