| ||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||
| Copyright © 2009. National Academy of Sciences. All rights reserved. Terms of Use and Privacy Statement |
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 217
Glossary
Acute-Phase Reactants. A diverse group of proteins that progressively
increase in the plasma during the first hours to days following tissue injury.
ADA (Adenosine Deaminase). An enzyme of the purine salvage pathway
that catalyzes the irreversible deamination of adenosine and 2'-deoxy-
adenosine.
ADA Deficiency. An autosomal recessive form of severe combined im-
munodeficiency disease in man.
ADCC (Antibody-Dependent Cytotoxic Cells). Lymphocytes bearing Fc
receptors that mediate a cellular cytotoxic reaction to target tissue with
the aid of Fc-bound specific antibody.
Allogeneic. Having cells that are antigenically distinct. Refers to intra
. . . .
species genetic vanat~ons.
ALS (Anti-Lymphocyte Serum). A specially prepared serum containing
Sources used to compile this glossary include the following:
Blakiston's Gould Medical Dictionary, 3d ea., McGraw-Hill Book Co., New York, 1,828
pp., 1972.
Immunology, I. Roitt, J. Brostoff, and D. Male, Cower Medical Publishing, London, 316 pp.,
1985.
International Dictionary of Medicine and Biology, vols. 1 and 2, John Wiley & Sons, New
York, 3,200 pp., 1986.
Advanced Immunology, D. Male, B. Champion, and A. Cooke, J. B. Lippincott Co., Phila-
delphia, 222 pp., 1987.
217
OCR for page 218
2 18 GLOSSARY
antibodies against lymphocytes. Used especially to prevent rejection of
transplanted organs.
Amyloidosis. Deposition of amyloid in various organs or tissues. Amyloid
is a family of nonrelated beta-pleated sheet proteins that share the char-
acteristic of extracellular fibril deposition.
ANA (Antinuclear Antibody). Any antibody capable of binding to com-
ponents of the cell nucleus.
Anemic. Characterized by a reduction of erythrocytes, hemoglobin, or
hematocrit to below normal levels.
Anterior Hypophysis. The anterior lobe of the pituitary gland.
Anti-DNP (Anti-Dinitrophenol). An antibody directed toward dinitrophe-
nol. Spontaneous elevations of this antibody in the plasma have been
associated with some autoimmune phenomena.
Anti-dsDNA (Anti-Double-Stranded DNA). An autoantibody frequently
seen in patients with systemic lupus erythematosus and certain related
connective tissue diseases.
Anti-IFN (Anti-Interferon). Antibodies directed against interferon.
Anti-SM (Anti-Smith). An autoantibody directed toward a nuclear antigen
present in active chromatin. It is resistant to both deoxyribonuclease (DNase)
and ribonuclease (RNase) and specific for the diagnosis of systemic lupus
erythematosus.
Anti-ssDNA (Anti-Single-Stranded DNA). An autoantibody frequently
seen in the plasma of people afflicted with autoimmune disease.
Ataxia Telangiectasia. An inherited disorder characterized by the onset
of progressive cerebellar ataxia in infancy or childhood, oculocutaneous
telangiectasia, frequent infections of the lungs and sinuses, and a propen-
sity for the development of malignant disease. It is often associated with
defects in cellular immunity and in the immunoglobulin system.
Atrophy. An acquired physiologic or pathologic local reduction in the size
of a cell, tissue, organ, or region of the body.
Autoantibodies. Antibodies produced by a host to its own tissues.
Autoimmune Disease. A disease involving a humoral or cell-mediated
immune attack against the tissues of one's own body.
Autoimmunity. A condition presumed to be caused by sensitization or loss
of tolerance to autochthonous products of the body. A failure of the immune
system to discriminate between self and nonself.
B Cells. Lymphocytes that secrete antibody and that are characterized by
the presence of certain surface membrane markers, that is, immunoglobulin
receptors.
Backcross. A cross between a hybrid and its parent or between a heter-
ozygote and a homozygote.
OCR for page 219
GLOSSARY 2 19
Balanced Stock. A genetic stock that is heterozygous for closely linked
genes and produces phenotypically recognized offspring types. One off-
spring type is used to produce the next generation and is of a predicted
genotype unless crossing over has occurred between the linked loci.
Barrier-Maintained Animals. Animals, usually defined-flora or patho-
gen-free, placed in an environment that can serve as a barrier to the
introduction of other microbes.
