Vaccine: capsular polysaccharide + toxoid

[Convalaria]

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What cells of immune system react on what part of the vaccine:

capsular polysaccharide - B-cells
toxoid - Th2 cells?

Thanks in advance!

 

[Phloston]

What cells of immune system react on what part of the vaccine:

capsular polysaccharide - B-cells
toxoid - Th2 cells?

Thanks in advance!

That's a good question. I'll take a guess, but immuno is not my strong point so anyone should feel free to correct/fill in my gaps.

With the polysaccharide, it can be phagocytosed by B-cells but can't be expressed on MHC-II molecules, so the Th cells will never see it. Since the Th2 cells are responsible for class-switching, there's no long-term protection (i.e. IgG Ab production). There's also no cell-mediated immunity (Th1 response) produced, if the vaccine makes it to the tissues, because phagocytosis by macrophages too requires MHC-II expression for the T-cell response.

With the toxoid, there's a proteinaceous component, so it will get expressed on MHC-II molecules. Therefore, phagocytosis by B-cells leads to a Th2 response and, ultimately, to class-switching via CD40-CD40L interaction.

I'm also not sure what you mean by which part of the vaccine..

 

[Convalaria]

I'm also not sure what you mean by which part of the vaccine..

By part I meant vaccine components: capsular polysaccharide, toxoid

Thank you, your post is very helpful, as usual 🙂

 

[sadaca]

hey guys,
I had a question relating to this . In my First Aid it says that capsular polysaccharide vaccines ARE conjugated meaning class switching occurs. But in Kaplan they say its only B cell and not conjugated. Could someone plz help me out with this? I know on boards it is asked and I am not sure what the correct way is here.

appreciate it