1050 Unit 1 Definitions Flashcards
Adaptive immunity
a type of resistance that is characterized by specificity for each individual pathogen or microbial agent, and the ability to remember a prior exposure, which results in an increased response to the pathogen upon repeated exposure. key cell involved is lymphocytes
Antibodies
glycoproteins produced by B lymphocytes and plasma cells in response to foreign substance exposure. Also known an immunoglobulin
Anitgens
macromolecules that is capable of eliciting formation of immunoglobulin or sensitized lymphocytes in an immunocompetent hosts
Attenuation
a process of producing nonpathological bacteria or rinses for use in vaccines. The organisms have been weakened by treatment with a chemicals, exposure to elevated/cold temperature or repeated passage in cell culture
B lymphocytes
cells derived from the bone marrow which play a key role in the humoral immune response; they develop into plasma cells that produces specific antibodies
Basophils
A type of WBC found in peripheral blood, containing granules that are involved in allergic reactions
Bone marrow
the largest tissue in the body, located un long bones, in which functions in the generation of hematopoietic cells and B cells maturation
cell-mediated immunity
a type of immunity in which T cells produce cytokines that help to regulate both the innate and adaptive immune response ( cytokines assist B cells in starting antibody production, eliminating tumors/target cells, rejecting grafts, stimulating hematopoiesis in bone marrow, initiate delayed hypersensitivity allergic reaction reactions
chemotaxins
a protein or other substances that acts as a chemical messenger to produce chemotaxis
clusters of differentiation
antigenic markers of leukocytes that are identified by groups of monoclonal antibodies expressing common or overlapping reactivity
cytokines
small protein that acts as a chemical messenger to affect the function or activity of other cells, especially cells of the immune system
dendritic cells
tissue cells covered with long membranous extensions. Shows antigens on its surface to other cells of immune system
Diapedesis
the process by which cells are capable of moving from the circulating blood to the tissues by squeezing through the wall of a blood vessel
Eosinophil
WBC that contains reddish-orange granules on wright-stained blood smears and is involved in allergic reactions, specifically against parasites
Germinal center
the interior of a secondary follicle where blast transformation of B cells take place
hematopoiesis
the production of blood cells from multipotent hematopoietic stem cells in the bone marrow
humoral immunity
protection from disease resulting from substances in the serum/plasma
immunity
the condition of being resistant to infection
immunology
the study of the reactions of a host when foreign substances are introduced into the body
innate immunity
(natural immunity) the ability of the individual to resist infection by means of normally present body functions
leukocytes
WBc’s
lymphocytes
the key WBC involved in the adaptive immune response
lymph nodes
a secondary lymphoid organ that is located along a lymphatic duct and whose purpose is to filter lymphatic fluid from the tissues and acts as a site for processing of foreign antigen
Macrophages
a WBC that engulfs and kills microbes and presents antigen to T cells
Mast cells
a tissue cell that plays a role in allergic reactions
Memory cells
progeny of an antigen-activated B or T cells that is able to respond to antigen more quickly than the parent cell.
monocytes
the largest WBC is peripheral blood. It migrates to the tissues to become a macrophages
Natural Killer cells
A type of lymphocytes that has the ability to kill target cells such as tumor cells and virus-infected cells without prior exposure to them
Neutrophils
WBC with a multi-lobed nucleus and a large number of neutral staining granules on a blood smear treated with wright. Its main function is phagocytosis. Involved in allergic reactions.
periarteriolar lymphoid sheath
white pulp of splenic tissue, which is made up of lymphocytes, macrophages, plasma cells, and granulocytes, it surrounds the central arteriole
phagotcytosis
the engulfment of cells or particulate matter by neutrophils, macrophages, and other cells
plasma cells
a differentiated B cells that actively secretes antibody’s.
