BIO - TERMS - IMMUNE Flashcards
12/23 rule
Phenomenon wherein two gene segments of an immunoglobulin or T-cell receptor can be joined only if one recognition signal sequence has a 12-base-pair spacer and the other has a 23-basepair spacer.
accelerated rejection
The more rapid rejection of a second graft after rejection of the first graft. It was one of the pieces of evidence that showed that graft rejection was due to an adaptive immune response.
acquired immune deficiency syndrome (AIDS)
A disease caused by infection with the human immunodeficiency virus (HIV-1). AIDS occurs when an infected patient has lost most of his or her CD4 T cells, so that infections with opportunistic pathogens occur.
acquired immunodeficiency (secondary immunodeficiency)
The inability, obtained during the life of an individual, to produce specific antibodies or T cells, due to drugs or disease.
active immunity
(i-myū′ni-tē) Activation of the immune system by a vaccine or by exposure to the naturally occurring infectious agent. Offers long-term protection because memory cells are formed. Compare to passive immunity.
Active immunization
Th e process of inducing an immune response by exposure to a vaccine; contrasts with passive immunization. (Chapter 8)
acute desensitization
An immunotherapeutic technique for rapidly inducing temporary tolerance to, for example, an essential drug such as insulin or penicillin in a person who is allergic to it. Also called rapid desensitization. When performed properly, can produce symptoms of mild to moderate anaphylaxis.
Acute infection
A common pattern of infection in which virus particles are produced rapidly, and the infection is resolved quickly by the immune system; survivors are usually immune to subsequent infection. (Chapter 5)
acute rejection
The rejection of a tissue or organ graft from a genetically unrelated donor that occurs within 10–13 days of transplantation unless prevented by immunosuppressant treatment.
adaptive immune system
System of lymphocytes providing highly specific and long-lasting defense against pathogens in vertebrates. It consists of two major classes of lymphocytes: B lymphocytes (B cells), which secrete antibodies that bind specifically to the pathogen or its products, and T lymphocytes (T cells), which can either directly kill cells infected with the pathogen or produce secreted or cell-surface signal proteins that stimulate other host cells to help eliminate the pathogen.
Adoptive transfer
Th e transfer of cells, usually lymphocytes, from an immunized donor to a nonimmune recipient. (Chapters 4 and 8)
agnathans
A class of vertebrate comprising jawless fish lacking adaptive immunity based on the RAG-mediated V(D)J recombination, but possessing a distinct system of adaptive immunity based on somatically assembled VLRs.
AIDS (acquired immunodefi ciency syndrome)
The usually fatal human disease in which the immune system is destroyed by the human immunodefi ciency virus (HIV).
airway hyperreactivity, hyperresponsiveness
The condition in which the airways are pathologically sensitive to both immunological (allergens) and nonimmunological stimuli, such as cold air, smoke, or perfumes. This hyperreactivity usually is present in chronic asthma.
allergen desensitization
An immunotherapeutic technique that aims either to change an allergic immune response to a symptom-free non-allergic response, or to develop immunologic tolerance to an allergen that has been causing unpleasant clinical symptoms. The procedure involves exposing an allergic individual to increasing doses of allergen.
allergic contact dermatitis
A largely T-cell-mediated immunological hypersensitivity reaction manifested by a skin rash at the site of contact with the allergen. Often the stimulus is a chemical agent, for example urushiol oil from the leaves of the poison ivy plant, which can haptenate normal host molecules to render them allergenic.
allograft rejection
The immunologically mediated rejection of grafted tissues or organs from a genetically nonidentical donor. It is due chiefly to recognition of nonself MHC molecules on the graft.
anti-lymphocyte globulin
Antiserum raised in another species against human T cells. It is used in the temporary suppression of immune responses in transplantation.
Artemis
An endonuclease involved in the gene rearrangements that generate functional immunoglobulin and T-cell receptor genes.
artificially acquired active immunity
The production of antibodies by the body in response to a vaccination.
artificially acquired passive immunity
The transfer of humoral antibodies formed by one individual to a susceptible individual, accomplished by the injection of antiserum.
aryl hydrocarbon receptor (AhR)
A basic helix-loop-helix transcription factor that is activated by various aromatic ligands including, famously, dioxin. It functions in the normal activity of several types of immune cells including some ILCs and IELs.
autoimmune lymphoproliferative syndrome (ALPS)
An inherited syndrome in which a defect in the Fas gene leads to a failure in normal apoptosis, causing unregulated immune responses, including autoimmune responses.
azathioprine
A powerful cytotoxic drug that is converted to its active form in vivo, which then kills rapidly proliferating cells, including proliferating lymphocytes; it is used as an immunosuppressant to treat autoimmune disease and in transplantation.
