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T cells (both CD4 "helper" and CD8 "cytotoxic" cells) are activated by antigen presenting cells (i.e. dendritic cells). This involves 3 different signals from the dendritic cell:
1. Major Histocompatibility Complex (MHC) presents an antigen (foreign peptide) to the T cell
2. A co-stimulatory signal (checking that it is a "professional" antigen presenting cell) which is a B7 molecule binding to a CD28 on the T cell
3. Cytokines (signalling molecule)
It is this 3rd type of signal, the cytokines which is important in the creation of the different T cells (CD8, or cytotoxic T cells and CD4, helper T cells).
Dendritic cells are able to release different cytokines, which cause T cell differentiation.
CD4 cells are presented antigen by MHC class II, whereas CD8 cells are presented antigen by MHC I.
What else can I help you with?
What binds with and releases chemicals that activate B cell and T cell and and macrophages?
Antigen-presenting cells (APCs) such as dendritic cells bind with antigens and present them to B cells, T cells, and macrophages, leading to their activation. This process is crucial for initiating immune responses against pathogens and foreign substances in the body.
What is meant by T cell priming?
T cell priming refers to the process by which naive T cells encounter antigen-presenting cells, receive signals, and become activated to mount an immune response against specific antigens. This activation is essential for T cells to differentiate into effector T cells capable of carrying out their immune functions.
Is T cell activation antigen specific?
Yes. The first signal that a T cell receives from an antigen presenting cell (dendritic cell) is MHC presenting an antigen (foreign peptide). This gives the T cell specificity to this antigen.
How can B cell mature into plasma cell?
The surface immunoglotulin that serves as the B-Cell antigen receptor (BCR) has two roles in B-cell activation. First, like the antigen receptor on T cells, it transmits signals directly to the cell's interior when it binds antigen. Second, the B-Cell antigen receptor delivers the antigen to intracellular sites where it is degraded and returned to the B-cell surface as peptides bound to MHC class II molecules.
What are the steps in cell mediated immune process?
Antigen presentation: Antigen-presenting cells (APCs) process and present antigens to T cells. T cell activation: APCs activate T cells by binding to their T cell receptors and providing co-stimulatory signals. T cell proliferation and differentiation: Activated T cells undergo clonal expansion and differentiate into effector T cells, such as cytotoxic T cells and helper T cells. Target cell destruction: Effector T cells recognize and kill infected or abnormal cells through various mechanisms, such as releasing cytotoxic molecules or activating other immune cells.
What is worse b cell lymphoma or t cell lymphoma?
t cell lymphoma
What is the first signal required for activation of a T cell?
The first signal required to activate a T cell is MHC(Major Histocompatibility Complex) presenting an antigen(foreign peptide) to the T cell receptor.
T cells and B cells activated only by what?
T cells are activated by antigens presented on the surface of antigen-presenting cells, such as dendritic cells. B cells are activated primarily by recognizing antigens with their B cell receptor, although they may also require T cell help for full activation.
What cell introduces epitopes to T cells?
Antigen-presenting cells (APCs), primarily dendritic cells, macrophages, and B cells, introduce epitopes to T cells. They process and present peptide fragments of antigens on their surface using major histocompatibility complex (MHC) molecules. This interaction is crucial for T cell activation, allowing them to recognize and respond to specific pathogens or infected cells. Dendritic cells are particularly effective at initiating T cell responses due to their ability to capture and present antigens in lymphoid tissues.
How helper T cell stimulate an increase in the number of B cell?
Helper T cells release cytokines that activate B cells by binding to their surface receptors. This interaction stimulates B cell proliferation and differentiation into plasma cells, which produce antibodies. This process helps increase the number of B cells specific to a particular antigen and enhances the immune response.
The size of a t-cell?
Between 5 and 10 microns, depending upon activation status
What are the double signals in T cell activation?
T cells receive 3 signals during activation:1. Major Histocompatibility Complex (MHC) presenting an antigen (foreign peptide) to the T cell receptor2. The co-stimulatory signal (B7 on the dendritic cell binding to CD28 on the T cell)The first signal ensures that the T cell is specific for the antigen it has been presented.The T cell cannot be activated without also recieveing the second signal. This is how the T cell checks that it has been presented an antigen by a "professional" antigen presenting cell.3. Cytokines (signalling molecules) are released by the dendritic cell - these cause the differentiation of the T cell
