A Complete Glossary for Immunology

Immunology is the study of the immune system and all of its organisms. It deals with all aspects in health and science related fields including diseases and disorders of the immune system, physiological functioning, as well as malfunctions and characteristics. The study of Immunology focuses on the protection of invading foreign organisms or macromolecules and the body?s responses to them. These foreign invaders include parasites such as bacteria, viruses and protozoa.

Immunology Glossary

Accessory Cell - Nonlymphocytic cells that assist in the introduction of T lymphocytes to antigens.
Affinity -The bond strength or relationship between two organisms resulting in the structure or structure parts.
Agglutination - The clumping together of bacteria exposed to specific immune serum.
Allelic - An alternative form of a series or pair of genes.
Allelic exclusion - The process in which one allele of a gene is silenced while the other is expressed.
Allergen - Substance that has the capabilities to trigger allergies or hypersensitivity.
Allergy - A condition of increased sensitivity to any element or substance.
Allogeneic - Antigenically distinct cells taken from different individuals that are of the same species.
Allograft - A graft between animals of a different genotype, but the same species.
Allotypes - Any of various allelic variants of a protein characterized by antigenic differences.
Alternate (Alternative) Pathway - Component of the immune system?s natural defense against invading infections.
Anaphylatoxin - A substance found in blood serum during complement fixation which acts as a advocate of inflammation by activating mast cell degranulation and histamine turn out.
Anaphylaxis - An organism?s intense reaction to a foreign element or substance which it has become sensitized.
Antibody - Gamma globulin proteins located in bodily fluids such as blood that assist the immune system in neutralizing foreign substances.
Antibody-dependent, cell-meditated cytotoxicity (ADCC) - Function of cell arbitrated immunity in which an effector cell lyses the target cell, which is bound by antibodies.
Antigen - Molecule that have the capabilities to induce and react to a response and binds to an antibody.
Antigen-binding site - Specialized ends of antibodies that secure specific antigens.
Antigen-presenting cell - Accompanying cell displaying a foreign antigen complex, it includes a major histocompatability complex (MHC) on the surface level.
Antigen receptor - Polypeptide chain of amino acids that matches the shape of the antigen to which it?s specific.
Antigenic determinant - Part of the antigenic molecule in which a specific immune response is expected.
Antigen processing - Biological process in which antigens are prepared for presentation to T lymphocytes.
Atopy - Allergic hypersensitivity that affects areas of the body that are not in direct association with an allergen.
Autograft - Tissue that is transplanted from one area of the body to another.
Autoimmunity (autoallergy) - A condition in which one?s own tissues are at risk due to the actions of the immune system, in an autoimmune disease.
Avidity - Combined strength of various bond interactions.
B lymphocyte (B cell) - Type of white blood cell, or leukocyte, that circulates throughout the blood.
Basophil - A cell having granules that strain readily with basic dyes.
Bence-Jones protein - Monoclonal globulin proteins that can be found in the urine or blood.
Blocking Antibody - Antibody that prevents other antibodies from combining with that antigen but does not have a reaction when combined with that antigen.
Bursa of Fabricius - Specialized organ found in various birds that is essential for B cell development.
Carcinoembryonic antigen (CEA) - Test that aggregates and measures the amount of protein in the blood in some cancers, especially large intestine cancer.
Carrier - Large immunogenic molecule that has an antigenic determinant which is attached to it.
Cell-meditated cytotoxicity (CMC) - Lysis of a target cell by an effector lymphocyte.
Cell-mediated immunity (CMI) - Reaction by immune T cells as differentiated from humoral immunity.
Chemotaxis - Rare occurrence in which the bodies cell direct their movements according to chemicals in its environment.
Class I, II, and III MHC molecules - Series of molecules that include immunoglobulin?s, T-cell receptors, CD8, CD4, also known as the Immunoglobulin?s Supergene Family.
Class switch - Mechanism in which the production of an antibody is switched from one class to another in a B cell.
