The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

OCR AS Biology - B and T lymphocyte help

As the title suggests, we're just learning about defence against disease in my biology class. I've come to revise the activation of B and T cells, but my revision book doesn't go into any more detail than a diagram that's not really labelled!

I'd really appreciate if someone could outline the activation of both cells (we hovered over clonal selection and clonal expansion in class) and how the roles of each cell differ? Do both cells produce antibodies? I don't think we need to go into too much detail at AS but this is my favourite topic in biology and I'm interested in getting a thorough understanding rather than just remembering the facts :smile:

A final (and hopefully short) question about macrophages:
I know that they're 'antigen presenting' cells - but what is meant by this? Do they present the antigens of the pathogen that they've destroyed or is it a different pathogen specific to the phagocyte?

I'm sorry if this is just a lot of stupid questions, thank you in advance for helping!
This is for OCR, but may help any other exam board idk
Please could someone correct me if im wrong

When your body is exposed to antigens or foreign bodies that the body does not recognise the immune system will be alerted. This triggers a secondary immune response. And APC are the antigens that have been killed (hydrolysed) by the lysosome in a phagocyte and then they are processed and placed on the cell surface membrane

There are two types:

Humoral Immune response and cell mediated response.

HIR:

1) Phagocytosis has occurred. After phagocytosis an APC will be placed on the cell surface membrane acting as a cell receptor.
2) The APC interacts with T-Helper cells making them produce interluekin 1 ( a cytokine)
3) Interleukin 1 stimulates the T-helper cell to make Interleukin 2 which then stimulates the differentiation of B helper cells into plasma cells (Plasma expansion)
4) The new plasma cells create alot of antigen-specific antibodies which then bind to the pathogens antigen. and destroy it by agglutination or neutralisation
5) After this has occured, B memory cells form

Cell mediated:

1) APC is made, etc...
2) Receptors on the T helper cell will fit the antigens active site which creates interluekin 1
3) This causes mitosis too occur causing these T-helper cells to divide rapidly
4) New cloned T-helper cells carry the antigen/bodies to a particular pathogen
5) The T hcells may turn into Memory cells, or produce interleukin for phagocytes


I'm not sure if that answers you question, but I just thought it may help you understand them a bit more :smile:
Original post by Medicineisgood
This is for OCR, but may help any other exam board idk
Please could someone correct me if im wrong

When your body is exposed to antigens or foreign bodies that the body does not recognise the immune system will be alerted. This triggers a secondary immune response. And APC are the antigens that have been killed (hydrolysed) by the lysosome in a phagocyte and then they are processed and placed on the cell surface membrane

There are two types:

Humoral Immune response and cell mediated response.

HIR:

1) Phagocytosis has occurred. After phagocytosis an APC will be placed on the cell surface membrane acting as a cell receptor.
2) The APC interacts with T-Helper cells making them produce interluekin 1 ( a cytokine)
3) Interleukin 1 stimulates the T-helper cell to make Interleukin 2 which then stimulates the differentiation of B helper cells into plasma cells (Plasma expansion)
4) The new plasma cells create alot of antigen-specific antibodies which then bind to the pathogens antigen. and destroy it by agglutination or neutralisation
5) After this has occured, B memory cells form

Cell mediated:

1) APC is made, etc...
2) Receptors on the T helper cell will fit the antigens active site which creates interluekin 1
3) This causes mitosis too occur causing these T-helper cells to divide rapidly
4) New cloned T-helper cells carry the antigen/bodies to a particular pathogen
5) The T hcells may turn into Memory cells, or produce interleukin for phagocytes


I'm not sure if that answers you question, but I just thought it may help you understand them a bit more :smile:


Omg you absolute god thank you so much, dont even do OCR but maybe i can stop crying over this topic now thank you :hugs: x
Original post by CoolCavy
Omg you absolute god thank you so much, dont even do OCR but maybe i can stop crying over this topic now thank you :hugs: x


ahaha no worries :smile:
Original post by Medicineisgood
This is for OCR, but may help any other exam board idk
Please could someone correct me if im wrong

When your body is exposed to antigens or foreign bodies that the body does not recognise the immune system will be alerted. This triggers a secondary immune response. And APC are the antigens that have been killed (hydrolysed) by the lysosome in a phagocyte and then they are processed and placed on the cell surface membrane

There are two types:

Humoral Immune response and cell mediated response.

HIR:

1) Phagocytosis has occurred. After phagocytosis an APC will be placed on the cell surface membrane acting as a cell receptor.
2) The APC interacts with T-Helper cells making them produce interluekin 1 ( a cytokine)
3) Interleukin 1 stimulates the T-helper cell to make Interleukin 2 which then stimulates the differentiation of B helper cells into plasma cells (Plasma expansion)
4) The new plasma cells create alot of antigen-specific antibodies which then bind to the pathogens antigen. and destroy it by agglutination or neutralisation
5) After this has occured, B memory cells form

Cell mediated:

1) APC is made, etc...
2) Receptors on the T helper cell will fit the antigens active site which creates interluekin 1
3) This causes mitosis too occur causing these T-helper cells to divide rapidly
4) New cloned T-helper cells carry the antigen/bodies to a particular pathogen
5) The T hcells may turn into Memory cells, or produce interleukin for phagocytes


I'm not sure if that answers you question, but I just thought it may help you understand them a bit more :smile:


That really does help thank you!! You've put it into words that's made it so much easier to understand :biggrin:
Original post by VetStudentOf2017
That really does help thank you!! You've put it into words that's made it so much easier to understand :biggrin:


Happy to help! I have edited it slightly tho :smile:)
Original post by Medicineisgood
Happy to help! I have edited it slightly tho :smile:)


Hi! Sorry to bring this up again, I just have a quick question! Is it the APC that produces interleukin 1 in both responses? Thank you :smile:
Original post by VetStudentOf2017
Hi! Sorry to bring this up again, I just have a quick question! Is it the APC that produces interleukin 1 in both responses? Thank you :smile:


hey, APCs just interacts with the receptors on the T helper cells which then stimulate the interleukins to being made.. so the t helper cell actually makes it

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you