Lymphocyte T-cells

The thymus is a lympho-epithelial organ, located within the upper thorax. One of its fimctions is the conversion of certain lymphoid hematopoietic precursor cells originating from the bone marrow into thymus-derived lymphocytes (T-cells). 

Adenosine deaminase deficiency is associated with an immunodeficiency disease in which both thymus-derived lymphocytes (T cells) and bone marrow-derived lymphocytes (B cells) are sparse and dysfunctional. Purine nucleoside phosphorylase deficiency is associated with a severe deficiency of T cells but apparently normal B cell function. Immune dysfunctions appear to result from accumulation of dGTP and dATP, which inhibit ribonucleotide reductase and thereby deplete cells of DNA precursors. 

Keywords C otoxic T lymphocytes T cell antigen receptor allogeneic hemopoietic stem cell transplantation acnte myeloid lenkemia... 

In addition, a distinction is made between cellular and humoral immune responses. The T lymphocytes (T cells) are responsible for cellular immunity. They are named after the thymus, in which the decisive steps in their differentiation take place. Depending on their function, another distinction is made between cytotoxic T cells (green) and helper T cells (blue). Humoral immunity is based on the activity of the B lymphocytes (B cells, light brown), which mature in the bone marrow. After activation by T cells, B cells are able to release soluble forms of their specific antigen receptors, known as antibodies (see p. 300), into the blood plasma. The immune system s memory is represented by memory cells. These are particularly long-lived cells that can arise from any of the lymphocyte types described. 

The massive atrophied change which takes place first in the thymus followed by the spleen could well explain the marked depressed function of thymus-dependent lymphocytes (T cells)—phytohemagglutinin-responsive cells—in peripheral blood of subjects with protein calorie malnutrition (J6, M18, S6, S12). 

Immune responses have often been described in terms of humoral and cellular components. The humoral response involves the small circulating B lymphocytes (B cells), the antibodies (immunoglobulins), and proteins of the complement system. The cellular response is mediated by another group of small lymphocytes, the T lymphocytes (T cells). They resemble B cells in appearance but have quite different functions. However, newer knowledge has provided a somewhat different description of the body s defense... 

Cells Dendritic cells Phagocytic cells (neutrophils, monocytes, macrophages) Cells that release inflammatory mediators (basophils, mast cells, eosinophils) Natural killer (NK) cells Dendritic cells B lymphocytes (B cells) T lymphocytes (T cells) Other antigen-presenting cells, e.g., macrophages... 

Lymphocytes (T cells)—a group of white blood cells of crucial importance to the adaptive part of the organism s immune system. There are many kinds of lymphocytes (Th 0, Th c, Th 1, Th 2, Th 17). Cytokines produced by T cells probably play a major role in orchestrating allergic inflammation. TH 1 cells produce IFN-y and IL-2 but not IL-4 or IL-5 after activation. TH2 cells produce mainly IL-4, IL-13, and IL-5 but not IL-2 or IFN-y. TH2 cells characterize human allergic responses and are present at mucosal surfaces during the late but not immediate response to an allergen exposure. 

T-cell receptor (TCR) a heterodimeric molecule found on the surface of T lymphocytes (T-cells) that is responsible for recognizing andgens bound to major histocompadbility complex (MHC) molecules. Upon andgen-receptor binding with MHC, a series of biochemical reacdons occur which acdvate the associated T-cell. 

Lymphocytes are the lymphatic system s foot soldiers. These cells identify enemy particles and attempt to destroy them. Lymphocytes fall into two general categories T lymphocytes (T cells) and B lymphocytes (B cells). T cells form in the thymus (in the chest), and B cells form in the bone marrow of the long, thick bones of the thigh, arm, spine, or pelvis. While T cells primarily attack viral antigens, B cells attack bacterial antigens. Both T and B cells travel in lymph, through lymphatic vessels, and into lymph nodes. 

Alemtuzumab CD52 Normal and malignant B-lymphocytes, T cells, NK cells, monocytes, macrophages, platelets (not hematopoietic stem cells) Chronic lymphocytic leukemia Hypersensitivity and infusion related reactions, profound immunosuppression... 

Kipps TJ. Functions of T lymphocytes T-cell receptors for antigen. In Beutler E, Lichtman MA, Coller BS, et al, eds. Williams Hematology, 6th ed. New York, McGraw-Hill, 2001 949. 

B cell chronic lymphocytic T cell prolymphocytic Nodular sclerosis Hodgkin s... 

T lymphocytes (T cells). Thymus-dependent lymphocytes that differentiate in the thymus to express T cell receptor molecules that are specifc for complexes comprising short peptides bound to and presented by major histocompatibility complex molecules. Different subpopulations of regulatory and effector cells. See -cytotoxic T lymphocytes, helper T lymphocytes, regulatory T cells, and suppressor T lymphocytes. 

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