MCB 100: Exam #3 Review Questions and Correct
Answers
Antigen processing and presentation
is a way for a cell to give information about its activities.
Why would a body cell that is not a phagocyte need to present antigens?
Non-phagocytic body cells can become infected with a virus.
How do phagocytes communicate to other cells what they have captured?
They present antigens from engulfed foreign cells.
Label the components of the activation of a Helper T cell by a dendritic cell.
A few months ago Dr. Trapper's, 4-year-old son, Caleb, woke him up at 3:00 am,
complaining that he didn't feel good. Caleb said his head and ears hurt, and he and his
bed were "all wiggly." He had a runny nose the past few days, but the Trappers had
thought nothing of it. Dr. Trapper took Caleb into the bathroom and noticed he looked
flushed and his glands appeared swollen compared to normal (see picture).
Dr. Trapper gave Caleb a hug and he felt very hot. A quick check with the thermometer
demonstrated he was running a fever of 101.8°F. Caleb didn't show any other obvious
symptoms. While somewhat concerned, Dr. Trapper was not overly worried as Caleb
had been a very healthy child and received all his vaccinations.
Which of the following is the most likely possible diagnosis for Caleb?
,Ear infection
While we usually think of fever as a bad thing, a fever is actually signifying that an
immune response is progressing! Overall, which of the following cytokines would be
most involved in increasing Caleb's fever response?
Interleukin-1
The examination led to a diagnosis of otitis media (OM), or an ear infection. The picture
on the left demonstrates a swollen, red eardrum with a fluid buildup behind the
membrane. The immune processes most involved in the inflammation seen behind
Caleb's eardrum would be attributed to:
Vasodilation of capillaries and accumulation of immune cells, fluid or pus
Most patients would happily accept a prescription for antibiotics from the pediatrician
and go home. But as a microbiologist, Dr. Trapper wanted to identify the infectious
etiology and see what was going on inside his son. Even though it's not standard
procedure for otitis media, he asked for some of the fluid contained behind the eardrum
to be collected with a syringe (tympanocentesis) so he could analyze it for culture and
sensitivity in his lab. He stained the fluid and examined it under the microscopic field.
Interestingly, although he did not find any noticeable bacterial organisms, he did find
high numbers of this characteristic responding cell type (picture), which could likely be
identified as a:
Neutrophil
Dr. Trapper wasn't going to give up easily and continued to scan the overall field for
bacterial clues, but all he found were more immune cells. Soon, he noticed something
,else interesting...several cells were interacting! The likely identities of these cells based
on morphologies could be best described as:
Adaptive immune cell and an antigen presenting cell
Caleb recovered without incident, but because there are millions of cases of ear
infections every year in the U.S., Dr. Trapper wanted to make sure that this would not
be the first of many recurrent ear infections for his son. He wanted to ensure that Caleb
did not have an underlying immunodeficiency that would cause his future responses to
fight antigens suboptimally. He asked the physician to do a serology analysis of Caleb,
which consisted of probing for each antibody isotype found and to report how much is
present. The analysis yielded the following results. What might you conclude from this?
Caleb has a normal response
If this particular antigen attempts to re-infect Caleb, it's in for a bigger fight. By getting
activation of adaptive immune cells such as B-cells and T-cells, the body generates an
extra layer of protection. What is a critical advantage for Caleb the next time he
encounters this antigen?
Anamnestic (memory) responses and future vaccinations to augment the response
Neutrophils are "first responders" during an inflammatory response. What is their
specific role?
Phagocytosis
Which of the following is a virulence factor specific to Gram-negative pathogens?
Lipid A
, Veterinarians and spelunkers (people who explore caves that may have large
populations of bats) should be vaccinated against rabies. The rabies vaccine is made by
treating the rabies virus with a chemical to render it non-infective. Based on this, how is
the rabies vaccine best characterized?
Inactivated
As you have seen, IgE is responsible for allergy, IgM is produced early in a primary
response, and IgG is produced early in a secondary response. Based on the diagram
provided, which part of an antibody molecule determines differences between an anti-
pollen IgE, IgG and IgM?
The stem (Fc)
A skin test was carried out with three potential allergens. The results (at 15 minutes
after exposure) are shown below. What do these results suggest?
This person has been sensitized to peanuts and has IgE bound to mast cells.
What is hemolysis?
The destruction of red blood cells.
What effect might a buildup of bilirubin have on a fetus?
A buildup of bilirubin may lead to severe neurological damage or death.
The destruction of blood cells leads to the release of large amounts of _____, which is
then degraded into bilirubin.
hemoglobin
When are anti-Rh antibodies developed by the adaptive immune system?
Anti-Rh antibodies are produced after exposure to the Rh antigen.