BCG vaccine
A live, attenuated strain of Mycobacterium bovis used to provide immunity to tuberculosis.
Bence Jones protein
Immunoglobulin light chains overproduced by some patients with multiple myeloma (a malignant plasma cell dyscrasia).
bone marrow
The tissue where all the cellular elements of the blood—red blood cells, white blood cells, and platelets—are initially generated from hematopoietic stem cells. The bone marrow is also the site of further B-cell development in mammals and the source of stem cells that give rise to T cells on migration to the thymus. Thus, bone marrow transplantation can restore all the cellular elements of the blood, including the cells required for adaptive immune responses.
Bruton’s tyrosine kinase (Btk)
A Tec-family tyrosine kinase important in B-cell receptor signaling. Btk is mutated in the human immunodeficiency disease X-linked agammaglobulinemia.
Burkitt lymphoma
A B-cell malignancy in which the myc proto-oncogene has been translocated to an immunoglobulin locus.
C-type lectins
Large class of carbohydrate-binding proteins that require Ca2+ for binding, including many that function in innate immunity.
calcineurin
A cytosolic serine/threonine phosphatase with a crucial role in signaling via the T-cell receptor. The immunosuppressive drugs cyclosporin A and tacrolimus inactivate calcineurin, suppressing T-cell responses.
cancer immunoediting
A process that occurs during the development of a cancer when it is acquiring mutations that favor its survival and escape from immune responses, such that cancer cells with these mutations are selected for survival and growth.
cellular immunology
The study of the cellular basis of immunity. central lymphoid organs, central lymphoid tissues The sites of lymphocyte development; in humans, these are the bone marrow and thymus. B lymphocytes develop in bone marrow, whereas T lymphocytes develop within the thymus from bone marrow-derived progenitors. Also called the primary lymphoid organs.
chronic granulomatous disease (CGD)
An immunodeficiency in which multiple granulomas form as a result of defective elimination of bacteria by phagocytic cells. It is caused by defects in the NADPH oxidase system of enzymes that generate the superoxide radical involved in bacterial killing.
chronic rejection
Late failure of a transplanted organ, which can be due to immunological or nonimmunological causes.
common mucosal immune system
The mucosal immune system as a whole, the name reflecting the fact that lymphocytes that have been primed in one part of the mucosal system can recirculate as effector cells to other parts of the mucosal system.
common myeloid progenitor (CMP)
Stem cells that can give rise to the myeloid cells of the immune system—macrophages, granulocytes, mast cells, and dendritic cells of the innate immune system. This stem cell also gives rise to megakaryocytes and red blood cells.
congenital immunodeficiency (primary immunodeficiency)
The inability, due to an individual’s genotype, to produce specific antibodies or T cells.
constant Ig domains (C domains)
Type of protein domain that makes up the constant regions of each chain of an immunoglobulin molecule.
CRIg (complement receptor of the immunoglobulin family)
A complement receptor that binds to inactivated forms of C3b.
cyclosporin A (CsA)
A powerful noncytotoxic immunosuppressive drug that inhibits signaling from the T-cell receptor, preventing T-cell activation and effector function. It binds to cyclophilin, and the complex formed binds to and inactivates the phosphatase calcineurin.
depleting antibodies
Immunosuppressive monoclonal antibodies that trigger the destruction of lymphocytes in vivo. They are used for treating episodes of acute graft rejection.
DiGeorge syndrome
Recessive genetic immunodeficiency disease in which there is a failure to develop thymic epithelium. Parathyroid glands are also absent and there are anomalies in the large blood vessels.
Dscam
A member of the immunoglobulin superfamily that in insects is thought to opsonize invading bacteria and aid their engulfment by phagocytes. It can be made in a multiplicity of different forms as a result of alternative splicing.
