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What effect does the repression of the class 1 MHC membrane proteins have on the cytotoxic t cells?
Repression of class 1 MHC membrane proteins can render infected or malignant cells invisible to cytotoxic T cells, preventing the immune system from recognizing and attacking these abnormal cells. This evasion strategy allows the cells to evade immune surveillance and continue proliferating unchecked.
What is the role of cytotoxic T cells and describe their mechanism of action?
The role of cytotoxic T cells is to alert Class I MHC molecules to a foreign antigen. This is achieved by the foreign antigen associating with the MHC molecule and being moved out to the cell surface, where the cytotoxic T cell alerts the MHC molecule of the infection.
What type of tcell can tell weather a cell is healthy or not?
Cytotoxic T cells, also known as CD8+ T cells, play a crucial role in determining whether a cell is healthy or not. They can recognize and eliminate infected or cancerous cells by detecting abnormal antigens presented on major histocompatibility complex (MHC) class I molecules. By assessing these signals, cytotoxic T cells help maintain the integrity of the immune system and prevent the proliferation of unhealthy cells.
Are MHC 1 proteins found on most cells of the body?
Yes, MHC class I proteins are found on most nucleated cells in the body. They play a key role in presenting endogenous antigens to cytotoxic T cells for immune surveillance and response.
What molecule displays an antigen on the surface of the cells?
Major histocompatibility complex (MHC) molecules display antigens on the surface of cells. There are two main classes: MHC class I, which presents antigens to CD8+ cytotoxic T cells, and MHC class II, which presents antigens to CD4+ helper T cells. These molecules play a crucial role in the immune response by enabling the recognition of foreign substances by T cells.
B cells and T cells belong to what class of agranular leukocytes?
B cells and T cells belong to the class of lymphocytes, which are a type of agranular leukocytes. They play a central role in the adaptive immune response by recognizing and targeting specific pathogens for destruction.
Is humoral immunity mhc class II?
No, it's cellulair. Handy to be recognized by the cytotoxic T-cells.
What effect does the repression of the class 1 MHC membrane proteins have on the cytotoxic t cells?
Repression of class 1 MHC membrane proteins can render infected or malignant cells invisible to cytotoxic T cells, preventing the immune system from recognizing and attacking these abnormal cells. This evasion strategy allows the cells to evade immune surveillance and continue proliferating unchecked.
What is the role of cytotoxic T cells and describe their mechanism of action?
The role of cytotoxic T cells is to alert Class I MHC molecules to a foreign antigen. This is achieved by the foreign antigen associating with the MHC molecule and being moved out to the cell surface, where the cytotoxic T cell alerts the MHC molecule of the infection.
When an antigen binds to a Class 1 MHC molecule it stimulates what cell?
Class I MHC molecules present antigens to cytotoxic T-cells (which are CD3+CD8+).
What type of tcell can tell weather a cell is healthy or not?
Cytotoxic T cells, also known as CD8+ T cells, play a crucial role in determining whether a cell is healthy or not. They can recognize and eliminate infected or cancerous cells by detecting abnormal antigens presented on major histocompatibility complex (MHC) class I molecules. By assessing these signals, cytotoxic T cells help maintain the integrity of the immune system and prevent the proliferation of unhealthy cells.
Are MHC 1 proteins found on most cells of the body?
Yes, MHC class I proteins are found on most nucleated cells in the body. They play a key role in presenting endogenous antigens to cytotoxic T cells for immune surveillance and response.
What is the type of major histocompatibility marker that's most likely found on a liver cell?
Answer Class II MHC protein. Class II are found in membranes of antigen-presenting cells-phagocytic cells and lymphocytes. The liver performs phagocytosis and antigen presentation.
What molecule displays an antigen on the surface of the cells?
Major histocompatibility complex (MHC) molecules display antigens on the surface of cells. There are two main classes: MHC class I, which presents antigens to CD8+ cytotoxic T cells, and MHC class II, which presents antigens to CD4+ helper T cells. These molecules play a crucial role in the immune response by enabling the recognition of foreign substances by T cells.
Difference between MHC class1 and MHC class2 molecules?
MHC proteins express antigens on a cell surface for T cells to identify whether the antigens presented are self or foreign. There are two classes MHC I and MHC II. They differ in which cells they require to activate depending on the pathogen present.
