Immunology

[keliao]

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Which of the follwing is NOT true about helper T cells?

a. they function in both cell-mediated and humoral immune responses.
b. They recognize polysaccharide fragments presented by class II MHC molecules.
c. they bear surface CD4 molecules.
d. they are subject to infection by HIV
e. When activated, they secrete cytokines.

I am not sure if the DAT will be this specific but you never know!!!..

 

[192LT192]

i believe humoral immunity is B cells so I would say A is false. the rest of the choices seem correct

 

[keliao]

i chose A too!!!...but the answer from my book says its B. which i dont understand why!!

Humoral immune response involves the activation and clonal selection of B cells.
Cell-mediated involves ~~~~ T cells.

 

[pbure9]

That's odd because Helper T cells do bind to Class II MHC's (cytoxic T cells bind to Class I MHC's).
Also, helper T cells are seen in the humoral response as they bind to B cells and release cytokines to allow them to differentiate into plasma or memory B cells.

 

[ucla2134]

Which of the follwing is NOT true about helper T cells?

a. they function in both cell-mediated and humoral immune responses.
b. They recognize polysaccharide fragments presented by class II MHC molecules.
c. they bear surface CD4 molecules.
d. they are subject to infection by HIV
e. When activated, they secrete cytokines.

I am not sure if the DAT will be this specific but you never know!!!..

Well, the answer is true since bacterial made out of peptide, not polysaccharide. So the right answer should be that it recognize the peptide fragments, not polysaccharide.

 

[pbure9]

Well, the answer is true since bacterial made out of peptide, not polysaccharide. So the right answer should be that it recognize the peptide fragments, not polysaccharide.

I was thinking that too... but technically they attach to antigens.. which can be protein or polysaccharide no?

 

[keliao]

Well, the answer is true since bacterial made out of peptide, not polysaccharide. So the right answer should be that it recognize the peptide fragments, not polysaccharide.

thanks!!.

 

[ttran9229]

I was thinking that too... but technically they attach to antigens.. which can be protein or polysaccharide no?

Your statement is generally correct for antigens, but Class II MHC molecules are protein based and typically found on the surface of antigen-presenting cells such as B cells, dendritic cells, and macrophages.

 

[pbure9]

Your statement is generally correct for antigens, but Class II MHC molecules are protein based and typically found on the surface of antigen-presenting cells such as B cells, dendritic cells, and macrophages.

Alright, I'll take your word on that. Thanks man. I doubt the DAT is this specific though. (Hope not 😎)