HMX IMMUNOLOGY FINAL 2026
TEST PAPER VERIFIED QUESTIONS
AND ANSWERS
◉ Which of the cells below are tissue resident sentinel cells Answer:
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) Answer:
Neutrophils
Monoctyes
◉ Mast cell Answer: Cells that release chemicals (such as histamine)
that promote inflammation.
◉ Neutrophil Answer: Most abundant leukocyte
Phagocyte that rapidly dies after ingesting microbe
◉ macrophage Answer: Phagocyte that cleans up apoptotic cells
◉ When a monocyte moves into the tissues, it changes rapidly and
becomes a ____________ . Answer: 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? Answer: 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 Answer:
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? Answer:
Immunodeficiency with a susceptibility to bacterial infections.
◉ The complement pathway initiated by host proteins that bind to
microbial sugars is called the ____________ pathway. Answer: 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? Answer: The TLRs that
recognize ssRNA and dsDNA are sequestered in endosomes.
◉ How can the antiviral state be propagated in the absence of immune
cells? Answer: 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?
Answer: 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. Answer: 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? Answer: 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)
Answer: 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?
Answer: Neutralization
◉ How many distinct peptide chains are found in a single molecule of
IgG? Answer: Each IgG antibody is comprised of two heavy chain and
two light chain peptide chains joined by disulfide bridges.
TEST PAPER VERIFIED QUESTIONS
AND ANSWERS
◉ Which of the cells below are tissue resident sentinel cells Answer:
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) Answer:
Neutrophils
Monoctyes
◉ Mast cell Answer: Cells that release chemicals (such as histamine)
that promote inflammation.
◉ Neutrophil Answer: Most abundant leukocyte
Phagocyte that rapidly dies after ingesting microbe
◉ macrophage Answer: Phagocyte that cleans up apoptotic cells
◉ When a monocyte moves into the tissues, it changes rapidly and
becomes a ____________ . Answer: 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? Answer: 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 Answer:
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? Answer:
Immunodeficiency with a susceptibility to bacterial infections.
◉ The complement pathway initiated by host proteins that bind to
microbial sugars is called the ____________ pathway. Answer: 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? Answer: The TLRs that
recognize ssRNA and dsDNA are sequestered in endosomes.
◉ How can the antiviral state be propagated in the absence of immune
cells? Answer: 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?
Answer: 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. Answer: 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? Answer: 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)
Answer: 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?
Answer: Neutralization
◉ How many distinct peptide chains are found in a single molecule of
IgG? Answer: Each IgG antibody is comprised of two heavy chain and
two light chain peptide chains joined by disulfide bridges.
