Immuno-this Flashcards
When stimulated by antibodies bound to a parasitic organism, Eosinophils destroy the parasite via ___ with enzymes from their cytoplasmic granules.
antibody-dependent cell-mediated cytotoxicity
What produces IL-5 for Eosinophils
Th2
Mast cells
IL-4 secreted by Th2 does what
IgE plasma cells
When a parasite invades the mucosa or enters the bloodstream, it is coated by IgG and IgA antibodies that bind the ______ located on the eosinophil cell surface.
This triggers eosinophil degranulation and release of ____ & ____ substances that damage and destroy antibody-bound parasites.
Fc receptors
cytotoxic proteins (major basic protein)
Reactive oxygen intermediates
*This mechanism is an example of antibody-dependent cell-mediated cytotoxicity (ADCC), which is also used by macrophages, neutrophils, and natural killer cells.
Type I hypersensitivity reactions: Eosinophils also synthesize prostaglandins, leukotrienes, and cytokines that contribute to the inflammation seen in ___ type 1 hypersensitivity and _____.
late-phase
chronic allergic reactions
The most specific cell surface marker of the monocyte-macrophage cell lineage is ___ which binds to bacterial lipopolysaccharide.
CD14
Monoclonal antibodies against the ___ antigen (Rituximab) have been successful in the treatment of lymphomas.
CD-20
Binding of ____ to CD20 results in B-cell cytotoxicity and phagocytosis, which reduces the B-cell population
This reduces inflammatory symptoms in a wide range of rheumatologic diseases.
rituximab
_____ activates macrophages, increases major histocompatibility complex expression, and promotes T helper 1 lymphocyte (Th1) differentiation.
Interferon-gamma (IFN-γ)
IFN-γ is produced primarily by _____ and _____ cells and is critical in immunity against viral and intracellular bacterial infections.
activated T lymphocytes
natural killer cells
Release assays test for latent tuberculosis infection by measuring the amount of ___ released by T lymphocytes when exposed to Mycobacterium tuberculosis unique antigens.
IFN-γ
One of the most important mediators of sepsis is _____, an acute-phase cytokine produced by activated macrophages
tumor necrosis factor-alpha (TNF-α)
*IL-1 and IL-6 too
a cytokine produced by activated T cells. It stimulates the growth and differentiation of stem cells in the bone marrow.
IL-3
a cytokine produced by Th2 T-helper cells. It stimulates the growth of B cells and increases the number of Th2 T-helper cells at the site of inflammation.
IL-4
a metabolite of arachidonic acid. Its main function is to stimulate neutrophil migration to the site of inflammation.
Leukotriene B4
released by MACROPHAGES and has anti-inflammatory roles in sepsis, including suppressing the release of IL-1 and TNF-α, and inhibiting lymphocyte proliferation.
Transforming growth factor-beta
Positive selection is the process by which only T cells expressing a TCR that is able to ____ are allowed to survive.
bind self MHC
Positive selection occurs in the _____ and involves interaction of T cells with ______ cells expressing self MHC
Thymic cortex
thymic cortical epithelial cells
Negative selection occurs after positive selection and is the process by which T cells possessing TCRs that bind _______ are eliminated by apoptosis.
with high affinity to self antigen or self MHC class I or II
Negative selection occurs in the _____ and involves interaction of the developing T cells with _______.
This process serves to eliminate T cells that may be overly autoreactive against self antigens and therefore may play a role in autoimmunity
thymic medulla
thymic medullary epithelial and dendritic cells.
Within the _____ of the lymph node, affinity maturation is accomplished by the process of _____ where the DNA coding for the immunoglobulin variable region is ______ at a very high rate.
This process results in new immunoglobulins with similar, better, or worse affinity for the antigen; only B cells expressing antibody with enhanced affinity for antigen will be selected for.
germinal center
somatic hypermutation
mutated randomly
___ is a T cell–specific surface protein that interacts with B7 on antigen-presenting cells, providing a costimulatory signal necessary for T-cell activation.
CD28
binds to B7 and has an inhibitory function on activated T cells.
CTLA-4
Many types of cancers evade immunodetection by increasing expression of ___ on their surface.
PD-L1
Isotype switching occurs in the germinal centers of lymph nodes and requires interaction of the ___ receptor on B-cells with the ____ expressed by activated T-cells.
CD40 CD40 ligand (CD154)
The earliest morphologic change that occurs after a superficial thermal burn is erythema due to the release of
preformed mediators (eg, histamine) from mast cells.
___ stimulates the differentiation of naive Th0 cells into Th1 cells. Patients with a deficiency are susceptible to severe mycobacterial infections due to the inability to mount a strong cell-mediated granulomatous immune response; therefore, they require treatment with ___
IL-12
IFN-γ
Formation of Th2 cells is induced by ___.
