IMMUNODEFICIENCY Flashcards
Two major kinds of defense have evolved that counter threats:
–________ immunity and _______ immunity
Innate; acquired
Innate immunity
– Is present _______________ and is effective from ____________
– Involves (specific or nonspecific?) responses to pathogens
before any exposure to pathogens
the time of birth
nonspecific
Acquired immunity, also called ______ immunity
– Develops only after ____________________ such as microbes, toxins, or other foreign substances
– Involves a ( specific or non-specific ?) response to pathogens
adaptive
exposure to inducing agents
very specific
Natural Killer Cells
Natural killer (NK) cells
– Patrol the body and attack ______-infected body cells and _____ cells
– Trigger ______ in the cells they attack
virus; cancer
apoptosis
The lymphatic system
– Plays a/an (active or passive?) role in defending the body from pathogens
Active
In acquired immunity, ________ provide specific defenses against infection
Acquired immunity
– Is the body’s ______ major kind of defense
– Involves the activity of ___________
lymphocytes
second
lymphocytes
An antigen is any foreign molecule
•That is specifically recognized by _________ and ______________
lymphocytes; elicits a response from them
A lymphocyte actually recognizes and binds
•To just a small, accessible portion of the antigen called an _______
epitope
Antigen Recognition by Lymphocytes
Two main types of lymphocytes
– B lymphocytes (B cells) and T lymphocytes Which circulate through the blood
The plasma membranes of both B cells and T cells
– Have about _______ antigen receptor that all recognize the same epitope
100,000
B Cell Receptors for Antigens
B cell receptors
Bind to (specific or non-specific?) , intact antigens
Are often called _________ or ___________
Specific
membrane antibodies or membrane immunoglobulins
B lymphocytes or B cells produce _______ involved in ______ immunity.
B cells are produced in the _______, where the initial stages of maturation occur, and travel to the _____ for final steps of maturation into __________ B cells.
antibodies; humoral
bone marrow; spleen
naive mature
B-cells are activated by the binding of ______ to ______ on its cell surface which causes the cell to divide and proliferate.
Some stimulated B-cells become ______ cells, which secrete _______.
Others become ____-lived ____ B-cells which can be stimulated at a later time to differentiate into plasma cells
antigen; receptors
plasma; antibodies
long; memory
Somatic hypermutation is a process that allows ____ cells to _________ that they use to produce antibodies.
This enables the B cells to _________ that are better able to _______ bacteria, viruses and other infections
B; mutate the genes
produce antibodies
bind to
Somatic hypermutation occurs in T- cell receptor genes
T/F
F
Somatic hypermutation does not occur in T- cell receptor genesh
Each T cell receptor
– Consists of ______ different polypeptide chains
two
T cells bind to (small or long?) fragments of antigens That are bound to normal cell-surface proteins called ______ molecules
Small
MHC
MHC molecules
MHC molecules
Are encoded by a family of genes called the ______________
major histocompatibility complex
Infected cells produce MHC molecules
– Which bind to _____________ and then are transported to the ______ in a process called __________
antigen fragments
Cell surface
antigen presentation
There are three types of antigen presenting cells in the body: __________,__________,__________ .
