3DI2 , 3DI3
29-416: IL-7 or IL 7 can refer to: Interleukin 7 Illinois's 7th congressional district Illinois Route 7 [REDACTED] Topics referred to by the same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to
58-422: A Wright's stained peripheral blood smear , a normal lymphocyte has a large, dark-staining nucleus with little to no eosinophilic cytoplasm. In normal situations, the coarse, dense nucleus of a lymphocyte is approximately the size of a red blood cell (about 7 μm in diameter). Some lymphocytes show a clear perinuclear zone (or halo) around the nucleus or could exhibit a small clear zone to one side of
87-840: A decrease in the entry of lymphocytes into lymph nodes, which can lead to a condition known as lymphocytosis, with a complete lymphocyte count of over 4000 per μl in adults or over 8000 per μl in children. This is unique in that many bacterial infections illustrate neutrophil-predominance instead. Lymphoproliferative disorders (LPD) encompass a diverse group of diseases marked by uncontrolled lymphocyte production, leading to issues like lymphocytosis, lymphadenopathy, and bone marrow infiltration. These disorders are common in immunocompromised individuals and involve abnormal proliferation of T and B cells, often resulting in immunodeficiency and immune system dysfunction. Various gene mutations, both iatrogenic and acquired, are implicated in LPD. One subtype, X-linked LPD,
116-417: A hierarchical fashion as well as in a more plastic fashion. The formation of lymphocytes is known as lymphopoiesis . In mammals , B cells mature in the bone marrow , which is at the core of most bones . In birds , B cells mature in the bursa of Fabricius , a lymphoid organ where they were first discovered by Chang and Glick, (B for bursa) and not from bone marrow as commonly believed. T cells migrate to
145-468: A pre-pro-B cell growth-stimulating factor. This cytokine is found to be a cofactor for V(D)J rearrangement of the T cell receptor beta (TCRß) during early T cell development. This cytokine can be produced locally by intestinal epithelial and epithelial goblet cells , and may serve as a regulatory factor for intestinal mucosal lymphocytes. Knockout studies in mice suggested that this cytokine plays an essential role in lymphoid cell survival. IL-7 binds to
174-433: A strong and rapid response if the same pathogen is detected again; this is known as acquired immunity . NK cells are a part of the innate immune system and play a major role in defending the host from tumors and virally infected cells. NK cells modulate the functions of other cells, including macrophages and T cells, and distinguish infected cells and tumors from normal and uninfected cells by recognizing changes of
203-421: A surface molecule called major histocompatibility complex (MHC) class I . NK cells are activated in response to a family of cytokines called interferons . Activated NK cells release cytotoxic (cell-killing) granules which then destroy the altered cells. They are named "natural killer cells" because they do not require prior activation in order to kill cells which are missing MHC class I. The X lymphocyte
232-463: A wide array of disorders involving B-cell (e.g., chronic lymphocytic leukemia) and T-cell (e.g., Sezary syndrome) abnormalities, each presenting distinct challenges in diagnosis and management. A low normal to low absolute lymphocyte concentration is associated with increased rates of infection after surgery or trauma . One basis for low T cell lymphocytes occurs when the human immunodeficiency virus (HIV) infects and destroys T cells (specifically,
261-574: Is a protein that in humans is encoded by the IL7 gene . IL-7 is a hematopoietic growth factor secreted by stromal cells in the bone marrow and thymus . It is also produced by keratinocytes , dendritic cells , hepatocytes , neurons , and epithelial cells , but is not produced by normal lymphocytes . A study also demonstrated how the autocrine production of the IL-7 cytokine mediated by T-cell acute lymphoblastic leukemia (T-ALL) can be involved in
290-403: Is a reported cell type expressing both a B-cell receptor and T-cell receptor and is hypothesized to be implicated in type 1 diabetes. Its existence as a cell type has been challenged by two studies. However, the authors of original article pointed to the fact that the two studies have detected X cells by imaging microscopy and FACS as described. Additional studies are required to determine
319-405: Is linked to mutations in the X chromosome, predisposing individuals to natural killer cell LPD and T-cell LPD. Additionally, conditions like common variable immunodeficiency (CVID), severe combined immunodeficiency (SCID), and certain viral infections elevate the risk of LPD. Treatment methods, such as immunosuppressive drugs and tissue transplantation, can also increase susceptibility. LPDs encompass
