Chemokine CXCL12: A CXC chemokine that is chemotactic for T-LYMPHOCYTES and MONOCYTES. It has specificity for CXCR4 RECEPTORS. Two isoforms of CXCL12 are produced by alternative mRNA splicing.Chemokine CXCL13: A CXC chemokine that is chemotactic for B-LYMPHOCYTES. It has specificity for CXCR5 RECEPTORS.Chemokine CXCL10: A CXC chemokine that is induced by GAMMA-INTERFERON and is chemotactic for MONOCYTES and T-LYMPHOCYTES. It has specificity for the CXCR3 RECEPTOR.Chemokine CXCL6: A CXC chemokine that has stimulatory and chemotactic activities towards NEUTROPHILS. It has specificity for CXCR1 RECEPTORS and CXCR2 RECEPTORS.Chemokine CXCL11: A CXC chemokine that is induced by GAMMA-INTERFERON. It is a chemotactic factor for activated T-LYMPHOCYTES and has specificity for the CXCR3 RECEPTOR.Chemokine CXCL1: A CXC chemokine with specificity for CXCR2 RECEPTORS. It has growth factor activities and is implicated as a oncogenic factor in several tumor types.Chemokine CXCL9: An INTEFERON-inducible CXC chemokine that is specific for the CXCR3 RECEPTOR.Chemokines, CXC: Group of chemokines with paired cysteines separated by a different amino acid. CXC chemokines are chemoattractants for neutrophils but not monocytes.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.Receptors, CXCR: Chemokine receptors that are specific for CXC CHEMOKINES.Chemokine CXCL5: A CXC chemokine that is predominantly expressed in EPITHELIAL CELLS. It has specificity for the CXCR2 RECEPTORS and is involved in the recruitment and activation of NEUTROPHILS.Receptors, CXCR4: CXCR receptors with specificity for CXCL12 CHEMOKINE. The receptors may play a role in HEMATOPOIESIS regulation and can also function as coreceptors for the HUMAN IMMUNODEFICIENCY VIRUS.Receptors, CXCR3: CXCR receptors that are expressed on the surface of a number of cell types, including T-LYMPHOCYTES; NK CELLS; DENDRITIC CELLS; and a subset of B-LYMPHOCYTES. The receptors are activated by CHEMOKINE CXCL9; CHEMOKINE CXCL10; and CHEMOKINE CXCL11.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.Chemokine CCL5: A CC-type chemokine that is a chemoattractant for EOSINOPHILS; MONOCYTES; and LYMPHOCYTES. It is a potent and selective eosinophil chemotaxin that is stored in and released from PLATELETS and activated T-LYMPHOCYTES. Chemokine CCL5 is specific for CCR1 RECEPTORS; CCR3 RECEPTORS; and CCR5 RECEPTORS. The acronym RANTES refers to Regulated on Activation, Normal T Expressed and Secreted.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.Receptors, Interleukin-8B: High-affinity G-protein-coupled receptors for INTERLEUKIN-8 present on NEUTROPHILS; MONOCYTES; and T-LYMPHOCYTES. These receptors also bind several other CXC CHEMOKINES.Chemokine CCL2: A chemokine that is a chemoattractant for MONOCYTES and may also cause cellular activation of specific functions related to host defense. It is produced by LEUKOCYTES of both monocyte and lymphocyte lineage and by FIBROBLASTS during tissue injury. It has specificity for CCR2 RECEPTORS.Chemokine CXCL2: A CXC chemokine that is synthesized by activated MONOCYTES and NEUTROPHILS. It has specificity for CXCR2 RECEPTORS.Chemokine CCL21: A CC-type chemokine with specificity for CCR7 RECEPTORS. It has activity towards DENDRITIC CELLS and T-LYMPHOCYTES.Chemotaxis, Leukocyte: The movement of leukocytes in response to a chemical concentration gradient or to products formed in an immunologic reaction.Chemokine CCL4: A CC chemokine with specificity for CCR5 RECEPTORS. It is a chemoattractant for NK CELLS; MONOCYTES and a variety of other immune cells. This chemokine is encoded by multiple genes.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.Chemokine CCL22: A CC-type chemokine with specificity for CCR4 RECEPTORS. It has activity towards TH2 CELLS and TC2 CELLS.Chemokine CCL3: A CC chemokine with specificity for CCR1 RECEPTORS and CCR5 RECEPTORS. It is a chemoattractant for NK CELLS; MONOCYTES; and a variety of other immune cells. This chemokine is encoded by multiple genes.Chemokine CCL17: A CC-type chemokine that is found at high levels in the THYMUS and has specificity for CCR4 RECEPTORS. It is synthesized by DENDRITIC CELLS; ENDOTHELIAL CELLS; KERATINOCYTES; and FIBROBLASTS.Receptors, Scavenger: A large group of structurally