macrophages, dendritic cells and В cells
After antigen presentation :
A nearby T cell
– Can then detect the _______ displayed on the _______ of APC
antigen fragment
cell’s surface
Peptide antigens are handled by (the same or different?) classes of MHC molecules
Different
Class I MHC molecules, found on ______________ cells of the body
It Display ________ antigens to _________ cells
almost all nucleated
peptide; cytotoxic T
Class II MHC molecules, located mainly on _______,_______, and ________
– it Display antigens to ___________ cells
dendritic cells, macrophages, and B cells
helper T
IMMUNODEFICIENCY
It is the absence or failure of normal function of _________________
Results in __________ disease
one or more elements of the immune system
immunodeficiency
Immunodeficiency
Can be classified as
–_________ (________)
– _________ (_________)
Primary (congenital)
– Secondary (acquired)
PRIMARY IMMUNODEFICIENCIES
Primary immunodeficiencies are _______ defects of the immune system
These defects may be in the _______ or __________ immune mechanisms
inherited
specific or nonspecific
PRIMARY IMMUNODEFICIENCIES
They are classified on the basis of the ____________ in the developmental or differentiation pathway of the immune system
site of lesion
B CELL DEFICIENCY
List 6
Common variable immundeficiency
X liked agammaglobuinemia
IgA deficiency
IgG subclass deficiency
Immunodeficiency with increased IgM
Transient hypogammaglobulinaemia of infancy
1- X-linked agammaglobulinaemia
In X-LA, __________________ fails
__________ B cells in blood
____________ lymph nodes and tonsils
_______ level or ______ of plasma immunoglobulins
Small amount of Ig___ in early age
Recurrent _____ infection
early maturation of B cells
Few or no
Very small
Reduced; absence
G; pyogenic
IgA and IgG subclass defeciency
Ig____ deficiency is most common
Patients tend to develop _______ disease
About ___% lack IgG2and IgG4
Susceptible to _______ infection
Result from failure in _______________ of B cells
A
immune complex
20; pyogenic
terminal differentiation
Immunodfeiciency with increased IgM (HIgM)
Results in patients with ___________ deficiency
Production of (small or large?) amount of IgM=_______ mg/dl of polyclonal IgM
Susceptible to _______ infection
Treatment by _________
Formation of Ig___ to neutrophils, platelets and other blood components
Due to inability of B cells to __________
IgA and IgG
Large ; >200
pyogenic
iv gamma globulin
M; isotype switching
Common Variable Immunodeficiency (CVID)
Defect in ____________ to B cells
Acquired _______ in the _____ or _____ decade of life
May follow ____ infection
Susceptibile to _____ infection
80% of patients have B cells that ________
B cells are not _______. They just fail to ___________
T cell signaling
agammaglobulinemia; 2nd or 3rd
viral; Pyogenic
are not functioning
defective; receive signaling from T lymphocytes
Hypogamaglobulinaemia of infancy
Due to delay in in Ig___ synthesis approximately up to ______
In normal infants synthesis begins at _________
( Normal or Abnormal?) B lymphocytes
Probably lack ________________
G; 36 months
3 months
Normal
help of T lymphocytes
DISORDERS of T CELLS
A. DiGeorge’s syndrome:
It the (most or least?) understood T-cell immunodeficiency
Also known as _______/________
Associated with ____parathyroidism, congenital _____ disease, ____ shaped mouth.
Defects results from abnormal ____________________ during ____________ when ———,——,——-,——, and _____ are being formed
Most
congenital thymic aplasia/hypoplasia
hypo; heart; fish
development of fetus during 6th-10th week of gestation
parathyroid, thymus, lips, ears and aortic arch
T cell deficiencies with variable degrees of B cell deficiency
1- Ataxia-telangiectasia:
Associated with a lack of ______________ (ataxis) and ___________ of the __________ area (telangiectasis).
T-cells and their functions are _____________
B cell numbers and IgM concentrations are ___________
coordination of movement
dilation of small blood vessels of the facial
reduced to various degrees.
normal to low.
Ataxia-telangiectasia:
IgM concentrations are ___________
IgG is often _______
IgA is considerably ______ (in 70% of the cases).
There is a (low or high?) incidence of malignancy, particularly _______ in these patients.
There is defect in chromosome ____ at the site of ___________ and _______ genes
Normal to low
reduced
reduced
High ; leukemia
14; T cell receptor ; Ig heavy chain
T cell deficiencies with variable degrees of B cell deficiency
Wiskott-Aldrich syndrome:
T cell function _________ despite __________
IgM concentrations are ______
IgG levels may be _______
IgA levels are _______.
IgE levels are ________
Boys with this syndrome develop severe _____________.
They respond poorly to ______ antigens and are prone to _______ infection.
progressively reduces ; normal blood levels
reduced; normal
elevated; elevated
eczema; polysaccharide
pyogenic
MHC DEFICIENCY
(__________ syndrome):
Due to defect in the ________ ———- (CIITA) protein gene, which results in a lack of ________ molecule on APC.
Patients have ——— CD4 cells and are infection prone
There are also individuals who have a defect in their __________ protein (TAP) gene and hence do not express the ________ molecules and consequently are deficient in _______ cells.
Bare leukocyte
MHC class II ; transactivator
class- II MHC ; fewer
transport associated ; class-I MHC
CD8+ T
Defects of the phagocytic system
1- Cyclic neutropenia:
It is marked by (low or high?) numbers of circulating _______ approximately every _______.
The neutropenia lasts about _____ during which the patients are ____________.
The defect appears to be due to _________ of neutrophil production.
