HMX Immunology Final Exam Questions
with 100% Correct Answers | Latest
Version 2024 | Verified
One of the most important advances in surgery arrived near the end of the nineteenth century. The
British surgeon Joseph Lister hypothesized that using techniques to sterilize surgical tools and clean the
skin at the site of the incision would reduce surgical site infections. Years later, Dr. Lister wrote this:
"Nothing was formerly more striking in surgical experience than the difference in the behavior of injuries
according to whether the skin was implicated or not. Thus, if the bones of the leg were broken and the
skin remained intact, the surgeon applied the necessary apparatus without any other anxiety than that
of maintaining a good position of the fragments, although the internal injury to bones and soft parts
might be very severe. If, on the other hand, a wound of the skin was present, communicating with the
broken bones, although the damage might be in other respects comparatively slight, the compound
fractu - ✔✔Epithelial barriers
Which of the cells below are tissue resident sentinel cells - ✔✔mast cell, macrophage, dendritic cell
Which of the cells below are circulating blood cells that will enter tissue in response to inflammation?
(select two answers) - ✔✔Neutrophils
Monoctyes
Mast cell - ✔✔Cells that release chemicals (such as histamine) that promote inflammation.
Neutrophil - ✔✔Most abundant leukocyte
Phagocyte that rapidly dies after ingesting microbe
macrophage - ✔✔Phagocyte that cleans up apoptotic cells
When a monocyte moves into the tissues, it changes rapidly and becomes a ____________ . -
✔✔macrophage
,Leukocyte adhesion deficiency (LAD) is a genetic defect that leads to recurrent infections in the tissue
and severe problems with wound healing. LAD patients also develop severe gingivitis (infections and
inflammation of the gums). In LAD, leukocyte migration into tissues is severely impaired. All of these
problems can be traced back to a genetic defect. Of the genetic defects listed below, which is the most
likely cause of LAD? - ✔✔A mutation that introduces a stop codon into a gene that encodes part of the
LFA-1 molecule (leading to a truncated protein).
Toll-like receptors for bacterial PAMPs are found on/in the - ✔✔cell membrane
There are a few different proteins that act as inhibitors of NF-kB. There is a very rare genetic disease in
which one of these proteins, IkBα, is mutated. The mutation substantially alters the stability of the IkBα
protein. In patients with this disease, IkBα protein expression does not change in response to stimuli that
cause IkBα degradation in healthy individuals. Consider the biological role of NF-kB inhibitors. What are
the most likely symptoms of this genetic defect? - ✔✔Immunodeficiency with a susceptibility to bacterial
infections.
The complement pathway initiated by host proteins that bind to microbial sugars is called the
____________ pathway. - ✔✔lectin pathway
ssRNA (single-stranded RNA) and dsDNA (double-stranded DNA) are present in mammalian cells. Why
don't our plasmacytoid dendritic cells activate an innate immune response against these self nucleic
acids that are necessary for normal cellular function? - ✔✔The TLRs that recognize ssRNA and dsDNA are
sequestered in endosomes.
How can the antiviral state be propagated in the absence of immune cells? - ✔✔Type I IFNs are
produced by infected epithelial cells; this induces anti-viral biochemical changes in the same cell and
adjacent cells.
A child presents with recurrent bacterial infections. Of the genetic defects described below, what is the
most likely cause of her disease? - ✔✔A mutation in the C3 gene that renders the C3 protein
nonfunctional.
____________ is the process by which something that is not otherwise recognized as a pathogen is
coated with proteins that make it more recognizable to the immune system. - ✔✔Opsonization
, The majority of the symptoms of tetanus infection are caused by the tetanus toxins, chiefly
tetanospasmin. Tetanospasmin is one of the deadliest toxins known; even very small doses (nanograms)
can be lethal. It targets the nerves, causing severe muscle spasms. The tetanus vaccine consists of
inactivated tetanus toxin; the vaccine is highly effective for preventing tetanus. Inoculation with the
tetanus vaccine leads to the production of protective antibodies. How do these antibodies prevent
tetanus? - ✔✔Neutralization
Streptococcus pneumoniae is an extracellular bacterium that is a leading cause of bacterial pneumonia
and meningitis, particularly in children and the elderly. Fortunately, most cases of S. pneumoniae can be
prevented with a vaccine that contains components of the bacterial capsule. The vaccine is known to
lead to the production of antibodies that recognize intact bacteria.