DTaP vaccine
A combined vaccine used to provide active immunity, containing diphtheria and tetanus toxoids and Bordetella pertussis cell fragments.
dysregulated self
Refers to changes that take place in infected or malignant cells that alter expression of various surface receptors that can be detected by the innate immune system.
effector cell
Cell that carries out the final response or function in a particular process. The main effector cells of the immune system, for example, are activated lymphocytes and phagocytes that help eliminate pathogens.
effector mechanisms
Those processes by which pathogens are destroyed and cleared from the body. Innate and adaptive immune responses use most of the same effector mechanisms to eliminate pathogens.
effector modules
This term refers to a set of immune mechanisms, either cell-mediated and humoral, innate or adaptive, that act together in the elimination of a particular category of pathogen.
effector T lymphocytes
The T cells that perform the functions of an immune response, such as cell killing and cell activation, that clear the infectious agent from the body. There are several different subsets, each with a specific role in an immune response.
elimination phase
Stage of anti-tumor immune response that detects and eliminates cancer cells, also called immune surveillance.
fibrinogen-related proteins (FREPs)
Members of the immunoglobulin superfamily that are thought to have a role in innate immunity in the freshwater snail Biomphalaria glabrata.
fingolimod
Small-molecule immunosuppressive drug that interferes with the actions of sphingosine, leading to retention of effector T cells in lymphoid organs.
FK-binding proteins (FKBPs)
Group of prolyl isomerases related to the cyclophilins and bind the immunosuppressive drug FK506 (tacrolimus).
framework regions
Relatively invariant regions that provide a protein scaffold for the hypervariable regions in the V domains of immunoglobulins and T-cell receptors.
gene rearrangement
The process of somatic recombination of gene segments in the immunoglobulin and T-cell receptor genetic loci to produce a functional gene. This process generates the diversity found in immunoglobulin and T-cell receptor variable regions.
Genetic drift
Diversity in viral genomes that arises as a result of errors during genome replication and immune selection. (Chapter 10)
genetic locus
The site of a gene on a chromosome. In the case of the genes for the immunoglobulin and T-cell receptor chains, the term locus refers to the complete collection of gene segments and C-region genes for the given chain.
germinal center
Sites of intense B-cell proliferation and differentiation that develop in lymphoid follicles during an adaptive immune response. Somatic hypermutation and class switching occur in germinal centers.
Globulins
Common proteins in the blood that are insoluble in water and soluble in salt solutions. Alpha, beta, and gamma globulins can be distinguished in human blood serum. Gamma globulins are important in developing immunity to diseases.
gnathostomes
The class of jawed vertebrates comprising most fish and all mammals. These possess an adaptive immunity based on the RAG-mediated V(D)J recombination.
Gram-negative binding proteins (GNBPs)
Proteins that act as the pathogen-recognition proteins in the Toll pathway of immune defense in Drosophila.
Griscelli syndrome
An inherited immunodeficiency disease that affects the pathway for secretion of lysosomes. It is caused by mutations in a small GTPase Rab27a, which controls the movement of vesicles within cells.
gut-associated lymphoid tissues (GALT)
Lymphoid tissues associated with the gastrointestinal tract, comprising Peyer’s patches, the appendix, and isolated lymphoid follicles found in the intestinal wall, where adaptive immune responses are initiated, and by lymphatics to mesenteric lymph nodes.
heavy-chain variable region (VH)
Referring to the V region of the heavy chain of an immunoglobulin.
hematopoietin superfamily
Large family of structurally related cytokines that includes growth factors and many interleukins with roles in both adaptive and innate immunity.
heterosubtypic immunity
Immune protection against a pathogen conferred by infection with a distinct strain, typically with reference to different influenza A serotypes.
hinge region
The flexible domain that joins the Fab arms to the Fc piece in an immunoglobulin. The flexibility of the hinge region in IgG and IgA molecules allows the Fab arms to adopt a wide range of angles, permitting binding to epitopes spaced variable distances apart.
homeostatic chemokines
Chemokines that are produced at steady-state to direct the localization of immune cells to lymphoid tissues.
host-versus-graft disease (HVGD)
Another name for the allograft rejection reaction. The term is used mainly in relation to bone marrow transplantation when immune cells of the host recognize and destroy transplanted bone marrow or hematopoietic stem cells (HSCs).
humanization
The genetic engineering of mouse hypervariable loops of a desired specificity into otherwise human antibodies for use as therapeutic agents. Such antibodies are less likely to cause an immune response in people treated with them than are wholly mouse antibodies.
humoral
Referring to effector proteins in the blood or body fluids, such as antibodies in adaptive immunity, or complement proteins in innate immunity.
hypersensitivity
An altered, enhanced immune reaction leading to pathological changes; also called allergy.
