Plasma Cells: Specialized forms of antibody-producing B-LYMPHOCYTES. They synthesize and secrete immunoglobulin. They are found only in lymphoid organs and at sites of immune responses and normally do not circulate in the blood or lymph. (Rosen et al., Dictionary of Immunology, 1989, p169 & Abbas et al., Cellular and Molecular Immunology, 2d ed, p20)Chemokine CXCL13: A CXC chemokine that is chemotactic for B-LYMPHOCYTES. It has specificity for CXCR5 RECEPTORS.Receptors, CXCR5: CXCR receptors isolated initially from BURKITT LYMPHOMA cells. CXCR5 receptors are expressed on mature, recirculating B-LYMPHOCYTES and are specific for CHEMOKINE CXCL13.Lymphoid Tissue: Specialized tissues that are components of the lymphatic system. They provide fixed locations within the body where a variety of LYMPHOCYTES can form, mature and multiply. The lymphoid tissues are connected by a network of LYMPHATIC VESSELS.Ovarian Follicle: An OOCYTE-containing structure in the cortex of the OVARY. The oocyte is enclosed by a layer of GRANULOSA CELLS providing a nourishing microenvironment (FOLLICULAR FLUID). The number and size of follicles vary depending on the age and reproductive state of the female. The growing follicles are divided into five stages: primary, secondary, tertiary, Graafian, and atretic. Follicular growth and steroidogenesis depend on the presence of GONADOTROPINS.Dendritic Cells, Follicular: Non-hematopoietic cells, with extensive dendritic processes, found in the primary and secondary follicles of lymphoid tissue (the B cell zones). They are different from conventional DENDRITIC CELLS associated with T-CELLS. They are derived from MESENCHYMAL STEM CELLS and are negative for class II MHC antigen and do not process or present antigen like the conventional dendritic cells do. Instead, follicular dendritic cells have FC RECEPTORS and C3B RECEPTORS that hold antigen in the form of ANTIGEN-ANTIBODY COMPLEXES on their surfaces for long periods for recognition by B-CELLS.Germinal Center: The activated center of a lymphoid follicle in secondary lymphoid tissue where B-LYMPHOCYTES are stimulated by antigens and helper T cells (T-LYMPHOCYTES, HELPER-INDUCER) are stimulated to generate memory cells.B-Lymphocytes: Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.Spleen: An encapsulated lymphatic organ through which venous blood filters.Lymph Nodes: They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.Antigens: Substances that are recognized by the immune system and induce an immune reaction.Hair Follicle: A tube-like invagination of the EPIDERMIS from which the hair shaft develops and into which SEBACEOUS GLANDS open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. (Stedman, 26th ed) Follicles of very long hairs extend into the subcutaneous layer of tissue under the SKIN.Leukemia, Plasma Cell: A rare, aggressive variant of MULTIPLE MYELOMA characterized by the circulation of excessive PLASMA CELLS in the peripheral blood. It can be a primary manifestation of multiple myeloma or develop as a terminal complication during the disease.Lymphotoxin beta Receptor: A member of the tumor necrosis factor receptor superfamily. It has specificity for LYMPHOTOXIN ALPHA1, BETA2 HETEROTRIMER and TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY MEMBER 14. The receptor plays a role in regulating lymphoid ORGANOGENESIS and the differentiation of certain subsets of NATURAL KILLER T-CELLS. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.Mice, Inbred C57BLLymphotoxin-alpha: A tumor necrosis factor family member that is released by activated LYMPHOCYTES. Soluble lymphotoxin is specific for TUMOR NECROSIS FACTOR RECEPTOR TYPE I; TUMOR NECROSIS FACTOR RECEPTOR TYPE II; and TUMOR NECROSIS FACTOR RECEPTOR SUPERFAMILY, MEMBER 14. Lymphotoxin-alpha can form a membrane-bound heterodimer with LYMPHOTOXIN-BETA that has specificity for the LYMPHOTOXIN BETA RECEPTOR.Follicle Stimulating Hormone: A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.B-Lymphocyte Subsets: A classification of B-lymphocytes based on structurally or functionally different populations of cells.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Chemokine CCL19: A CC-type chemokine with specificity for CCR7 RECEPTORS. It has activity towards T LYMPHOCYTES and B LYMPHOCYTES.Receptors, CCR7: CCR receptors with specificity for CHEMOKINE CCL19 and CHEMOKINE CCL21. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS.Chemokine CCL21: A CC-type chemokine with specificity for CCR7 RECEPTORS. It has activity towards DENDRITIC CELLS and T-LYMPHOCYTES.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.Mice, Inbred BALB CPropylene Glycols: Derivatives of propylene glycol (1,2-propanediol). They are used as humectants and solvents in pharmaceutical preparations.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Neoplasms, Plasma Cell: Neoplasms associated with a proliferation of a single clone of PLASMA CELLS and characterized by the secretion of PARAPROTEINS.Cell Movement: The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.Peyer's Patches: Lymphoid tissue on the mucosa of the small intestine.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Palatine Tonsil: A round-to-oval mass of lymphoid tissue embedded in the lateral wall of the PHARYNX. There is one on each side of the oropharynx in the fauces between the anterior and posterior pillars of the SOFT PALATE.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.Antigens, Neoplasm: Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.Antigens, Surface: Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.Dendritic Cells: Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Adoptive Transfer: Form of passive immunization where previously sensitized immunologic agents (cells or serum) are transferred to non-immune recipients. When transfer of cells is used as a therapy for the treatment of neoplasms, it is called adoptive immunotherapy (IMMUNOTHERAPY, ADOPTIVE).Plasma: The residual portion of BLOOD that is left after removal of BLOOD CELLS by CENTRIFUGATION without prior BLOOD COAGULATION.Receptors, Cytokine: Cell surface proteins that bind cytokines and trigger intracellular changes influencing the behavior of cells.Thymus Gland: A single, unpaired primary lymphoid organ situated in the MEDIASTINUM, extending superiorly into the neck to the lower edge of the THYROID GLAND and inferiorly to the fourth costal cartilage. It is necessary for normal development of immunologic function early in life. By puberty, it begins to involute and much of the tissue is replaced by fat.