Exam 1 Vocabulary BIO 537

Integrin

Cell-surface glycoprotein receptor important in mediating cell-to-cell adhesion interactions.

M cell

Cells associated with mucosa-associated lymphoid tissue that specialize in pathogen and antigen delivery to those tissues.

Lymphocyte

Cells of the lymphoid arm of hematopoiesis, including the cells of the adaptive immune system (T cells and B cells) and some cells of the innate immune system (innate lymphoid cells and NK cells).

Self-antigen

Constituent of normal tissue that stimulates an immune response. Also known as autoantigen.

Hematopoiesis

Development of cells of the circulatory system from a common stem cell ancestor.

Lipopolysaccharide (LPS)

Endotoxin that is a major component of cell walls in gram-negative bacteria.

Toll-like receptor (TLR)

Innate immune cell receptor family capable of recognizing a variety of different microbial products and activating key signaling cascades to induce an innate immune response.

Scavenger receptor

Innate immune cell receptor that binds to negatively charged molecules at the surface of microorganisms.

Allergen

Innocuous foreign molecule that can elicit a hypersensitivity response.

Microbiota

Microbial species that reside in symbiosis with an organism on or in tissues such as the skin and intestines.

Receptor

Molecule (typically a protein) that binds to another molecule to sense the environment, interact with other cells, and respond to stimuli.

Lectin

Molecule capable of binding to carbohydrates.

Antigen

Molecule recognized b a T-cell receptor, immunoglobulin, or antibody.

Protease inhibitor

Molecule that is capable of preventing the enzymatic activity of proteases.

Platelet

Nonnucleated product of megakaryocytes that functions in blood clotting.

Vaccine

Nonpathogenic product from a pathogen formulated to be administered to stimulate a primary immune response and provide protection from infection by that specific pathogen.

Opportunistic pathogens

Organism with the potential to cause disease in an immunocompromised host.

Respiratory burst

Process of oxygen consumption due to the action of NADPH oxidase.

Immunization

Process used to prevent disease by exposing an individual to a nonpathogenic product of a pathogenic organism to promote mounting of a primary immune response and immunological memory.

Immunological memory

Production of memory T cells and memory B cells during clonal expansion which act in a faster, more robust adaptive immune response upon subsequent contact with the same antigen.

Apoptosis

Programmed cell death; results in the formation of cellular debris removed via phagocytic cells such as macrophages.

Opsonin receptor

Protein capable of recognizing an opsonin on a foreign pathogen or molecule.

Immunity

State of being resistant to infection by a specific pathogen.

Agranulocyte

White blood cell that is devoid of granules. Refers to lymphocytes (B cells, T cells, NK cells, innate lymphoid cells) and monocytes (macrophages, dendritic cells).

Dendritic cell

White blood cell that specializes in phagocytosis of foreign pathogens and presentation of antigen epitopes to the adaptive immune system.

Macrophage

Agranulocyte that specializes in phagocytosis of foreign antigens and apoptotic cells.

Defensin

Antimicrobial peptide that is capable of disrupting cellular membranes by inserting into them.

Plasma cell

B cell that has been activated by an antigen and specializes in the secretion of antibodies into plasma.

Immunology

Branch of biomedical science that studies immunity and the mechanisms of the immune response.

Cytotoxic T cell

CD8-positive T cell that has been activated by recognition of a specific epitope; targets cells with intracellular infections through the actions of cytokines and cytotoxins.

Glycoprotein

Cell-adhesion molecule containing specific carbohydrates that binds to selectin.

Selectin

Cell-adhesion molecule that binds to specific carbohydrates on another cell-adhesion molecule.

Intracellular adhesion molecule (ICAM)

Cell-adhesion molecule that mediates cell-to-cell contact, commonly with integrins.

Monocyte

Circulating white blood cell that migrates to tissue and differentiates into a macrophage or a dendritic cell.

Lymphatic system

Circulatory system of lymph and lymphoid tissue that allows for lymphocyte migration to and from these tissues.

Membrane-attack complex (MAC)

Complex of complement proteins C5, C6, C7, C8, and C9 that work in concert to form holes in bacterial and eukaryotic membranes.

Inflammasome

Complex of proteins that interact to produce a means to efficiently activate caspase-1 and allow efficient activation of IL-1.

Interferon (IFN)

Cytokine that activates cells important in targeting viral infection.

Interleukin (IL)

Cytokines secreted by white blood cells.

Memory cells

Differentiated long-lived T cells and B cells that drive secondary immune responses.

Lysozyme

Enzyme present in saliva, tears, and respiratory tract fluid that cleaves the polysaccharide of bacterial cell walls.

Granzyme

Enzymes produced by cytotoxic innate and adaptive immune cells that promote the induction of apoptosis to limit the presence of an intracellular infection.

Lymph

Fluid of the lymphatic system that allows for plasma and lymphocyte movement to and from lymphoid tissue.

Basophil

Granulocyte responsible for the clearance of parasites.

Neutrophil

Granulocyte that migrates to sites of infection and phagocytoses pathogens located there.

Eosinophil

Granulocyte that specializes in clearance of parasitic infections.

Mast cell

Granulocyte that specializes in induction of an inflammatory response; often closely associated with IgE isotype antibodies.

Allergy

Hypersensitivity reaction to an innocuous foreign antigen.

Effector cell

Immune system cell that has been activated and changes its function to specialize in pathogen recognition and destruction.

Tolerance

Inactivation of immune response against self-antigens.

Cytosolic innate receptor

Intracellular receptor capable of recognizing PAMPs that my be present in the cytosol of cells.

Lymphoid follicle

Location within a lymphoid node where activated T cells migrate to promote activation of B cells during an infection.