IgW
Type of heavy-chain isotype present in cartilaginous fishes composed of six immunoglobulin domains.
iHog
Protein with four or five immunoglobulin-like domains and two or three fibronectin-type-III-like domains; located on the cell surface and thought to serve as co-receptors for Hedgehog proteins.
IL-1β
A cytokine produced by active macrophages that has many effects in the immune response, including the activation of vascular endothelium, activation of lymphocytes, and the induction of fever.
immune evasion
Mechanisms used by pathogens to avoid detection and/ or elimination by host immune defenses.
immune modulation
The deliberate attempt to change the course of an immune response, for example by altering the bias toward TH1 or TH2 dominance.
immune system
The tissues, cells, and molecules involved in innate immunity and adaptive immunity.
immunization
Method of inducing adaptive immune responses to pathogens or foreign molecules, usually involving the co-injection of an adjuvant, a molecule (often of microbial origin) that helps activate innate immune responses required for the adaptive responses.
immunocytochemistry
An anatomical method that uses antibodies to study the location of molecules within cells.
immunodeficiency
The absence of an adequate immune response; may be congenital or acquired.
immunodeficiency diseases
Any inherited or acquired disorder in which some aspect or aspects of host defense are absent or functionally defective.
immunodiffusion test
A test consisting of precipitation reactions carried out in an agar gel medium.
immunoelectrophoresis
The identification of proteins by electrophoretic separation followed by serological testing.
immunoevasins
Viral proteins that prevent the appearance of peptide:MHC class I complexes on the infected cell, thus preventing the recognition of virus-infected cells by cytotoxic T cells.
immunogenic
Any molecule that, on its own, is able to elicit an adaptive immune response on injection into a person or animal.
immunoglobulin fold
The tertiary structure of an immunoglobulin domain, comprising a sandwich of two β sheets held together by a disulfide bond.
immunoglobulin-like domain (Ig-like domain)
Protein domain structurally related to the immunoglobulin domain.
immunoglobulin-like proteins
Proteins containing one or more immunoglobulin-like domains, which are protein domains structurally similar to those of immunoglobulins.
immunomodulatory therapy
Treatments that seek to modify an immune response in a beneficial way, for example to reduce or prevent an autoimmune or allergic response.
Immunopathology
Pathological changes caused partly or entirely by the immune response. (Chapters 1 and 5)
immunoproteasome
A form of proteasome found in cells exposed to interferons. It contains three subunits that are different from the normal proteasome.
immunoreceptor tyrosine-based inhibition motif (ITIM)
Sequence motifs in the signaling chains of inhibitory receptors that are sites of tyrosine phosphorylation, leading to inhibitory signaling, such as through recruitment of phosphatases that remove phosphate groups added by tyrosine kinases.
immunoreceptor tyrosine-based switch motif (ITSM)
A sequence motif present in the cytoplasmic tails of some inhibitor receptors.
inflammatory chemokines
Chemokines that are produced in response to infection or injury to direct the localization of immune cells to sites of inflammation.
inflammatory mediators
Chemicals such as cytokines produced by immune cells that act on target cells to promote defense against microbes.
interferon regulatory factor (IRF)
A family of nine transcription factors that regulate a variety of immune responses. For example, IRF3 and IRF7 are activated as a result of signaling from some TLRs. Several IRFs promote expression of the genes for type I interferons.
IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked)
Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome. A very rare inherited condition in which CD4 CD25 regulatory T cells are lacking as a result of a mutation in the gene for the transcription factor FoxP3, leading to the development of autoimmunity.
IRAK4 deficiency
An immunodeficiency characterized by recurrent bacterial infections, caused by inactivating mutations in the IRAK4 gene that result in a block in TLR signaling.
isotype
The designation of an immunoglobulin chain in respect of the type of constant region it has. Light chains can be of either κ or λ isotype. Heavy chains can be of μ, δ, γ, α, or ε isotype. The different heavy-chain isotypes have different effector functions and determine the class and functional properties of antibodies (IgM, IgD, IgG, IgA, and IgE, respectively).