Basophils. A circulating polymorphonuclear leukocyte that has a small
number of prominent purple or black cytoplasmic granules when stained
with Romanowsky dyes. The granules contain histamine and chondroitin
sulfate. In tissues it is called a mast cell.
BCGF-2 (B-Cell Growth Factor Type 2~. Isolated from murine T-cell
cultures this 50- to 55-kilodalton glycoprotein drives activated B cells to
maturation.
BGG (Bovine Gamma-Globulin).
serum of cattle.
The gamma-globulin fraction from the
C3bi. Inactivated form of the split product of the third component of com-
plement, C3b.
Calcitonin. A single-chain polypeptide hormone, apparently existing as
several active fractions, secreted by the thyroid gland and the ultimobran-
chial bodies. A calcitoninlike substance has also been extracted from por-
cine adrenal glands. In hypercalcemia the hormone rapidly lowers blood
calcium by inhibiting bone resorption; it also increases urinary excretion
of phosphate. Called by some investigators thyrocalcitonin.
Centromere. A small body at the constriction in a chromosome where it
is attached to a spindle fiber.
Chediak-Higashi Syndrome. A human syndrome (with homologous ge-
netic disorders in many mammalian species) with deeply staining, coarse
peroxidase-positive granules in the cytoplasm of neutrophils and eosino-
phils. These granules are associated with albinism, hepatosplenomegaly,
lymphadenopathy, and recurrent skin and pyogenic infections. When al-
binism is absent, the condition is called the Steinbrinck type. See the beige
(by) mutation of mice (p. 401.
Chemotaxis. Increased directional migration of cells, particularly in re-
sponse to concentration gradients of certain chemotactic factors.
Chromosome. Intranuclear elements composed of DNA and protein that
carry the hereditary factors (genes) and are present at a constant number
. , .
1n eacn species.
Class I MHC Antigens. Antigens encoded by the major histocompatibility
complex (MHC) of genes that are found on all nucleated cells and are
composed of two polypeptide chains of 45 and 12 kilodaltons.
OCR for page 220
220 GLOSSARY
Class II MHC Antigens. Also known as Ia antigens, they are found on
antigen-presenting cells and are composed of two polypeptide chains of
28 and 32 kilodaltons.
cM (Centimorgans). One one-hundreth of a Morgan. A measurement of
length along the chromosome having a corrected crossover frequency of
1 percent.
CMI (Cell-Mediated Immunity). A term used to refer to immune reactions
that are mediated by cells rather than by antibody or other humoral factors.
Codominant. Of or pertaining to two alleles that are both expressed in a
heterozygote. The phenotype is the additive function of the two alleles.
Coisogenic Strain. A congenic strain whose difference is limited to a single
genetic locus.
Complement. Any one of a group of at least nine factors, designated C1,
C2, etc., that occur in the serum of normal animals and enter into various
immunologic reactions. Complement is generally absorbed by combina-
tions of antigen and antibody and, with the appropriate antibody, can lyse
erythrocytes, kill or lyse bacteria, enhance phagocytosis and immune ad-
herence, and exert other effects. Complement activity is destroyed by
heating the serum at 56°C for 30 minutes.
ConA (Concanavalin A). A lectin produced by the jack bean that combines
membrane glycoproteins containing alpha-glucoside or alpha-mannoside
groups and serves as a mitogen for T cells.
Congenic Strain. A strain that differs from the parental inbred strain at
one restricted region of the genome.
Contact Sensitivity. Also called contact hypersensitivity. An epidermal
reaction characterized by eczema and caused when an antigen is applied
to previously sensitized skin.
Conventional Environment. Environmental conditions where the micro-
bial flora are unknown and uncontrolled.
Coombs' Positive Hemolytic Anemia. Anemia characterized by the at-
tachment of anti-erythrocyte antibody and leading to sequestration of eryth-
rocytes in the reticuloendothelial system or to complement-mediated
intravascular hemolysis.
CRI (Cross-Reactive Idiotype). An idiotype that can be detected on two
different antibodies is termed a cross-reactive idiotope, and the antibodies
that share them are cross-reactive idiotypes.
Cyclosporine A. An immunosuppressive drug commonly used in organ
transplantation. It appears to mediate its suppressive effect mainly through
CD4+ (helper) T cells.
Cytotoxic T Cell (Tc). A thymic-derived lymphocyte that circulates in
search of a target cell displaying a determinant recognized by its receptor.
