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T cells receive 3 signals during activation:
1. Major Histocompatibility Complex (MHC) presenting an antigen (foreign peptide) to the T cell receptor
2. 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
What else can I help you with?
What signals does a t cell require in order to divide?
T cells require signaling through the T cell receptor (TCR) upon recognition of a specific antigen presented by antigen-presenting cells, as well as co-stimulatory signals from molecules like CD28 on the T cell and CD80/86 on the antigen-presenting cell. These signals are necessary for T cell activation and proliferation.
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.
What structure on the macrophage activates the t cell?
The structure on the macrophage that activates T cells is the Major Histocompatibility Complex (MHC) molecule, specifically MHC class II. Macrophages present processed antigens on these MHC class II molecules to CD4+ T helper cells, initiating T cell activation. This interaction is crucial for the adaptive immune response, as it helps T cells recognize and respond to specific pathogens. Additionally, co-stimulatory signals from other surface proteins on the macrophage are necessary for full T cell activation.
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 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.
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.
How do t helper 1 cells activate and assist in the activation of t cells?
T helper 1 cells activate and assist in the activation of T cells by releasing signaling molecules called cytokines. These cytokines help stimulate T cells to multiply and become more effective in fighting off infections. Additionally, T helper 1 cells can directly interact with T cells to provide necessary signals for their activation and function.
The size of a t-cell?
Between 5 and 10 microns, depending upon activation status
What is a cell that can receive and transmit signals?
Actually all cells can send and receive signals. For example every cell has a CD95(FASr) which receives signals from natural killer cells or T cells and results in cell death. Also all cells send signals through cell membrane receptors to neighboring cells. These signals prevent neighboring cell colonies from growing too big.(The lack of these signals is one of the problems with certain cancer cells)
What types of t cells are formed during activation?
T cells can be divided into CD4 cells (T helper cells) and CD8 cells (cytoxic T cells).There are then many different types of T helper cells, the main ones being TH1 and TH2 cells. TH1 cells are involved in antigen presentation and cellular immunity (eg. phagocytic cells). TH2 cells are involved in humoral immunity (production of antibodies) and allergy reactions.The cytokines (signalling molecules) released by the dendritic cell during T cell activation are responsible for the differentiation of T cells into different types. Further cytokines then cause the differentiation into TH1, TH2, etc.(There are also regulatory T cells which suppress the functions of other T cells to prevent the immune system attacking self molecules)
Do cardiac muscles have T tubules?
Yes, cardiac muscles do have T tubules. T tubules are invaginations of the cell membrane that help transmit electrical signals throughout the muscle cell, allowing for coordinated contraction.
What sag stand for?
SAG stands for Super Antigen which is a body of Antigens which result in non - specific activation of T - cells which lead to what is called polyclonal T cell activation and colossal cytokine release. There are Pathogenic Microbes which can produce SAGs which act as a type of security system adjacent to the immune system. SAG's obtain good capacity of stimulating stimulate as much as 20% of the body's T-cell when compared to regular antigen - induced T - cell response.
