Question 1

Inhalation of allergenic pollen in a susceptible person causes the induction of what primary event, triggering an allergy reaction?
A) crosslinking of IgE-sensitized mast cells
B) immediate anaphylaxis
C) binding to sensitized cytotoxic T cells
D) increased cAMP levels
E) immediate leukotriene release

Accepted Answer

Inhalation of allergenic pollen in a susceptible person can lead to the binding of the allergen to IgE antibodies on the surface of mast cells. This crosslinking of IgE-sensitized mast cells triggers the release of inflammatory mediators such as histamine, leading to the symptoms of an allergic reaction. Therefore, the primary event triggering an allergy reaction is the crosslinking of IgE-sensitized mast cells.

Question 2

Some patients suffering from bare lymphocyte syndrome (BLS), a rare immunodeficiency, have a genetic mutation in their TAP1/TAP2 genes causing the production of a defective TAP transporter. Describe what effect this has on antigen processing and in what cells.

Accepted Answer

The answer of Some patients suffering from bare lymphocyte syndrome...

Question 3

A surgical patient infected with a blood-borne Staphylococcus would initially produce an anti-staphylococcal antibody of the IgM class. Why is that?

Accepted Answer

The answer of A surgical patient infected with a blood-borne...

Question 4

A Herpesviridae viral infection would most likely stimulate which immune cells for clearance of the infection?
A) cytotoxic T cells
B) helper T cells
C) B cells
D) mast cells
E) macrophages

Accepted Answer

Herpesviridae viruses are known to establish latency in host cells, making it difficult for the immune system to completely clear the infection. However, cytotoxic T cells can recognize and eliminate virus-infected cells by inducing apoptosis, which is an effective mechanism for controlling the spread of the virus. Helper T cells, B cells, mast cells, and macrophages can also play a role in the immune response to herpesvirus infection, but cytotoxic T cells are the most important effector cells in this context.

Question 5

If you are infected with the cold virus one year, why can you still catch a cold again the next year, even if your immune system is working properly?

Accepted Answer

The answer of If you are infected with the cold...

Question 6

A patient with recurring nut allergies enrolls in an experimental desensitization trial at the local allergy clinic. What should this patient expect?
A) injection of large doses of suspected antigen over the next few months, with the hope that he will begin producing anti-allergen IgA
B) injection of small doses of anti-antigen antibody over the next few months, with the hope that he will begin producing anti-antibody IgE
C) injection of small doses of suspected antigen over the next few months, with the hope that he will begin producing anti-allergen IgG
D) injection of medium doses of suspected antigen over the next few days, with the hope that he will begin producing anti-allergen IgM
E) injection of medium doses of anti-antigen antibody over the next few years, in hopes of removing all anti-antigen IgE

Accepted Answer

The patient should expect injection of small doses of suspected antigen over the next few months with the hope that he will begin producing anti-allergen IgG. This is the standard protocol for desensitization therapy, where the patient is gradually exposed to increasing doses of the allergen in order to build up tolerance and reduce the severity of allergic reactions. IgG antibodies are the most common type of antibody and are involved in long-term immunity.

Question 7

Staphylococcal exfoliative toxin (exfoliatin A) reacts in the human body as a superantigen. Intoxication with this means: A) polyclonal T-cell stimulation by overriding the normal route of antigen presentation B) monoclonal B-cell stimulation without T-cell signaling C) direct overactivation of T_H1 cells, causing a T_C cell response only D) dramatic down-regulation in genes that control all cells producing pro-inflammatory cytokines E) decreased antigen presentation by the antigen-presenting cells, followed by autoantibody formation

Accepted Answer

Staphylococcal exfoliative toxin acts as a superantigen, which means it is able to override the normal route of antigen presentation and stimulate a polyclonal T-cell response. This can result in the release of large amounts of pro-inflammatory cytokines and a systemic inflammatory response.

Question 8

How can a person who has taken penicillin for a childhood ear infection later develop an allergy to penicillin when prescribed that drug again?

Accepted Answer

The answer of How can a person who has taken...

Question 9

Myasthenia gravis is an autoimmune neuromuscular disease characterized by weakness of the skeletal muscles due to antiacetylcholine receptor antibodies. Thymectomy is a successful treatment for this condition in some patients because it:
A) removes all autoreactive B cells from the body
B) primes antigen-presenting cells to reverse their response to self tissue
C) neutralizes the autoantibodies from the body
D) produces proteins to bind the autoantibodies before reaching their target
E) prevents further miseducation of T-cell populations

Accepted Answer

Thymectomy is effective in treating myasthenia gravis because the thymus gland plays a crucial role in the education of T cells, including the development of self-tolerance. In myasthenia gravis, the thymus gland is often abnormal, and its removal can prevent the further production of autoreactive T cells that help drive the disease process.

Question 10

Why is type AB blood considered to be the "universal recipient"? Explain what this means in terms of the antigens and antibodies present in blood types.

Accepted Answer

The answer of Why is type AB blood considered to...

Question 11

How does increasing cellular telomerase activity within a memory B cell increase the life span of that cell, and why is this important?