It must recognize target cell antigen in association with class I major
histocompatibility complex determinants.
OCR for page 221
GLOSSARY 22 1
Defined-Flora. Animals that have a microbial flora that is completely known.
Delayed-Type Hypersensitivity. A type IV immunologic reaction initiated
by T lymphocytes and characterized by a delayed inflammatory response.
Previous sensitization is required. Examples include response to Myco-
bacterium tuberculosis (tuberculin test) and contact dermatitis (poison ivy).
Dendritic Cells. Antigen-presenting cells present in lymph nodes, spleen,
and at low levels in blood that are particularly active in stimulating T cells.
DES (Diethylstilbestrol). A nonsteroid estrogen used as a substitute for
the natural estrogenic hormones, it is more readily absorbed from the
alimentary canal than most of the natural hormones and hence is suitable
for oral use.
Diabetes Mellitus. An inherited chronic disorder of carbohydrate metab-
olism caused by a disturbance of the normal insulin mechanism and char-
acterized by hyperglycemia, glycosuria, and alterations of protein and fat
metabolism. It produces polyuria, polydipsia, weight loss, ketosis, aci-
dosis, and coma.
DNFB (2,4-Dinitro-l-Fluorobenzene). A chemical that, when applied top-
ically to skin, sensitizes the host so that a second application causes contact
. . .
sensltlvlty.
Dysgenesis. Abnormal development of anything, usually of an organ or
individual. Impairment or loss of the ability to procreate.
EAE (Experimental Allergic Encephalomyelitis).
A disease state induced
by the inoculation of allogeneic spinal cord that is characterized by in-
flammation of the brain and spinal cord.
Erythropoiesis. The differentiation and proliferation of erythrocytes.
FACS (Fluorescence-Activated Cell Sorting). A procedure for mechan-
ically separating cells based on the presence of membrane-bound fluores-
cent dyes. Commonly, the dye is attached to a specific antibody, which
directs it to a particular plasma membrane determinant.
Fc Receptors. Membrane receptors in cells capable of binding the Fc
portion of immunoglobulin molecules.
FTS (Facteur Thymique Serique). A nine-amino-acid residue thymic hor-
mone; also called thymulin.
F Number. Indicates the number of filial or brother x sister generations.
GA (Garlic Acid). 3,4,5-Trihydroxybenzoic acid, C7H6Os, formerly used
internally as an astringent; esters of the acid are used as antioxidants.
Gene. The biologic unit of heredity. It is self-reproducing and located at
a specific location (locus) on a specific chromosome.
Genotype. The genetic material inherited from parents; not all of it
necessarily expressed in the individual (cf. phenotype).
OCR for page 222
222 GLOSSARY
Germfree Environment. An environment free of all known microbes.
Germfree Isolator. An apparatus used to maintain animals in a germfree
environment.
GIF (Glucocorticoid Increasing Factor). A substance made by certain
lymphocytes that exerts its stimulatory effect through the pituitary gland.
Glomerulonephritis. An acute or chronic, usually bilateral, diffuse non-
suppurative inflammatory kidney disease primarily affecting the glomeruli.
It is characterized by proteinuria; cylindruria; hematuria; and often edema,
hypertension, and nitrogen retention.
Glucocorticoid. An adrenal cortex hormone that affects the metabolism
of glucose. Any related natural or synthetic substance that functions sim-
ilarly. In pharmacologic doses, these substances have immunosuppressive
effects.
Gnotobiotic.
Germfree animals or germfree animals into which a defined
microflora is introduced. The defined flora should be few in number and
nonpathogenic.
gp70 (GIycoprotein 70~. A 70,000-dalton c1Ycoorotein found on the en-
velope of murine leukemia viruses.
GM-CSF (Granulocyte-Macrophage Colony Stimulating Factor). A
glycoprotein hormone that stimulates mveloir1 nro~.nitor oellc to nrorl~lr~
neutrophils, macrophages, and eosinophils.
GVH (Graft-Versus-Host Reactions). An immunologic reaction charac
.
O ~
' - - --J _ ~ _ _ = ~_ ~ ^
terlzed by donor (grafted) lymphocytes attacking host cells based on the
recognition of histocompatibility antigens on host cells not present on the
donor lymphocytes and the inability of host lymphocytes to reject the
donor cells.
Haplotype. A set of genetic determinants located on a single chromosome.