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Lymphotoxin-beta: A membrane-bound tumor necrosis family member found primarily on LYMPHOCYTES. It can form a heterotrimer (LYMPHOTOXIN ALPHA1, BETA2 HETEROTRIMER) with the soluble ligand LYMPHOTOXIN-ALPHA and anchor it to the cell surface. The membrane-bound complex is specific for the LYMPHOTOXIN BETA receptor.Multiple Myeloma: A malignancy of mature PLASMA CELLS engaging in monoclonal immunoglobulin production. It is characterized by hyperglobulinemia, excess Bence-Jones proteins (free monoclonal IMMUNOGLOBULIN LIGHT CHAINS) in the urine, skeletal destruction, bone pain, and fractures. Other features include ANEMIA; HYPERCALCEMIA; and RENAL INSUFFICIENCY.Immunologic Memory: The altered state of immunologic responsiveness resulting from initial contact with antigen, which enables the individual to produce antibodies more rapidly and in greater quantity in response to secondary antigenic stimulus.Receptors, Chemokine: Cell surface glycoproteins that bind to chemokines and thus mediate the migration of pro-inflammatory molecules. The receptors are members of the seven-transmembrane G protein-coupled receptor family. Like the CHEMOKINES themselves, the receptors can be divided into at least three structural branches: CR, CCR, and CXCR, according to variations in a shared cysteine motif.Antigens, CD: Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.CD4-Positive T-Lymphocytes: A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.Chromatography, Affinity: A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)T-Lymphocytes, Helper-Inducer: Subpopulation of CD4+ lymphocytes that cooperate with other lymphocytes (either T or B) to initiate a variety of immune functions. For example, helper-inducer T-cells cooperate with B-cells to produce antibodies to thymus-dependent antigens and with other subpopulations of T-cells to initiate a variety of cell-mediated immune functions.Endothelium, Lymphatic: Unbroken cellular lining (intima) of the lymph vessels (e.g., the high endothelial lymphatic venules). It is more permeable than vascular endothelium, lacking selective absorption and functioning mainly to remove plasma proteins that have filtered through the capillaries into the tissue spaces.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Chemokines, CC: Group of chemokines with adjacent cysteines that are chemoattractants for lymphocytes, monocytes, eosinophils, basophils but not neutrophils.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Lymphocytes: White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.Chemotaxis, Leukocyte: The movement of leukocytes in response to a chemical concentration gradient or to products formed in an immunologic reaction.Immunophenotyping: Process of classifying cells of the immune system based on structural and functional differences. The process is commonly used to analyze and sort T-lymphocytes into subsets based on CD antigens by the technique of flow cytometry.Ovary: The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.Immunoglobulins: Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Paraproteinemias: A group of related diseases characterized by an unbalanced or disproportionate proliferation of immunoglobulin-producing cells, usually from a single clone. These cells frequently secrete a structurally homogeneous immunoglobulin (M-component) and/or an abnormal immunoglobulin.T-Lymphocyte Subsets: A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.Kinetics: The rate dynamics in chemical or physical systems.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.L-Selectin: Cell adhesion molecule and CD antigen that serves as a homing receptor for lymphocytes to lymph node high endothelial venules.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.Granuloma, Plasma Cell: A slow-growing benign pseudotumor in which plasma cells greatly outnumber the inflammatory cells.Lymphatic System: A system of organs and tissues that process and transport immune cells and LYMPH.Sphingosine: An amino alcohol with a long unsaturated hydrocarbon chain. Sphingosine and its derivative sphinganine are the major bases of the sphingolipids in mammals. (Dorland, 28th ed)Granulosa Cells: Supporting cells for the developing female gamete in the OVARY. They are derived from the coelomic epithelial cells of the gonadal ridge. Granulosa cells form a single layer around the OOCYTE in the primordial ovarian follicle and advance to form a multilayered cumulus oophorus surrounding the OVUM in the Graafian follicle. The major functions of granulosa cells include the production of steroids and LH receptors (RECEPTORS, LH).Receptors, Lysosphingolipid: A subfamily of lysophospholipid receptors with specificity for LYSOSPHINGOLIPIDS such as sphingosine-1-phosphate and sphingosine phosphorylcholine.Organ Specificity: Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.Ovulation: The discharge of an OVUM from a rupturing follicle in the OVARY.Bone Marrow Cells: Cells contained in the bone marrow including fat cells (see ADIPOCYTES); STROMAL CELLS; MEGAKARYOCYTES; and the immediate precursors of most blood cells.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Receptors, Antigen, T-Cell: Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (ANTIGENS, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.Bone Marrow: The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Binding, Competitive: The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.Receptors, Lymphocyte Homing: Cell surface glycoproteins on lymphocytes and other leukocytes that mediate adhesion to specialized blood vessels called high endothelial venules. Several different classes of lymphocyte homing receptors have been identified, and they appear to target different surface molecules (addressins) on high endothelial venules in different tissues. The adhesion plays a crucial role in the trafficking of lymphocytes.Antibody Affinity: A measure of the binding strength between antibody and a simple hapten or antigen determinant. It depends on the closeness of stereochemical fit between antibody combining sites and antigen determinants, on the size of the area of contact between them, and on the distribution of charged and hydrophobic groups. It includes the concept of "avidity," which refers to the strength of the antigen-antibody bond after formation of reversible complexes.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Plasmacytoma: Any discrete, presumably solitary, mass of neoplastic PLASMA CELLS either in BONE MARROW or various extramedullary sites.Mice, Mutant Strains: Mice bearing mutant genes which are phenotypically expressed in the animals.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Follicular Fluid: The fluid surrounding the OVUM and GRANULOSA CELLS in the Graafian follicle (OVARIAN FOLLICLE). The follicular fluid contains sex steroids, glycoprotein hormones, plasma proteins, mucopolysaccharides, and enzymes.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Receptors, Antigen, B-Cell: IMMUNOGLOBULINS on the surface of B-LYMPHOCYTES. Their MESSENGER RNA contains an EXON with a membrane spanning sequence, producing immunoglobulins in the form of type I transmembrane proteins as opposed to secreted immunoglobulins (ANTIBODIES) which do not contain the membrane spanning segment.Antigens, Protozoan: Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.Lymphopenia: Reduction in the number of lymphocytes.Antigens, CD40: A member of the tumor necrosis factor receptor superfamily with specificity for CD40 LIGAND. It is found on mature B-LYMPHOCYTES and some EPITHELIAL CELLS, lymphoid DENDRITIC CELLS. Evidence suggests that CD40-dependent activation of B-cells is important for generation of memory B-cells within the germinal centers. Mutations of the gene for CD40 antigen result in HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 3. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.Antigens, CD3: Complex of at least five membrane-bound polypeptides in mature T-lymphocytes that are non-covalently associated with one another and with the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL). The CD3 complex includes the gamma, delta, epsilon, zeta, and eta chains (subunits). When antigen binds to the T-cell receptor, the CD3 complex transduces the activating signals to the cytoplasm of the T-cell. The CD3 gamma and delta chains (subunits) are separate from and not related to the gamma/delta chains of the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA).Cell SeparationLymphocyte Count: The number of LYMPHOCYTES per unit volume of BLOOD.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Immunity, Humoral: Antibody-mediated immune response. Humoral immunity is brought about by ANTIBODY FORMATION, resulting from TH2 CELLS activating B-LYMPHOCYTES, followed by COMPLEMENT ACTIVATION.Antigens, Polyomavirus Transforming: Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Cytokines: Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Theca Cells: The flattened stroma cells forming a sheath or theca outside the basal lamina lining the mature OVARIAN FOLLICLE. Thecal interstitial or stromal cells are steroidogenic, and produce primarily ANDROGENS which serve as precusors of ESTROGENS in the GRANULOSA CELLS.HLA Antigens: Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Immunoglobulin M: A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally being called a macroglobulin.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Antigen Presentation: The process by which antigen is presented to lymphocytes in a form they can recognize. This is performed by antigen presenting cells (APCs). Some antigens require processing before they can be recognized. Antigen processing consists of ingestion and partial digestion of the antigen by the APC, followed by presentation of fragments on the cell surface. (From Rosen et al., Dictionary of Immunology, 1989)Estradiol: The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.Immunization: Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).Chemotaxis: The movement of cells or organisms toward or away from a substance in response to its concentration gradient.Chemokines: Class of pro-inflammatory cytokines that have the ability to attract and activate leukocytes. They can be divided into at least three structural branches: C; (CHEMOKINES, C); CC; (CHEMOKINES, CC); and CXC; (CHEMOKINES, CXC); according to variations in a shared cysteine motif.Progesterone: The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.Oocytes: Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Epitopes: Sites on an antigen that interact with specific antibodies.Venules: The minute vessels that collect blood from the capillary plexuses and join together to form veins.Interferon-gamma: The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.Antigens, Fungal: Substances of fungal origin that have antigenic activity.Affinity Labels: Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Syndecan-1: A syndecan that interacts with EXTRACELLULAR MATRIX PROTEINS and plays a role CELL PROLIFERATION and CELL MIGRATION.Immune System: The body's defense mechanism against foreign organisms or substances and deviant native cells. It includes the humoral immune response and the cell-mediated response and consists of a complex of interrelated cellular, molecular, and genetic components.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.H-2 Antigens: The major group of transplantation antigens in the mouse.Autoimmunity: Process whereby the immune system reacts against the body's own tissues. Autoimmunity may produce or be caused by AUTOIMMUNE DISEASES.T-Lymphocytes, Regulatory: CD4-positive T cells that inhibit immunopathology or autoimmune disease in vivo. They inhibit the immune response by influencing the activity of other cell types. Regulatory T-cells include naturally occurring CD4+CD25+ cells, IL-10 secreting Tr1 cells, and Th3 cells.Antigens, Helminth: Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.Antibody Specificity: The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.Cell Communication: Any of several ways in which living cells of an organism communicate with one another, whether by direct contact between cells or by means of chemical signals carried by neurotransmitter substances, hormones, and cyclic AMP.Immunoglobulin A: Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.Antigen-Presenting Cells: A heterogeneous group of immunocompetent cells that mediate the cellular immune response by processing and presenting antigens to the T-cells. Traditional antigen-presenting cells include MACROPHAGES; DENDRITIC CELLS; LANGERHANS CELLS; and B-LYMPHOCYTES. FOLLICULAR DENDRITIC CELLS are not traditional antigen-presenting cells, but because they hold antigen on their cell surface in the form of IMMUNE COMPLEXES for B-cell recognition they are considered so by some authors.Ovalbumin: An albumin obtained from the white of eggs. It is a member of the serpin superfamily.Histocompatibility Antigens Class II: Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.Immune Tolerance: The specific failure of a normally responsive individual to make an immune response to a known antigen. It results from previous contact with the antigen by an immunologically immature individual (fetus or neonate) or by an adult exposed to extreme high-dose or low-dose antigen, or by exposure to radiation, antimetabolites, antilymphocytic serum, etc.Antibodies: Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Hair: A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Autoimmune Diseases: Disorders that are characterized by the production of antibodies that react with host tissues or immune effector cells that are autoreactive to endogenous peptides.Molecular Weight: The sum of the weight of all the atoms in a molecule.Stromal Cells: Connective tissue cells of an organ found in the loose connective tissue. These are most often associated with the uterine mucosa and the ovary as well as the hematopoietic system and elsewhere.Cell Adhesion: Adherence of cells to surfaces or to other cells.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.HLA-DR Antigens: A subclass of HLA-D antigens that consist of alpha and beta chains. The inheritance of HLA-DR antigens differs from that of the HLA-DQ ANTIGENS and HLA-DP ANTIGENS.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Carcinoembryonic Antigen: A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment.Antigens, CD45: High-molecular weight glycoproteins uniquely expressed on the surface of LEUKOCYTES and their hemopoietic progenitors. They contain a cytoplasmic protein tyrosine phosphatase activity which plays a role in intracellular signaling from the CELL SURFACE RECEPTORS. The CD45 antigens occur as multiple isoforms that result from alternative mRNA splicing and differential usage of three exons.Homeostasis: The processes whereby the internal environment of an organism tends to remain balanced and stable.