Accepted Answer

The answer of How does increasing cellular telomerase activity within...

Question 12

A 30-year-old woman presents in the emergency room with hives. After a full examination, it is determined that the zoo she visited that morning caused the reaction. What was the most likely cause of this response?
A) type I hypersensitivity reaction
B) type II hypersensitivity reaction
C) type III hypersensitivity reaction
D) type IV hypersensitivity reaction
E) type V hypersensitivity reaction

Accepted Answer

Hives are a common symptom of a type I hypersensitivity reaction, which is also known as an immediate hypersensitivity reaction. This type of reaction occurs when the immune system overreacts to a foreign substance, such as an allergen, and releases histamine and other chemicals that cause inflammation and allergic symptoms. In this case, it is likely that the woman had an allergic reaction to an animal, plant, or insect at the zoo that triggered her immune system to respond in this way.

Question 13

A mutation that caused a person to have an ineffective complement C6 protein would have a direct effect on formation of:
A) complement-antibody complex
B) C3 convertase
C) C3b opsonins for phagocytosis
D) membrane attack complex
E) C5 convertase

Accepted Answer

The complement C6 protein is necessary for the formation of the membrane attack complex, which is a critical component of the complement system's role in destroying foreign pathogens. Without functional C6, the membrane attack complex cannot form, and the complement system would not be able to effectively eliminate pathogens from the body.

Question 14

The binding of released histamine to an H1 receptor during an allergic attack induces a pro-inflammatory state through which pathway(s)?
A) classical complement pathway
B) lipoxygenase pathway and cyclooxygenase pathway
C) signal transduction pathway, causing IL-2 production
D) lectin complement pathway
E) epinephrine-producing pathway

Accepted Answer

The lipoxygenase pathway and cyclooxygenase pathway are two pathways that produce pro-inflammatory mediators such as leukotrienes and prostaglandins, respectively. These mediators contribute to the symptoms of an allergic reaction, such as bronchoconstriction and vasodilation. Binding of histamine to an H1 receptor can activate these pathways and induce the pro-inflammatory state. The other pathways listed (classical complement pathway, lectin complement pathway, signal transduction pathway causing IL-2 production, and epinephrine-producing pathway) do not directly contribute to the pro-inflammatory response induced by histamine binding to an H1 receptor.

Question 15

Omenn syndrome is an immune disorder associated with mutations in the recombination-activating genes (RAG1 and RAG2) needed for gene switching in lymphocytes. What effect would this mutation have on B cells, T cells, and the overall health of the adaptive immune response?

Accepted Answer

The answer of Omenn syndrome is an immune disorder associated...

Question 16

Describe the structure of a typical IgG antibody, including the F(ab')₂ and Fc portions.

Accepted Answer

The answer of Describe the structure of a typical IgG...

Question 17

Regulation of complement destruction of normal body cells is controlled by:
A) CD8, serum factor C3b, and serum albumin
B) CD58, serum factor H, and decay-accelerating factor
C) CD4, serum factor Bb, and decay-accelerating factor
D) MHC I, serum factor C5a, and serum lipoprotein
E) MHC II, serum albumin, and T regulatory cells

Accepted Answer

The regulation of complement destruction of normal body cells is primarily controlled by serum factors, such as factor H and decay-accelerating factor, which prevent the complement system from attacking healthy cells. CD58 is also involved in this process, but not as a primary regulator. CD8 and CD4 are involved in T cell activation, but not directly involved in complement regulation. MHC I and II are involved in presenting antigens to T cells, but not in the regulation of complement. Serum factors C3b, Bb, and C5a are all components of the complement system, not regulators. Serum albumin and lipoprotein do not play a significant role in the regulation of complement. T regulatory cells are involved in the regulation of the immune response, but not specifically in complement regulation.

Question 18

In 2004, doctors successfully used gene therapy with a severely defective leukemia virus to insert a cytokine receptor gene needed for T-cell development into the bone marrow of four children with severe combined immunodeficiency (SCID). What is SCID, and how did doing this procedure address the disease?

Accepted Answer

The answer of In 2004, doctors successfully used gene therapy...

Question 19

Why are macrophages, monocytes, mast cells, and dendritic cells considered "professional" antigen-presenting cells, whereas fibroblasts are considered "nonprofessional" antigen-presenting cells?

Accepted Answer

The answer of Why are macrophages, monocytes, mast cells, and...

Question 20

An activated T_C cell trying to kill off influenza infection in the lungs would: A) release pro-inflammatory cytokines throughout the entire lung B) produce monoclonal anti-influenza antibodies C) activate B cells to make influenza-specific plasma cells D) bind to the infected host cells, then release perforin and granzymes E) travel to the thymus and undergo positive selection

Accepted Answer

An activated T_C cell is a cytotoxic T cell that functions to directly kill infected host cells. This is achieved by binding to the infected host cell and releasing perforin and granzymes, which induce cell death. Therefore, choice D is the best answer. Choices A, B, and C describe functions of other immune cells and are not directly related to the function of a cytotoxic T cell. Choice E is incorrect because activated T cells do not travel to the thymus, as they have already undergone selection in the thymus before being activated.

