immuno board review Flashcards
defense against organisms that enter the body
inflammation: immune cells (neutrophils), chemical mediators (cytokines)
complement activation
antigen presentation by activation of adaptive immune system
are all examples of what kind of immunity
innate
histamine is part of the exudative component of inflammation)
what does histamine do?
vasodilation of arterioles –> blood flow
increased permeability of blood vessels (by producing endothelial gaps in the venules* and arterioles –> a net loss of blood plasma ( exudate high in plasma proteins)
the exudate will provide opsonins (IgG and C3b) and dilutes the bacterial toxins)
what does the exudate released by histamine stimulate provide?
opsonins (IgG and C3b)
Q on boards
during the first few seconds of inflammation the arterioles will be constricted.
what is this due to?
a neurogenic reflex (pain)
not part of the inflammation
lecukocyte migration and extravasation what three steps?
margination
transmigration (diapedesis)
chemotaxis
Q on boards
the process of extravasation takes place predominantly through the endothelium of the?
venules
integrin is a cell adhesion molecule that promotes _____binding of the leukocytes to the endothelial cells ?
tight binding
a pt on corticosteroids. you would expect an increase in what cell in the blood
neutrophils
corticosteriod have a demargination effect on the neutrophils –> inc neutrophil count
what chemotaxic agents stimulate leukocyte movement (neutrophils)
C5a
IL-8
LT- B4
Kallikrein
ON THE BOARDS
neonate presenting with
omphalitis, pneumonia, or periotonitis
what is the pathology of this disease
Leukocyte adhesion def (LAD)
leukocytosis but no abscess formation bc granulocytes cannot migrate to the site of infection
two substypes
- mut in B chain of CD18 Integrin subunit (required for tight binding of neutrophils to endothelium)
- dec selectin required for rolling neutrophils along endothelial surface
what disease ahs a dec CD18 integrin subunit
Leukocyte adhesion def type 1
TB produces _____ that inhibits leukocyte migration –> chronic granuloma formation
cord factor
what type of lesion will form if a splinter is left in the skin?
granuloma or chronic inflammation
or collection of cells (macrophages w. fibrobast)
Q on boards
what cells are found in the skin and have branched projections
dendritic cells
involving neutrophilic respiratory burst pathway
can H2O2 kill microbes
.false
it cannot kill microbes
only hypochloride can.
major basic protein is secreted by eosinophils and
has a good cytotoxic effect on ______ vs a minor activity on ?
this is a o2 independent microbial kiling mechanism
strong effect on Parasites
minor activity on bacteria
opsonization.
is the process of binding the antigen by ?
IgG and or C3b to facillitate pahgocytosis.
how? they cover the negative charge on the antigen by binding to Fc and CR1 receptors on the antigen surface.
Q on boards
a pt with gram negative sepsis. the endotoxin (lipopolysaccharide) Lipid A will activate what on macrophages to induce sepsis?
toll like receptor 4 (TLR4) on the macrophages to induce
IL-1 –> fever
TNF a and NO –> vasodilation, hypotension
what is responsible for gram - sepsis
TNF -a
on the boards
chronic granulomatous disease (NADPH oxidase def) is caused by?
persistence of chronic inflammation.
this was the answer.
CGD
has what type of inheritance
what is the main problem in this disease
pts have increased susceptibility to what organisms?
defect of NADPH oxidase –> dec reactive oxygen species (superoxide) and dec resiratory burst in neutrophils
X linked
Catase + organism. (staph, pseudomonas Aspergillus, nocardia, )
pt with CGD
nitroblue tetrazolium dye will show?
dihydrorhodamine (flow cytometry) test will show?
treatment?
nitroblue tetrazolium dye reduction test fails to turn blue
abnormal dihydrorhodamine shows dec green fluorescence
tx: interferon gamma
triad of symptoms
- recurrent pyogenic infections (by staphylococci and streptococci)
- partial albinism (** oculocutaneous albinism)
3. peripheral neuropathy. –> progess to neurodegeneration, infiltrative lymphohistiocytosis.
horizontal nystagmus
peripheral blood smear shows giant granules in graunlocytes and platelets (impaired emptying phagocytic cells)
whats the cause of this disease
lysosomal trafficking regulator gene (LYST)
microtubule dysfunction in phagosome-lysosome fusion
what disease
autosomal recessive
recurrent acute/chronic infections with no pus formation (bc lack of leukocyte recruitment
no signs of inflammation except .fever
no umbilical cord stump rejection
leukocyte adhesion def.