It improves the immune response against extracellular bacteria or ___
IL-4
viruses
TH2 Immunity type: Function: Cytokines secreted (4): Result:
Humoral (antibody-mediated)
Activate B cells, promote class-switching
IL-4, 5, 10, & 13
Secretion of antibodies
TH1 Immunity type: Function: Cytokines secreted (3): Result:
Cell-mediated
Activate macrophages & CD8+ T cells
IL-2, IFN-γ, lymphotoxin β
Cytotoxicity; delayed hypersensitivity
If the antigen is presented by a macrophage, the macrophage will produce ___, which stimulates TH0 differentiation into ___ cells which produce interferon-gamma (IFN-γ).
IL-12
Th1
IFN-γ is responsible for activation of the macrophage and ____ response against intracellular organisms, such as _____.
CD8+ cytotoxic
mycobacteria
a potent chemotactic agent, drawing more neutrophils and monocytes to the site of inflammation.
C5a
IL-1
Secreted by and functions:
Macrophages
↑ Neutrophil & macrophage migration
↑ Acute-phase reactants, fever & shock
IL-2
Secreted by and functions:
T cells
↑ T-cell activation & proliferation
↑ NK cell & macrophage activity
↑ B-cell growth
IL-3
Secreted by and functions:
T cells
↑ Hematopoiesis
IL-4
Secreted by and functions:
TH2 cells
↑ TH2-cell differentiation
↑ B-cell growth
↑ Isotype switching to IgE
IL-5
Secreted by and functions:
TH2 cells
↑ Differentiation of eosinophils
↑ Isotype switching to IgA
IL-6
Secreted by and functions:
Macrophages
↑ T- & B-cell growth
↑ Osteoclast activity
↑ Acute-phase reactants & fever
IL-8
Secreted by and functions:
Macrophages & T cells
↑ Neutrophil activation & chemotaxis
IL-10
Secreted by and functions:
TH2 cells
↓ TH1-cell differentiation
↓ Cell-mediated immunity & APC activity
↑ B-cell function
IL-12
Secreted by and functions:
Macrophages
↑ TH1-cell differentiation
↑ NK-cell & CD8+ T-cell activity
IFN- gamma
Secreted by and functions:
TH1 cells & NK cells
↑ Intracellular killing by macrophages
↑ MHC class I & II expression
↑ TH1-cell differentiation
TGF- Beta
Secreted by and functions:
Most cell types
↓ Immune cell function
↑ Matrix synthesis & angiogenesis
GM- CSF
Secreted by and functions:
T cells Macrophages
↑ Growth & differentiation of myeloid progenitors
TNF- Alpha
Secreted by and functions:
Macrophages
↑ Inflammation & cell-mediated immunity
↑ Acute-phase reactants, fever & shock
Type IV (delayed) hypersensitivity reactions (Candida extract skin test, granulomatous inflammation, contact dermatitis) are characterized by erythema and induration that develops 24-48 hours after repeat exposure to an antigen. Inflammation in these reactions is mediated through cytokines, \_\_\_\_, and macrophage recruitment.
T lymphocytes
CD8+ cytotoxicity
Type I (immediate)
Mediated by and examples:
IgE-mediated
Anaphylaxis
Urticaria
Type II (cytotoxic)
Mediated by and examples:
IgG & IgM autoantibody-mediated
Autoimmune hemolytic anemia
Goodpasture syndrome
Type III (immune complex)
Mediated by and examples:
Antibody-antigen complex deposition
Serum sickness
Poststreptococcal glomerulonephritis
Lupus nephritis
Type IV (delayed type)
Mediated by and examples:
T cell- & macrophage-mediated
Contact dermatitis
Tuberculin skin test
AB blood
Ag:
Ab:
A and B antigen
No Antibodies
O blood
Ag:
Ab:
No Antigens
Anti-A and Anti-B
(IgM and IgG)
A blood
Ag:
Ab:
A antigen B antibody (IgM)
mothers with blood type __ also produce IgG antibodies which can cause Hemolytic disease of the fetus and newborn (HDFN)
O
Describe Initial, Early and Late phase reactions for Type 1 HSR
Initial:
IL-5 =Eosinophils
IL-4, IL-12 = IgE and Mast cell priming
Early:
IgE cross link = Histamine and Leukotriene causing vasodilation and wheel and flare (immediate)
Late:
Eosinophils release Major Basic Protein, Tissue Damage, INDURATION
The late phase of dermatologic type I hypersensitivity reactions manifests as an indurated skin lesion hours after exposure to the allergen due to local tissue damage caused by _____ released from eosinophils.
major basic protein
Type 1 HSR immediate type mediated by:
Type 4 HSR delayed type mediated by:
TH2 (CD4+)
macrophages, CD4+ helper T cells, and CD8+ cytotoxic T cells
recurrent episodes of abdominal pain and an episode of facial swelling likely has angioedema due to ___ deficiency.
