Specific memory in Innate Immune System

[Nite]

HI all,

Just want to hear any opinion regarding this topic:



How possible issit for Innate Immune System to have "specific memory"



thx and regards!

[Dr.Stein]

There is NO memory, whatever it is, in innate immune system

[Nite]

yeah that's what my lecturer told me too:D. coz so far... what is everybody believe is that there is NO specific memory in innate immune system...

however, recent study in invertebrate (which have only innate immune system), particularly in Biomphalaria glabrata, suggest that there might be specificity and memory invertebrate's innate immune system.. (read a paper by Joachim Kurtz: "Specific Memory Within Innate Immune Systems")

Was just wondering if anybody have any clues(or creative ideas) of what must the INNATE SYSTEM possess to establish a specific memory?
how POSSIBLE is it that innate immune system can have memory?

[Dr.Stein]

In invertebrates, they use lectin and pattern recognition to "memorize" antigens. Maybe those what is so-called "innate immune system specific memory" I don't read te paper yet, will try to get it for sure. If you have it, please send me the copy. Thanks in advance

[Nite]

hm.. what do you mean by "memorize" the antigens?

pattern recognition through TLRs (Toll like receptors)? and the lectin part refers to Mannose Binding Lectin or Mannose Binding Protein?
How do they memorize the Ag? I thought at most they can only enhanced the immunity against closely related Ag (to the first immune insult) at some period of time?

[Dr.Stein]

OMG, you flood me with a lot of questions Please gimme time to give my best answer for you, ok?

BTW, is that you who sending me Dr.Kurtz's paper thru Y! Mail? Thank you again Well, now I got it two: one from you and the other one from Dr.Kurtz himself. Thanks for bridging me to have a contact with him. He is a nice guy

[Nite]

hahaha. I was too excited sorry about that .

yah, the paper is from me:D.

and I do agree that he is a very nice guy. My friend sent him an email regarding this topic. To our surprise, he replied us.

[Dr.Stein]

I think you can take your questions to him and just let him answer

Well, I try to answer...

Memorizing antigen - The immune system has a component called immunological memory derived from a differentiation of B-cell into memory cell. As being educated during its development, this cell functions to memorize the appropriate antigen/peptide previously exposed to it. Next time the body is re-infected by similar antigen, the proper immune response will be activated rapidly because of this memory.

Pattern recognition - A system used by immune cells of innate immunity to recognize antigen, whether it is self or nonself molecules, to define what they will do to that antigen, generating immune response or immune tolerance. Pattern recognition is mediated by PRRs (Pattern Recognition Receptors), a class of surface protein.

Glycoprotein molecules known as pattern-recognition receptors are found on the surface of a variety of body defense cells. They are so named because they recognize and bind to pathogen-associated molecular patterns - molecular components associated with microorganisms but not found as a part of eukaryotic cells. These include bacterial molecules such as peptidoglycan, teichoic acids, lipopolysaccharide, mannans, flagellin, pilin, and bacterial DNA. There are also pattern-recognition molecules for viral double-stranded RNA (dsRNA) and fungal cell walls components such as lipoteichoic acids, glycolipids, mannans, and zymosan. Many of these pattern recognition receptors are known as toll-like receptors.

Lectin - Lectin is the most primitive immune system. Proteins found in plants and animals that bind to sugar residues and can agglutinate cells. In plants, the real functions of lectins are not known, while in animals are known to participate in a wide range of cellular activities. Several animal lectins perform innate recognition, e.g. C-type lectins (collectins, selectins), S-type lectins (limulin, echinoectin), Pentraxins, soluble lectins, etc.

Lectins play important roles in the immune system by recognising carbohydrates found exclusively on pathogens. Polysaccaride are also found in the cell wall of prokaryotic microorganisms. Some are unique to microbes, such as lipoplysaccharide (LPS) of bacteria. These allows microbes to adhere to host tissue, although their presence also providea the basis for innate recognition by soluble lectins.