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#1732872779999348-427: Is stimulated by IL-3 ). It also stimulates proliferation of all cells in the lymphoid lineage ( B cells , T cells and NK cells ). It is important for proliferation during certain stages of B-cell maturation, T and NK cell survival, development and homeostasis . IL-7 is a cytokine important for B and T cell development. This cytokine and the hepatocyte growth factor ( HGF ) form a heterodimer that functions as
377-565: The CD4 subgroup of T lymphocytes, which become helper T cells). Without the key defense that these T cells provide, the body becomes susceptible to opportunistic infections that otherwise would not affect healthy people. The extent of HIV progression is typically determined by measuring the percentage of CD4 T cells in the patient's blood – HIV ultimately progresses to acquired immune deficiency syndrome (AIDS). The effects of other viruses or lymphocyte disorders can also often be estimated by counting
406-466: The ELISPOT or secretion assay techniques can be used. In the circulatory system , they move from lymph node to lymph node. This contrasts with macrophages , which are rather stationary in the nodes. A lymphocyte count is usually part of a peripheral complete blood cell count and is expressed as the percentage of lymphocytes to the total number of white blood cells counted. A general increase in
435-817: The IL-7 receptor , a heterodimer consisting of Interleukin-7 receptor alpha and common gamma chain receptor . Binding results in a cascade of signals important for T-cell development within the thymus and survival within the periphery. Knockout mice which genetically lack IL-7 receptor exhibit thymic atrophy , arrest of T-cell development at the double positive stage, and severe lymphopenia . Administration of IL-7 to mice results in an increase in recent thymic emigrants, increases in B and T cells, and increased recovery of T cells after cyclophosphamide administration or after bone marrow transplantation. IL-7 promotes hematological malignancies (acute lymphoblastic leukemia, T cell lymphoma). Elevated levels of IL-7 have also been detected in
464-434: The antigen, either by releasing antibodies (in the case of B cells), cytotoxic granules ( cytotoxic T cells ) or by signaling to other cells of the immune system ( helper T cells ). Memory T cells remain in the peripheral tissues and circulation for an extended time ready to respond to the same antigen upon future exposure; they live weeks to several years, which is very long compared to other leukocytes. Microscopically, in
493-480: The blood stream and mature in a distinct primary organ, called the thymus . Following maturation, the lymphocytes enter the circulation and peripheral lymphoid organs (e.g. the spleen and lymph nodes ) where they survey for invading pathogens and/or tumor cells. The lymphocytes involved in adaptive immunity (i.e. B and T cells) differentiate further after exposure to an antigen ; they form effector and memory lymphocytes. Effector lymphocytes function to eliminate
522-558: The homeostasis of both CD8+ and CD4+ T cells with a commensurate decrease in the percentage of CD4+CD25+Foxp3+ T regulatory cells. No objective cancer regression was observed, however a dose limiting toxicity (DLT) was not reached in this study due to the development of neutralizing antibodies against the recombinant cytokine . Associated with antiretroviral therapy, IL-7 administration decreased local and systemic inflammations in patients that had incomplete T-cell reconstitution. These results suggest that IL-7 therapy can possibly improve
551-445: The immune response, while other T cells, called cytotoxic T cells , produce toxic granules that contain powerful enzymes which induce the death of pathogen-infected cells. Following activation, B cells and T cells leave a lasting legacy of the antigens they have encountered, in the form of memory cells . Throughout the lifetime of an animal, these memory cells will "remember" each specific pathogen encountered, and are able to mount
580-733: The intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=IL-7&oldid=1108839220 " Category : Letter–number combination disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Interleukin 7 3574 16196 ENSG00000104432 ENSMUSG00000040329 P13232 P10168 NM_000880 NM_001199886 NM_001199887 NM_001199888 NM_008371 NM_001313888 NM_001313889 NM_001313890 NP_000871 NP_001186815 NP_001186816 NP_001186817 NP_001300817 NP_001300818 NP_001300819 NP_032397 Interleukin 7 ( IL-7 )