J gene
A small gene that participates in the assembly of an immunoglobulin gene in developing B lymphocytes.
killer cell immunoglobulin-like receptors (KIRs)
Large family of receptors present on NK cells, through which the cells’ cytotoxic activity is controlled. The family contains both activating and inhibitory receptors.
lamina propria
A layer of connective tissue underlying a mucosal epithelium. It contains lymphocytes and other immune-system cells.
lentiviruses
A group of retroviruses that include the human immunodeficiency virus, HIV-1. They cause disease after a long incubation period.
leukocyte adhesion deficiencies (LADs)
A class of immunodeficiency diseases in which the ability of leukocytes to enter sites infected by extracellular pathogens is affected, imparing elimination of infection. There are several different causes, including a deficiency of the common β chain of the leukocyte integrins.
leukocyte receptor complex (LRC)
A large cluster of immunoglobulin-like receptor genes that includes the killer cell immunoglobulin-like receptor (KIR) genes.
light chain, L chain
The smaller of the two types of polypeptide chains that make up an immunoglobulin molecule. It consists of one V and one C domain, and is disulfide-bonded to the heavy chain. There are two classes, or isotypes, of light chain, known as κ and λ, which are produced from separate genetic loci.
light-chain variable region (VL)
Referring to the V region of the light chain of an immunoglobulin.
lingual tonsils
Paired masses of organized peripheral lymphoid tissue situated at the base of the tongue, in which adaptive immune responses can be initiated. They are part of the mucosal immune system. See also palatine tonsils.
long-term non-progressors
HIV-infected individuals who mount an immune response that controls viral loads such that they do not progress to AIDS despite the absence of antiretroviral therapy. See also elite controllers.
lymphoid organs
Organized tissues characterized by very large numbers of lymphocytes interacting with a nonlymphoid stroma. The central, or primary, lymphoid organs, where lymphocytes are generated, are the thymus and bone marrow. The main peripheral, or secondary, lymphoid organs, in which adaptive immune responses are initiated, are the lymph nodes, spleen, and mucosa-associated lymphoid organs such as tonsils and Peyer’s patches.
mannose-binding lectin (MBL)
Mannose-binding protein present in the blood. It can opsonize pathogens bearing mannose on their surfaces and can activate the complement system via the lectin pathway, an important part of innate immunity.
MHC class I deficiency
An immunodeficiency disease in which MHC class I molecules are not present on the cell surface, usually as a result of an inherited deficiency of either TAP-1 or TAP-2.
MHC class II deficiency
A rare immunodeficiency disease in which MHC class II molecules are not present on cells as a result of various inherited defects. Patients are severely immunodeficient and have few CD4 T cells.
mixed essential cryoglobulinemia
Disease due to the production of cryoglobulins (cold-precipitable immunoglobulins), sometimes in response to chronic infections such as hepatitis C, which can lead to the deposition of immune complexes in joints and tissues.
Monoclonal gammopathy
Overproduction of a single immunoglobulin by a plasma cell clone.
mucosa-associated lymphoid tissue (MALT)
Generic term for all organized lymphoid tissue found at mucosal surfaces, in which an adaptive immune response can be initiated. It comprises GALT, NALT, and BALT (when present).
mucosal associated invariant T cells (MAIT)
Primarily γ:δ T cells with limited diversity present in the mucosal immune system that respond to bacterially derived folate derivates presented by the nonclassical MHC class Ib molecule MR1.
myelomonocytic series
Innate immune cells derived from myelomonocytic bone marrow precursors, including neutrophils, basophils, eosinophils, monocytes, and dendritic cells.
N-nucleotides
Nontemplated nucleotides inserted by the enzyme terminal deoxynucleotidyl transferase into the junctions between gene segments of T-cell receptor and immunoglobulin heavy-chain V regions during gene segment joining. Translation of these N-regions markedly increases the diversity of these receptor chains.
nasal-associated lymphoid tissue (NALT)
Organized lymphoid tissues found in the upper respiratory tract. In humans, NALT consists of Waldeyer’s ring, which includes the adenoids, palatine, and lingual tonsils, plus other similarly organized lymphoid tissue located around the pharynx. It is part of the mucosal immune system.
naturally acquired passive immunity
The natural transfer of humoral antibodies, for example, transplacental transfer.