What are the most likely mechanisms activated by these antibodies that result in protection against S.
pneumoniaeinfection? (select two answers) - ✔✔The key is that S. pneumoniae is an extracellular
bacterium. The vaccine elicits a humoral immune response, which generates antibodies that bind to the
surface of the bacterium. The antibodies bound to bacteria can activate complement (direct killing of the
bacteria) and opsonization followed by phagocytosis. ADCC is usually directed against viral proteins
displayed on the surface of cells. It is conceivable that antibodies could neutralize the function of
bacterial components, but direct killing by complement and phagocytosis are the best-characterized
mechanisms for eliminating extracellular bacteria.
There is strong interest in developing a vaccine that would prevent human immunodeficiency virus (HIV)
infection or substantially reduce viral loads in a person with HIV. HIV infects immune cells by binding to a
receptor called CD4 on the surface of those cells. Laboratory studies have identified rare antibodies that
bind to intact HIV viral particles and effectively control the virus in certain individuals. Structural studies
revealed that some of these antibodies bind to a protein on the surface of HIV at the same location
where this protein binds to CD4.
What is the most likely mechanism of action of these antibodies? - ✔✔Neutralization
How many distinct peptide chains are found in a single molecule of IgG? - ✔✔Each IgG antibody is
comprised of two heavy chain and two light chain peptide chains joined by disulfide bridges.
How many distinct binding sites are found in a single molecule of IgG? - ✔✔Two
Which of the following antibodies is protected from proteases that are commonly found in the gut? -
✔✔IgA
with 100% Correct Answers | Latest
Version 2024 | Verified
One of the most important advances in surgery arrived near the end of the nineteenth century. The
British surgeon Joseph Lister hypothesized that using techniques to sterilize surgical tools and clean the
skin at the site of the incision would reduce surgical site infections. Years later, Dr. Lister wrote this:
"Nothing was formerly more striking in surgical experience than the difference in the behavior of injuries
according to whether the skin was implicated or not. Thus, if the bones of the leg were broken and the
skin remained intact, the surgeon applied the necessary apparatus without any other anxiety than that
of maintaining a good position of the fragments, although the internal injury to bones and soft parts
might be very severe. If, on the other hand, a wound of the skin was present, communicating with the
broken bones, although the damage might be in other respects comparatively slight, the compound
fractu - ✔✔Epithelial barriers
Which of the cells below are tissue resident sentinel cells - ✔✔mast cell, macrophage, dendritic cell
Which of the cells below are circulating blood cells that will enter tissue in response to inflammation?
(select two answers) - ✔✔Neutrophils
Monoctyes
Mast cell - ✔✔Cells that release chemicals (such as histamine) that promote inflammation.
Neutrophil - ✔✔Most abundant leukocyte
Phagocyte that rapidly dies after ingesting microbe
macrophage - ✔✔Phagocyte that cleans up apoptotic cells
When a monocyte moves into the tissues, it changes rapidly and becomes a ____________ . -
✔✔macrophage
,Leukocyte adhesion deficiency (LAD) is a genetic defect that leads to recurrent infections in the tissue
and severe problems with wound healing. LAD patients also develop severe gingivitis (infections and
inflammation of the gums). In LAD, leukocyte migration into tissues is severely impaired. All of these
problems can be traced back to a genetic defect. Of the genetic defects listed below, which is the most
likely cause of LAD? - ✔✔A mutation that introduces a stop codon into a gene that encodes part of the
LFA-1 molecule (leading to a truncated protein).