609-532: The main type of cell found in lymph , which prompted the name "lymphocyte" (with cyte meaning cell). Lymphocytes make up between 18% and 42% of circulating white blood cells. The three major types of lymphocyte are T cells , B cells and natural killer (NK) cells. They can also be classified as small lymphocytes and large lymphocytes based on their size and appearance. Lymphocytes can be identified by their large nucleus. T cells ( thymus cells) and B cells ( bone marrow - or bursa -derived cells ) are
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#1732872779999638-745: The major cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity , whereas B cells are primarily responsible for humoral immunity (relating to antibodies ). The function of T cells and B cells is to recognize specific "non-self" antigens, during a process known as antigen presentation . Once they have identified an invader, the cells generate specific responses that are tailored maximally to eliminate specific pathogens or pathogen-infected cells. B cells respond to pathogens by producing large quantities of antibodies which then neutralize foreign objects like bacteria and viruses . In response to pathogens some T cells, called T helper cells , produce cytokines that direct
667-416: The nature and properties of X cells (also called dual expressers). Mammalian stem cells differentiate into several kinds of blood cell within the bone marrow . This process is called haematopoiesis . All lymphocytes originate, during this process, from a common lymphoid progenitor before differentiating into their distinct lymphocyte types. The differentiation of lymphocytes follows various pathways in
696-478: The nucleus. Polyribosomes are a prominent feature in the lymphocytes and can be viewed with an electron microscope . The ribosomes are involved in protein synthesis , allowing the generation of large quantities of cytokines and immunoglobulins by these cells. It is impossible to distinguish between T cells and B cells in a peripheral blood smear. Normally, flow cytometry testing is used for specific lymphocyte population counts. This can be used to determine
725-505: The number of lymphocytes is known as lymphocytosis , whereas a decrease is known as lymphocytopenia . An increase in lymphocyte concentration is usually a sign of a viral infection (in some rare case, leukemias are found through an abnormally raised lymphocyte count in an otherwise normal person). A high lymphocyte count with a low neutrophil count might be caused by lymphoma . Pertussis toxin (PTx) of Bordetella pertussis , formerly known as lymphocytosis-promoting factor, causes
754-414: The oncogenic development of T-ALL and offer novel insights into T-ALL spreading. The three-dimensional structure of IL-7 in complex with the ectodomain of IL-7 receptor has been determined using X-ray diffraction . IL-7 stimulates the differentiation of multipotent (pluripotent) hematopoietic stem cells into lymphoid progenitor cells (as opposed to myeloid progenitor cells where differentiation
783-402: The percentage of lymphocytes that contain a particular combination of specific cell surface proteins, such as immunoglobulins or cluster of differentiation (CD) markers or that produce particular proteins (for example, cytokines using intracellular cytokine staining (ICCS)). In order to study the function of a lymphocyte by virtue of the proteins it generates, other scientific techniques like
812-456: The plasma of HIV-infected patients . IL-7 as an immunotherapy agent has been examined in many pre-clinical animal studies and more recently in human clinical trials for various malignancies and during HIV infection . Recombinant IL-7 has been safely administered to patients in several phase I and II clinical trials . A human study of IL-7 in patients with cancer demonstrated that administration of this cytokine can transiently disrupt
841-864: The quality of life of those patients. IL-7 could also be beneficial in improving immune recovery after allogenic stem cell transplant. This article incorporates text from the United States National Library of Medicine , which is in the public domain . Lymphocyte A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates . Lymphocytes include T cells (for cell-mediated and cytotoxic adaptive immunity ), B cells (for humoral , antibody -driven adaptive immunity ), and innate lymphoid cells (ILCs; "innate T cell-like" cells involved in mucosal immunity and homeostasis), of which natural killer cells are an important subtype (which functions in cell-mediated , cytotoxic innate immunity ). They are
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