What drug is contraindicated in this illness?
C1 inhibitor (C1INH)
ACE-I
C1INH prevents _____ thereby limiting activation of the complement cascade. It also blocks kallikrein-induced conversion of kininogen to ____, a potent vasodilator that also causes increased vascular permeability.
Low levels of ___ (2) are noted on labs
C1-mediated cleavage of C2 and C4,
bradykinin
C4, C1
Opioids (eg, morphine) can generate a pseudoallergic response by ______, releasinghistamine and other vasoactive mediators.
directly stimulating mast cell degranulation
_____ cause a nonimmunologic reaction can cause itching, urticarial rash, wheezing, hypotension, and tachycardia that closely mimictrue IgE-mediated type 1 hypersensitivity (eg, anaphylaxis)
Opioids
Vancomycin (REDMAN)
Iodine contrast
Angioedema with Itchiness and wheels:
Angioedema withOUT Itchiness and wheels:
Mast cell activation (Type I HSR, Opioids, etc.)
Excess Bradykinin (ACE-I and C1 inhibitor deficiency)
____ is the result of widespread mast cell and basophil degranulation and the release of preformed inflammatory mediators, including histamine and tryptase.
Anaphylaxis
____ is relatively specific to mast cells and can be used as a marker for mast cell activation.
Tryptase
First-generation antihistamines are considered potentially inappropriate medications for ___ patients, especially those with pre-existing cognitive or functional impairment.
elderly
second-generation antihistamines are less ___, do not readily cross the blood-brain barrier, and are usually nonsedating.
lipophilic
____ can cause significant side effects due to blockade of cholinergic, alpha-adrenergic, and serotonergic pathways.
First-generation antihistamines
Asplenic patients are prone to infections caused by encapsulated organisms such as
Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.
Adenosine deaminase (ADA) inhibition/absence is highly
lymphocytotoxic
*can cause SCID
DiGeorge syndrome causes an extreme deficiency in the number of mature ____, leading to poor development of the lymph node ______.
In contrast, agammaglobulinemia causes an absence of ____, preventing _______ from forming in the lymph node cortex.
T lymphocytes; Paracortex
B cells; primary lymphoid follicles and germinal centers
Patients with XLA have _____ in the peripheral blood and lymphoid tissues and ____
As a result, they are at increased risk of infection with _______ bacteria and increased susceptibility to certain viral and parasitic infections
low or absent B cells
pan-hypogammaglobulinemia
pyogenic (encapsulated)
Deficiencies of _____ can lead to recurrent infections with Neisseria meningitidis or gonorrhoeae.
C5-C9, the components of the complement membrane attack complex,
*Peticheal rash on trunk, palms, soles, extremities
is a rare immunodeficiency resulting from a defect in ___, an integrin component that allows for leukocyte adherence and transmigration through endothelial walls. These patients present with delayed separation of the umbilical cord, poor wound healing, and recurrent cutaneous infections without pus formation.
Leukocyte adhesion deficiency
CD18
The failure of this patient’s neutrophils to turn blue on nitroblue tetrazolium testing is characteristic of
chronic granulomatous disease, a condition most often caused by an X-linked mutation affecting NADPH oxidase.
In SCID, toxic levels of adenosine accumulate within lymphocytes in this condition, leading to lymphocyte cell death and resultant _______. Patients with this condition can be treated with hematopoietic cell transplantation or gene therapy.
cellular and humoral immunodeficiency
eczema, recurrent infections, and thrombocytopenia.
Wiskott-Aldrich syndrome (WAS)
In patients with WAS, ____ are both abnormally shaped and deficient, causing
petechiae,
purpura,
hematemesis,
epistaxis
that can be present at birth.
platelets
In WAS, A deficiency in B cells results in recurrent ___ infections due to an inability to mount a humoral immune response against organisms with a polysaccharide capsule.
Patients also have T-cell deficiency, leading to infections with _____.
Severe recurrent infections develop after _____
Treatment is with HLA-matched ____
pyogenic
(Neisseria meningitidis, Hib, Strept. Pneumoniae)
opportunistic pathogens
(Pneumocystis jiroveci)
Maternal IgGl/IgA are degraded (6 months)
bone marrow transplantation.
Patients with Chédiak-Higashi syndrome have coagulation defects and recurrent pyogenic infections due to the dysfunction of _______.
However, they also typically have oculocutaneous albinism, peripheral neuropathy, and giant cytoplasmic granules on peripheral blood smear.
phagocyte phagosome-lysosome fusion
*shitty highway syndrome
With maternal blood types A or B, hemolytic disease of the fetus and newborn very rarely occurs because maternal antibodies (anti-A or anti-B) are of the __ type and cannot cross the placenta.
IgM
Unlike Rh disease, HDFN can occur with the __ pregnancy because anti-A and anti-B antibodies are formed early in life
first