Hashimoto's Thyroiditis. A chronic autoimmune disease of the thyroid,
more common in women, that presents as thyroid gland enlargement and
hypothyroidism. The gland is densely infiltrated with lvmnhonvte.s once is
ultimately destroyed.
Hematocrit. The percentage of the whole-blood volume occ~nier1 hv ~.rvth-
rocytes after centrifugation.
Hemizygous. ~1 ~r - _
_ J _ _ _< _ _ _ _ J ~
_ J _~ J _^A
the presence of only one of a pair of genes that influence
one cleterm~nat~on or a specific trait. For example, a male has few alleles
on his Y chromosome; therefore, most of the alleles on his X chromosome
are expressed whether they are dominant or recessive.
Henoch-Schonlein Purpura. A disease, primarily of young children, con-
sisting of small-vessel vasculitis seen as raised red spots on the skin,
glomerulonephritis, abdominal pain, fever, and arthritis. It is thought to
be a form of allergic vasculitis.
OCR for page 223
GLOSSARY 223
HEPA (High-Eff~ciency Particulate Air Filter). A filter capable of re-
taining 99.97 percent of a 0.3-~m diameter monodispersed aerosol.
Heterozygosity. Having dissimilar alleles in one or more pairs of gene
loci.
Heterozygote. An individual that has different alleles in the corresponding
loci of homologous chromosomes and does not breed true.
HGG (Human Gamma-Globulin). The gamma-globulin fraction of hu-
man serum. An extract of serum from hyperimmune humans that is used
as passive immunotherapy in patients exposed to an infectious disease,
for example, rabies immune globulin.
Histamine. 4-~2-Aminoethyl)-imidazole, C5H,N3, an amine occurring as
a decomposition product of histidine that stimulates visceral muscles; di-
lates capillaries; and stimulates salivary, pancreatic, and gastric secretions.
It is found in the granules of the basophils and mast cells responsible for
anaphylactic reactions.
Holandric Inheritance. Transmission of a trait via the male lineage; trans-
mitted through genes on the Y chromosome.
Homozygote. An individual that has identical alleles in the corresponding
loci of homologous chromosomes and breeds true.
Hybrid. The offspring of a cross between two inbred strains.
Hypergammaglobulinemia. The increased concentration of immunoglob-
ulins in the blood seen in a wide variety of clinical disorders.
Hyperplasia. Excessive fo~ation of tissue; an increase in the size of a
tissue or organ caused by an increase in the number of cells.
Ia-Associated Antigen. A surface antigen of mouse cells, such as B lym-
phocytes and macrophages, that is determined by the I-A region of the
major histocompatibility complex.
Idiotope. A single antigenic determinant on an antibody V region.
Idiotype. The antigenic characteristic of the V region of an antibody.
IL-I (Interleukin-1~. An acute-phase reactant synthesized by many cell
types, including monocytes and lymphocytes. This hormone has many
effects, including the activation of resting T cells, the promotion of syn-
thesis of other lymphokines, and the activation of macrophages and en
dothelial cells.
IL-2 (Interleukin-2~. A growth factor for activated T cells, this hormone
is derived from lymphocytes and promotes the synthesis of other lym
phokines.
IL-3 (Interleukin-3~. A multilineage colony stimulating factor released by
T cells that appears to act synergistically with granulocyte-macrophage
colony stimulating factor to stimulate hematopoiesis. It is also a growth
factor for mast cells.
OCR for page 224
224 GLOSSARY
IL-4 (Interleukin-4~. Also known as B-cell stimulating factor type l, this
is a growth factor for B cells and induces class II major histocompatibility
complex antigen expression on their surfaces. This hormone also enhances
the cytolytic activity of cytotoxic T cells and is a mast cell growth factor.
IL-6 (Interleukin-64. Also known as B-cell stimulating factor type 2 or
B-cell differentiation factor, it induces the differentiation of activated B
cells into immunoglobulin-secreting plasma cells.
Immune Complex. The product of an antigen-antibody reaction that can
also contain components of the complement system.
Immunodeficiency. The inability of the host to eliminate or neutralize
foreign substances.
Immunologic Memory. A phenomenon characterized by the presence in
the body of an expanded set of clonally derived antigen-specific lympho-
cytes that can be rapidly recruited to produce an augmented immune re-
sponse on subsequent exposure to the specific antigen.
