2022 exam 3 questions Flashcards
the secondary adaptive immune response to pathogens is faster than the first adaptive immune response due to the presence of what?
memory cells
the English physician Edward Jenner developed a method of prevention known as vaccination. he discovered that inoculation of individuals with ______________ prevent the disease known as smallpox.
cowpox
activated B cells within germinal centers can
differentiate into effector plasma cells or memory B cells
the Pfizer/BioNTech and Moderna vaccines against SARS-CoV-2, the causative agent of COVID-19 are __________ vaccines.
mRNA
which is the first class of immunoglobulin secreted by plasma cells during the primary response?
IgM
memory B cells are quickly activated upon a second encounter with a pathogen, producing immunoglobulins that have undergone what process?
somatic hypermutation and isotype switching
the secondary immune response is primed by ________________ cells.
memory
during a secondary immune response, naive B cells _______________________ if they recognize the same pathogen as a memory B cell.
are inhibited
the incorporation of ______________ into vaccines helps to elicit an inflammatory response.
adjuvants
the first memory T cells produced during clonal expansion are T memory stem cells, which can differentiate into what types of cell(s)?
central memory T cells or effector memory T cells
which of the following represents the correct sequence of events during a mucosal immune response?
pathogen infection –> pathogen delivery to lamina propria –> pathogen destruction in lamina propria –> healthy mucosal tissue
all of the following are activated in a mucosal immune response except
NFkB
antibodies are important for protection during
both systemic and mucosal immunity
which of the following is a cell of innate immune system and would respond to proteins during a helminth infection by secreting IL-5 to promote activation of granulocytes?
ILC2
which of the following occurs in mucosal immunity but not in systemic immunity?
pathogens are delivered to the lamina propria through M cells
which of the following is the correct definition of systemic immunity?
it is the innate and adaptive immune responses that protect most of our body
what role does the normal microbiota play in protecting mucosal surfaces?
it competes with pathogens for space and nutrients
intestinal macrophages, gut dendritic cells, and innate lymphoid cells function in the innate immune response to combat mucosal infection without inducing
the typical inflammatory response
the most common immunoglobulin produced by plasma cells in the lamina propria is
IgA
the main function of the MALT is to
centralize activation of an adaptive immune response at mucosal surfaces
when two variants of influenza virus enter the same host cell, new viruses containing aspects of both variants can be produced in a process is known as
antigenic shift
many species of bacteria have multiple ________________ that exhibit different surface molecules and thus are not recognized by the same immunoglobulins.
serotypes
an extracellular pathogen that can inhibit function of the actin cytoskeleton is
Yersinia pestis
the bacterial species Listeria monocytogenes escapes the phagosome after it is phagocytosed by creating holes in the phagosome membrane using
the toxin listeriolysin O
a superantigen produced by bacteria can result in
the immune response becoming dysfunctional
destruction of virus-infected host cells occurs primarily through the direct action of
cytotoxic T cells
a survival method used by an intracellular pathogen is to avoid ______________________ fusion inside the phagocyte.
phagolysosome
some bacteria perform degradation of IgA on mucosal surfaces using an IgA
protease
the RNA genome of influenza virus is replicated by a RNA polymerase that does not have proofreading abilities, thus errors can be introduced, changing the surface molecule structures in a process known as
antigenic drift
viruses can incorporate their viral genomes into a host cell and undergo a dormant state known as
latency
severe combined immunodeficiencies often are due to the lack of which cell subsets?
lymphocytes
what would be the expected phenotype of a mouse that does not express Bruton’s tyrosine kinase (BTK)?
lack of B-cells only
DiGeorge syndrome is caused by a missing or impaired
thymus
patients with hereditary angioneurotic edema (HANE) have low levels of plasma C2 and C4 complement proteins, resulting in potentially life-threatening conditions. which protein is most commonly mutated in such patients?
C1INH
human immunodeficiency virus (HIV) is a
retrovirus
classical NK cell deficiency can be caused by improper hematopoiesis due to haploinsufficiency of which transcription factor?
GATA2
individuals with Omenn syndrome lack which proteins from somatic recombination?
RAG1 or RAG2
_____________ immunodeficiency can be due to environmental factors, such as exposure to toxins .
secondary
B-cell immunodeficiencies are the most prevalent inherited immunodeficiencies because
inherited immunodeficiencies in innate or T cells result in significant morbidity compared to B-cell immunodeficiencies
in Chediak-Higashi syndrome, patients have defects in proteins that control lysosomal trafficking because
lysosomes aren’t able to fuse with phagosomes, resulting in inefficient destruction of bacteria
reactions that occur when immunoglobulins stimulate an unwanted response following immune complex formation are called type ____ hypersensitivity reactions.
III
which type of reaction occurs when a small amount of allergen is injected into the skin via an insect bite or sting or as part of testing to diagnose specific allergies?
Wheal and flare
mast cell degranulation can also activate smooth muscle fiber contraction, which
prompts coughing, sneezing, vomiting, or diarrhea to expel a pathogen from the mucosal tissue
delayed-type reactions caused by the activation of T cells by a foreign, but harmless, antigen are called type ___ hypersensitivity reactions.