Low ; neutrophil; three weeks
A week; susceptible to infection
poor regulation
Defects of the phagocytic system
Chronic granulomatous disease (CGD):
CGD is characterized by marked _______,___________, and __________
In majority of patients with CGD, the deficiency is due to a defect in ________ that participate in phagocytic ________.
lymphadenopathy, hepato-splenomegaly and chronic draining lymph nodes.
NADPH oxidase
respiratory burst
Defects of the phagocytic system
Leukocyte Adhesion Deficiency:
Leukocytes lack the complement receptor _____ due to a defect in _____ or _____ peptides and consequently they cannot respond to _________.
Alternatively there may a defect in _____ molecules, ________ or _______ arising from defective ______ or _______ peptides, respectively.
These molecules are involved in ______ and hence defective neutrophils cannot respond effectively to chemotactic signals.
CR3; CD11; CD18; C3b opsonin.
integrin ; LFA-1 or mac-1
CD11a or CD11b
diapedesis
Defects of the phagocytic system
Chediak-Higashi syndrome:
This syndrome is marked by reduced (slower rate) ________ and _______ accompanied by inability of _______________________ and _____ deficiency.
Respiratory burst is _______.
Associated with ______ defect, _______ and _________ disorders
intracellular killing and chemotactic movement
phagosome and lysosome fusion
proteinase; normal
NK cell
platelet and neurological
Disorders of complement system:
Complement abnormalities also lead to increased ______________
The most serious among these is the __________ which may arise from _____________ or deficiency in _________ or ________
susceptibility to infections.
C3 deficiency
low C3 synthesis
factor I or factor H.
Disorders of complement system
SEVERE COMBINED IMMUNODEFICENCY
In about ____% of SCID patients the immunodeficiency is ______ whereas in the other half the deficiency is ________.
They are both characterized by ______________________________ and __________ of __________________
Patients with SCID are susceptible to a variety of bacterial, viral, mycotic and protozoan infections.
50; x-linked; autosomal
an absence of T cell and B cell immunity
absence (or very low numbers) of circulating T and B lymphocytes.
Disorders of complement system
The x-linked SCID is due to a defect in _______-chain of ________ also shared by ____,_____,_____, and ______, all involved in lymphocyte _______ and/or ______
gamma
IL-2
IL-4, -7, -11 and 15
proliferation and/or differentiation.
Disorders of complement system
The autosomal SCIDs arise primarily from defects in ______________ or ____________ (PNP) genes which results is accumulation of _______ or ______ , respectively, and cause toxicity to ___________ cells
adenosine deaminase (ADA)
purine nucleoside phosphorylase
dATP or dGTP
lymphoid stem
Diagnosis of SCID
Is based on _______ of T and B cells and _______ measurement.
Severe combined immunodeficiency can be treated with ________________
enumeration
immunoglobulin
bone marrow transplant
IMMUNODEFICIENCY CAUSED BY DRUGS (IATROGENIC)
- CORTICOSTEROIDS
Cause changes in _____________
Depletion of _____ cells
Monocytopenia
Decreased in circulating _______ and _______
Inhibition of _________ and ________ Inhibit cytokine synthesis
circulating leukocytes
CD4
eosinophils and basophils
T cell activation and B cell maturation
IMMUNODEFICIENCY CAUSED BY DRUGS (IATROGENIC)
METHOTREXATE
A ___________ Of _______
Blocks ________________ pathways essential for __________
Prolonged use for treatment reduces _____________
Structural analogue of folic acid
folic acid dependent synthetic
DNA synthesis
immunoglobulin synthesis
IMMUNODEFICIENCY CAUSED BY DRUGS (IATROGENIC)
CYCOLOSPORIN
Have severe effects on __________________ and functions
It binds to _______ which are believed to have a critical role in _______
Also inhibit ____ dependent signal transduction
T cell signaling
immunophilins
signal transduction
IL 2
IONIZING RADIATION
___-rays or _____ rays used in tumour treatment destroys lymphoid tissues also.
Ionizing radiation generally kills ______ cells in a _______ manner but also affects ______________
X
gamma
proliferating
highly selective
resting lymphocytes
INFECTIONS
– Results in more or less _____________________
HIV pathogenesis is a direct consequence of its __________ of immune responsiveness affecting especially _________-cells
general immunosuppression.
severe depression
CD4 T
Malnutritoion
Includes
– Starvation especially in (children or adults?)
–________ causing loss of vital nutrients for building the bodies immune system
children
Enteropathies