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Luteinizing Hormone: A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.Mice, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.Inflammation: A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Antigens, CD8: Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. CD8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.Receptors, Cell Surface: Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Proliferating Cell Nuclear Antigen: Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Antigens, Viral, Tumor: Those proteins recognized by antibodies from serum of animals bearing tumors induced by viruses; these proteins are presumably coded for by the nucleic acids of the same viruses that caused the neoplastic transformation.Lysophospholipids: Derivatives of PHOSPHATIDIC ACIDS that lack one of its fatty acyl chains due to its hydrolytic removal.Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Immunoenzyme Techniques: Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Immunity, Cellular: Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.Antigens, CD19: Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Chemokines, CXC: Group of chemokines with paired cysteines separated by a different amino acid. CXC chemokines are chemoattractants for neutrophils but not monocytes.Bursa of Fabricius: An epithelial outgrowth of the cloaca in birds similar to the thymus in mammals. It atrophies within 6 months after birth and remains as a fibrous remnant in adult birds. It is composed of lymphoid tissue and prior to involution, is the site of B-lymphocyte maturation.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Immune Sera: Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Splenectomy: Surgical procedure involving either partial or entire removal of the spleen.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Antigens, CD44: Acidic sulfated integral membrane glycoproteins expressed in several alternatively spliced and variable glycosylated forms on a wide variety of cell types including mature T-cells, B-cells, medullary thymocytes, granulocytes, macrophages, erythrocytes, and fibroblasts. CD44 antigens are the principle cell surface receptors for hyaluronate and this interaction mediates binding of lymphocytes to high endothelial venules. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)T-Lymphocytes, Cytotoxic: Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.Histocompatibility Antigens: A group of antigens that includes both the major and minor histocompatibility antigens. The former are genetically determined by the major histocompatibility complex. They determine tissue type for transplantation and cause allograft rejections. The latter are systems of allelic alloantigens that can cause weak transplant rejection.Antibody-Producing Cells: Cells of the lymphoid series that can react with antigen to produce specific cell products called antibodies. Various cell subpopulations, often B-lymphocytes, can be defined, based on the different classes of immunoglobulins that they synthesize.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Cell Adhesion Molecules: Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis.Organ Size: The measurement of an organ in volume, mass, or heaviness.Antigens, Differentiation: Antigens expressed primarily on the membranes of living cells during sequential stages of maturation and differentiation. As immunologic markers they have high organ and tissue specificity and are useful as probes in studies of normal cell development as well as neoplastic transformation.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.CD40 Ligand: A membrane glycoprotein and differentiation antigen expressed on the surface of T-cells that binds to CD40 ANTIGENS on B-LYMPHOCYTES and induces their proliferation. Mutation of the gene for CD40 ligand is a cause of HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 1.
... are antigen-experienced CD4+ T cells found in the periphery within B cell follicles of secondary lymphoid organs such as lymph ... go on to differentiate either into special plasma cells capable of producing high affinity antibodies against foreign antigen, ... similar to B cell activation by T-cell independent antigens, a quick burst of low affinity plasma cell production is formed but ... Pre-TFH cells are functionally very similar to other TFH cells in facilitating germinal center B cell reactions however, in ...
Follicular B cells (FO B cells) are a type of B cell that reside in primary and secondary lymphoid follicles (containing ... cell help to promote effective primary immune responses and antibody isotype switching and to establish high-affinity B cell ... Antibody responses against proteins are believed to involve follicular B cell pathways in secondary lymphoid organs. Mature B ... Nutt, Stephen L.; Hodgkin, Philip D.; Tarlinton, David M.; Corcoran, Lynn M. "The generation of antibody-secreting plasma cells ...
... naive follicular B cells are activated in the presence of TFH cells within the follicles of secondary lymphoid organs (i.e. ... B cell clones that have mutated and gained higher affinity surface immunoglobulin that better recognize antigen receive ... differentiate into plasma cells that have improved affinity towards antigen (therefore more efficient than their earlier the ... generation of plasma cells in clearing the infection), (ii) affinity matured memory B cells, or (iii) retained in the germinal ...
... activation occurs in the secondary lymphoid organs (SLOs), such as the spleen and lymph nodes. After B cells mature in ... These processes are facilitated by TFH cells within the GC and generate both high-affinity memory B cells and long-lived plasma ... B cells activated by TI antigens go on to proliferate outside lymphoid follicles but still in SLOs (GCs do not form), possibly ... In birds, B cells mature in the bursa of Fabricius, a lymphoid organ. (The "B" from B cells comes from the name of this organ, ...
They present the antigen to T cells and, if there is a T cell with the appropriate T cell receptor, it will be activated. B ... In the lymphatic system the lymph node is a secondary lymphoid organ. A lymph node is enclosed in a fibrous capsule and is made ... If a cell is stimulated, it will go on to produce more antibodies (a plasma cell) or act as a memory cell to help the body ... As part of the reticular network there are follicular dendritic cells in the B cell follicle and fibroblastic reticular cells ...
... and B cells. Cells[edit]. In the lymphatic system a lymph node is a secondary lymphoid organ.[1] Lymph nodes contain ... there are follicular dendritic cells in the B cell follicle and fibroblastic reticular cells in the T cell cortex. The ... increasing its antigen binding affinity and changing its effector function. Proliferation of cells within a lymph node will ... If a cell is stimulated, it will go on to produce more antibodies (a plasma cell) or act as a memory cell to help the body ...
The other 95% of T cells begin a process of apoptosis, a form of programmed cell death. Secondary or peripheral lymphoid organs ... For example, the follicles expand significantly when encountering a foreign antigen. The selection of B cells, or B lymphocytes ... which removes plasma while leaving the blood cells. Roughly 17 litres of the filtered plasma are reabsorbed directly into the ... Lymphocytes enter the lymph nodes through specialised high endothelial venules found in the paracortex. A lymph follicle is a ...
