23 exam 2 Flashcards
which cells play an important role in pathogen clearance by activating other cells during an adaptive immune response?
T cells
T cells that recognize antigen presented on MHC class 1 typically are
activated to fight off intracellular pathogens
a T cell that has CD4 as a coreceptor is a(n) ____ cell
helper T
all the alleles of every MHC class 1 and class 2 gene is an individual make up that person’s ____, which provides the overall MHC diversity
haplotype
which of these is the major stimulatory signal molecule for naïve T-cells?
CD28
what enzyme adds nucleotides to gene segments during recombination?
TdT
which of these proteins includes beta2 microglobulin in its structure?
MHC class 1
nearly all nucleated cells express which of these?
MHC class 1
the invariant chain is important for which of these?
exogenous antigen presentation on MHC class 2
which of these are effector B cells that secrete soluble immunoglobulins?
plasma cells
which statement about B cells is true?
they are localized in the T-cell zone of a secondary lymphoid tissue and can activate naïve T-cells if they recognize the same antigen
interaction between the T-cell receptor and an MHC-peptide complex, coupled with the proper costimulatory signaling, promotes the formation of a(n)
immunological synapse between the T cell and an APC
the most important type of cells in T-cell activation are ____
dendritic cells
following activation, naïve T-cells differentiate into what?
effector cells
what happens when dendritic cells secrete the chemokine CCL18?
T-cells migrate to lymph nodes
which of these is not a common antigen presenting cell for T-cell activation?
hepatocyte
which of these is an important chemokine receptor found on T-cells?
CCR7
ZAP-70 is involved in activating what type of cells?
T-cells
which of these migrate from the bone marrow to the spleen?
transitional B cells
during the development of B cells, successful recombination of what leads to creation of a B-cell receptor?
the successful recombination of a heavy chain locus
rearrangement of the heavy chain loci is tested through the use of a surrogate light chain during the ____
early pre-B cell stage
hematopoietic stem cells (HSCs) must be able to interact with and receive signals from specialized cells in the bone marrow known as what?
stromal cells
where do B-cell first form during embryogenesis?
yolk sac
which of these has low amount of IgM and high amounts of IgD on their cell surface?
B-2 B cells
which population of B-cells seem to be self-renewing?
B-1 B cells
where do most immature B-cells head to when first formed?
spleen
What is a T1 cell?
a transitional stage of a B-cell
immunoglobulin structure consists of which of these?
two heavy and two light polypeptide chains
immunoglobulin molecules____
are expressed as membrane-bound or secreted soluble molecules
B-cell activation requires interaction of specific cell-surface proteins associated with immunoglobulins known as what?
Ig-alpha and Ig-beta chains
the ___ region of an antibody plays an important role in binding to receptors of certain immune system cells, including macrophages, dendritic cells, and granulocytes such as mast cells
Fc
which isotype of antibody is most important for mucosal immunity
IgA
what term refers to where an antibody bind on an antigen?
epitope
which group of macromolecules are the most antigenic?
polypeptides
alternative mRNA splicing is involved in _____ in the heavy chain
VDJ-C joining (D-J and V-DJ were ruled out and hypermutation doesn’t make sense)
the action of AID causes cytosines to be converted to what?
uracil
cross-presentation of antigens can occur through a process called what?
cytosolic diversion
what is the function of TAP in antigen presentation?
transport of peptides into the ER
MHC class I molecules are found on what cells?
all somatic cells
which subunit of the IL-2 receptor converts it from low affinity to high affinity?
alpha
which of these are most important for stimulating macrophage activity?
Th1
which signaling pathway in B- and T-cells most involves the action of calcium?
IP3 pathway
what enzyme is responsible for forming IP3 and DAG during cell signaling?
phospholipase c (PLC)
at what location does most somatic hypermutation occur?
germinal centers
which of these antibodies is not formed as a result of isotype switching?
IgD
which of these antibodies in not released into the serum in appreciable amounts?
IgD
which effector cytokine is most important for developing helper T-cells?
IL-4
activation of Fas via its ligand leads to what process?
apoptosis
what is the “second key” to activate and arm a naïve B-cell?
CD40 ligand
what kind of b-cells are mostly found in the peritoneum?
B-1 B-cells
which immune organ is most responsible for dealing with blood-borne pathogens?
spleen
which of the following is not a direct function of antibodies?
cell lysis
how many protein chains make up an antibody?
four
what hold the chains of an antibody molecule together?
disulfide bonds
which of these pairs is representative of endogenous antigen presentation?
MHC class I interacting with CD8
____ T-cells activate other immune system cells
effector
CTLA4 ___ regulates T-cell activity
down
the most common type of T-cell receptor in the adult human body is ____
alpha/beta
MHC class II presents ___ peptides than does MHC class I
longer
class I MHC molecules are loaded with antigen in the _____
ER
CCL19 is produced in the ____ to attract naïve T-cells
lymph nodes
_____ is the main signal that allows T-cells to reenter circulation
sphingosine-1-phosphate
signaling between a T-cell and a dendritic cell occurs in the immunological _____
synapse
MAP kinases are mostly activated by ____-dependent mechanisms
DAG
Th17 cells mostly stimulate _____
neutrophils
_____ are the most common kind of B cells in our body
B-2 B
stem cell factor is found on the surface of ____ cells in the bone marrow
stromal
the cytokine ___ drives lymphocytes toward becoming B cells
IL-7
in B-cell receptor formation, the ___ chain is made first
heavy
a total of ___ chromosomes contain antibody protein genes
three
the first structure of antibodies was worked out by ____
Ehrlich
antibodies gain additional specificity through a process called ______
affinity maturation
coating of a pathogen with antibodies is called ____
opsonization
____ is the isotype of antibody formed in the primary immune response
IgM
IgE binds to ____ and is associated with allergies
mast cells