primary follicle
a cluster of B cells that have not yet been stimulated by antigen
primary lymphoid organs
the organs in which lymphocytes mature: these are bone marrow and the thymus
secondary follicle
a cluster of cells that are proliferating in response to specific antigen. Has germinal center And stimulated B cells
secondary lymphoid organs
organs that include the spleen, lymph nodes, appendix. tonsils and other mucosal-associated lymphoid tissue where the main contact with foreign antigens takes place
spleen
The largest secondary lymphoid organ in the body, located in the upper left quadrant of the abdomen. it function is to filter out aged cells and foreign antigens
T lymphocytes
cells that mature in the thymus which play important roles in cell-mediated immunity and produce cytokines that assist the humoral immune response
thymocyte
immature lymphocytes, found in the thymus, that undergoes differentiation to become a mature T cells
acute-phase reactants
normal serum proteins that increase rapidly because of infection, injury or trauma to the tissue
thymus
serves as the site for differentiation of T cells
alpha1-antitrypsin (AAT)
an acute-phase protein that acts as an inhibitor of proteases released from WBC
antibody dependent cellular cytotoxicity (ADCC)
the process of destroying antibody-coated target cells by natural killer cells, monocytes, macrophages and neutrophils, all of which have specific receptors for an antibody
ceruloplasmin
an acute-phase reactant that acts as the principal copper transporting protein in human plasma
chemotaxis
the migration of cells in the direction of a chemical messenger
complement
a series of proteins that are normally present in serum and whose overall functions are medication of inflammation and destruction of foreign cells
c-reactive protein (CRP)
a trace of constituent of serum that increases rapidly following infection or trauma to the body and acts as an opsonin to enhance phagocytosis
defensins
small catonic proteins that, which released from lysosomal granules, can kill bacteria and many fungi by destroying their cell walls
diapedesis
the process by which cells capable of moving from the circulating blood to the tissues by squeezing through the wall of a blood vessel
external defense system
structural barriers that prevent most infectious agents from entering the body
fibrinogen
an acute-phase reactant that changes to fibrin and forms clots in the bloodstream
haptoglobin
an acute-phase reactant that binds irreversibly to free hemoglobulin released by intravascular hemolysis
inflammation
cellular and humoral mechanisms involved in overall reaction of the body to the injury or invasion by an infectious agent
innate immunity
the ability of the individual to resist infection by means of normally present body functions
innate lymphoid cell (ILC)
family of cell the contribute to an innate immunity and tissue remodeling ILC’s develop from the common lymphoid progenitor and have lymphoid morphology but do not possess antigen specific receptors
internal defense system
defense mechanism inside the body in which both cells and soluble factors play essential parts
microbiota
microorganisms of a particular site, habitat, or geological period
opsonins
serum proteins that attach to a foreign substance and enhance phagocytosis
oxidative burst
an increase in oxygen consumption in phagocytic cells, which generate oxygen radicals used to kill engulf microorganism
pathogen-associated molecular patterns (PAMPs)
structural patterns of carbohydrates, nucleic acids, bacterial peptides or microorganisms that are recognized by the pathogen recognition receptors on the cells of the innate immune system
pattern recognition receptors (PRR)
receptors on cells of the innate immune system that binds to PAMPs on pathogenic microorganism
phagocytosis
the engulfment of cells or particulate matter by neutrophils, macrophages and other cells
phagolysosome
the structure formed by the fusion of cytoplasmic granules and a phagosome during the process of the phagocytosis
phagosome
a vacoule formed within a phagocytic cell as pseudopodia surround a particle during the process of phagocytosis
serum amyloid A
(SAA) an acute phase protein that acts as a chemical messenger to activate monocytes and macrophages in order to increase inflammation
Toll like-receptors
receptors found on human leukocytes and other cell types that recognize microorganisms and aid in their digestion
adjuvant
a substance administered with a immunogen that enhances and potentiates the immune system
alleles
an alternate form of a gene that codes for a slightly different form of the same product
alloantigen
an antigen that is found in another member of the hosts species and that is capable of eliciting an immune component host
antigen presentation
the process by which degraded peptides in cells are transported to the plasma membrane with MHC molecules so that T cells can then recognize them
autoantigen
an antigen that belongs to the host and is not capable of eliciting an immune response under normal circumstances
Class I (MHC) molecules
proteins coded for by genes at three loci (A, B, and C) in the MHC. They are expressed on all nucleated cells and are important to consider in the transplantation of tissues
Class II (MHC) molecules
proteins coded for by the DR, DP, and DQ loci of the MHC. They are found on B cells, macrophages, activated T cells, monocytes, dendritic cells and endothelium and are important to consider in the transplantation of tissues.