Immunoglobulins. Proteins of animal origin with known antibody activity
or a protein related by chemical structure and hence antigenic specificity.
They can be found in plasma, urine, spinal fluid, and other body tissues
and fluids and include such proteins as myeloma and Bence Jones protein.
Inbreed. To mate brother x sister each generation.
Inbred Strain. A strain produced by at least 20 generations of brother x
sister inbreeding.
Incisor Teeth. The two cutting teeth nearest the midline in each quadrant
of the dentition. Also called dentes incisive.
Intercrossing. The mating of diploid individuals who are both heterozy-
gous for one or more of the same alleles at given loci.
Interferons. Proteins that are formed by animal cells in the presence of a
virus, that prevent viral reproduction, and that are capable of inducing
resistance to a variety of viruses in fresh cells of the same animal species.
There are three classes: alpha, beta, and gamma. Alpha interferon (IFNa)
is made by lymphocytes and macrophages and is 18-20 kilodaltons in
size. Beta interferon (IFNQ) is synthesized by fibroblasts and epithelial
cells. Alpha and beta interferons were once called type 1 interferon. Gamma
interferon (IFNy), also called type 2 interferon, is synthesized by lym-
phocytes. All three interferons can be induced during viral infection. They
have antiviral and antiproliferative effects, and all induce class I major
histocompatibility complex antigens.
Islets of Langerhans.
Islets of the pancreas containing hormone-producing
cells: beta cells produce insulin; alpha cells produce glucagon.
Isotypes. Genetic variation within a family of proteins or peptides such
that every member of a species has each isotype of the family represented
in its genome (e.g., immunoglobulin classes).
OCR for page 225
GLOSSARY 225
Kappa ('c) Chain. One of the immunoglobulin light-chain isotypes.
Ketosis. A condition in which ketones are present in the body in excessive
amounts. The acidosis of diabetes mellitus.
Lambda (A) Chain. One of the immunoglobulin light-chain isotypes.
Laminar Flow. Air flow characterized by the absence of turbulence.
Langerhans' Cells. Stellate cells of the mammalian epidermis and clerks
presumed to belong to the melanocyte series, revealed by gold ~mpreg-
nation, and containing nonmelanized disklike organelles. They are antigen-
presenting cells that emigrate to the local lymph nodes to become dendritic
cells. They are particularly active at presenting antigen to T cells.
Lentivirus. One member of the virus family Retroviridae. Many species
.
have the ability to infect animals, including man, and have long incubation
periods. These viruses usually are not oncogenic.
Linked Genes. In eukaryotic cells, genes are said to be linked if they are
carried on the same chromosome, that is, do not segregate randomly.
Lipid A. The endotoxic component of lipopolysaccharide.
LPS (Lipopolysaccharide). A compound of a lipid with a polysaccharide.
A component of gram-negative bacteria that is liberated on bacterial death
and might be responsible for shock; also called endotoxin.
Lymphadenopathy. Lymph node enlargement.
Lymphoblasts. A blast cell, considered a precursor or early form of a
lymphocyte.
Lymphocyte Activating Factor.
Lymphokines. A generic term for molecules other than antibodies that are
involved in signaling between cells of the immune system and are produced
by lymphocytes (cf. interleukins).
Lymphomas. Any neoplasm, usually malignant, of the lymphatic tissues.
Lymphopenia. Lymphocytopenia. A reduction in the number of circulating
lymphocytes.
Lymphopoietic.
Also called interleukin-l.
Lymphocytopoiesis. Production of lymphocytes.
Macrophages.
derived from
defense mechanisms.
A phagocytic cell that is found in many tissues, that is
a blood monocyte, and that has an important role in host
MALT (Mucosal-Associated Lymphoid Tissue).
Generic term for lym
phoid tissue associated with the mucosa of the gastrointestinal tract, bron
chial tree, urinary tract, and other systems.
Mast Cell. A small cell similar in appearance to a basophil and found
associated with mucosal epithelial cells. These cells are dependent on T
cells for proliferation, and they contain cytoplasmic granules laiden with
heparin, slow reactive substance of anaphylaxis, and eosinophil chemo
OCR for page 226
226 GLOSSARY
tactic factor of anaphylaxis, which are released when antigen binds to
membrane-bound IgE.
Melanocyte. The epidermal cell that synthesizes melanin.
Membrane Attack Complex. A multimolecular complex formed by the
activation of the terminal components of the complement pathway and
responsible for cytolysis.