Classical pathway - Activation of the complement system in which a group of proteins mediate a certain antibody response.
Clonal deletion - The deactivation process between B and T cells prior to developing into immunocometent lymphocytes but post expressed self-antigen receptors.
Clonal selection theory - Biological model that attempts to represent how an individual's immune system responds to specific kinds of infections as well as how B and T lymphocytes are chosen for antigen abolishing.
Cluster determinant (CD) - Cluster of antigens in which antibodies react, which are a representative of a cell surface marker.
Combinatorial joining - The merge of certain DNA segments in order to develop new genetic information.
Complement - Group of serum proteins that concur in the mediation of reactions in the immune system.
Complement components - Enzymatic system of serum proteins that occur from classical as well as alternative pathways which result in phagocytosis, target cell lysis, chemotaxis and opsonization.
Complement receptor - A receptor of the complement system that detect pathogens by mechanisms not mediated by antibodies.
Constant region (C region) - The carboxyl-terminal part of an antibody unit.
Coombs' test - Two separate clinical blood tests that are used to detect antibodies or complement proteins bound red blood cells surfaces in certain diseases and conditions.
Cross-reactivity - Reaction between and antibody and antigen which was generated against a similar, but different antigen.

Cytokines - Substances that are secreted by certain cells which carry signals between local, therefore exerting an impact on other cells.
Cytotoxic (Cytolytic) T cell - T lymphocyte sub-group which have the capabilities to actuate death on tumor or infected cells.
D gene - Small part of immunoglobulin heavy-chain as well as T cell receptor DNA.
Delayed type hypersensitivity (DTH) - The reaction to an antigen from a T cell that results in the release of lymphokines and the introduction of monocytes and macrophages.
Determinant - The site on the surface of an antigen molecule in which an antibody is attached.
Differentiation antigen - Large macromolecule discovered by immune reagents.
Domain - Part of an immunoglobulin molecule that is translated by a special compact portion of DNA.
DR antigens - Antigen-presenting cells found in B cells in the MHC class II.
Enhancing antibodies - Antibodies that act to strengthen the survival of a tumor graft.
Enzyme-linked immunosorbent assay (ELISA) - Technique used to detect the antigen or antibody presence in a sample.
Eosinophil - Type of leukocyte cell within its cytoplasm and a bilobate nucleus.
Eosinophil chemotactic factor of anaphylaxis (ECF-A) -Attracting of anaphylaxis and eosinophils during the substrate release of mast cells.
Epitope - Three-dimensional surface of an antigen molecule that is derived from nonself proteins.
Equivalence Zone - The zone in which neither an antigen nor antibody is in excess in a precipitin reaction.
Exon - The sequence of nucleic acid found in mature RNA molecules.
Fab - Portion of an antibody formed by division of the antibody with the enzyme papain.
F(ab')2 - Segment of an antibody which contains two antigen-binding areas that are generated by a chasm of the antibody molecule with the enzyme papsin.
Fc - Portion of an antibody that lacts antigen-binding areas, which are formed by division with papain.
Fc receptor (FcR) - A receptor on a cell surface, with a binding affinity for the Fc part of antibodies.
Fluorescent antibody - Antibody that is coupled with fluorescent light used to identify antigen on tissues, on cells, and on microorganisms.
Freund's complete adjuvant - The combination of mineral oil and an antigen solution to be used as an immunopotentiator.
Genotype - Genetic makeup of a cell or organism
Germ line - Developing or mature individual in a sequence of germ cells that have a genetic makeup that may be passed onto a child.
Graft versus host reaction (GVH) - Condition of an organ, organism, system or part of each caused by environmental stress.
HLA complex - Antigens in chromosome 6 that contain proteins that enable the immune system to distinguish proteins or tissues.
H-2 complex - Major histocompatiblity complex found in mice.
Haplotype - Conjunction of alleles at various loci transmitted as one on the same chromosome.
Hapten - Small molecule that is able to draw out an immune response when combined with a larger carrier.