diverse cell surface receptors that mediate endocytic uptake of modified LIPOPROTEINS. Scavenger receptors are expressed by MYELOID CELLS and some ENDOTHELIAL CELLS, and were originally characterized based on their ability to bind acetylated LOW-DENSITY LIPOPROTEINS. They can also bind a variety of other polyanionic ligand. Certain scavenger receptors can internalize micro-organisms as well as apoptotic cells.Chemokine CCL19: A CC-type chemokine with specificity for CCR7 RECEPTORS. It has activity towards T LYMPHOCYTES and B LYMPHOCYTES.Chemokine CX3CL1: A CX3C chemokine that is a transmembrane protein found on the surface of cells. The soluble form of chemokine CX3CL1 can be released from cell surface by proteolysis and act as a chemoattractant that may be involved in the extravasation of leukocytes into inflamed tissues. The membrane form of the protein may also play a role in cell adhesion.Chemokines, CC: Group of chemokines with adjacent cysteines that are chemoattractants for lymphocytes, monocytes, eosinophils, basophils but not neutrophils.Interleukin-8: A member of the CXC chemokine family that plays a role in the regulation of the acute inflammatory response. It is secreted by variety of cell types and induces CHEMOTAXIS of NEUTROPHILS and other inflammatory cells.Heterocyclic Compounds: Ring compounds having atoms other than carbon in their nuclei. (Grant & Hackh's Chemical Dictionary, 5th ed)Chemotaxis: The movement of cells or organisms toward or away from a substance in response to its concentration gradient.Mice, Inbred C57BLPlatelet Factor 4: A CXC chemokine that is found in the alpha granules of PLATELETS. The protein has a molecular size of 7800 kDa and can occur as a monomer, a dimer or a tetramer depending upon its concentration in solution. Platelet factor 4 has a high affinity for HEPARIN and is often found complexed with GLYCOPROTEINS such as PROTEIN C.Chemokine CCL7: A monocyte chemoattractant protein that has activity towards a broad variety of immune cell types. Chemokine CCL7 has specificity for CCR1 RECEPTORS; CCR2 RECEPTORS; and CCR5 RECEPTORS.Chemokine CCL20: A CC-type chemokine with specificity for CCR6 RECEPTORS. It has activity towards DENDRITIC CELLS; T-LYMPHOCYTES; and B-LYMPHOCYTES.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.Chemokine CCL11: A CC-type chemokine that is specific for CCR3 RECEPTORS. It is a potent chemoattractant for EOSINOPHILS.Chemokine CCL1: A CC-type chemokine secreted by activated MONOCYTES and T-LYMPHOCYTES. It has specificity for CCR8 RECEPTORS.Neutrophil Infiltration: The diffusion or accumulation of neutrophils in tissues or cells in response to a wide variety of substances released at the sites of inflammatory reactions.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.Chemokine CCL27: A CC-type chemokine with specificity for CCR10 RECEPTORS. It is constitutively expressed in the skin and may play a role in T-CELL trafficking during cutaneous INFLAMMATION.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.Up-Regulation: A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.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.Receptors, CCR2: CCR receptors with specificity for CHEMOKINE CCL2 and several other CCL2-related chemokines. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; MACROPHAGES; BASOPHILS; and NK CELLS.Receptors, CCR1: CCR receptors with specificity for a broad variety of CC CHEMOKINES. They are expressed at high levels in MONOCYTES; tissue MACROPHAGES; NEUTROPHILS; and EOSINOPHILS.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.Receptors, CCR5: CCR receptors with specificity for CHEMOKINE CCL3; CHEMOKINE CCL4; and CHEMOKINE CCL5. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; MACROPHAGES; MAST CELLS; and NK CELLS. The CCR5 receptor is used by the HUMAN IMMUNODEFICIENCY VIRUS to infect cells.Chemokine CCL8: A monocyte chemoattractant protein that attracts MONOCYTES; LYMPHOCYTES; BASOPHILS; and EOSINOPHILS. Chemokine CCL8 has specificity for CCR3 RECEPTORS and CCR5 RECEPTORS.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.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.