MHC (Major Histocompatibility Complex). A genetic region found in
all mammals whose products are primarily responsible for the rapid re-
jection of grafts between individuals and that function in signaling between
lymphocytes and cells expressing antigen.
~,, _ _ ~ ~
O -- ~
MHV (Mouse Hepatitis Virus). A single-stranded RNA virus of the family
Coronaviridae, genus Coronavirus. MHV infections are usually subclinical
in immunocompetent mice but can cause severe illness and death in im-
munodeficient mice.
Mitogens. Substances that cause cells, particularly lymphocytes, to un-
dergo cell division.
MLC (Mixed Lymphocyte Culture). The proliferative assay system for
T-cell recognition of foreign antigen on allogeneic cells, in which response
is measured by DNA synthesis (intercollation of radiolabeled nucleic acid).
MLR (Mixed Lymphocyte Reaction). See MLC.
Monoclonal Antibodies. Antibodies arising from a single clone of B lym-
phocytes.
MuLV (Murine Leukemia Virus). An RNA virus of the family Retro-
viridae. An endogenous virus of mice that causes leukemias and related
malignancies in some mouse strains. Strain susceptibility is influenced by
a number of genes, including Fv-l, Fv-2, In, nu, hr. and Ir.
Mutations. A change in the characteristics of an organism produced by an
alteration in the hereditary material. The alteration in the ~ermnlasm might
involve an addition of one or more complete sets of chromosomes; the
addition or loss of a whole chromosome; or some change within a chro-
mosome, ranging from a gross rearrangement, loss, or addition of a larger
or smaller section to a minute rearrangement or change at a single locus.
A small change at a single locus is called a gene mutation or, more simply,
mutation in the restricted use of the term.
Myelopoiesis. The process of formation and development of blood cells
in the bone marrow.
~r D
N. Indicates the number of backcrosses made to an inbred strain.
Necrosis. The pathologic death of a cell or group of cells.
NK (Natural Killer) Cells. A group of lymphocytes with the intrinsic
ability to recognize and destroy some virally infected cells and some tumor
cells.
Nephritogenic. Giving rise to inflammation of the kidney.
OCR for page 227
GLOSSARY 227
NTAs (Natural Thymocytotoxic Antibodies). Autoantibodies directed
against determinants present on thymic-derived lymphocytes, as defined
by complement-dependent lysis of target thymocytes.
Oncornavirus. Any of the various tumor-producing viruses of the family
Retroviridae. Also called oncovirus.
Osteoclast. A multinuclear giant cell responsible for bone absorption and
destruction.
Ovarian Transplantation. A technique of placing a compatible ovary in
the ovarian capsule (from which the original ovary has been removed) of
a selected host.
Osteopetrosis. A heterogeneous group of hereditary disorders that share
generalized sclerosis and fragility of the skeleton and elevated serum acid
phosphatase.
Osteosclerosis. An abnormal thickening of bone.
P-1SE. A transmembrane portion of the envelope of certain oncoviruses
thought to be responsible for viral-associated immunosuppression.
Parabiosis. The experimental surgical fusing together of two individuals
or embryos so that the effects of one partner on the other can be studied.
Parathyroid Hormone. A polypeptide hormone in parathyroid glands that
regulates blood calcium levels.
Pathogen-Free Environment. An environment free of all known patho-
genic microorganisms, tested pathogens, or both.
PBB (Polybrominated Biphenyl). Any of a series of stable compounds
in which the hydrogen atoms in biphenyls are replaced by bromine. These,
along with polychlorinated bichenvls. are serious toxic pollutants in the
environment.
~,
PBLs (Peripheral Blood Lymphocytes).
in blood.
Penetrance.
Circulating lymphocytes found
The percentage of organisms with a given genetic constitution
that show the corresponding hereditary characteristic.
Peyer's Patches. Specialized lymphoid tissue found in the intestinal tract.
PFC (Plaque-Forming Cell). An antibody-secreting B cell that can be
recognized by the production of a hemolytic plaque.
PG (Propylgallate). 3,4,5-Trihydroxybenzoic acid propyl ester, an an-
tioxidant.
PHA (Phytohemagglutinin). A lectin isolated from red kidney beans that
is mitogenic for T cells.
Phagocytosis. Ingestion of foreign or other particles by certain cells.
Phenotype. The expressed characteristics of an individual (cf. genotype).