Heavy chain (H chain) - High-molecular weight polypeptide that consists in an immunoglobulin molecule.
Helper T cells - Sub-group of lymphocytes that establish the capabilities and maximize the potential of the immune system.
Heterophile antigen - Substance that is seen in unrelated species yet have similar serologic properties.
Hinge region - Section of a crystalline form of tRNA that transfers into an -L- shape while under electron microscopy.
Histocompatibility - Property of having similar alleles of a set of genes known as the major histocompatiblity complex.
Humoral immunity - Immunity mediated by antibodies produced in the B lymphocyte lineage cells.
Hybridoma - Essential resource used in the fields of molecular immunology for therapeutic and experimental reasons.
Hypersensitivity - Undesirable outcomes that are caused by a normal immune system.
Hypervariable regions - Located within a nuclear DNA in which pairs of nucleotides have substitutes or repeat.
Ia - -Immune response-associated- proteins that are found in antigen-presenting and B cell in mice.
Idiotype - The similarities between immunoglobulin series and T cell receptors during antigen binding.
Immediate-type hypersensitivity - Anaphylactic reaction that can cause a range of symptoms from mild health problems to death.
Immune adherence - Adherence of antigen antibodies complexes covered with antibody cells bearing complement receptors.
Immune complex - Soluble antigen created from the binding of an antibody.
Immune modulators - Chemicals that effect and influence the immune system.
Immune response (Ir) gene - Gene that determines a lymphocytes ability to mount an immune response to certain antigens.
Immunogen - Any substance or element that stimulates an immune response.
Immunoglobulin (Ig) - Class of structurally related proteins that consist of two pairs of polypeptide chains.
Interferon - Proteins created and released from lymphocytes in response to the presence of pathogens.
Interleukins - Group of cytokines that signal molecules and secret proteins in leukocytes, or white blood cells.
Internal image - Spatial configuration of an anti-idiotype antibody combining site.
Intron - DNA region which consists within a gen that is not transformed into a protein.
Isograft - Graft of tissue that are genetically identical between two tissues.
Isohemagglutinins - Agglutination in red blood cells caused by agents.
Isotypes - Genetic variations in the constant region of the heavy chair lg classes.
Isotype switch - Mechanism that changes a B cell antibody production from one class to another.
J chain (joining chain) - Polypeptide chain that join heavy chains to form dimmers of iga and igm.
J gene - Gene for the joining segment of polypeptide chain that link to the constant regions of heavy chains of immunoglobulins and light.
K cell - Digestive system cells that synthesize gastric inhibitory polypeptide.
Killer T cell - Large T cell that functions in a cell-mediated immunity by lysing and invading target cells that have certain surface antigens.
Light chain (L chain) - One of two small polypeptide chains that when linked to heavy chains, make up the antibody molecule.
Linkage disequilibrium - Non-random connection of alleles at two or more loci that are not necessarily associated with the same chromosome.
Lymphocyte - A kind of white blood cell that can be found in the vertebrate immune system.
Lymphokines - Subcategory of cytokines created by a lymphocyte immune cell that coordinate immune system response by signaling between certain cells.
Macrophage - White blood cells found in various tissues, produced by monocytes.
Macrophage-activating factor (MAF) - Lymphokine that primes macrophages in order to become cytotoxic to tumors.
Major histocompatibility complex (MHC) - Vast genomic region found in most vertebrates.
Mast cell - Resident cell that contains many granules that are rich in heparin and histamine.
Memory - The ability to retain, store and recall various information.
MHC class I molecule - First primary class of major histocompatibility complex molecules found on nucleated cells on the body.
MHC class II molecule - Only found on a limited number cell types such as B cells, dendritic cells and macrophages.
MHC restriction - The act of a T cell recognizing a peptide antigen only when bound to a specific MHC molecule.
Migration inhibition factor (MIF) - Glucocorticoid counter-regulator located within the immune system.