Nfil3
A transcription factor important during the development of several types of immune cells including certain types of NK cells.
NFκB protein
Latent transcription regulator that is activated by various intracellular signaling pathways when cells are stimulated during immune, inflammatory, or stress responses. Also has important roles in animal development.
non-structural protein 1 (NS1)
An influenza A virus protein that inhibits TRIM25, an intermediate signaling protein downstream of the viral sensors RIG-I and MDA-5, thereby promoting evasion of innate immunity.
nonproductive rearrangements
Rearrangements of T-cell receptor or immunoglobulin gene segments that cannot encode a protein because the coding sequences are in the wrong translational reading frame.
Omenn syndrome
A severe immunodeficiency disease characterized by defects in either of the RAG genes. Affected individuals make small amounts of functional RAG protein, allowing a small amount of V(D)J recombination.
oncolytic virus
Virus that infects and kills tumor cells or causes an immune response against tumor cells.
palatine tonsils
Paired masses of organized peripheral lymphoid tissues located on each side of the throat, and in which an adaptive immune response can be generated. They are part of the mucosal immune system.
passive immunity
Immunity, obtained from another individual or an animal, that does not result in the formation of memory cells. Compare to active immunity.
Polyclonal gammopathy
Nonspecific overproduction of immunoglobulins.
polymeric immunoglobulin receptor (pIgR)
The receptor for polymeric immunoglobulins IgA and IgM on basolateral surfaces of mucosal and glandular epithelial cells that transports IgA (or IgM) into secretions.
post-transplant lymphoproliferative disorder
B-cell expansion driven by Epstein–Barr virus (EBV) in which the B cells can undergo mutations and become malignant. This can occur when patients are immunosuppressed after, for example, solid organ transplantation.
pre-B-cell receptor
Receptor produced by pre-B cells that includes an immunoglobulin heavy chain, as well as surrogate light-chain proteins, Igα and Igβ signaling subnits. Signaling through this receptor induces the pre-B cell to enter the cell cycle, to turn off the RAG genes, to degrade the RAG proteins, and to expand by several cell divisions.
prednisone
A synthetic steroid with potent anti-inflammatory and immunosuppressive activity used in treating acute graft rejection, autoimmune disease, and lymphoid tumors.
primary immunodeficiencies
A lack of immune function that is caused by a genetic defect.
privileged site (tissue)
An area of the body (or a tissue) that does not elicit an immune response.
progressive multifocal leukoencephalopathy (PML)
Disease in immunocompromised patients caused by opportunisitic infection by JC virus, for example as a consequence of immunotherapy.
rapamycin
An immunosuppressant drug that blocks intracellular signaling pathways involving the serine/threonine kinase mammalian target of rapamycin (mTOR) required for the inhibition of apoptosis and T-cell expansion. Also called sirolimus.
secondary lymphoid follicle
A follicle containing a germinal center of proliferating activated B cells during an ongoing adaptive immune response.
secretory component (SC)
Fragment of the polymeric immunoglobulin receptor that remains after cleavage and is attached to secreted IgA after transport across epithelial cells.
Sjögren’s syndrome
An autoimmune disease in which exocrine glands, particularly the lacrimal glands of the eyes and salivary glands of the mouth, are damaged by the immune system. This results in dry eyes and mouth.
Skint-1
A transmembrane immunoglobulin superfamily member expressed by thymic stromal cells and keratinocytes that is required for the development of dendritic epidermal T cells, which are a type of γ:δ T cell.
somatic diversification theories
Gerenal hypotheses proposing that the immunoglobulin repertoire was formed from a small number of V genes that diversified in somatic cells. Cf. germline theory.
staphylokinase
Staphylococcal protease that cleaves immunoglobulins bound to its surface, thereby preventing complement activation.
surrogate light chain
A protein in pre-B cells, made up of two subunits, VpreB and λ5, that can pair with a full-length immunoglobulin heavy chain and the Igα and Igβ signaling subunits and signals for pre-B-cell differentiation.
systemic immune system
Name sometimes given to the lymph nodes and spleen to distinguish them from the mucosal immune system.