Pleiotropic. The occurrence of multiple effects produced by a given gene.
OCR for page 228
228 GLOSSARY
PMN (Polymorphonuclear Leukocyte). The mature neutrophil leukocyte,
so-called because of its segmented and irregularly shaped nucleus.
Pneumonitis. Inflammation of the lungs in which the exudate and inflam-
matory cell incursion is primarily interstitial.
Poly(A-U) (Polyadenylic-Polyuridylic Acid). A synthetic RNA polymer.
Polyarteritis Nodosa. A systemic disease characterized by widespread in-
flammation of small- and medium-sized arteries in which some of the foci
are nodular. Complications of the process, such as thrombosis, lead to
retrogressive changes in the tissues and organs supplied by the affected
vessels with a correspondingly diverse array of symptoms and signs. It is
also called periarteritis nodosa or disseminated necrotizing periarteritis.
Poly (I-C). One of the synthetic RNA polymers that induce the local pro-
duction of interferon. It has been used experimentally in the topical treat-
ment of acute herpesvirus infection of the cornea.
Prokaryotic. Pertaining to a unicellular organism that has a single chro-
mosome, lacks a nuclear membrane, and usually has a rigid peptidoglycan
wall.
PGE2 (Prostaglandin E21. An unsaturated fatty acid 20 carbons in length
with an internal cyclopentane ring. It causes vasodilatation, inhibits gastric
secretion, induces labor and abortion, and is immunosuppressive. A de-
rivative of arachidonic acid.
Protein A. A cell wall component of certain strains of staphylococci that
binds to a site in the Fc region of most IgG isotypes.
PWM (Pokeweed Mitogen). A mitogen for B cells.
RCS (Reticulum-Cell Sarcomas). A malignant tumor in which the pre-
dominant cell type is an anaplastic reticulum cell. Multinucleated cells
also occur. Also called histiocytic sarcoma.
Recombinant Inbred. A strain formed by crossing two inbred strains,
followed by 20 or more generations of brother x sister mating.
Reed-Sternberg Cell. A large binucleated or multinucleated cell, 15-45
~m in diameter, that is derived from the reticuloendothelial system. It is
a distinctive giant cell found in all Hodgkins' lymphomas.
Repulsion. The occurrence of two linked loci, each in the heterozygous
state, with the mutant alleles on different homologous chromosomes.
RES (Reticuloendothelial System). A diffuse system of phagocytic cells,
many of which are derived from bone marrow stem cells. It is associated
with the connective tissue framework of the liver, spleen, lymph nodes,
and other serous cavities. The site of renewal for endothelial cells is thought
to be existing endothelial cells rather than bone marrow.
Retroviral. Relating to retroviruses, RNA viruses belonging to the family
Retroviridae that are characterized by the presence of a reverse transcriptase
(RNA-dependent ONA polymerase) enzyme.
OCR for page 229
GLOSSARY 229
RFs (Rheumatoid Factors). A group of autoantibodies that are directed
against the Fc fragment of the heavy chain of IgG.
RFLP (Restriction Fragment Length Polymorphism). DNA fragments
of various sizes resulting from the action of endonucleases cleaving DNA
at specific sites (restriction enzymes).
Semidominant. Incomplete dominance.
Serotonin. 5-Hydroxytryptamine, CloHl2N2o, which is present in many
tissues, especially blood and nervous tissue. It stimulates a variety of
smooth muscles and nerves and is postulated to function as a neurotrans-
mitter.
Serum Alkaline Phosphatase. Serum levels of a specific phosphatase en-
zyme found in various tissues. Elevation of this enzyme in the serum
usually indicates hepatobiliary disease in mammals.
SAA (Serum Precursor Amyloid). An alpha-globulin that displays acute-
phase increases and is believed to be the precursor of the amyloid A fibrils
present in secondary amyloidosis.
SDS Gel Electrophoresis. A form of polyacrylamide gel electrophoresis
conducted with sodium dodecyl sulfate (SDS) in the buffer.
SPF (Specific-Pathogen-Free). Free of specifically defined pathogenic mi-
croorganisms.
Splenomegaly. Increased spleen size; it is seen in a number of parasitic
infections, hemolytic anemias, and lymphomas and is also measured in
the Simonson assay for graft-versus-host reactions.
SRBC (Sheep Red Blood Cell). A T-cell-dependent target antigen often
used in hemolytic plaque assays of immune responsiveness.
