Why Do T Cells Activate Killer T Cells?

The immune system is made up of several types of cells that work together to fight infections. Lymph cells (called lymphocytes) are the main type of cell in the adaptive immune system. There are 2 types of lymph cells: T cells and B cells. When B cells respond to an infection, they change into plasma cells. The plasma cells are found mainly in the bone marrow—the soft, inner part of some bones. The plasma cells

a. This function is mediated by T cells and B cells (memory cells) in our body via adaptive immunity. The adaptive immune system evolved in early vertebrates and allows for a stronger immune response as well as immunological memory, where each pathogen is “remembered” by a signature antigen. The adaptive immune response is antigen-specific and requires the recognition of specific “non-self” antigens during a process called antigen presentation. Antigen specificity allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells. The ability to mount these tailored responses is maintained in the body by memory cells. Should a pathogen infect the body more than once, these specific memory cells are used to quickly eliminate it. So basically killer T cells will identify antigens present on foreign cells. These antigens are not found in any of the cells inside our body. Therefore, T cells will identify them and kill them.

The developmental routes for these cells are very complex and unique but there are similarities. B-cells produce antibodies to bind onto foreign bodies that have invaded the host organism; this allows cells such as cytotoxic T-cells will then destroy the infected cell/structure. On the other hand, T-cells such as T-helper cells that secrete cytokines to control immune responses and cytotoxic T-cells that destroy pathogenic cells and structures.

The organs that make up the lymphatic and immune system are the tonsils, spleen, thymus gland, lymph nodes, and lymphatic vessels. White blood cells (leukocytes), red blood cells (erythrocytes), plasma, and platelets (thrombocytes) make up the blood. Lymphocytes are leukocytes (white blood cells) that help the body fight off diseases. Two types of lymphocytes are B cells and T cells. Lymphocytes recognize antigens, or foreign substances/matter, in the body. Lymphocytes are a classification of agranulocytes, or cells (-cytes) without (a-) granules (granul/o) in the cytoplasm. B cells are created from stem cells, which are located in the bone marrow. B cells respond to antigens by becoming plasma cells. These plasma cells then create antibodies. Memory B cells produce a stronger response with the next exposure to the antigen. B cells fight off infection and bacteria while T cells defend against viruses and cancer cells. A hormone created by the thymus gland called thymosin changes lymphocytes into T cells. The thymus gland is active when you are a child and slowly shrinks, as you get older. T cells bind to the antigens on the cells and directly attack them. T cells secrete lymphokines that increase T cell production and directly kill cells with antigens. There are three types of T cells: cytotoxic T cells, helper T cells, and memory T cells.

makes antibodies (also called immunoglobulins) that help attack and kill germs. Lymphocytes are in many areas of the body, such as lymph nodes, the bone marrow, the intestines, and the bloodstream.

Lymphocytes- These leukocytes are comprised of B and T cells. B cells secrete antibodies and the T cells kill infections. Therefore lymphocytes aid in defending the immune system.

They are known as T- Lymphocytes and B-Lymphocytes. B-cells are usually distinguished with humoral immunity because b-cells circulate freely through the lymph system. Whereas T-cells are distinguished by humoral immune response because they act with antigens within other cells. Once these lymphocyte have been produced with the help of bone marrow stromal cells (which are a type of stem cell that is present in red bone marrow) they are released into the blood stream where they travel up to the thymus, and other lymphoid organs. When B-cells, also known as memory cells, leave the bone marrow, they become activated (true b-cells) This process involves the addition of a membrane protein known as immunoglobin M. (IgM) This membrane protein acts a receptor for antigens. Therefore they can said to be the binding site for antibodies. Once an antigen attaches itself to IgM receptor, a signal transduction pathway occurs through tails that descend down into the cells cytoplasm causing them to release antibodies. The second cell type, T-cells, are produced in the bone marrow, through the the same way B-cells are produced. The only difference is they mature in the thymus. This occurs because they undergo genetic recombination of their alpha

The structure on the inside of the T-Cell is like a regular cell structure. It has a nucleus, Golgi body, Mitochondria, Cell membrane, Vacuole, Lysosome, E.R., Ribosomes and Cytoplasm. It is like a rankled up piece of paper on the outside and on the inside it is like a cell we have been looking at in our books. It functions to body in the immune system. When it detects bad cells in the immune system thin it attacks it. A t-cell is produced by the thousand in the bone marrow. T-Cells Also circulate the blood.

