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