Minor histocompatibility antigens - Receptors on a cells surface of donated organs that have the ability to give immunological responses to some organ transplants.
Mitogen - Chemical substance that help a cell to begin cell division which in turns, triggers mitosis.
Mixed lymphocyte reaction - Measure of histocompatibility at the HL-A locus.
Monoclonal - Group of cells that are created from a one ancestral cell from iterated cellular replication.
Monocyte - A Kind of white blood cell, which repopulates macrophages as well as dendritic cells.
Monokines - Type of cytokine that is produced by macrophages and monocytes.
Myeloma - Cancer of the white blood cells, or plasma cells.
NK cell - exert a effect in rejection of tumors that are infected by viruses and are a major component in the innate immune system.
Null cells - Large lymphocyte without membrane associated proteins or surface markers from T or B lymphocytes.
Opsonin - Molecules that perform as binding enhancers used in phagocytosis.
Opsonization - The process in which bacteria is altered due to opsonins.
Paratope - Part of a molecule of antibody that binds to an antigen.
Passive immunization - Transfer of active humoral immunity from one organism to another.
Phagocytosis - Protist and phagocyte cellular process from an internal phagosome to a cell membrane.
Phenotype - Visible characteristic of an organism, such as development or physiological properties.
Pinocytosis - Form of endocytosis in which small particles are brought to a cell which bind with lysosomes to break down particles.
Plasma cell - White blood cells that produce large amounts of antibodies.
Polyclonal activator - Substance that help activate B cells and T cells, regardless of their specific specifications.
Polymorphism - Having various alleles of a gene that express different phenotypes in a population.
Polymorphonuclear leukocyte - Type of white blood cell that consists of a nucleus that is deeply divided to resemble multiple nuclei.
Primary lymphoid organs - Sites where diverse population functionally matures and lymphocytes are generated to disperse through the body.
Primary responses - First exposure to a foreign invader or material in the body.
Prophylaxis - Refers to public and medical health measures that must be taken to prevent health problems and disease.
Radioallergosorbent test (RAST) - Blood test that is used to determine what substances in the body, if any, a person is allergic to.
Radioimmunoassay (RIA) - Extremely sensitive technique used to measure amounts of antigens.
Reagin - Antibody found in the blood that have genetic predisposition to allergies.
Respiratory burst - Fast release of reactive oxygen species by various kinds of cells.
Reticuloendothelial system - Consists of phagocytic cells that gather in lymph nodes and the spleen.
Rheumatoid factor - Auto-antibody most relevant in rheumatoid arthritis that is against the Fc portion of lgG.
Second set rejection - Rejection of a transplant that occurs when the individual had been sensitised to a graft.
Secondary lymphoid organs - Sites where lymphocytes are most active.
Secretory component - Component of IgA that consists of a polymeric immunoglobulin receptor.
Serum sickness - Reaction similar to an allergy when the immune system rejects certain medications, antiserum or injected proteins.
Slow-reacting substance of anaphylaxis (SRS-A) - Mixture of leukotrienes LTC4, LTD4 and LTE4 that are secreted by mast cells during an anaphylactic reaction.
Suppression - Act that decreases the activation of the immune system.
Syngeneic - Immunologically compatible or genetically identical.
Syngraft - Graft of tissue from a donor who is genetically identical to that of the recipient.
T cell - Involved in major cell mediated immunity which are different from other types of lymphocyte cells.
T-dependent antigen - Require the presence of helper cells in order to stimulate antibody production using B cells.
T-independent antigen - Able to trigger B cells in order to produce antibodies without T cells being present.
Titre - Quantity of antibodies that are present in an organism.
Tolerance - Process in which the immune system does not attack antigens.
Toxoid - Suppressed bacterial toxin that has been weakened by chemicals or heat treatments while its immunogenicity remains constant.
Unresponsiveness - Marked by failure or immunological non-response non-reacting quality.
Vaccination - Administration of vaccines to result in the immunity of a disease and prevent the effects of infection by pathogens.