T cell

Lymphocyte that is the primary cell involved in the cell-mediated adaptive immune response; once activated, functions to activate other immune cells or target intracellular infections.

B cell

Lymphocyte that is the primary cell involved in the humoral adaptive immune response; recognizes specific antigens using cell surface immunoglobulins and differentiates into plasma cells or centrocytes when activated.

Secondary lymphoid tissue

Lymphoid tissue that serves as a location for activating lymphocytes.

Primary lymphoid tissue

Lymphoid tissue that serves as a location for lymphocyte development.

Diapedesis

Mechanism by which a leukocyte squeezes between two endothelial cells.

Innate Immunity

Mechanisms used by the immune system that target pathogens based on common components and in a relatively nonspecific manner.

Adaptive immunity

Mechanisms used by the immune system that target specific products of pathogens through the use of T cells and B cells.

Phagolysosome

Membrane-bound organelle that results from fusion of a lysosome with a phagosome; specializes in digestion of phagocytosed material.

Phagosome

Membrane-bound vesicle created during the internalization of a pathogen during phagocytosis.

Pathogen-associated molecular pattern (PAMP)

Molecules commonly seen on the surfaces of microorganisms that have been conserved evolutionarily but are absent on the surface of eukaryotic cells; used by innate immune cells to recognize foreign microorganisms.

Lysosome

Organelle in eukaryotic cells that facilitates digestion of internalized material due to the presence of digestive enzymes and toxic substances.

Pathogen

Organism with the potential to cause disease.

Intracellular pathogen

Pathogen that resides within a cell of the infected organism.

Extracellular pathogen

Pathogen that resides within an organism without being enclosed by a host's cellular membrane.

Antigen-presenting cells

Phagocytic cells of the innate immune system that process engulfed materials and present them to T cells and B cells.

Progenitor cell

Precursor cell that can differentiate into several specialized blood cell types during hematopoiesis.

Thymus

Primary lymphoid tissue that serves as the location for T cell development.

Bone marrow

Primary lymphoid tissue that serves as the location of hematopoiesis and the maturation of B cells.

Clonal selection

Process by which a specific T cell or B cell recognizes its antigen through action of its receptor.

Phagocytosis

Process of engulfing and killing cells through receptor binding and endocytosis.

Extravasation

Process of migration of neutrophils from circulation to a site of infection.

Clonal expansion

Proliferation and differentiation of a T cell or B cell that has engaged its receptor with its antigen.

Complement component 3 (C3)

Protein component of the complement system that is cleaved during complement activation to produce C3a (a chemokine) and C3b (an opsonin).

Perforin

Protein present in granules of cytotoxic immune cells that can form small pores in target cells.

Opsonin

Protein product on a pathogen surface that marks the pathogen for phagocytosis by neutrophils and macrophages.

Immunoglobulins

Proteins made by B cells that act as specific antigen receptors for B-cell recognition, activation, and effector function.

Pattern recognition receptor (PRR)

Proteins on the surface of innate immune cells that are capable of recognizing molecules known as PAMPs.

Fc receptor

Receptor on the surface of an innate immune cell capable of recognizing the Fc component (tail region) of an immunoglobulin.

Adhesion molecule

Receptor on the surfaces of two interacting cells that aid in cellular contact.

Erythrocyte

Red blood cell responsible for transporting oxygen from the lungs to peripheral tissues.

Epitope

Region of an antigen that is recognized by an immunoglobulin, antibody, or T-cell receptor.

Inflammation

Response triggered by cytokines that results in vasodilation, redness, and swelling; this response aids the innate immune response by promoting immune cell migration to a site of infection and immune cell action at an infection site.

Spleen

Secondary lymphoid tissue important in red blood cell filtration and monitoring pathogen presence in the bloodstream.

Lymph Node

Secondary lymphoid tissue that contains anatomy specialized in antigen presentation to T cells and B cells and lymphocyte activation and proliferation.

Mucosa-associated lymphoid tissue (MALT)

Secondary lymphoid tissue that specializes in the uptake and clearance of pathogens at mucosal surfaces.

Antibodies

Soluble immunoglobulins synthesized by B cells to bind to antigens; act to neutralize pathogens and toxins, aid in complement activation, and aid as a tag to promote phagocytosis.

Cytokine

Soluble protein product secreted by cells to aid the immune system by increasing inflammation, chemotaxis to sites of infection, or immune cell signaling and differentiation.

Chemokine

Soluble secreted protein that acts as an attractant molecule to promote cell migration to a specific area.

lymphoid tissue

Specialized tissue of the lymphatic system that functions in the development and activation of T cells and B cells.

Complement

System of soluble plasma proteins that act to opsonize and lyse pathogens; also known as complement system.

Cluster of differentiation (CD)

System used in the nomenclature of different cell-surface molecules in white blood cells.

Immune Response

The body's response to the presence of foreign particles or microorganisms (antigens).

Nuclear factor kB (NfkB)

Transcription factor that activates gene expression during both innate and adaptive immune responses; inactivated by binding to IkB in the cytoplasm.

Innate lymphoid Cell (ILC)

White blood cell of the innate immune system that works to activate other innate immune cells, including macrophages and dendritic cells, at a site of infection.

Natural Killer (NK) cell

White blood cell of the innate immune system that works to clear intracellular infections, including those caused by viruses.

Granulocyte

White blood cell that contains granules. Refers to neutrophils, basophils, eosinophils, and mast cells.

Megakaryocyte

White blood cell that specializes in the production of platelets.

Leukocyte

White blood cell. Includes granulocytes, agranulocytes, and cells involved in blood clotting.