C3b opsonatization stimulates opsonization
def –> recurrent pyogenic sinus and respiratory infections (from encapsulated organisms)
Which one is not opsonized?
A. strept pneumonia
B. N. Mengingitis
C. N. Gonorrhea
N gonorrheae
bc it is not encapsulated.
C3a
C5a
stimulate?
anaphylaxis
(C5b, C6-9) + C3 –> (membrane attack complex) –> .perforation of the pathogen cell membrane —> cytolysis
def leads to>
inc risk of disseminated Neisseria bacteremia
C1 esterase inhibitor def –?
classic finding:edema of skin (periorbitial) + mucosal surfaces
Hereditary angioedema
characterized by dec C4 levels.
avoid ACE inhibitors.
C55 and CD59 def –>
Paroxysmal nocturnal hemoglobinuria
what do CD55 and CD59 do
block C3 and C5 convertase
what falls under Acquired (specific) immunity
humoral immune response
- mediated by B lymphocytes –> antibodies (Ig M, …)
Cell-mediated immune rxn
-it is the main function of T .cells;
in addition to regulation of antibody production by B cells
Question on boards
pt with recurrent Bacterial infections
problem is B cells
where are they located in
LN ?
Spleen?
LN: the outer cortex in germinal center of the ocrtical follicles
spleen: lymphoid follicles of the white pulp
on the boards
pt with recurrent fungal infections. what cell is def
T cells
where are they located in the LN and Spleen
LN: paracortical area
Spleen periarteriolar lymphoid sheaths in the white pulp
immunoglobulin will perform their functions by
opsonization (by coating the microorganism to make them susceptible to phagocytosis
complement cascade activation. –> microbial cell wall lysis (IgG and IgM)
neutralization - preventing bacterial adherence to mucosa.
on the boards
6-8 month old infant
w/ recurrent bacterial infections
large tonsils and palpable lymph nodes
labs: high IgM , low levels of other types of Ig
**what the cause?
CD-40 ligand on helper T cells is absent
diagnosis hyper-IgM syndrome
what immunoglobulin is a monomer in circulation but when secreted it forms a dimer linked by J chains
IgA
what immunoglobulin is the
primary immune response and complement fixation
IgM
on the boards (immunoglobulin pearls
IgM In the serum of a neonate this indicates what? and what is the most likely cause?
indicates intrauterine infection
look for congenital rubella.
since IgM cant cross the placenta like (igG)
which immunodeficiency disease has
low IgM
elvated IgA and normal IgE (maybe elevated)
pt have inc susceptibility to pyogenic infections, eczema, and thrombocytopenia –> petechiae and bleeding
wiskott-Aldrich syndrome
wiskott Aldirhc syndrome
pts have an increase risk for what malignancies
what is the treatment
leukemia and lymphoma
tx: bone marrow transplantation
what is the TCR complex?
TCR + CD3
know that CD3 is seen in both CD4 and CD8 T cells.
and is involved in the transduction of signals into the T cell after bidning TCR with antigen.
Q on boards
in positive selection in the thymic .cortex
thymocytes (immature T cell) that do not bind to the MHC/antigen complex will die via what mechanism?
lack of growth signals
Q on boards
where do lymphocytes have both CD 4 and CD8 expression
immature T cells in the cortex of the thymus.
during negative selection in the thymus
thymocytes that strongly interact with self antigen will be removed by?
apoptosis
Q
if pt has mutation of the FAS protein this will block the process of apoptosis
this puts the pt at increased risk for?
autoimmune disorders
bc no apoptosis in negative selection in thymus –> persistent auto -reactive lymphocytes
Interleukins are mainly secreted by?
helper CD4+ T lymphocytes
garanteed question on boards
IL-1 is secreted by macrophages and acts on the ? –> fever ( like IL-6)
il-1 acts on the hypothalamus
know for boards
IL-4 –>
IL-5 –>
IL-4 —> IgE production
IL-5 —> inc eosinophils and inc IgA production
example how IL-6 can cause fever
il-6 –> able to cross BBB –> inc synthesis of PGE2 in the hypothalamus –> changing the body temps setpoint