IV
inflammatory mediators, such as TNF-alpha, increase
migration of other immune cells to the site of infection and also inhibit pathogen division and survival
reactions caused by the production of immunoglobulins that recognize host cell-surface molecules and target cells containing these molecules via the complement pathway or antibody-dependent cell-mediated cytoxicity are called type ___ hypersensitivity reactions.
II
molecules that can specifically trigger a type I hypersensitivity response are known as
allergens
ABO blood types are determined by the presence or absence of the three glycolipid antigens
H, A and B
the stimulation of an immune response by an innocuous substance is called
hypersensitivity
_______________ are capable of secreting inflammatory mediators such as histamine and prostaglandins and toxic molecules, including major basic protein, peroxidase, cationic protein, and a cellular neurotoxin.
eosinophils
DPT vaccine
older vaccine
diphtheria, pertussis, tetanus
toxoid vaccine: inactive antigen is injected, neutralization of toxins via immunoglobulin production
inactivation by formalin or heat treatment
given by injection (intramuscular, thigh)
IgG
Tdap vaccine
newer diphtheria, pertussis, tetanus vaccine
toxoid and inactivated
inactivation by formalin or heat treatment
booster (recommended every 10 years)
given by injection (intramuscular, thigh)
IgG
Pfizer COVID vaccine
rapid development and production
mRNA vaccine
inactivated vaccines: require booster, first dose does not elicit an immune response that provides a high level of protection
given by injection (arm)
IgG
Salk polio vaccine
inactivated vaccine: composed of killed or inactivated pathogens, formalin or heat treatment
given by injection
IgG
Sabin polio vaccine
live attenuated vaccine: utilize pathogens that has lost its ability to cause disease but does not kill the pathogen, survives in host without causing disease
closely mimics infection
administered orally (swallowed)
promotes IgA response over IgG
Listeria monocytogenes
bacteria live in the cytosol of host cells following phagocytosis
escape phagosome, avoiding destruction by the host cell
uses a pore-forming toxin (listeriolysin O) to punch holes in the phagosome membrane
allows bacteria to escape into the cytosol, where it is protected from phagocytes and neutralizing antibodies
lateral movement, adjacent cell spreading
mycobacterium tuberculosis
prevents fusion of the phagosome by targeting proteins involved in membrane trafficking and fusion
coats surface and prevents docking
uses protein phosphatases to dephosphorylate and inactivate the host proteins involved in these processes
block acidification of the interior of the phagosome by preventing assembly of the proton pumps made by the host cell
Neisseria spp. (gonorrhea)
use multiple gene copies of Opa outer membrane protein, each copy has its own expression switch
allows bacteria to vary expression of Opa on the surface and avoid the host immune response
express variants of their pilin gene, allowing different pili to be expressed on the bacterial surface
vary sugars at ends of the lipooligosaccharide molecules found in their outer membranes
block lymphocyte activation or lymphocyte effector mechanisms
degrade IgA at mucosal surfaces using an enzyme
varicella zoster
causes chickenpox and shingles
herpes virus
immune system must recognize a viral infection and destroy the infected host cell
can limit antigen presentation within the host cell, minimizing CD8 T-cell activation
viral latency: ability to remain dormant, needs to be reactivated
staphylococcus aureus
degrade IgA at mucosal surfaces using an enzyme
recurring bacterial infections
bind to both MHC class II molecules and T-cell receptors
stimulates a very strong nonspecific T-cell response
cause inflammation
superantigen
blocks IgA action and the complement pathway
prevents phagocytosis
blocks C5 (formation of the MAC)
hypersensitivity type 1
allergic response
immediate, seconds
granulocytes (mast cells, eosinophils, basophils)
IgE
leads to release of inflammatory mediators from the granulocytes
Fc epsilon receptors
causes symptoms of allergy such as rhinitis or anaphylaxis
mast cell: expel pathogen
basophils: pathogen expulsion, parasites
eosinophils: secretion of inflammatory mediators (histamine, prostaglandins) and toxic molecules
allergen specificity
hypersensitivity type II
complications with circulatory system
cell mediated, minutes
classical complement pathway or antibody-dependent cell-mediated cytotoxicity
IgG (can also be IgM)
recognizes cell-surface molecules and destroys
ex. blood transfusion reactions
reactions include: opsonization in phagocytosis, activation of complement on recognized cells, activation of antibody-dependent cell-mediated cytotoxicity
Fc gamma
C3b recognition
result in destruction of the cell through phagocytosis, lysis through action of the MAC, or destruction by NK cells
hypersensitivity type III
complexes, minutes to hours
phagocyte
IgG (or IgM)
recognize soluble antigens and form immune complexes
results in the unnecessary activation of complement and activation of phagocytic cells
ex. serum sickness and Arthus reaction
abnormal activation of inflammatory responses and cells that attempt to clear the immune complexes
disruption of normal phagocytosis
hypersensitivity type IV
delayed, > 2 days
no antibody
delayed type cytotoxic T-cell (TD cell)
caused by delayed activation of T cells by a foreign, harmless antigen
ex. contact dermatitis and granulomas
chronic infection
APCs
sensitization and effector phase
induced by intracellular bacteria, viruses, fungi