epitope
the portion of antigens to which an antibody can attach itself
haplotype
a set of genos that are located close together on a chromosome and are usually inherited as a single unit
hapten
a small molecule which, when combined with a larger carrier such as a protein, can elicit the production of antibodies which bind specifically to
heteroantigens
an antigen of a species different from that of the host, such as other animals, plants, or microorganism
heterophil antigen
an antigen that exists in unrelated plants or animals buts its either identical or closely related so that antibody to one will cross-react with antibody to the other
immunogenicity
the ability of an immunogen to stimulate a host response
immunogen
any substance that capable of inducing an immune response
invariant chain
a protein that associates with human leukocyte antigen (HLA) class II antigens shortly after they are synthesized to prevent interaction
linear epitope
amino acids following one another on a single polypeptide chain that act as a key antigenic site
major histocompatibility complex (MHC)
found on all nucleated cells in the body. The protein regulate the immune response and play a role in a graft rejection
transporters associated with antigen processing
(TAP 1 and TAP 2 ) proteins that are responsible for the adenosine triphosphate (ATP)- dependent transport of newly synthesized short peptides from the cytoplasm to the lumen of endoplasmic reticulum for binding to class I human leukocytes antigen (HLA) antigens
allelic expression
the selection of the an allele on one chromosome only
antigen-dependent stage
final phase of B cell development in the bone marrow that results in mature B cells that have not been exposed to antigen
antigen-independent phase
If a B cell is stimulated by antigen, it undergoes transformation to blast stage that eventually forms memory cells and antibody secreting plasma cells.
B cell receptors
is a transmembrane protein on the surface of a B cell.
cell-mediated immunity
a type of immunity in which T cells produce cytokines that help to regulate both the innate and adaptive immune response. ( cytokines assist B cells in starting autobody production, eliminating tumor/target cells, rejecting grafts, stimulating hematopoiesis in bone marrow and initiate delayer hypersensitivity allergic reactions )
central tolerance
destruction of potentially self-reactive T and B cells as they mature in either the thymus or the bone marrow
chemokines
a large family of homologous cytokines that promote migration of WBC through chemotaxis (chemical messengers)
clonal expression
proliferation of lymphocytes during an immune response to create a population of identical cells, all capable of responding to same antigen
cytotoxic t cells
express CD8 receptors. Interact with antigen and class I MHC proteins
double-negative thymocyte
stage in the development of T cells when neither CD4 and CD8 is expressed
double-positive thymocyte
stage in the development of T cells when both CD4 and CD8 antigens are expressed
effector cells
mature, functional T lymphocytes or B lymphocytes that carry out the functions of immune response
humoral immunity
production of antibodies by plasma cells
immature B cells
a phase in the growth of B cells characterized by the appearance by the appearance of complete IgM antibody molecules on the cell surface
isotype switching
a unique an amino acid sequence that is common to all immunoglobulin molecules of a given class in a given species
memory cells
progeny of an antigen-activated B or T cell that is able to respond to antigen more quickly than the parent cells.
MHC restrictions
the selection of thymocytes that will only interact with the major histocompatibility complex antigens on host cells
negative selection
process that takes place among the surviving DP T cells in the corticomedullary region and the medulla of the thymus. Strong reactions with peptides other than MHC antigens triggers apoptosis
plasma cells
a differentiated B cells that actively secrets antibody
positive selection
the process that takes place when the CD3-ab (alpha-beta) receptor complex (TCR) is complete and expressed on cell surface that allows only DP cells with functional TCR receptors to survive
Pre-B cells
the stage of development of a B cells in which rearrangement of the genes that code for the heavy chain region of antibody occurs
Pro-B cells
a stage in B cells development where the heavy chain part of the antibody molecules is present
single positive stage
a stage in T cells development characterized by the process of the surface CD4 and CD8 but not both markers
surrogate light chain
consists of two short polypeptide chains that are noncovalently associated with each other along with short chains, Iga(alpha) and IgB(beta)
T cell receptors
(TCR) a protein complex found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides
t-dependent antigens
T-cell help that is reguired inorder for B cells to respond to antigen
T follicle helper
(Tfh) a subpopulation of T helper cells that remains in the lymph nodes, where they interact with B cells and plasma cells
Th1 cells
(T helper 1 cells) produce IFN-y, IL-2 and TNF-B(beta), which protect against in intracellular pathogens by activating cytotoxic lymphocytes and macrophages
Th2 cells
(T helper 2 cells) produce a variety of interleukins including IL-4, IL-5, IL-6, IL-9, IL-10 and IL-13. The essential role is to help B cells produce antibodies again in extracellular pathogens and to generally regulate B cell activity
T helper cells
express CD4 receptor. Recognize antigen along with class II MHC protein
T-independent antigens
antigens that are able to elicit antibody formation in the absence of T cells
T-regulatory cells
(Treg) possess the CD4 antigen as well as the CD25. Play an important role in suppressing the immune response to self-antigens
Thymocytes
immature lymphocyte, found in the thymus, that are committed to becoming T cells
B cell
remain and mature in bone marrow
clonal deletion
process of elimination of clones of T cells that would bye capable of an autoimmune response
variable regions
contained by both alpha and beta chains on TCR recognizes specific antigens
cell flow cytometry
automated system for identifying cells based on the scattering of lights as cells flow single file in a stream of fluid by a laser beam