"How do they memorize the Ag? I thought at most they can only enhanced the immunity against closely related Ag (to the first immune insult) at some period of time?"

What does the word "they" refer to? I do not get your point here. Please explain me more..

[Nite]

In invertebrates, they use lectin and pattern recognition to "memorize" antigens.

sorry for the unclear question, my real question is how lectin n pattern recognition 'memorize' Ags?

erm... so far as I know, I did not hear of any formation of memory cells similar to the acquired immunity (B or T cells) in the innate system..

"How do they memorize the Ag? I thought at most they can only enhanced the immunity against closely related Ag (to the first immune insult) at some period of time?"

What does the word "they" refer to? I do not get your point here. Please explain me more..

'they' refer to the lectin and the pattern recognition of the innate system in invertebrate.



Thanks for the explanation for lectin. I learned something new . Btw, recognition base on lectin is non-specific rite? not all of them are found in the invertebrate rite?

[Dr.Stein]

The surface of microorganisms typically bear repeating patterns of molecular structure. The innate immune system recognizes such pathogens by means of receptors that bind features of these regular patterns. I put the word "memorize" (with apostrophes) because it is NOT the real memorizing as that memory cells in adaptive immunity do. Here, in this case, because lectin can recognize and distinguish foreign molecules of microorganisms they encounter from self molecules, on the next time they encounter the same pathogen, they know what they must do: clump them together. Pathogen recognition and discrimination from self is due to recognition of a particular orientation of certain sugar residues, as well as their spacing, which is found ONLY on pathogenic microbes and NOT on host cells. That's what I meant by "memorizing antigen". I know that's my own definition, that's why the apostrophes exist I hope this explanation works.

I am sorry but it seems for me that you are going round and round thru your questions. I found myself being confused because of that. Well, I hope this is only my own problem in interpreting your sentences. Here I quoted your sentences and highlight things to make it straight like this way:

- sorry for the unclear question, my real question is how lectin n pattern recognition 'memorize' Ags? ---> Lectin is one of innate immunity components, so lectin use pattern recognition to recognize pathogens from self molecules

- erm... so far as I know, I did not hear of any formation of memory cells similar to the acquired immunity (B or T cells) in the innate system.. ---> Memory cell is derived from lymphocyte, lymphocyte is a component of adaptive immunity, no lymphocyte plays a role in innate immunity, so no memory cell will arise, except that would be another "memory cell" that derived from another cell not lymphocyte

- Btw, recognition base on lectin is non-specific rite? ---> Of course, lectin is innate immnuty that IS indeed non-specific!

- not all of them are found in the invertebrate rite? ---> You use "they" again pfff... I think it refers to "lectin" again... And what do you mean by "not all of them"? Invertebrates can have similar lectin type, e.g. collectin, but also can have special one for a species that cannot be found in another species, e.g. limulin as I told you before.

Ooh I am tired on explaining this

[Nite]

thank you for the explanation . ooh ic.. i misunderstood yr "memory".... I thought it was to put emphasize on the word . . So lectin has a similar overall function as any PRRs: non-specific recognition of the pathogen.. but only that lectin can help to enhance immune reaction against re-infection of similar pathogens.

Pathogen recognition and discrimination from self is due to recognition of a particular orientation of certain sugar residues, as well as their spacing, which is found ONLY on pathogenic microbes and NOT on host cells.

I thought Pathogen recognition and self-non-self differentiation are based on two different mechanisms? That is pathogen (non-self pathogenic) recognition is done by innate immune system (through PRRs).
And self/non-self differentiation is achieved through differentiation of self MHC molecules from non-self MHC and peptide molecules? That is the non-self molecules will trigger an immune response..

hm.. maybe my understanding of immunology is too basic and over-simplified..

[victor]

That is the non-self molecules will trigger an immune response..

I think infected cells will trigger an immune response...am I wrong?