Natural killer T cells (NKT), not to be confused with Natural Killer cells or killer T cells (CTL), are a heterogeneous subset of T cells recognized by their unique innate and adaptive molecular characteristics and markers. Perhaps the most defining characteristic of natural killer T cell is the ability to recognize lipid antigens in the context of CD1d molecules, associated to β2-microglobulin (Laurent, Renault, Farce, Chavatte, & Hénon, 2014). CD1d molecules are predominantly expressed by Antigen Presenting cells, particularly Marginal Zone B cells (MZB). NKT cells have been divided into two main subsets: type I NKT cells that use a canonical invariant TCR α-chain and recognize α-galactosylceramide (α-GalCer), a powerful antitumor stimulant, and type II NKT cells that use a more diverse αβ TCR repertoire and do not recognize α-GalCer (Macho-Fernandez & Brigl, 2015. Notably, α-GalCer-activated Type I NKT cells are capable of substantial crosstalk with other cell types of the innate and adaptive immune systems (Matsuda et al. 2008; Parekh et al. 2007). However, Type II NKT cells display more of a heterogeneous TCR and lack Vα14-Jα18 rearrangement, thus the reason for their inability to recognize α-GalCer. Conversely, type II NKT cells recognize a naturally occurring self-glycolipid and sulfatide, which is enriched in several membranes, including myelin in the central nervous system (CNS), β-cells in the pancreas, kidney, and liver (Marrero, Ware, & Kumar,

The adaptive immune response utilizes T-Lymphocytes, in particular CD4+ T Cell (T Helper Cells) and CD8+ T Cell (T Cytotoxic Cells), B-Cells, Natural Killer (NK Cells), macrophages and Dendritc Cells (DC) in response to a viral infection. All of these cells act as a conduit for the innate and adaptive immune systems. The activation of T and B-cells is the beginning of the adaptive immune response that involves a specific, memory-induced response. . T-Lymphocytes have four types: T-Helper Cells (CD4+),

Healthy individuals have their immune system working properly to protect them from pathogens. Leukocytes are a part of the immune system that circulate in the blood (white cells). Lymphocytes are one subset of leukocytes that recognize and respond to their specific antigens (e.g.\ peptides from an external agent). T cells are a group of lymphocytes that mature in the thymus. Under exposure to their specific antigen, conventional T cells are activated, leading to secretion of growth cytokines (predominantly interleukine 2, denoted IL-2), and expression of the interleukine 2 receptor which triggers cytokine driven proliferation \cite{deboer87,thornton98,BOP2006}. However, the immune system can cause damage by targeting erroneously self antigens

The body’s immune system starts to fight back using T cells and Macrophage. The T cells attack and kill the virus cells, whereas the Macrophage eat the diseased cells. But how do they know how to attack?

The adaptive immune response is antigen-specific and requires the recognition of specific “non-self” antigens during a process called antigen presentation. Antigen specificity allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells. The ability to mount these tailored responses is maintained in the body by "memory cells". Should a pathogen infect the body more than once, these specific memory cells are used to quickly eliminate it. so basically killer T cells will identify antigens present on foreign cells. These antigens are not found in any of the cells inside our body. So T cells will identify them and kill them.

The next cells are the T cells. There are many different types of T-cells. One is the Killer T-cell. They can recognize invaders with feelers on the outside of the cell and if the cell is infected, it can destroy the cell. Another type is the helper T-cell. The helper t-cell functions more as support. It matures B-cells and tells them to make antibodies by secreting a protein. A helper t-cell also activates the killer t-cell. The last major t-cell is the memory t-cell. If you get sick, the memory t-cell will remember the antigen and will the immune system be able to defeat the same disease faster. The next cell is the Natural Killer Cell. These cells are lymphocytes that destroy viruses by releasing a protein that makes the affected cell “program” itself for death. The process it destroys itself is called apoptosis. (Kidshealth.org)

Vaccines interact with three main cell types after an infection: macrophages, T lymphocytes, and B lymphocytes/antibodies (Understanding How Vaccines Work, 2013). The macrophages are the white blood cells that attack and consume the pathogen (Understanding How Vaccines Work, 2013). They leave behind parts of the pathogen, which are known as antigens (Understanding How Vaccines Work, 2013). The when the body comes in contact with the antigen, it recognizes that it is foreign body and that it is dangerous, it signals a response to attack it (Understanding How Vaccines Work, 2013). The antibodies are the cell that attack the antigen left by the macrophages (Understanding How Vaccines Work, 2013). The antibodies are produced by B lymphocytes, and the B lymphocytes are a type of defensive white blood cell (Understanding How Vaccines Work, 2013). The T lymphocytes are another type of defensive white blood cell (Understanding How Vaccines Work, 2013). They attack cells that have already been infected with a pathogen (Understanding How Vaccines Work, 2013). Without these three main cell types, a person would have no chance to fight off an