The Central And Peripheral B Cell Tolerance

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

“Humoral immunity is a type of immune response that depends on antibodies.” The response begins when a pathogen binds to a B cell. The B cell will engulf the pathogen and display a part of the antigen on its exterior. Once a T cell is exposed to the antigen-presenting B cell, the T cell will release proteins to activate the B cell. Now that the B cell is activated, it will produce antibodies to cause the pathogens to clump together. In the last stage of humoral immunity, phagocytes will engulf and destroy the pathogens.

IgG – funtions in neutralizing, opsonation, compliment activation, antibody dependent cell-mediated cytocity, neonatal immunity, and feedback inhibition of B-cells and found in the blood.

Lymphocytes that become part of antibody-mediated immunity arm of the adaptive immune response develop in the:

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.

When a virus invades the human body there is an assortment of responses from the immune system relying largely on the particular pathogen type. Viruses invade the host with the purpose of replication to ensure survival. My cytosolic virus is a single stranded RNA virus. The virus is surrounded by an envelope with a lipid membrane. Inside the envelope are matrix proteins, integrase, protease, reverse transcriptase and the RNA genome. All viruses contain three proteins necessary for their survival; one for replication, one for packaging and delivering it to more host cells and a protein that modifies the function or structure of the host

When injury or infection occurs inflammation ensues. Inflammation is a defense response of the body that signals for the immune system to manage/fight off infection. White blood cells and macrophages are key components of this process. On a cellular level, immunity is created by exposure to foreign antigens. When the body encounters the foreign antigens it produces antibodies to destroy the antigens. B cells, a type of white blood cell, produce these antibodies. The antigen is then stored in the memory of the B cells so that when the same antigen is encountered in the future, our body can fight off the pathogen

Tissue sample presented with large population of B cells, labelled with CD20, in follicles and macrophages labelled with CD68 were also visible in the intrafollicular zone, both are indicative of a humoral immune response.

The immune system is a network of tissues, cells, and organs which cooperate with each other to shield the body from infectious diseases. When the body is invaded with foreign microbes, the immune system attempts to identify the microbes by triggering responses. When an individual is exposed to the Measles disease, the immune system response results to the patient having a high fever, coughing and having a runny nose. This is an innate response of the body to eliminate fatal infections and diseases. However, this innate response is controlled by the receptors which are embedded in the genes of the individual. Therefore, it is only able to control certain patterns of pathogens and is unable to record new pathogens that enter the body. This is where the adaptive immunity response comes to record all new findings of the invading pathogen and bacteria and the best defence to fight off the infection. The adaptive immunity consists of two different types of cells that defend the body. The T-cell and B-cell receptors have specific roles to help the immune system to defend from infections. The B-cell receptors contain molecules that recognises numerous types of viruses and bacteria. The T-cell receptor has similar molecule structure of relating to immunoglobulins. The difference between the T-cell receptors to the B-cell receptors is the ability to recognise short peptide

Immunology basically involves understanding the immune system and how it responds to various disease conditions. the immune system consists of a number of components. Traditionally, it is divided into humoral and cellular immune responses. It can also be distinguished into innate and adaptive immunity. The innate immunity can discriminate between normal tissues , self and newly encountered non-self-proteins while the adaptive immunity is the more complex system aimed at the eradication of intracellular pathogens. To do this, antigen derived from such pathogens that are often new to the host organism, need to be recognised by receptor-bearing specialised immune cells which respond to a complex system of stimulatory and costimulatory signals. Better understanding of the human immune system has led to the identification of a number of tumor-associated antigens in the 1980s and the development of various immunotherapeutic approaches. In recent years, identification of the specific antigenic MHC class I epitopes, advancements in genetic engineering, gene delivery, and cell-based therapeutic approaches allowed development of the novel immunotherapeutics.

Spleen tyrosine kinase (SYK) is a cytoplasmic non-receptor tyrosine kinase that has been shown to be involved in intracellular signaling pathways of a number of diverse cell types. Structurally, SYK is a 72k Da protein with two SRC homology 2 domains and a kinase domain. It has a well-documented and crucial role in intracellular signaling of adaptive immune cells via immunoreceptor tyrosine-based activation motifs (ITAMs) of the classical immunoreceptors; B cell receptors, T cell receptors and Fc receptors. Activation of these receptors leads to the phosphorylation of the ITAMs’ cytoplasmic tyrosine residues resulting in the recruitment and activation of SYK. For activation, both of SYK’s SH2 domains needs to bind to the phosphorylated ITAMs of the receptor, or phosphorylation can occur at a tyrosine residue in either of the interdomains. This initial phosphorylation leads to the autophosphorylation of other tyrosine residues in the interdomains or the kinase domain, resulting in ITAM release and sustained activation.

They are of two type; phagocytes and lymphocytes. “Phagocytes are cells that engulf foreign bodies that might harm the normal functioning of the body (Gordon, 2005).” Lymphocytes on the other hand are white blood cells that allow the body to identify and recall previous foreign bodies and destroy them. Lymphocytes are of two types; B cells and T cells. B cell matures in the bone marrow and makes antibodies that that attacks bacteria and toxins. T cells multiply in thymus and are capable of producing an immune response. “The cellular component of the immune system comprises a range of cell types that are responsible for the activation, execution and termination of immune responses. T cells play a central role in the immune system, and are a perfect example of the complexity of the immune network (Cretney, & Nutt 2011, 10 p. 19).”

Answer: The are two types of lymphocytes B cells, which mature in the bone marrow, and T cells, which mature in the thymus, a gland in the chest B and T cells eventually make their way to lymph nodes and other lymphatic organs. There are different types of b cell and t cell. both are lymphocytes, a subclass of white blood cell. the t cells are mainly used in identifying antigens and releasing chemicals which attract macrophages, to destroy the antigen. b cells are used in the production of antibodies. when they encounter a new antigen, plasma cells and

T cells play a central role in the activation of cellular immunity and are of key importance to the maintenance of immunological memory. In cellular immunity, the effector phase is triggered once the T cell receptors (TCRs) expressed on the surface of T lymphocytes engages specific peptide antigens (Ags) presented by MHC molecules, and regarded as one of the key discoveries in our understanding of the adaptive immune response. Presumably, due to the selective pressure exerted by the pathogens, T cells have evolved to recognize a range of chemically distinct antigens such as lipids and vitamin B metabolites and challenged the prevailing view that T cells are solely reactive to peptide antigens presented by MHC molecules. Perhaps one of the