lymphocyte
Physiology
(noun)
A type of white blood cell that includes T cells, B cells, and NK cells.
Biology
Microbiology
Examples of lymphocyte in the following topics:
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Development of the Dual Lymphocyte System
- B cells and T cells are the major types of lymphocytes.
- During this process, all lymphocytes originate from a common lymphoid progenitor before differentiating into their distinct lymphocyte types.
- The formation of lymphocytes is known as lymphopoiesis.
- The lymphocytes involved in adaptive immunity (i.e.
- All lymphocytes originate during this process from a common lymphoid progenitor before differentiating into their distinct lymphocyte types.
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Clonal Selection and Tolerance
- It was hypothesized that it is the age of the lymphocyte that defines whether an antigen that is encountered will induce tolerance, with immature lymphocytes being tolerance sensitive.
- clonal selection of the B and T lymphocytes:1.
- Immature lymphocytes with various receptors 3.
- Mature, inactive lymphocytes 5.
- Cloned activated lymphocytes.
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Tests That Differentiate Between T Cells and B cells
- T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes.
- T-lymphocytes can be distinguished from other lymphocytes like B cells and natural killer cells (NK cells) by the presence of a T cell receptor (TCR) on the cell surface.
- T-lymphocytes express CD3, CD4, CD8, or CD25 markers.
- B-lymphocytes express CD19 marker.
- A scanning electron microscope (SEM) image of a single human lymphocyte.
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Lymphoid Cells
- A lymphocyte is a type of white blood cell in the vertebrate immune system.
- A lymphocyte is a type of white blood cell in the immune system.
- Lymphocytes are vital for normal immune system function.
- All lymphocytes originate from a common lymphoid progenitor cell known as a lymphoblast, before differentiating into their distinct lymphocyte types.
- The formation of lymphocytes is known as lymphopoiesis.
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Lymphoid Tissue
- Lymphoid tissue consists of many organs that play a role in the production and maturation of lymphocytes in the immune response.
- The lymphoid tissue may be primary or secondary depending upon its stage of lymphocyte development and maturation.
- Specialized lymphoid tissue supports proliferation and differentiation of lymphocytes.
- Central or primary lymphoid organs generate lymphocytes from immature progenitor cells such as lymphoblasts.
- Secondary lymphoid tissue provides the environment for the antigens to interact with the lymphocytes.
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Clonal Selection of Antibody-Producing Cells
- Each lymphocyte bears a single type of receptor with a unique specificity (by V(D)J recombination).
- Those lymphocytes bearing receptors for self molecules will be deleted at an early stage.
- B cells that have not been activated by antigen are known as naive lymphocytes; those that have met their antigen, become activated, and have differentiated further into fully functional lymphocytes are known as effector B lymphocytes.
- Clonal selection of lymphocytes: 1) A hematopoietic stem cell undergoes differentiation and genetic rearrangement to produce 2) immature lymphocytes with many different antigen receptors.
- Those that bind to 3) antigens from the body's own tissues are destroyed, while the rest mature into 4) inactive lymphocytes.
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Clonal Selection and T-Cell Differentiation
- Clonal selection is an theory that attempts to explain why lymphocytes are able to respond to so many different types of antigens.
- The theoretical basis of clonal selection is the assumption that lymphocytes bearing an antigen receptor for an antigen exist long before antigen presentation occurs, explained by the idea of random mutations (VDJ recombination) that occur during lymphocyte maturation.
- It is also assumed that most lymphocytes never encounter the antigen for which they bear a receptor.
- This assumes that random mutations resulted in lymphocytes that were autoreactive instead of reactive to non-self antigens.
- Clonal selection of lymphocytes: 1) A hematopoietic stem cell undergoes differentiation and genetic rearrangement to produce 2) immature lymphocytes with many different antigen receptors.
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Cytotoxic T Lymphocytes and Mucosal Surfaces
- Approximately 0.1 percent of all cells in the blood are leukocytes, which include monocytes (the precursor of macrophages) and lymphocytes.
- On maturation, T and B lymphocytes circulate to various destinations.
- Antigen-presenting cells (APCs) in the lymph nodes capture and process antigens, informing nearby lymphocytes about potential pathogens.
- The spleen is also the site where APCs that have trapped foreign particles in the blood can communicate with lymphocytes.
- Lymph nodes are filled with lymphocytes that purge infecting cells.
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Lymphocytes
- A lymphocyte is a type of white blood cell in the vertebrate immune system.
- A lymphocyte is a type of white blood cell in the immune system, including both the B and T cells of the adaptive immune system and natural killer (NK) cells of the innate immune system .
- While these are the main categories of T lymphocytes, there are other subtypes within these categories as well as additional categories that are not fully understood.
- Regulatory B cells (B reg cells) are immunosuppresive B cells that secrete anti-inflammatory cytokines (such as IL-10) to inhibit autoimmune lymphocytes.
- A scanning electron microscope (SEM) image of a single human lymphocyte.
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Natural Killer Cells
- Lymphocytes are leukocytes (white blood cells) that are histologically identifiable by their large, darkly-staining nuclei; they are small cells with very little cytoplasm .
- After a pathogen enters the body, infected cells are identified and destroyed by natural killer (NK) cells, which are a type of lymphocyte that can kill cells infected with viruses or tumor cells (abnormal cells that uncontrollably divide and invade other tissue).
- While NK cells are part of the innate immune response, they are best understood relative to their counterparts in the adaptive immune response,T cells, which are also classified as lymphocytes.
- T cells are lymphocytes that mature in the thymus gland and identify intracellular infections, especially from viruses, by the altered expression of major histocompatibility class (MHC) I molecules on the surface of infected cells.
- Lymphocytes, such as NK cells, are characterized by their large nuclei that actively absorb Wright stain and, therefore, appear dark colored under a microscope.