Answers
Antigen processing and presentation
is a way for a cell to give information about its activities.
Why would a body cell that is not a phagocyte need to present antigens?
Non-phagocytic body cells can become infected with a virus.
How do phagocytes communicate to other cells what they have captured?
They present antigens from engulfed foreign cells.
Label the components of the activation of a Helper T cell by a dendritic cell.
A few months ago Dr. Trapper's, 4-year-old son, Caleb, woke him up at 3:00 am,
complaining that he didn't feel good. Caleb said his head and ears hurt, and he and his
bed were "all wiggly." He had a runny nose the past few days, but the Trappers had
thought nothing of it. Dr. Trapper took Caleb into the bathroom and noticed he looked
flushed and his glands appeared swollen compared to normal (see picture).
Dr. Trapper gave Caleb a hug and he felt very hot. A quick check with the thermometer
demonstrated he was running a fever of 101.8°F. Caleb didn't show any other obvious
symptoms. While somewhat concerned, Dr. Trapper was not overly worried as Caleb
had been a very healthy child and received all his vaccinations.
Which of the following is the most likely possible diagnosis for Caleb?
,Ear infection
While we usually think of fever as a bad thing, a fever is actually signifying that an
immune response is progressing! Overall, which of the following cytokines would be
most involved in increasing Caleb's fever response?
Interleukin-1
The examination led to a diagnosis of otitis media (OM), or an ear infection. The picture
on the left demonstrates a swollen, red eardrum with a fluid buildup behind the
membrane. The immune processes most involved in the inflammation seen behind
Caleb's eardrum would be attributed to:
Vasodilation of capillaries and accumulation of immune cells, fluid or pus
Most patients would happily accept a prescription for antibiotics from the pediatrician
and go home. But as a microbiologist, Dr. Trapper wanted to identify the infectious
etiology and see what was going on inside his son. Even though it's not standard
procedure for otitis media, he asked for some of the fluid contained behind the eardrum
to be collected with a syringe (tympanocentesis) so he could analyze it for culture and
sensitivity in his lab. He stained the fluid and examined it under the microscopic field.
Interestingly, although he did not find any noticeable bacterial organisms, he did find
high numbers of this characteristic responding cell type (picture), which could likely be
identified as a:
Neutrophil
Dr. Trapper wasn't going to give up easily and continued to scan the overall field for
bacterial clues, but all he found were more immune cells. Soon, he noticed something
,else interesting...several cells were interacting! The likely identities of these cells based
on morphologies could be best described as:
Adaptive immune cell and an antigen presenting cell
Caleb recovered without incident, but because there are millions of cases of ear
infections every year in the U.S., Dr. Trapper wanted to make sure that this would not
be the first of many recurrent ear infections for his son. He wanted to ensure that Caleb
did not have an underlying immunodeficiency that would cause his future responses to
fight antigens suboptimally. He asked the physician to do a serology analysis of Caleb,
which consisted of probing for each antibody isotype found and to report how much is
present. The analysis yielded the following results. What might you conclude from this?
Caleb has a normal response
If this particular antigen attempts to re-infect Caleb, it's in for a bigger fight. By getting
activation of adaptive immune cells such as B-cells and T-cells, the body generates an
extra layer of protection. What is a critical advantage for Caleb the next time he
encounters this antigen?
Anamnestic (memory) responses and future vaccinations to augment the response
Neutrophils are "first responders" during an inflammatory response. What is their
specific role?
Phagocytosis
Which of the following is a virulence factor specific to Gram-negative pathogens?
Lipid A
, Veterinarians and spelunkers (people who explore caves that may have large
populations of bats) should be vaccinated against rabies. The rabies vaccine is made by
treating the rabies virus with a chemical to render it non-infective. Based on this, how is
the rabies vaccine best characterized?
Inactivated
As you have seen, IgE is responsible for allergy, IgM is produced early in a primary
response, and IgG is produced early in a secondary response. Based on the diagram
provided, which part of an antibody molecule determines differences between an anti-
pollen IgE, IgG and IgM?
The stem (Fc)
A skin test was carried out with three potential allergens. The results (at 15 minutes
after exposure) are shown below. What do these results suggest?
This person has been sensitized to peanuts and has IgE bound to mast cells.
What is hemolysis?
The destruction of red blood cells.
What effect might a buildup of bilirubin have on a fetus?
A buildup of bilirubin may lead to severe neurological damage or death.
The destruction of blood cells leads to the release of large amounts of _____, which is
then degraded into bilirubin.
hemoglobin
When are anti-Rh antibodies developed by the adaptive immune system?
Anti-Rh antibodies are produced after exposure to the Rh antigen.
