Immunology Module 13

What is the consequence if the Fc receptor (FcγRIIB1) and the B-cell receptor are cross-linked on the surface of an antigen-specific naive B cell?

Apoptosis in induced

How does RhoGAM mediate its intended clinical effect?

By preventing activation of RhD-specific naive B cells

Which of the following combinations would be of concern to an obstetrician caring for a woman during her second pregnancy in the context of hemolytic disease of the newborn? The maternal blood type is given first, followed by the blood type of the mother's firstborn baby.

Concerning combinations. O RhD−; A RhD+, and AB RhD−; O RhD+ Safe combinations A RhD+; O RhD−, B RhD+; AB RhD−

Which of the following describe requirements for immunological memory to be sustained?

Correct Answer(s) Appropriate cytokines and microenvironment are needed. Incorrect Answer(s) Lymphocytes require occasional stimulation through their antigen receptors. Antigen must be retained in the body.

Why do memory cells respond more strongly during a secondary immune response than naive lymphocytes do in a primary immune response?

Correct Answer(s) Memory B cells have high-affinity B-cell antigen receptors. Memory cells are activated more quickly. Memory cells are more numerous. Incorrect Answer(s) Memory B cells interact more effectively with antigen-presenting cells and hence are activated more rapidly compared to naive B cells. Memory T cells have higher affinity T-cell antigen receptors than effector T-cells.

In which way does the B-cell population that participates in a secondary adaptive immune response differ from the B-cell population that participates in a primary adaptive immune response?

Correct Answer(s) Antigen-specific memory B cells in a secondary response outnumber naive B cells in a primary response by 10- to 100-fold. The antibodies produced in a secondary response have higher affinity for antigen than the antibodies produced in a primary response. Incorrect Answer(s) Engagement of FcγRIIB1 on B cells in a primary response is needed to stimulate their activation. IgM is produced at a higher level in a secondary immune response.

Which of the following are mechanisms that cause the death of plasma cells?

Correct Answer(s) induction of apoptosis through an inhibitory signal delivered through FcγRIIB1 inhibition of contact with stromal cells in the bone marrow Incorrect Answer(s) exhaustion due to the demands of protein synthesis activation of death receptors by NK cells

Which of the following statements correctly describe long-lived pathogen-specific plasma cells?

Correct Answer(s). Their antibodies can bind to a pathogen and deliver it to an antigen-presenting cell, which then mediates a secondary immune response. Their antibodies can bind to a pathogen and deliver it to effector cells of innate immunity. They require IL-6 for long-term maintenance. Incorrect Answer(s). They survive for only a few months before they die by apoptosis. They secrete only low-affinity antibody.

This figure depicts how memory responses to mutable viruses erode over the course of successive infections. Choose the answer choice that best describes the mechanism responsible for this phenomenon.

Engagement of FcyRIB1 on naive B cells by high affinity igG prevents the activation of new antigen-specific B cells during sequential infections with variants of influenza.

What cell type remains after an adaptive immune response and is responsible for maintaining the steady-state level of pathogen-specific antibody in the circulation?

Long-lived plasma cells

Which of the following lymphocytes do NOT give rise to antigen-specific memory cells?

NK cells

Which antibody blocks the attachment of microbes to the surface of human cells?

Neutralizing

What is the term for the type of resistance provided against a pathogen months after infection by that same pathogen?

Protective immunity

Neutralizing antibodies against Streptococcus pyogenes, the causative agent of strep throat, are specific for which molecule (which inhibits their attachment to the mucosal epithelium)?

Protein F

Which of the following correctly describes the nature of the metabolic reprogramming that occurs when a naive T cell becomes activated during the primary immune response to a pathogen?

The T cell changes from catabolism to anabolism.

Which of the following best explains why a healthy individual infected with a cold virus early in the winter does not initiate a new adaptive immune response when exposed to the same virus at the end of the winter season?

The antibodies made against the virus during the first round of invsion are available month later to neutralize the same virus when it invades the host again.

Which of the following best explains why approximately half the population of the United States has immunity to smallpox even though the smallpox vaccination was discontinued in 1972?

Those who were vaccinated before 1972 have immunity to the virus on each encounter.

When will an existing influenza-specific memory B-cell population cease dominating the immune response to subsequent influenza infections?

When an influenza strain causing a new infection lacks all of the B-cells epitopes of the original strain that stimulated production of the memory B-cells population

What is a toxoid?

a bacterial product modified for use as a vaccine.

What is RhoGAM?

an anti-RhD IdG antibody that is infused into RhD women during pregnancy

Primary adaptive immune responses are mediated by short-lived pathogen-specific______________B and T cells, whereas secondary adaptive immune responses are mediated by long-lived pathogen-specific______________ cells. Some effector cells can be long-lived, such as the plasma cell, which resides in the_______________________nd produces steady-state levels of pathogen-specific

effector memory bone marrow antibody

After antigen activation of a naive CD8 T cell, the cell undergoes an asymmetric division, resulting in one daughter cell that is an effector T cell and one that is a memory T cell. Sort the following statements according to the type of T cell that they describe.

effector T cell: Proximal to dendritic cell High levels of mTORC1 activity memory T cell metabolic program similar to naive T cells. distal to dendritic cell

One objective of the primary adaptive immune response is to form________cells, which ensure that future invasions by the same pathogen are dealt with using a heightened level of recognition and potency. These cells are_________providing a robust and fine-tuned immune response to future invasions by the same pathogen. This is the basis for the__________and effective vaccination.

memory long-lived secondary adaptive immune response.

Sarah Stern, a herpetologist, was bitten on the hand by a poisonous snake known as the Gaboon viper while carrying out fieldwork in South Africa. Almost immediately, pain and swelling occurred at the site of the fang marks. She was taken to the local hospital and within hours exhibited clinical signs of envenomation including fever, cardiovascular abnormalities, hypotension, hematuria, coagulation defects, and angioedema. A chartered flight delivered SAIMR polyvalent antivenom to the hospital, and it was administered without delay. The antivenom used is prepared by the South African Institute for Medical Research from the serum of hyperimmunized horses and is useful against 10 of South Africa's most deadly snake venoms. Within hours improvement was observed. Stern made a complete recovery and was released from the hospital 24 hours after all symptoms had abated. The administration of antivenom is an example of which of the following?

passive immunization

What is the effect of sequential infections with variants of influenza virus on the nature of the antibody response that is stimulated?

the antibody response in inhibited against variant epitopes in a subsequent infection with a similar, but not identical, strain

What is the process by which anemia arises in hemolytic disease of the newborn?

uptake of opsonized erythrocytes by fetal macrophages in the spleen.

Match each toxin with the correct associated disease.

whooping cough: pertussis toxin food poisoning: staphylococcal enterotoxin gas gangrene: clostridial α-toxin scarlet fever: erythrogenic toxin