Lecture 15: Elements of the Immune System

Which of the following characteristics is associated with the innate immune response?

Which of these is considered a physical barrier in the innate immune system?

Which of these processes is directly facilitated by complement activation?

In the context of immune responses, what is an antigen?

What is the primary role of dendritic cells in initiating an adaptive immune response?

Which type of immune cell is responsible for directly killing infected or abnormal cells?

What is the key characteristic that differentiates the adaptive immune response from the innate immune response?

Which of the following best describes an 'immunogen'?

An epitope is best described as:

Following activation in the lymph nodes, what is the primary role of effector T cells?

What is the main function of plasma cells?

Which of the following characteristics is unique to the adaptive immune response compared to the innate immune response?

What is the role of CD4+ T helper cells (Th) in the adaptive immune response?

Which of the following represents the correct sequence of events in the adaptive immune response?

What is the role of the lymphatic system, particularly lymph nodes, in the adaptive immune response?

How does the secondary adaptive immune response typically differ from the primary immune response?

Which of the following best describes the function of Toll-like receptors (TLRs)?

A researcher is studying a new virus and observes that the body's initial response involves activation of complement and phagocytosis by macrophages, but no antibody production. This suggests that the response is primarily driven by:

A patient lacks the ability to produce functional T helper cells. Which of the following immune functions would be most affected in this patient?

Which of the following processes is most directly associated with the resolution of an infection and the establishment of long-term immunity?

A child is born with a genetic defect that impairs the function of their dendritic cells. How would this most likely affect their immune system?

Which of the following is the most critical role of cytokines in the immune system?

If a previously vaccinated individual is exposed to the same antigen years later, which of the following components of the adaptive immune system would mount the quickest response?

What is the significance of Hepatitis A IgM being positive and Hepatitis A IgG being negative?

After stepping on a rusty nail, compared to the initial tetanus shot, how will the immune response differ to the booster?

The body's first response to a pathogen is the __________ immune response. It is comprised of __________ barriers, involves detection by __________, and induces __________.

True or false: The adaptive immune response is rapid (minutes to hours), has limited recognition and specificity, and is the same for each pathogen (no memory).

True or false: Dendritic cells can activate both CD4+ and CD8+ T cells.

CD4+ T helper cells assist the ongoing immune response in the __________. __________ cells differentiate into plasma cells.

Which of the following is a primary determinant of the adaptive immune system's ability to mount a more rapid and effective response upon subsequent exposure to the same pathogen?

Suppose a person has a genetic mutation that prevents the production of functional complement proteins. Which of the following immune processes would be most directly impaired?

In immunology, what distinguishes an antigen from a hapten?

A researcher discovers a new cell type in the immune system that expresses both T cell receptors (TCRs) and B cell receptors (BCRs). Which of the following functions would be most plausible for this cell type, assuming it is functional?

A researcher is developing a novel vaccine strategy that aims to enhance the presentation of antigens by dendritic cells to T cells. Which of the following approaches would most likely achieve this goal?

Which of these is the LEAST likely outcome of the adaptive immune system's response to a novel pathogen?

What is the role of natural killer (NK) cells in the innate immune response?

What is the function of chemokines within the immune system?

What is the result of plasma and blood proteins the infiltrate tissue?

Which response is slower to develop and is highly specific and adapted for a particular pathogen?

What is the function of antibodies which are created by plasma cells?

What is a consequence of a nail disrupting the physical barrier of the skin?

Which of the following statements best describes the relationship between innate and adaptive immunity?

Cytokines can trigger specific receptors and chemokines to do what?

Which immunological mechanism is MOST likely to mediate the rapid containment of viral dissemination during the initial hours of a systemic viral infection, prior to the initiation of adaptive immunity?

A researcher mutates the gene encoding for a crucial component of the NADPH oxidase complex in macrophages. Which of the following immunological processes would be MOST directly compromised?

Which of the following scenarios would MOST likely result in the activation of the alternative pathway of complement, leading to opsonization and lysis of a microbial pathogen?

A novel therapeutic agent selectively inhibits the interaction between the co-stimulatory molecule B7 (CD80/CD86) on antigen-presenting cells (APCs) and CD28 on T cells. What downstream effect would MOST directly impair?

Consider a scenario where an individual possesses a homozygous loss-of-function mutation in the gene encoding FoxP3. This mutation would MOST severely impair the function of which T cell subset?