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.Macrophage Inflammatory Proteins: Heparin-binding proteins that exhibit a number of inflammatory and immunoregulatory activities. Originally identified as secretory products of MACROPHAGES, these chemokines are produced by a variety of cell types including NEUTROPHILS; FIBROBLASTS; and EPITHELIAL CELLS. They likely play a significant role in respiratory tract defenses.Cell Line, Tumor: A cell line derived from cultured tumor cells.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.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.Receptors, CCR4: CCR receptors with specificity for CHEMOKINE CCL17 and CHEMOKINE CCL22. They are expressed at high levels in T-LYMPHOCYTES; MAST CELLS; DENDRITIC CELLS; and NK CELLS.Receptors, Interleukin-8A: High-affinity G-protein-coupled receptors for INTERLEUKIN-8 present on NEUTROPHILS; MONOCYTES; and BASOPHILS.Mice, Inbred BALB CT-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.Receptors, CCR3: CCR receptors with specificity for CHEMOKINE CCL11 and a variety of other CC CHEMOKINES. They are expressed at high levels in T-LYMPHOCYTES; EOSINOPHILS; BASOPHILS; and MAST CELLS.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Cell Adhesion: Adherence of cells to surfaces or to other cells.Macrophages: The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)Endothelial Cells: Highly specialized EPITHELIAL CELLS that line the HEART; BLOOD VESSELS; and lymph vessels, forming the ENDOTHELIUM. They are polygonal in shape and joined together by TIGHT JUNCTIONS. The tight junctions allow for variable permeability to specific macromolecules that are transported across the endothelial layer.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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.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.Receptors, CCR10: CCR receptors with specificity for CHEMOKINE CCL27. They may play a specialized role in the cutaneous homing of LYMPHOCYTES.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Receptors, CCR8: CCR receptors with specificity for CHEMOKINE CCL1. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; and MACROPHAGES.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.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.Chemokine CCL24: A CC-type chemokine with specificity for CCR3 RECEPTORS. It is a chemoattractant for EOSINOPHILS.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.Receptors, Cytokine: Cell surface proteins that bind cytokines and trigger intracellular changes influencing the behavior of cells.Monocyte Chemoattractant Proteins: Chemokines that are chemoattractants for monocytes. These CC chemokines (cysteines adjacent) number at least three including CHEMOKINE CCL2.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.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.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.Receptors, CCR: Chemokine receptors that are specific for CC CHEMOKINES.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.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Chemokines, CX3C: Group of chemokines with the first two cysteines separated by three amino acids. CX3C chemokines are chemotactic for natural killer cells, monocytes, and activated T-cells.Chemotactic Factors: Chemical substances that attract or repel cells. The concept denotes especially those factors released as a result of tissue injury, microbial invasion, or immunologic activity, that attract LEUKOCYTES; MACROPHAGES; or other cells to the site of infection or insult.Receptors, CCR6: CCR receptors with specificity for CHEMOKINE CCL20. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Transfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Monokines: Soluble mediators of the immune response that are neither antibodies nor complement. They are produced largely, but not exclusively, by monocytes and macrophages.Monocytes: Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.Neutrophils: Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.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)Receptors, HIV: Cellular receptors that bind the human immunodeficiency virus that causes AIDS. Included are CD4 ANTIGENS, found on T4 lymphocytes, and monocytes/macrophages, which bind to the HIV ENVELOPE PROTEIN GP120.Duffy Blood-Group System: A blood group consisting mainly of the antigens Fy(a) and Fy(b), determined by allelic genes, the frequency of which varies profoundly in different human groups; amorphic genes are common.