Exam #4 Flashcards

A sensitized mast cell degranulates rapidly after its surface-bound IgE is bound/crosslinked by an allergen (fact).
True/False: In a sense, sensitized mast cells are similar to B cells in that each is antigen specific (i.e. each mast cell is sensitized to one and only one allergen).

Which one of the following genetically-modified mice would be able to experience a normal type I hypersensitivity reaction?

a. A mouse that lacked a functional gene for the RAG enzyme complex.

b. A mouse that lacked the genes for the enzymes that perform immunoglobulin class-switching.

c. A mouse that lacked a functional gene for the high affinity Fcε(epsilon) R1 receptor.

d. A mouse that lacked a functional poly Ig receptor.

e. A mouse that lacked a functional FOXN1 gene which is required for development of a thymus.

A disease called mastocytosis is caused by the production of too many mast cells (fact). One form of mastocytosis is called urticaria pigmentosa. In this disease mast cells in the skin spontaneously degranulate at an abnormally high rate (fact).
Which one of the following symptoms is least likely to be associated with urticarial pigmentosa.

a.Increased production of IgE-secreting plasma cells.

b.Increased infiltration of leukocytes from bloodstream into affected area.

c.Increased permeability of blood vessels in affected area.

d.Hives (red rash) in affected area.

e.Pain and/or itching in affected area.

True or False: The isotype of the monoclonal antibodies just described as being useful in treating type-I hypersensitivity reactions is most likely IgE.

Which two (2) of the following antigens are most accurately described as being allergens?

a. A protein present in cat dander (shed skin cells from a cat).

b. A protein expressed by a virus that causes disease in the lung.

c. A toxin expressed by a bacteria that causes "food poisoning".

d. A protein expressed by a fungus that causes skin lesions.

e.A protein present in the venom injected by a fire ant.

True/False: Mast cells develop in a primary lymphoid tissue and they perform their primary functions within a secondary lymphoid tissue.

Individuals that do not inherit a functional gene called AID only produce IgM in response to antigen exposures because their B cells are unable to perform class-switching (fact). Which one of the following conditions would these individuals be able to experience?

a.Inflammation at site of bacteria infection in skin.

b.Asthmatic attack following inhalation of cat dander.

c.Wheal and flair reaction following mosquito bite.

d.Hay fever following inhalation of rag week pollen.

e.Food allergy following ingestion of peanut.

Billy Parker is allergic to the venom in a bee sting. At the age of 8, little Billy gets stung on the arm by a bee for the very first time while trying to steal honey from his neighbor’s beehive. Having a short memory and an insatiable appetite for honey, Billy tries to steal honey at age 9 and gets stung again. Which of the following do you think caused Billy the most discomfort ?

a.The first bee sting

b.The second bee sting

c.The spanking he received from his mom for being a thief.

d.His conscience.

One form of a clinical condition called chronic urticaria is actually an autoimmune disease caused by the production of antibodies that bind to the high affinity FcεR1 receptor which triggers mast cell degranulation (fact). Which one of the following statements is false?

a.The FcεRI complex is probably not expressed at high levels in the bone marrow.

b.The isotype of the antibodies that cause this condition is probably not IgE.

c.The antibodies that cause this condition induce the same changes in mast cells as an allergen does.

d.This condition is treated with anti-inflammatory drugs.

e.Individuals suffering from this condition are most likely hyperallergic to an abnormally large number of allergens.

Rhogam is isolated from the blood plasma of Rh-negative individuals (donors) who have volunteered to be immunized by the Rh antigen. Most donors that are used to produce Rhogam receive periodic immunizations with Rh+ blood to boost their anti-Rh antibody levels. Do you think there are more male Rhogam donors or more female Rhogam donors?

a. More female donors

b. More male donors

Review the structures of the A,B and O antigens and then discuss with a classmate why individuals with blood types A or B do not make antibodies to the O antigen (remember type O is the universal donor blood type). Then randomly select answer A or B below.

True/False: The nude mouse (lack of thymus) would not be able to experience a normal Arthus reaction.

Bill lacks a functional genes for complement protein C9 and for the protein called CD8 (his cells cannot produce a functional C9 or CD8 protein). Bacteria X enters Bill's arm through a break in the skin. 12 hours later there is redness, heat, swelling, and pain at the site of infection. Which one of the following statements about this situation is true?

a.Bill is experiencing a Type I hypersensitivity reaction.

b.Bill is experiencing a Type II hypersensitivity reaction.

c.Bill is experiencing a Type III hypersensitivity reaction.

d.Bill is experiencing a Type VI hypersensitivity reaction.

e.Bill is not experiencing a hypersensitivity reaction.

True/False: In general, hypersensitivity reactions result from the failure of one or more components of the immune system to properly differentiate between self and non-self antigens.