Stem Cell. Pluripotent cells that can serve as progenitor cells for the lym-
phoid lineage or the myeloid lineage or both (hemopoietic stem cell).
SV40 (Simian Virus 40~. A papovavirus commonly seen in tissues of Old
World monkeys without being associated with disease.
Synergistic. An agent that increases the action or effectiveness of another
agent when combined with it.
Syugeneic. Individuals or tissues that have identical genotypes, for ex-
ample, animals of the same inbred strain.
SLE (Systemic Lupus Erythematosus). An autoimmune disease of hu-
mans usually involving antinuclear antibodies and characterized by skin
rash, hematologic alterations, and glomerulonephritis.
TCDD (Tetrachlorodibenzo-p-Dioxin). One member of a group com-
monly referred to as dioxins that is widespread in the environment and is
. .
1mmunosuppresslve.
T-Cell- or Thymic-Derived Lymphocytes. One of the two major classes
of lymphocytes with important immune regulatory and effector functions.
OCR for page 230
230 GLOSSARY
T cells must pass through the thymus during development, and they carry
certain characteristic surface markers such as theta and the CD3 antigens.
Tdt (Terminal Deoxyoucleotidyl Transferase). An enzyme present in
pre-T or thymic stem cells. It is present in cortical but lost in medullary
and peripheral cells.
Th Cell or Helper T Lymphocyte. A functional subclass of T cells that
can help generate cytotoxic T cells and cooperate with B cells in the
production of an antibody response. Helper T cells usually recognize an-
tigen in association with class II major histocompatibility complex mol-
ecules. Currently defined using CD4 markers.
Thymulin. An 867-dalton peptide isolated from thymus and serum that
appears to be responsible for T-cell differentiation. Also known as facteur
thymique serique (FTS).
Thymus. An organ found in the thoracic or cervical regions of mammals
that is composed of lymphatic tissue in which minute concentric bodies,
the remnants of epithelial structures, or thymic corpuscles are found. This
organ is necessary for the development of thymic-derived lymphocytes
and is the source of several hormones involved in T-cell maturation, for
example, thymosin, thymopoietin, thymulin, and thymocyte humoral fac-
tor.
Thymus-Dependent Antigen. An antigen that requires an immune re-
sponse from thymic-derived lymphocytes in order to elicit an immune
response from B lymphocytes.
Thymus-Independent Antigen. An antigen that does not require the par-
ticipation of T lymphocytes to elicit an immune response in B cells.
Ti or TCR (T-Cell Antigen Receptor). The antigen receptor of T cells
composed of two polypeptide chains and closely associated with the T3
surface membrane molecules.
TLI (Total Lymphoid Irradiation). X-irradiation directed toward lym-
phoid organs throughout the body.
Tolerance. A state of specific immunologic unresponsiveness.
Ts Cell or Suppressor T Lymphocyte. A subpopulationfs) of T cells that
acts to reduce the immune responses of other T or B cells. Suppression
can be antigen specific, idiotype specific, or nonspecific under different
circumstances. At present, cells with this function cannot be identified
using one marker, although many appear to carry the CD8 molecule.
Type 1 Antigens. T-cell-independent (TI) antigens that can stimulate both
Lyb-5 + and Lyb-5 - B cells in the mouse. TI type 2 antigens only stimulate
Lyb-S+ B cells.
UVR (Ultraviolet Radiation). Radiation with a wavelength shorter than
that of the violet end of the visible spectrum and longer than that of x rays
OCR for page 231
GLOSSARY 231
(from 180 to 390 nary). Exposure to UVR can be associated with tissue
damage, malignant transformation, or immunosuppression.
Vibrissae. One of the hairs in the vestibule of the nose. One of the long,
coarse hairs on the face of certain animals; "whiskers."
Viral-Antibody-Free. Free of circulating anti-viral antibodies to specific
viruses, usually pathogenic viruses.
Vitiligo. A condition of the skin characterized by a failure to form melanin,
with patches of depigmentation that often have a hyperpigmented border
and enlarge slowly.
Wild Type. Of or relating to a genetic locus or an allele that specifies a
phenotype that predominates in natural populations or that is designated
as normal.
Xenografts. A transplant from one species to another; sometimes used to
indicate a wider genetic or species disparity than in a heterograft.
OCR for page 232
Representative terms from entire chapter:
major histocompatibility