Which statement accurately captures the functional distinction between central and effector memory T cells?

A patient with a genetic defect exhibits impaired somatic hypermutation (SHM) in B cells within germinal centers. Which of the following immunological consequences is MOST likely to arise from this defect?

A group of researchers discovers a novel pathogen that evades detection by most pattern recognition receptors (PRRs). However, it is highly susceptible to complement-mediated lysis. Which complement pathway is MOST likely responsible for the initial recognition and activation in this scenario?

Which of the following best describes the concept of 'linked recognition' in the context of T-dependent B cell activation?

A researcher is investigating the mechanisms of immunological tolerance in the thymus. If the AIRE (autoimmune regulator) gene is non-functional in thymic epithelial cells (TECs), what outcome would be MOST likely?

A patient diagnosed with Chronic Granulomatous Disease (CGD) suffers from recurrent bacterial and fungal infections due to a defect in NADPH oxidase. Which of the following immune cell functions is directly impaired due to this defect?

A researcher discovers a novel cytokine that inhibits differentiation, proliferation, and activation-induced cytolytic activity of NK cells. Considering this cytokine's function, which receptor interaction is MOST likely being targeted?

Consider a patient with a mutation leading to non-functional mannose-binding lectin (MBL). During a systemic bacterial infection with a pathogen expressing mannose-rich polysaccharides, which early event in the innate immune response would be MOST affected?

In the context of T cell development in the thymus, what is the MOST critical role of MHC class II molecules expressed on cortical thymic epithelial cells (cTECs)?

A patient undergoes a bone marrow transplant. Post-transplant, the patient develops graft-versus-host disease (GVHD) targeting the skin, liver, and gastrointestinal tract. Which immune cell type is MOST directly responsible for mediating the tissue damage in GVHD?

Which of the following mechanisms is MOST critical for maintaining peripheral tolerance to self-antigens and preventing autoimmune reactions?

A researcher is studying the process of antigen presentation by dendritic cells (DCs). Which of the following modifications would MOST effectively promote cross-presentation of exogenous antigens onto MHC class I molecules?

Which function would be MOST impaired in a patient with a complete deficiency in the common gamma chain (γc) subunit shared by the receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21?

A researcher discovers that a particular virus encodes a protein that directly inhibits the function of TAP (Transporter associated with Antigen Processing). What immunological consequence would be MOST likely to arise from this viral immune evasion?

Which mechanism contributes MOST directly to the establishment of long-term immunological memory following a primary infection?

A patient with a mutation in the gene encoding ζ-chain (CD3ζ) of the T cell receptor (TCR) complex exhibits impaired T cell activation. Which of the following downstream signaling events would be MOST directly affected?

A researcher discovers a novel immunomodulatory molecule that selectively enhances the suppressive activity of regulatory T cells (Tregs). Which therapeutic application would be MOST appropriate for this molecule?

What immunological event is MOST directly associated with the establishment of germinal centers within secondary lymphoid organs?

Consider a scenario where a pathogen has evolved a mechanism to specifically block the transport of MHC class II molecules from the endoplasmic reticulum to the Golgi apparatus. What immunological consequence would MOST likely arise from this evasion strategy?

A researcher is investigating potential adjuvants to enhance vaccine efficacy. Which mechanism would MOST effectively enhance the activation of antigen-presenting cells (APCs) and promote strong adaptive immune responses?

A patient presents with recurrent, severe infections due to a genetic defect that impairs neutrophil migration from the bloodstream to sites of inflammation. Which molecular deficiency would be MOST likely to cause this phenotype?

Which of the following best describes the primary mechanism by which antibodies mediate neutralization of viral pathogens?

In the context of B cell development, what is the MOST critical role of the pre-B cell receptor (pre-BCR)?

A new therapy aims to enhance adaptive immunity by agonizing the receptor for interleukin-15 (IL-15R). This would directly enhance the activity of?

Consider a patient with an inherited deficiency in C1q, a component of the classical complement pathway. Which symptom would the patient likely experience?

A novel virus has been discovered that infects cells but avoids recognition of both TLRs and NLRs. What innate immune mechanisms would be effective against this virus?

In what cells do the majority of somatic mutations occur to allow affinity maturation?

How do Cytotoxic T Lymphocytes (CTLs) recognize infected cells?

A 20-year-old is bitten by a venomous snake for the first time, and injected with antivenom. What kind of immunity will the antivenom create?

In a patient with a genetic mutation causing complete absence of thymus, what will happen?

How do complement proteins cause lysis?

What is the primary function of helper T cells?

If lymph nodes are surgically removed, what would happen?

Consider a scenario where a hypothetical pathogen, 'Xantho-mortis,' possesses an extremely high mutation rate, rendering it capable of altering its surface antigens within hours of initial immune recognition. Which immunological mechanism would likely be MOST effective in controlling such a pathogen?

In a genetically engineered mouse model, researchers selectively ablate the expression of the gene encoding the NLRP3 inflammasome specifically within dendritic cells (DCs). Upon infection with a common intracellular bacterium, which immunological consequence would be MOST anticipated?

A researcher isolates a novel cytokine, 'Immunoglobulin Differentiation Factor-X' (IDF-X), which selectively promotes the differentiation of IgM-secreting B cells into IgG3-secreting plasma cells. Furthermore, IDF-X requires interaction with a co-receptor expressed solely on marginal zone B cells for its activity. Which aspect of the adaptive immune response would this cytokine MOST directly impact?

Researchers are studying a novel viral strain that specifically targets and inhibits the expression of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) within dendritic cells (DCs). Which downstream immunological consequence is MOST likely to arise from this viral immune evasion tactic?

A patient presents with a rare genetic defect characterized by a complete lack of functional Janus kinase 3 (JAK3) protein. Given the role of JAK3 in cytokine receptor signaling, what aspect of immune function would be MOST severely compromised in this individual?

Researchers are investigating a novel therapeutic strategy to enhance the efficacy of cancer immunotherapy. They discover a small molecule that selectively inhibits the activity of SHP-1 (Src homology region 2 domain-containing phosphatase-1) within cytotoxic T lymphocytes (CTLs). What is the MOST likely mechanism by which this molecule would enhance CTL-mediated tumor cell killing?

A laboratory develops a new drug that activates the alternative complement pathway. What potential danger must be avoided when using this drug?

Which process is the LEAST likely outcome of the adaptive immune system's response to a novel pathogen?

What is the result of plasma and blood proteins infiltrating tissue?

Consider a novel therapeutic agent designed to specifically inhibit the enzymatic activity of caspase-1 within macrophages. What downstream immunological consequence would MOST likely result from the administration of this agent in the context of an acute bacterial infection?

Within a lymph node, a researcher observes that antigen-presenting cells (APCs) are clustering near the subcapsular sinus (SCS) and efficiently capturing intact, unprocessed antigens directly from afferent lymph. Which specific APC population is MOST likely mediating this process?

A group of researchers is investigating a novel mechanism of immune regulation involving a previously uncharacterized subset of CD8+ T cells. They discover that these cells express high levels of a unique inhibitory receptor, 'Inhibitory Receptor-X' (IR-X), and that engagement of IR-X by its ligand on target cells leads to suppression of T cell receptor (TCR) signaling. Which scenario would be MOST likely to promote the differentiation and expansion of these IR-X+ CD8+ T cells?

Researchers are studying the effects of a novel immunosuppressive drug on T cell activation. They discover that the drug selectively inhibits the activity of calcineurin, a phosphatase that is essential for activating the transcription factor NFAT (nuclear factor of activated T cells). What downstream effect would MOST directly impair?

In the context of B cell receptor (BCR) signaling, what is the MOST critical function of the IgM/IgD co-receptors, Igα (CD79a) and Igβ (CD79b)?

A researcher is investigating the developmental origins of invariant natural killer T (iNKT) cells within the thymus. Which unique characteristic distinguishes iNKT cell development from conventional αβ T cell development?

Consider a patient diagnosed with severe combined immunodeficiency (SCID) due to a mutation in the recombination activating gene 1 (RAG1). What immunological defect would be MOST directly responsible for the patient's extreme susceptibility to infections?

A research team isolates a novel protein, 'Connective Tissue Modulator-Zeta' (CTM-ζ), secreted by fibroblasts in chronically inflammed tissues. CTM-ζ specifically binds to and inhibits the enzymatic activity of matrix metalloproteinases (MMPs) in the extracellular matrix. What immunological consequence would be MOST directly associated with the activity of CTM-ζ?

Suppose a researcher is investigating a way of increasing T-cell recognition of tumor cells in the hopes of developing an effective cancer therapy. They discover that tumor cells are engulfing certain key cytokines that would otherwise activate T-cells. What can the researcher do to counteract this?