It was recently shown that the FcRn (neonatal Fc receptor) transports maternal IgE across the placenta and into the circulation of the fetus (fact). True/False: This finding suggests that a newborn child could experience a type I hypersensitivity reaction (allergic reaction) the very first time they encountered the antigen bound by the maternal IgE.

You decide to get rich and produce a drug consisting of an Rh-specific monoclonal antibody to replace the drug called Rhogam (which we discussed in lecture). In order for your monoclonal antibody to function in the same way that Rhogam does, which one of the following isotypes should your monoclonal antibody be?

a.IgE

b.IgG

c.IgD

d.IgA

e.IgM

Today we will discuss an autoimmune disease called autoimmune hemolytic anemia which occurs when the body produces antibodies against antigens present on the person's own red blood cells. This disease results in anemia due to the fact that many red blood cells are destroyed after being bound by the antibodies. The immune mechanism responsible for this autoimmune disease is most similar to which of the hypersensitivity reactions?

a.Type I

b.Type II

c.Type III

d.Type IV

e.Not similar to any of the hypersensitivity reaction mechanisms.

Joe inherited two non-functional genes for complement protein C3 and his body does not produce the C3 protein. Which type of hypersensitivity reaction is Joe more likely to experience than a normal person that is capable of producing normal levels of C3?

a.Type I

b.Type II

c.Type III

d.Type IV

Rituximab is a monoclonal antibody-based drug that is used to treat each of the three autoimmune diseases we just discussed. Rituximab binds to a protein called CD20 that is present on the surface of B cells. True/False: The reason that Rituximab is useful for treating these antibody-based autoimmune diseases is because it induced antibody-producing B cells to become anergic.

The T4 thyroid hormone (thyroxine) is produced by the thyroid gland and is often administered as a treatment for thyroid-based diseases. Grave’s disease and Hashimoto’s thyroiditis are both autoimmune diseases that affect normal function of the thyroid gland. Thyroxine is used to treat one of them. Which one of these two diseases do you think responds best to treatment with thyroxine?

a.Grave's disease

b.Hashimoto's thyroiditis

As you just learned, rheumatic fever is caused by antibodies that were induced by a bacterial infection, but which cross-react (bind) with a self antigen present on heart muscle (fact). Which one of the following vaccines works because of its ability to induce the production of cross-reactive antibodies (not cross-reactive with a self antigen)?

a.The Gardasil vaccine (VLP vaccine for HPV).

b.The oral poliovirus vaccine (OPV).

c.The smallpox vaccine (Jennerian vaccine).

d.The hepatitis B virus vaccine (Subunit vaccine).

e.The rabies vaccine administered to wildlife (Vector-based vaccine).

True/False: Including killed mycobacterium tuberculosis cells in the flu vaccine would likely lead to enhanced antibody and T cell responses against flu antigens.

True/False: In general, all autoimmune diseases result from the failure of the adaptive immune system to appropriately differentiate between harmful non-self and harmless non-self.

Person A has never experienced an autoimmune disease. Person B has recently been diagnosed with Graves disease, one of the antibody-based autoimmune diseases we discussed in last lecture. True/False: Person B is more likely than person A to have autoreactive B cells in their body.

Four of the five mice described below would be expected to experience higher than normal levels of autoimmunity. Which one of the mice would not be expected to experience higher than normal levels of autoimmunity?

a.A mouse that lacks a functional FOXP3 gene which results in the inability to produce Tregs.

b.The nude mouse (lacks a thymus)

c.A mouse that is unable to perform the process of negative selection during B cell development in the bone marrow.

d.A mouse that is unable to express the AIRE transcription factor in the thymus.

e.A mouse that has dendritic cells that constitutively (constantly) express high levels of the B7 protein.

True/False: The signals that activate a naive Th cell in response to a bacterial infection are fundamentally different than the signals that activate an autoreactive naive Th cell that induces the inflammation associated with Hashimoto's thyroiditis.

True/False: It would be dangerous to administer immunosuppressive drugs to an individual that was experiencing an autoimmune disease.

The immunological mechanism/processes that cause a hyperacute rejection of a transplanted organ are similar to which one of the following types of hypersensitivity reactions?

a.Type I

b.Type II

c.Type III

d.Type IV

Person X is donating a kidney to person Q. A cross-match assay is performed and yields a negative result (no reactivity).
True/False: Based on the result from the cross-match assay it is not necessary to perform a mixed lymphocyte reaction (MLR) as that assay will also yield a negative result.

True/False: It is reasonable to assume that minor histocompatibility genes are clustered together in a complex of genes on a single chromosome similar to how the major histocompatibility genes are linked together in the major histocompatibility complex.