Such that, a B cell that has successfully gained mutations that confer a higher affinity surface antibody towards antigen gains ... are sites within secondary lymphoid organs - lymph nodes and the spleen where mature B cells proliferate, differentiate, and ... and in turn present it to cognate CD4+ TFH cells at the border that demarcates the T cell zone and B cell follicles (also known ... center as an antibody producing plasma cell which are cells that secrete large quantities of antibody or a memory B cell that ...
B cells immediately join the circulatory system and travel to secondary lymphoid organs in search of pathogens. T cells, on the ... For example, the follicles expand significantly when encountering a foreign antigen. The selection of B cells, or B lymphocytes ... which removes plasma while leaving the blood cells. Roughly 17 litres of the filtered plasma is reabsorbed directly into the ... Lymphoid leukaemias and lymphomas are now considered to be tumours of the same type of cell lineage. They are called "leukaemia ...
... these cells (termed recent thymic emigrants (RTE)) egress from the thymus and home to secondary lymphoid organs (SLO; spleen ... The variable region determines what antigen the T cell can respond to. CD4+ T cells have TCRs with an affinity for Class II MHC ... the virus has a relatively low affinity towards T cells (and has a higher affinity for macrophages), resulting in a slow kill ... "Molecular interactions mediating T-B lymphocyte collaboration in human lymphoid follicles. Roles of T cell-B-cell-activating ...
... but it is produced also by a broad variety of cell types including lymphoid cells, mast cells, endothelial cells, cardiac ... integral component of plasma membrane. • phagocytic cup. • external side of plasma membrane. • extracellular region. • plasma ... animal organ morphogenesis. • apoptotic signaling pathway. • negative regulation of alkaline phosphatase activity. • regulation ... Whereas high concentrations of TNF induce shock-like symptoms, the prolonged exposure to low concentrations of TNF can result ...
This process begins when naïve B cells bind antigen near the interface of B and T cell areas of secondary lymphoid organs. ... the germinal center reaction yields MBCs and LLPCs of higher affinity than the initial wave of short-lived plasma cells (SLPCs ... In contrast, lower affinity binding selects for entry of naïve B cells into follicles where germinal centers are formed. After ... plasma cells/blasts (CD19+ CD21− CD20−), naive B cells (CD19+ CD27−CD10−), immature B cells (CD19+ CD10+), classical MBCs (CD19 ...
B-cell disorders are divided into defects of B-cell development/immunoglobulin production (immunodeficiencies) and excessive/ ... Secondary B lymphopoiesis is an antigen-dependent process and occurs in the germinal center of peripheral lymphoid organs with ... of lymphoid tissue and differentiate into short-lived plasma cells and memory cells after first being stimulated by antigen- ... Centroblasts progress to centrocytes with high-affinity antibody production, and then they differentiate further to long-term ...
... provide a microenvironmental niche for B and T cells in the primary and secondary follicles of lymphoid organs (2), and are ... microanatomic site for the generation of memory B cells and plasma cells with high-affinity Abs, consists of the dark and light ... Stimulation of T cells with Con A in the presence of HK cells resulted in increased numbers of T cells that underwent cell ... 3C8 antigen is a novel protein expressed by human follicular dendritic cells. Biochem. Biophys. Res. Commun. 303: 624-630. ...
... are antigen-experienced CD4+ T cells found in the periphery within B cell follicles of secondary lymphoid organs such as lymph ... go on to differentiate either into special plasma cells capable of producing high affinity antibodies against foreign antigen, ... similar to B cell activation by T-cell independent antigens, a quick burst of low affinity plasma cell production is formed but ... Pre-TFH cells are functionally very similar to other TFH cells in facilitating germinal center B cell reactions however, in ...
... in peripheral lymphoid organs, where follicular T helper (Tfh) cells interact with mature, antigen-stimulated B cells. ... Since many B cell malignancies develop in GC-the place of physiological Th cell-B cell interaction-Th cells are a central part ... Research efforts aiming to elucidate such mechanisms are of high importance as therapeutic targeting of these malignant ... Physiological T cell help for B cells takes place in germinal centers (GC) ...
Follicular B cells (FO B cells) are a type of B cell that reside in primary and secondary lymphoid follicles (containing ... cell help to promote effective primary immune responses and antibody isotype switching and to establish high-affinity B cell ... Antibody responses against proteins are believed to involve follicular B cell pathways in secondary lymphoid organs. Mature B ... Nutt, Stephen L.; Hodgkin, Philip D.; Tarlinton, David M.; Corcoran, Lynn M. "The generation of antibody-secreting plasma cells ...
Study B Cells - Denzin 4/5/16 flashcards from Tom Kuriakose ... high affinity Ig-expressing B cellaffinity maturation [plays ... in spleen and other lymphoid organs.... follicular B cells : protein antigen + helper T → germinal center rxn → T-dep, isotype- ... clones of plasma cells → secreted antibodies. *clones of memory B cellssecondary immune response ... process: activated B cells move into lymphoid centers and form germinal centers in follicles → undergo heavy prolif (bc not ...
... affinity maturation, suggesting a crucial role of follicular helper T (Tfh) cells in their production. However, less than 1% of ... Various lymphoid Tfh cell subsets have been characterized, including pre Tfh (pTfh), germinal center Tfh (GC Tfh) and the ... Various lymphoid Tfh cell subsets have been characterized, including pre Tfh (pTfh), germinal center Tfh (GC Tfh) and the ... More recently, circulating Tfh-like cells (cTfh) have been identified. Meanwhile, advances in single-cell technologies have ...
... differentiation process in the B cell follicles of secondary lymphoid organs, such as spleen and lymph nodes. In GCs, B cells ... rapidly proliferate and somatically mutated high-affinity antibody secreting cells, i.e. plasma cells, are generated from naïve ... B cells in response to T cell-dependent antigen. To date, the scientific community has relied on animal models to generate high ... where hydrogels model T cell-like selection process to generate high affinity antibody secreting cells.. [1] A. Purwada, A. ...
... where high-affinity switched Ig isotypes are generated and from where memory B cells and plasma cells emerge. Thus, in ARHGEF1- ... This interaction is accomplished via the migration of B and T cells to the same area of secondary lymphoid organs (SLOs) after ... Subsequent to a productive T-B cell interaction, activated B cells migrate into B cell follicles, form germinal centers - ... To mount TD antibody responses, B cells must physically interact with T cells that are specific for the same antigen. ...
... specialized microenvironments within B cell follicles of secondary lymphoid organs termed germinal center (GC) dark zones (DZs ... Differentiation of germinal center B cells into plasma cells is initiated by high-affinity antigen and completed by Tfh cells. ... cells. Here, we show that human GC B cells have intrinsically higher-affinity thresholds for both B cell antigen receptor (BCR ... or high-affinity antigen-containing PLB. Red arrowheads on low-affinity naïve B cell are extended membrane ruffles and on high- ...
... that secrete IL-21 and interact with antigen-specific B-cells via co-stimulatory molecules. In this article, we discuss the ... we discuss the role of IL-21 in the activation and differentiation of B-cells and consider the mechanisms of IL-21 and B-cell ... that secrete IL-21 and interact with antigen-specific B-cells via co-stimulatory molecules. In this article, ... role of IL-21 in the activation and differentiation of B-cells and consider the mechanisms of IL-21 and B-cell interaction. An ...
Tonsils are secondary lymphoid organs found in lymph node. It has a large GC in which B cell follicles are developed. In GC, B ... Once the T cells fail to discriminate self-reactive B cells from the normal antigen-specific B cells, high-affinity ... plasma cell differentiation, memory B cell formation) [4].. Similarly to B cells which express a high level of CXCR5 and ... This type of antigen presentation facilitates the relocation of primed CD4 T cells from T cell zone to B cell follicles to form ...
... and thus of the B-cell repertoire, is the result of very complex immunogenetic mechanisms. So, this chapter gives a brief ... then undergo somatic mutation to generate high-affinity memory B-cells and long-lived plasma cells (LLPCs). GC formation ... in secondary lymphoid organs (SLOs), within lymph nodes for the antigen that is carried into them from the tissues, or within ... Nonspecific B-cells. Small B cells that are not specific for the antigen are repelled from the primary follicles, as the blast ...
... secondary lymphoid organs, making routine analysis of these cells impractical [8, 18]. However, recently circulating ... T cells termed follicular helper T cells (TFH), located in the B-cell follicle by virtue of expression of the chemokine ... Autoantibodies in RA are usually of the IgG subclass and demonstrate high affinity for their targets, characteristics ... Within germinal centres, the fate of developing B cells is determined by their ability to present antigen to a specialised ...
... of which only B cells with higher affinity B cell receptors can bind. FDCs are present in the follicles of secondary lymphoid ... It follows that the conventional products of germinal centers in these organs, such as memory B cells and Ab-producing plasma ... and plasma cells (CD38; data not shown). As shown in Fig. 1⇓, most germ cell tumors harbored a considerable immune cell ... 1⇓, B, E, and K), B cells (Fig. 1⇓, C, F, and L) and plasma cells (data not shown; fewer in number and sparsely distributed). ...
Selected GC B cells further differentiate into long-lived plasma cells or memory B cells with high affinity B cell receptors of ... that acquire antigen before homing to the T cell zones of draining secondary lymphoid organs (Figure 4). There, they activate ... Th cells migrate to the border between the B cell follicles and the T cell zone where they encounter antigen-activated B cells ... Th cells migrate to the border between the B cell follicles and the T cell zone where they encounter antigen-activated B cells. ...
... experiments to raise antibodies to Salmonella antigens Bursa was later found to be the organ in which antibody producing cells ... a lymphoid organ in the cloacal region of the chicken Bursectomy - no apparent effect None of the bursectomised chickens made ... antibody producing cells were thereafter called B cells Mammals do not have a bursa of Fabricius ... The discovery of B cell immunity Bruce Glick, Ohio State University Studies on the function of the bursa of Fabricius, ...
... suggesting that all B cells scan antigen trapped in GCs. Consistent with this observation, high-affinity antigen-specific B ... Lymphoid structures, complete with B cell follicles, germinal centers, and T cell zones, form in the lung in response to ... Tonsil IRTA1+ cells expressed the memory B-cell marker CD27 but not mantle cell-, germinal center-, and plasma cell-associated ... Secondary lymphoid organs, such as spleen and lymph nodes, accelerate and amplify immune responses to antigens or pathogens in ...
... and B cells. Cells[edit]. In the lymphatic system a lymph node is a secondary lymphoid organ.[1] Lymph nodes contain ... there are follicular dendritic cells in the B cell follicle and fibroblastic reticular cells in the T cell cortex. The ... increasing its antigen binding affinity and changing its effector function. Proliferation of cells within a lymph node will ... If a cell is stimulated, it will go on to produce more antibodies (a plasma cell) or act as a memory cell to help the body ...
... infiltration by Th2 cells, and protumor-polarized innate inflammatory cells result in the promotion of tumor development and ... Recent insights into the molecular and cellular mechanisms underlying cancer development have revealed that immune cells ... Mature antigen-committed B cells migrate to secondary lymphoid organs (lymph nodes or spleen, predominantly). Upon antigen ... lymphoid follicles and/or metastatic lymph nodes with IgM+ lymphoid cells were statistically related to breast tumors of high ...
... as do secondary lymphoid organs, leading to the de novo formation of B cell follicles and T cell areas, a phenomenon referred ... antigen challenge), indicating that aLNs can support the development of memory B cells and long-lived plasma cells. Memory CD4+ ... High- and low-affinity IgG1 NP-specific AFCs were detected (with NP3-OVA and NP30-OVA, respectively, a detecting antigens) by ... an important feature of a secondary lymphoid organ, and there is vigorous B cell proliferation and plasma cell generation. T ...