Quiz 24: The Adaptive Immune Response

Inhalation of allergenic pollen in a susceptible person causes the induction of what primary event, triggering an allergy reaction?

Some patients suffering from bare lymphocyte syndrome (BLS), a rare immunodeficiency, have a genetic mutation in their TAP1/TAP2 genes causing the production of a defective TAP transporter. Describe what effect this has on antigen processing and in what cells.

A surgical patient infected with a blood-borne Staphylococcus would initially produce an anti-staphylococcal antibody of the IgM class. Why is that?

A Herpesviridae viral infection would most likely stimulate which immune cells for clearance of the infection?

If you are infected with the cold virus one year, why can you still catch a cold again the next year, even if your immune system is working properly?

A patient with recurring nut allergies enrolls in an experimental desensitization trial at the local allergy clinic. What should this patient expect?

Staphylococcal exfoliative toxin (exfoliatin A) reacts in the human body as a superantigen. Intoxication with this means:

How can a person who has taken penicillin for a childhood ear infection later develop an allergy to penicillin when prescribed that drug again?

Myasthenia gravis is an autoimmune neuromuscular disease characterized by weakness of the skeletal muscles due to antiacetylcholine receptor antibodies. Thymectomy is a successful treatment for this condition in some patients because it:

Why is type AB blood considered to be the "universal recipient"? Explain what this means in terms of the antigens and antibodies present in blood types.

How does increasing cellular telomerase activity within a memory B cell increase the life span of that cell, and why is this important?

A 30-year-old woman presents in the emergency room with hives. After a full examination, it is determined that the zoo she visited that morning caused the reaction. What was the most likely cause of this response?

A mutation that caused a person to have an ineffective complement C6 protein would have a direct effect on formation of:

The binding of released histamine to an H1 receptor during an allergic attack induces a pro-inflammatory state through which pathway(s) ?

Omenn syndrome is an immune disorder associated with mutations in the recombination-activating genes (RAG1 and RAG2) needed for gene switching in lymphocytes. What effect would this mutation have on B cells, T cells, and the overall health of the adaptive immune response?

Describe the structure of a typical IgG antibody, including the F(ab')₂ and Fc portions.

Regulation of complement destruction of normal body cells is controlled by:

Why are macrophages, monocytes, mast cells, and dendritic cells considered "professional" antigen-presenting cells, whereas fibroblasts are considered "nonprofessional" antigen-presenting cells?

An activated T_C cell trying to kill off influenza infection in the lungs would:

Quiz 24: The Adaptive Immune Response

Inhalation of allergenic pollen in a susceptible person causes the induction of what primary event, triggering an allergy reaction?

Some patients suffering from bare lymphocyte syndrome (BLS), a rare immunodeficiency, have a genetic mutation in their TAP1/TAP2 genes causing the production of a defective TAP transporter. Describe what effect this has on antigen processing and in what cells.

A surgical patient infected with a blood-borne Staphylococcus would initially produce an anti-staphylococcal antibody of the IgM class. Why is that?

A Herpesviridae viral infection would most likely stimulate which immune cells for clearance of the infection?

If you are infected with the cold virus one year, why can you still catch a cold again the next year, even if your immune system is working properly?

A patient with recurring nut allergies enrolls in an experimental desensitization trial at the local allergy clinic. What should this patient expect?

Staphylococcal exfoliative toxin (exfoliatin A) reacts in the human body as a superantigen. Intoxication with this means:

How can a person who has taken penicillin for a childhood ear infection later develop an allergy to penicillin when prescribed that drug again?

Myasthenia gravis is an autoimmune neuromuscular disease characterized by weakness of the skeletal muscles due to antiacetylcholine receptor antibodies. Thymectomy is a successful treatment for this condition in some patients because it:

Why is type AB blood considered to be the "universal recipient"? Explain what this means in terms of the antigens and antibodies present in blood types.

How does increasing cellular telomerase activity within a memory B cell increase the life span of that cell, and why is this important?

A 30-year-old woman presents in the emergency room with hives. After a full examination, it is determined that the zoo she visited that morning caused the reaction. What was the most likely cause of this response?

A mutation that caused a person to have an ineffective complement C6 protein would have a direct effect on formation of:

The binding of released histamine to an H1 receptor during an allergic attack induces a pro-inflammatory state through which pathway(s) ?

Omenn syndrome is an immune disorder associated with mutations in the recombination-activating genes (RAG1 and RAG2) needed for gene switching in lymphocytes. What effect would this mutation have on B cells, T cells, and the overall health of the adaptive immune response?

Describe the structure of a typical IgG antibody, including the F(ab')2 and Fc portions.

Regulation of complement destruction of normal body cells is controlled by:

Why are macrophages, monocytes, mast cells, and dendritic cells considered "professional" antigen-presenting cells, whereas fibroblasts are considered "nonprofessional" antigen-presenting cells?

An activated TC cell trying to kill off influenza infection in the lungs would:

Describe the structure of a typical IgG antibody, including the F(ab')₂ and Fc portions.

An activated T_C cell trying to kill off influenza infection in the lungs would: