What determines whether an antigen binds to a T-helper cell or a B lymphocyte?

Watch
BethMay17
Badges: 1
Rep:
?
#1
Report Thread starter 5 years ago
#1
AS Biology - What determines whether an antigen binds to a T-helper cell or a B lymphocyte?
0
reply
kkboyk
Badges: 21
#2
Report 5 years ago
#2
(Original post by BethMay17)
AS Biology - What determines whether an antigen binds to a T-helper cell or a B lymphocyte?
It's been long since I did this, so I forgot some stuff. Anyone can correct me if I'm wrong

I think you're a bit confused by the role of these two cells: as the name implies, T-helper cells helps other cells. This is done by activating T-killer cells to destroy to the cell (or even macrophage), as well as activate B-lymphocytes for the production of antibodies (as well as memory cells) in which would agglutinate with the same antigen present in the body.

Edit: lymphocytes are specific to one antigen only, and its the surface receptors that determines which antigen to bind to.
0
reply
BethMay17
Badges: 1
Rep:
?
#3
Report Thread starter 5 years ago
#3
(Original post by kkboyk)
It's been long since I did this, so I forgot some stuff. Anyone can correct me if I'm wrong

I think you're a bit confused by the role of these two cells: as the name implies, T-helper cells helps other cells. This is done by activating T-killer cells to destroy to the cell (or even macrophage), as well as activate B-lymphocytes for the production of antibodies (as well as memory cells) in which would agglutinate with the same antigen present in the body.

Edit: lymphocytes are specific to one antigen only, and its the surface receptors that determines which antigen to bind to.
Does this mean that B-cells can only be activated by T-helper cells releasing cytokines? Because I thought that B-cells can also be activated by binding to antigens on the plasma membrane of antigen-presenting cells or antigens in the blood. This surely implies that B-cells can deal with antigens by proliferating and differentiating into plasma cells (releasing antibodies), without the involvement of T-helper cells?
0
reply
kkboyk
Badges: 21
#4
Report 5 years ago
#4
(Original post by BethMay17)
Does this mean that B-cells can only be activated by T-helper cells releasing cytokines? Because I thought that B-cells can also be activated by binding to antigens on the plasma membrane of antigen-presenting cells or antigens in the blood. This surely implies that B-cells can deal with antigens by proliferating and differentiating into plasma cells (releasing antibodies), without the involvement of T-helper cells?
The antigen binds to the B-cell, and then is engulfed amd digested. The fragments of the antigens are expressed on the B-cells outer surface (on the receptor), which a T-helper cell then binds to and release cytokines causing the B-cell to become activated (clonal expansion occurs). Humoral and cell-mediated response occur at the same time, but the cell-mediated response focuses on destroying solely the infected cells (which shoe signs of distress on their receptors).

The proliferafion and differentiation occur as a result of the B-cell becoming activated.

Hope I explained it well
0
reply
Asklepios
  • Study Helper
Badges: 19
Rep:
?
#5
Report 5 years ago
#5
(Original post by BethMay17)
Does this mean that B-cells can only be activated by T-helper cells releasing cytokines? Because I thought that B-cells can also be activated by binding to antigens on the plasma membrane of antigen-presenting cells or antigens in the blood. This surely implies that B-cells can deal with antigens by proliferating and differentiating into plasma cells (releasing antibodies), without the involvement of T-helper cells?
B-cells can also become activated in a T-cell independent manner. This happens when they express their immunoglobulins (mainly IgM and IgD) on their surface, known at the B-cell receptor (BCR). Antigens can bind to the BCR and this triggers clonal expansion via a downstream signal. Toll-like receptors and pattern recognition receptors also play a role in B-cell activation through the detection of PAMPs.

During B-cell development in the bone marrow, self-antigens bind to the BCR and this results in negative selection to ensure there are no self-reactive antibodies.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Feeling behind at school/college? What is the best thing your teachers could to help you catch up?

Extra compulsory independent learning activities (eg, homework tasks) (18)
7.35%
Run extra compulsory lessons or workshops (37)
15.1%
Focus on making the normal lesson time with them as high quality as possible (44)
17.96%
Focus on making the normal learning resources as high quality/accessible as possible (35)
14.29%
Provide extra optional activities, lessons and/or workshops (64)
26.12%
Assess students, decide who needs extra support and focus on these students (47)
19.18%

Watched Threads

View All