T-cell areas
Regions of peripheral lymphoid organs that are enriched in naive T cells and are distinct from the follicles. They are the sites at which adaptive immune responses are initiated.
tacrolimus
An immunosuppressant polypeptide drug that binds FKBPs and inactivates T cells by inhibiting calcineurin, thus blocking activation of the transcription factor NFAT. Also called FK506.
Tbet
A transcription factor active in many immune cell types but most typically associated with ILC1 and TH1 function.
thioester-containing proteins
Homologs of complement component C3 that are found in insects and are thought to have some function in insect innate immunity.
thymic stromal lymphopoietin (TSLP)
Thymic stroma-derived lymphopoietin. A cytokine thought to be involved in promoting B-cell development in the embryonic liver. It is also produced by mucosal epithelial cells in response to helminthic infections, and promotes type 2 immune responses through its actions on macrophages, ILC2s, and TH2 cells.
tingible body macrophages
Phagocytic cells engulfing apoptotic B cells, which are produced in large numbers in germinal centers at the height of an adaptive immune response.
transitional immunity
Referring to the recognition by some adaptive immune system (e.g., MAIT, γ:δ T cells) of non-peptide ligands expressed as a consequence of infection, such as various MHC class Ib molecules.
type 1 immunity
Class of effector activities aimed at elimination of intracellular pathogens.
type 2 immunity
Class of effector activities aimed at elimination of parasites and promoting barrier and mucosal immunity.
type 3 immunity
Class of effector activities aimed at elimination of extracellular pathogens such as bacteria and fungi.
vaccine
A weakened pathogen, or part of a pathogen, used to stimulate the immune system and produce memory cells; provides artificially acquired active immunity.
variable Ig domains (V domains)
The amino-terminal protein domain of the polypeptide chains of immunoglobulins and T-cell receptor, which is the most variable part of the chain.
viral set point
In human immunodeficiency virus infection, the level of HIV virions persisting in the blood after the acute phase of infection has passed.
Virokine
A secreted viral protein that mimics cytokines, growth factors, or similar extracellular immune regulators. (Chapters 3 and 5)
Wiskott–Aldrich syndrome (WAS)
An immunodeficiency disease characterized by defects in the cytoskeleton of cells due to a mutation in the protein WASp, which is involved in interactions with the actin cytoskeleton. Patients with this disease are highly susceptible to infections with pyogenic bacteria due to defects in T-follicular helper cell interactions with B cells.
X-linked hypohidrotic ectodermal dysplasia and immunodeficiency
A syndrome with some features resembling hyper IgM syndrome. It is caused by mutations in the protein NEMO, a component of the NFκB signaling pathway. Also called NEMO deficiency.
X-linked immunodeficiency
An immunodeficiency disease in mice due to defects in the protein tyrosine kinase Btk. Shares the gene defect with X-linked agammaglobulinemia in humans, but leads to a milder B cell defect than seen in the human disease.
X-linked lymphoproliferative (XLP) syndrome
Rare immunodeficiency diseases that result from mutations in the gene SH2D1A (XLP1) or XIAP (XLP2). Boys with this deficiency typically develop overwhelming Epstein–Barr virus infection during childhood, and sometimes lymphomas.
ZFP318
A spliceosome protein expressed in mature and activated B cells, but not immature B cells, that favors splicing from the rearranged VDJ exon of immunoglobulin heavy chain to the Cδ exon, thereby promoting expression of surface IgD.
β sandwich
A secondary protein structure composed of two β sheets that fold such that one lies over the other, as in an immunoglobulin fold.
β1i (LMP2), β2i (MECL-1), β5i (LMP7)
Alternative proteasome subunits that replace the constitutive catalytic subunits β1, β2, and β5 that are induced by interferons and produce the immunoproteasome.
κ chain
One of the two classes or isotypes of immunoglobulin light chains. K63-linkages In polyubiquitin chains, the covalent ligation of lysine 63 amino group of one ubiquitin protein with the carboxy terminus of a second ubiquitin. This type of linkage is most associated with activation of signaling by formation of a scaffold recognized by signaling adaptors such as TAB1/2.
λ chain
One of the two classes or isotypes of immunoglobulin light chains.