What is a callystatin?
A callystatin is any of a class of cytotoxic polyketides, found in marine sponges of the genus Callyspongia, which have antibiotic activity.
What is the function of the cytotoxic T cells?
Cytotoxic T cell's primary responsibility is to kill infected cells. I'll start from the beginning. From a progenitor cell in the bone marrow, the T cell will begin maturation in the thymus. In the thymus it begins in the cortex as a pro T cell. In this stage it is considered a double negative cell (I'll explain more later). Here it has the beta chain (V,D,J's) rearranged. Next it becomes a pre T cell. By now the T cell has finished rearranging its beta chain and now begins rearrangement of its alpha chain. Both the beta and alpha chain under go allelic exclusion. This prevents one of the alleles from being expressed (this would be mom's or dad's). If the pro T cell made a beta chain from your mothers allele, your father's allele would be suppressed. This is an important feature, otherwise you could accidentally make a stop codon and that would stop your T cell development right there. So as a pre T cell it continues to proliferate and it upregulates CD3, CD4 and CD8. You have two types of T cells that it can mature to. CD4 and CD8. A CD4 T cell is also known as a helper T cell and a CD8 T cell is also called a cytotoxic T cell. They function very differently but at this point the T cell doesn't know which one it will become. Therefore it is at this juncture a double positive thymocyte. The next phase is an immature T cell. Here the alpha chains have finished rearrangement (also allelic exclusion applies here). Now the cell will undergo positive and negative selection. The immature T cell is tested by thymic epithelial cells (TEC). TEC's have a unique feature that belongs to professional antigen presenting cells (APC's) and that is expressing both MHC class I and MHC class II on its cell surface. An immature T cell that can bind to a TEC's MHC class I or MHC class II is positively selected to continue maturation. This is an important step because ensures that your T cells are specific for your body's MHCs. However, if the immature sticks too strongly, it will be neglected and eventually die. You don't want a mature T cell that binds way too strongly on your own cells either. Those that don't bind at all will also die by neglect. The strict standards ends up killing about 95% of all maturing T cells. The immature T cell that was capable of binding to MHC class I molecule is signaled to become a CD8 or cytotoxic cell and the immature T cell that was capable of binding to MHC class II molecule is signaled to become a CD4 or helper T cell. Now that your immature T cells have been primed to your own body, it will undergo negative selection. In this process it is exposed to other types of cells, dendritic cells and macrophages. Dendritic cells and macrophages are part of your APCs. If the T cell binds too strongly it will also die by neglect. Congratulations! Your immature T cell is now a mature naive T cell. It is now ready to leave your thymus and it will be stored mainly in your lymph nodes to await an infection. Now that your cytotoxic T (CD8) cell has been made, it waits in your lymph node for an infection. A dendritic cell (remember these guys? they are present all over your body) will come in through an afferent lymphatic vessel from the source of infection. An important feature of cytotoxic T cells is that it targets cytoplasmic infection, or more specifically viruses. Generally viruses proliferate within a cell and antibodies cannot get to them if the virus is residing inside one of your own cells. So the dendritic cell gets infected and travels through the afferent lymphatic vessel into your lymph nodes. Here waits all of your adaptive immunity responses. It's an ambush! Your cytotoxic cells have been waiting for this moment. The cytotoxic cell that is specific for the antigen that is presented on the dendritic cell latches on. There are two signals that activate the cytotoxic (CD8) cell. B7 from the dendritic cell attaches to CD28 on the cytotoxic T cell and CD8 attaches to the dendritic cell. The cytotoxic cell is now activated and it is now on a mission to destroy. It secretes IL-2 which binds to itself. This is an autocrine function that signals the cytotoxic cell to replicate like crazy. Your army travels out through the efferent lymphatic vessel into your blood stream. Eventually it arrives to the cells that are infected. It is capable of binding to the same antigens that it first recognized from the dendritic cell that brought it inside initially. It latches on with CD8 and releases its' weapons. Perforin is released which punches holes into the cell and granzymes are also released which induces apoptosis (cell death). Memory T cells are also made to fight against future infection. These are long lasting cells. Your other T cells (remember them?) the helper T cells come by and deactivate your cytotoxic T cells with FasR and CTLA-4. Hope that helps.