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).Cell Migration Inhibition: Phenomenon of cell-mediated immunity measured by in vitro inhibition of the migration or phagocytosis of antigen-stimulated LEUKOCYTES or MACROPHAGES. Specific CELL MIGRATION ASSAYS have been developed to estimate levels of migration inhibitory factors, immune reactivity against tumor-associated antigens, and immunosuppressive effects of infectious microorganisms.Intercellular Signaling Peptides and Proteins: Regulatory proteins and peptides that are signaling molecules involved in the process of PARACRINE COMMUNICATION. They are generally considered factors that are expressed by one cell and are responded to by receptors on another nearby cell. They are distinguished from HORMONES in that their actions are local rather than distal.Inflammation Mediators: The endogenous compounds that mediate inflammation (AUTACOIDS) and related exogenous compounds including the synthetic prostaglandins (PROSTAGLANDINS, SYNTHETIC).Tumor Necrosis Factor-alpha: Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.NF-kappa B: Ubiquitous, inducible, nuclear transcriptional activator that binds to enhancer elements in many different cell types and is activated by pathogenic stimuli. The NF-kappa B complex is a heterodimer composed of two DNA-binding subunits: NF-kappa B1 and relA.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Chemotactic Factors, Eosinophil: Cytotaxins liberated from normal or invading cells that specifically attract eosinophils; they may be complement fragments, lymphokines, neutrophil products, histamine or other; the best known is the tetrapeptide ECF-A, released mainly by mast cells.Leukocytes: White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).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.HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.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.Down-Regulation: A negative regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.Lipopolysaccharides: Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)Th2 Cells: Subset of helper-inducer T-lymphocytes which synthesize and secrete the interleukins IL-4, IL-5, IL-6, and IL-10. These cytokines influence B-cell development and antibody production as well as augmenting humoral responses.Epithelial Cells: Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.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.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Lymph Nodes: They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.Leukocytes, Mononuclear: Mature LYMPHOCYTES and MONOCYTES transported by the blood to the body's extravascular space. They are morphologically distinguishable from mature granulocytic leukocytes by their large, non-lobed nuclei and lack of coarse, heavily stained cytoplasmic granules.Th1 Cells: Subset of helper-inducer T-lymphocytes which synthesize and secrete interleukin-2, gamma-interferon, and interleukin-12. Due to their ability to kill antigen-presenting cells and their lymphokine-mediated effector activity, Th1 cells are associated with vigorous delayed-type hypersensitivity reactions.Angiostatic Proteins: Proteins that specifically inhibit the growth of new blood vessels (ANGIOGENESIS, PHYSIOLOGIC).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.Eosinophils: Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.Immunity, Innate: The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.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.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.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.Coculture Techniques: A technique of culturing mixed cell types in vitro to allow their synergistic or antagonistic interactions, such as on CELL DIFFERENTIATION or APOPTOSIS. Coculture can be of different types of cells, tissues, or organs from normal or disease states.Transendothelial and Transepithelial Migration: The passage of cells across the layer of ENDOTHELIAL CELLS, i.e., the ENDOTHELIUM; or across the layer of EPITHELIAL CELLS, i.e. the EPITHELIUM.