... and provide critical help for antigen-specific B cell maturation to high-affinity memory cells and long-lived plasma cells (28 ... organized structures contain distinct T cell zones and B cell follicles with reactive GC similar to secondary lymphoid organs. ... In secondary lymphoid organs, T cells and B cells segregate to separate zones based on CCR7 and CXCR5 expression (28). Upon ... In secondary lymphoid organs, such as LNs, CXCL13 is expressed by stromal cells and Th cells in GC, with its ectopic expression ...
B-cell maturation takes place in a specialized lymphoid organ called the ileal Peyers patch. The generative organs are those ... The bone marrow is the most important source of hematopoiesis-derived cells in adult mammals. Lymphocytes reside in lymphoid ... tissues for various periods of time, the duration depending largely on whether the lymphocytes are activated by antigen. ... organs and tissues essential for the function of immune cells, anatomic factors that influence the immune response, trafficking ...
... accompanied by affinity maturation which induces the survival of B cells that bind to the particular antigen with high affinity ... Lymphoid tissue is found in many organs, particularly the lymph nodes, and in the lymphoid follicles associated... ... into plasma cell. Plasma cell. Plasma cells, also called plasma B cells, plasmocytes, and effector B cells, are white blood ... With repeated exposures to the same antigen, a host will produce antibodies of successively greater affinities. A secondary ...
  • Over the past decades, it has become increasingly clear that cancer cells depend on interactions with the tumor microenvironment for growth and survival. (intechopen.com)
  • Since many B cell malignancies develop in GC-the place of physiological Th cell-B cell interaction-Th cells are a central part of the tumor microenvironment of B cell leukemia and lymphoma. (intechopen.com)
  • SNAs composed of immunomodulatory oligonucleotides and tumor-specific antigens induce the immune system to clear tumors, and are thus promising as cancer vaccines. (mrs.org)
  • However, much work is still needed to fully understand how the materials architecture of the SNA (structure), for instance how the antigen and adjuvant are assembled into the SNA surface, affects immune system activation and tumor clearance (function). (mrs.org)
  • We found that activated T-cells killed five times more tumor cells when the peptide antigen was conjugated to the complementary oligonucleotide compared to when a mixture of linear oligonucleotides and peptide antigens was used. (mrs.org)
  • Like several other tumor types, germ cell tumors often harbor an immune cell infiltrate that can include substantial numbers of B cells. (jimmunol.org)
  • Molecular characterization of the Ig variable region from 320 sequences expressed by germ cell tumor-infiltrating B cells revealed clear evidence of Ag experience, in that the cardinal features of an Ag-driven B cell response were present: significant somatic mutation, isotype switching, and codon insertion/deletion. (jimmunol.org)
  • Because characterization of the immune cell infiltrate of germ cell tumors has thus far been limited to immunohistochemical analysis, the nature of the B cell response within the tumor microenvironment is not well understood. (jimmunol.org)
  • Molecular characterization of the Ab repertoire revealed that the tumor-infiltrating B cells had undergone clonal expansion and isotype switching and had accumulated somatic mutations, all cardinal features of an Ag-driven B cell response. (jimmunol.org)
  • Collectively, our results suggest that the tumor-associated B cell repertoire is most likely shaped through expression of specific Ag(s). (jimmunol.org)
  • At the same time, DCs take up foreign antigens (including tumor antigens) and migrate to lymphoid organs, where they present their antigens to adaptive immune cells. (biomedcentral.com)
  • A major limitation of adoptive immunotherapy is the availability of T cells specific for both terminally differentiated tumor cells and their clonogenic precursors. (aacrjournals.org)
  • Furthermore, activated MILs target both the terminally differentiated CD138 + plasma cells and the myeloma precursor as shown by profound inhibition in a tumor clonogenic assay. (aacrjournals.org)
  • The presence of antigen in the marrow microenvironment seems to be important for the maintenance of tumor specificity. (aacrjournals.org)
  • Taken together, these results highlight the intrinsic tumor specificity of MILs and describe a novel approach for the generation of tumor-specific T-cell populations suitable for adoptive immunotherapy of multiple myeloma. (aacrjournals.org)
  • Ideally, strategies using a polyclonal T-cell population of both CD4 + and CD8 + T cells targeting multiple tumor-associated antigens offer the possibility of inducing a more comprehensive and effective antitumor response. (aacrjournals.org)
  • They include the ability to overcome tumor-specific T-cell tolerance, to efficiently isolate and expand tumor-specific T cells that maintain antigenic specificity, and to grow reasonable numbers of these cells to enable the generation of a clinically meaningful response when infused into the properly prepared host environment. (aacrjournals.org)
  • 1 - 3 Although this hypothesis was postulated in early reports, 4 - 6 definite proof of their existence came from recent studies in leukemia, where among the complete tumor cell population only a small subset of cells could initiate, regenerate and maintain the leukemia after transplantation into immunocompromised mice. (haematologica.org)
  • 9 Another cell surface marker, the CD133 glycoprotein, defined the tumor-initiating cells of brain and colon carcinomas. (haematologica.org)
  • 12 , 13 In addition, studies in glioblastoma and breast cancers support the view that cancer stem cells are more resistant to radiotherapy and chemotherapy-induced apoptosis, which allows these cells to survive and generate tumor relapse. (haematologica.org)
  • The specific variable (V)-region and constant (C)-region coding sequences that the tumor cells used were present on the same DNA restriction fragment in the tumor cells but on two different restriction fragments in the embryos. (nih.gov)
  • The B cell tumor arose from a single B cell and therefore makes a single species of antibody molecule. (nih.gov)
  • This complex relationship, together with the potential to pharmacologically influence chromosome missegregation frequencies in cancer cells, offers previously unrecognized means to limit tumor growth and its response to therapy. (jci.org)