Toll-like receptors for bacterial PAMPs are found on/in the - ✔✔cell membrane
There are a few different proteins that act as inhibitors of NF-kB. There is a very rare genetic disease in
which one of these proteins, IkBα, is mutated. The mutation substantially alters the stability of the IkBα
protein. In patients with this disease, IkBα protein expression does not change in response to stimuli that
cause IkBα degradation in healthy individuals. Consider the biological role of NF-kB inhibitors. What are
the most likely symptoms of this genetic defect? - ✔✔Immunodeficiency with a susceptibility to bacterial
infections.
The complement pathway initiated by host proteins that bind to microbial sugars is called the
____________ pathway. - ✔✔lectin pathway
ssRNA (single-stranded RNA) and dsDNA (double-stranded DNA) are present in mammalian cells. Why
don't our plasmacytoid dendritic cells activate an innate immune response against these self nucleic
acids that are necessary for normal cellular function? - ✔✔The TLRs that recognize ssRNA and dsDNA are
sequestered in endosomes.
How can the antiviral state be propagated in the absence of immune cells? - ✔✔Type I IFNs are
produced by infected epithelial cells; this induces anti-viral biochemical changes in the same cell and
adjacent cells.
A child presents with recurrent bacterial infections. Of the genetic defects described below, what is the
most likely cause of her disease? - ✔✔A mutation in the C3 gene that renders the C3 protein
nonfunctional.
____________ is the process by which something that is not otherwise recognized as a pathogen is
coated with proteins that make it more recognizable to the immune system. - ✔✔Opsonization
, The majority of the symptoms of tetanus infection are caused by the tetanus toxins, chiefly
tetanospasmin. Tetanospasmin is one of the deadliest toxins known; even very small doses (nanograms)
can be lethal. It targets the nerves, causing severe muscle spasms. The tetanus vaccine consists of
inactivated tetanus toxin; the vaccine is highly effective for preventing tetanus. Inoculation with the
tetanus vaccine leads to the production of protective antibodies. How do these antibodies prevent
tetanus? - ✔✔Neutralization
Streptococcus pneumoniae is an extracellular bacterium that is a leading cause of bacterial pneumonia
and meningitis, particularly in children and the elderly. Fortunately, most cases of S. pneumoniae can be
prevented with a vaccine that contains components of the bacterial capsule. The vaccine is known to
lead to the production of antibodies that recognize intact bacteria.
What are the most likely mechanisms activated by these antibodies that result in protection against S.
pneumoniaeinfection? (select two answers) - ✔✔The key is that S. pneumoniae is an extracellular
bacterium. The vaccine elicits a humoral immune response, which generates antibodies that bind to the
surface of the bacterium. The antibodies bound to bacteria can activate complement (direct killing of the
bacteria) and opsonization followed by phagocytosis. ADCC is usually directed against viral proteins
displayed on the surface of cells. It is conceivable that antibodies could neutralize the function of
bacterial components, but direct killing by complement and phagocytosis are the best-characterized
mechanisms for eliminating extracellular bacteria.
There is strong interest in developing a vaccine that would prevent human immunodeficiency virus (HIV)
infection or substantially reduce viral loads in a person with HIV. HIV infects immune cells by binding to a
receptor called CD4 on the surface of those cells. Laboratory studies have identified rare antibodies that
bind to intact HIV viral particles and effectively control the virus in certain individuals. Structural studies
revealed that some of these antibodies bind to a protein on the surface of HIV at the same location
where this protein binds to CD4.
What is the most likely mechanism of action of these antibodies? - ✔✔Neutralization
How many distinct peptide chains are found in a single molecule of IgG? - ✔✔Each IgG antibody is
comprised of two heavy chain and two light chain peptide chains joined by disulfide bridges.
How many distinct binding sites are found in a single molecule of IgG? - ✔✔Two
Which of the following antibodies is protected from proteases that are commonly found in the gut? -
✔✔IgA