  • Although Bcl2 activation is a prerequisite for human follicular lymphoma, it does not appear to be sufficient to initiate the tumor, because sensitive polymerase chain reaction (PCR) procedures can detect the t(14;18) translocation at low frequency in the B cells of a substantial proportion of healthy individuals. (bloodjournal.org)
  • For example, we recently observed that PMN occasionally release phagocytosed cells after killing them intracellularly3, which may enable the pathogens to be subsequently taken up and processed by professional antigen presenting cells. (healthyconnectionsinc.com)
  • During an immune response, professional antigen-presenting cells (APCs) endocytose foreign material (typically bacteria or viruses ), which undergoes processing , then travel from the infection site to the lymph nodes . (wikipedia.org)
  • studied both normal mice and mice in which the particular types of dendritic cell can be depleted. (elifesciences.org)
  • Other experiments that depleted some other types of dendritic cell - but not those that produce CD301b - completely abolished the antibody response of the mice. (elifesciences.org)
  • In Paper II, we employed dendritic cell (DC) based immunotherapy in an attempt to induce apoB100-specific regulatory T (Treg) cells that can exert anti-inflammatory functions in developing plaques. (wesrch.com)
  • The mechanisms that regulate B cell memory and the rapid recall response to antigen remain poorly defined. (rupress.org)
  • Accordingly, long-range migration of cells and short-range communication by local chemical signaling and by cell-cell contacts are vital to the control of an immune response. (pubmedcentralcanada.ca)
  • Cellular homing and migration within lymphoid organs, antigen recognition, and cell signaling and activation are clearly vital during an immune response, but these events had not been directly observed in vivo until recently. (pubmedcentralcanada.ca)
  • The ZOO meeting series has become a landmark event in the field of cell adhesion and migration due to unique theme selection, high scientific profile with excellent speakers and limited number of attendees ( (radboudumc.nl)
  • Despite the similarities, the functions of Rap1 and Rap2 have not been completely elucidated although recent studies suggest that both Rap proteins may be involved in cell migration and adhesion. (ubc.ca)
  • Nevertheless, there is evidence that thioglycollate-induced B cell migration is enhanced in FHL2-deficient mice ( 31 ). (immunohorizons.org)
  • Recognizing cell tracks as a whole will enable studying and quantifying more complex patterns of cell behavior, e.g. switches in migration mode or dependence of the phagocytosis efficiency on the number and type of preceding interactions. (healthyconnectionsinc.com)
  • To allow the quantitative motility evaluation of label-free individual cells, we previously created algorithm for migration and relationship monitoring (AMIT)9,10, which allowed monitoring of label-free immune cells in bright-field microscopy movies. (healthyconnectionsinc.com)
  • In vitro , these cells are able to induce the production of IgG, IgA and IgM when co-cultured with B cells [ 4 , 5 ]. (plos.org)
  • Mitochondrial membrane potential and MTT assays were performed to observe the in vitro effects of IL-22 treatment on HSG cells, and results indicate that IL-22 does not induce apoptosis in HSG cells, but instead halts the cell cycle at the G2-M phase. (ufl.edu)
  • Placenta has been known as the source of cells capable to induce the repair of the damaged vascular system and is added for all diabetic patients with microangiopathy, the same angiopathy that is the underlying pathology of any & all ultimately deadly diabetic complications. (bio-cellular-research.com)
  • Both microenvironment within the marrow and the influence of soluble mediators that act as colony stimulation factors determine the celltype in which the pluripotent stem cell develops. (verdec.com)
  • Furthermore, the pSS salivary gland microenvironment provided niches rich in factors vital for plasma cell survival. (biomedcentral.com)
  • For continuous survival and renewal, it is essential that parent cells retain their stemness after division and daughter cells integrate intrinsic and extrinsic cues from a highly regulated microenvironment referred to as a niche. (molcells.org)
  • In agreement with previous reports ( 16 ), large numbers of antigen-specific T cells were found in the T cell zone 3 days after immunization with 4-hydroxy-3-nitrophenylacetyl-ovalbumin (NP-OVA). (sciencemag.org)
  • This ability allows the B cell to switch from making membrane -bound antibody to making secreted antibody, or from making one class of antibody to making another, all without changing the antigen-specificity of the antibody. (nih.gov)
  • IgG-switched memory B cells in IL-6 knock-in mice displayed a diverse antibody repertoire and high specificity against immunized antigen. (bloodjournal.org)
  • Alternatively a recent research of full-length proteins and many deletion mutants indicated in insect cells demonstrated that COL1 and NC1 aren't necessary for trimerization of collagen IX even though the COL1-NC1 region may be important for string specificity (16). (health-media.net)
  • Such conjugates and/or cytotoxic compounds may be effective for treating a range of diseases, such as cancer, with a relatively high activity at a relatively low, non-toxic dose. (patents.com)
  • The internalization of PRP-protein conjugates by antigen-presenting cells (APC) followed by major histocompatibility complex (MHC) presentation ( 6 , 8 ) is required for the stimulation of cytokine-secreting T cells, activation of polysaccharide-specific B cells, and Ig-isotype switching. (asm.org)
  • Thus, antigen stimulation greatly increases the antibody arsenal. (nih.gov)
  • B10 cells area functionally defined subset currently identified only by their competency to produce and secreteIL-10 following appropriate stimulation. (biomedcentral.com)
  • MNZ B cells are naïve cells in a quiescent state and may participate in GC reactions upon proper stimulation. (biomedcentral.com)
  • In pancreatic islets, acts as a modulator of beta-cells function through the up-regulation of PDX1 and NKX6-1 and consequent stimulation of insulin secretion in response to glucose. (uniprot.org)
  • Fatty acids (FAs) and FA-metabolites are major structural and metabolic constituents of the cell, functioning also as modulators of signal transduction pathways or transcription factors induced by several stimuli (Duplus et al. (sciencepop.org)
  • T cell help ( 19 ) and CD40-CD40 ligand interactions greatly influence the initiation ( 20 )( 21 )( 22 ) and function ( 23 )( 24 ) of the GC reaction. (rupress.org)
  • While leukemia-originating stem cells are critical in the initiation and maintenance of leukemias, the existence of similar cell populations that may generate B-cell lymphoma upon mutation remains uncertain. (haematologica.org)