Lecture 20: Antigen Processing & Presentation

Which of the following cell types is considered the MOST potent antigen-presenting cell (APC)?

Endogenous antigens are typically loaded onto which type of MHC molecule?

Which of the following molecules is NOT directly involved in the MHC class I antigen processing pathway?

Cross-presentation is a process that allows which type of antigen to be presented on MHC class I molecules?

What is the primary function of the TAP (Transporter associated with Antigen Processing) protein?

Which of the following best describes cross-dressing in the context of antigen presentation?

What is the functional consequence of MHC polymorphism in a population?

Codominant expression of MHC genes ensures that:

Which of the following non-classical MHC molecules is known for interacting with NK cell receptors?

Which of the following is NOT a characteristic of MHC class I molecules?

What is the primary function of HLA-DM in antigen presentation?

Which of the following describes the structural difference between MHC class I and MHC class II molecules?

The proteasome is primarily responsible for:

Certain viruses can interfere with antigen presentation pathways. Which of the following viral mechanisms would MOST directly inhibit MHC I presentation of viral antigens?

Which of the following is NOT a characteristic of 'professional' antigen-presenting cells (APCs)?

In the context of antigen processing and presentation, what is the role of ERAP (ER-resident aminopeptidase)?

Which of the following is the MOST accurate description of MHC restriction?

Which of the following immune deficiencies would MOST directly impair MHC class I presentation?

An experiment is conducted where cells are treated with a drug that inhibits the acidification of endosomes. Which of the following processes would be MOST directly affected?

Which of the following best describes the function of CD1 molecules?

Which of the following statements best describes the role of invariant chain (Ii) in MHC class II antigen processing?

A patient has a genetic defect that results in non-functional beta-2 microglobulin. What is the MOST likely immunological consequence?

A researcher discovers a new molecule that enhances the stability of peptide-MHC class I complexes on the cell surface. This molecule would MOST likely enhance:

What is the role of the enzyme Cathepsin S in MHC Class II antigen processing?

Which of the following is the MOST likely outcome if a cell lacked the ability to express MHC molecules?

A researcher is studying the immune response to a novel intracellular bacterium. They observe that CD8+ T cells are activated, but MHC class I expression is abnormally low. Which of the following proteins might the bacterium be targeting to suppress the immune response?

What is the significance of linkage disequilibrium in the context of HLA genes?

A mutation in the gene encoding for ERAP1 results in a loss of function. Which of the following would be MOST directly affected by this mutation?

A patient with a rare genetic disorder has a complete absence of MHC class II expression. Which of the following immune cell interactions would be MOST directly impaired in this individual?

A researcher is investigating a new viral protein that interferes with antigen presentation. They find that this protein prevents the association of B2-microglobulin with MHC class I heavy chain. What is the MOST likely consequence of this interference?

A therapeutic strategy aims to enhance the immune response against tumor cells by increasing the expression of MHC class I molecules on the tumor cell surface. Which of the following cytokines would be MOST appropriate to use for this purpose?

A patient presents with a mutation affecting the function of HLA-DO. Understanding its role, what downstream effect would you predict?

A researcher is studying antigen processing in a novel cell type and observes peptide loading onto MHC class I molecules in the absence of TAP. Which of the following pathways is MOST likely responsible for antigen presentation in this scenario?

Consider a scenario where a virus has evolved a mechanism to downregulate the expression of both MHC class I and MIC molecules on infected cells. This strategy would MOST directly impair which two immune cell populations?

A researcher is trying to design a vaccine that will elicit a strong CD8+ T cell response against a specific tumor antigen. Which of the following strategies would be MOST effective in ensuring that the tumor antigen is efficiently presented on MHC class I molecules?

A new drug is developed that specifically blocks the function of calnexin. Which of the following processes would be MOST directly inhibited by this drug?

If a patient exhibits a chronic infection resulting from the inability to properly clear intracellular pathogens due to a defect in CD40L, which of the following professional APC cell types, responsible for bridging innate and adaptive immunity, would MOST directly contribute to the observed symptoms?

Consider an individual lacking functional non-classical MHC Ib molecule HLA-G. Which of the following immune responses would MOST likely be affected in this individual?

Which of the following is an example of an alloantigen?

What is the MAIN function of the invariant chain (Ii) in MHC class II antigen processing?

Which of the following BEST describes the term 'MHC restriction'?

Why is polymorphism in MHC genes important for population survival?

Which of the following is the MOST likely function of non-classical MHC class Ib molecules?

A researcher is studying a novel viral protein that inhibits the function of ERAP. Which of the following processes would be MOST directly affected?

A cell is unable to acidify its endosomes. Which of the following processes will be MOST affected?

A researcher discovers a new molecule that enhances the stability of peptide-MHC class I complexes on the cell surface, but only for certain viral antigens. This molecule would MOST likely enhance:

How does cross-dressing MOST directly contribute to CD8+ T cell activation?

In a scenario where a virus downregulates both MHC class I and MIC molecules on infected cells, which two immune cell populations would be MOST directly impaired?

Given the known promiscuity of MHC class II molecules, how does the immune system prevent excessive cross-reactivity that could lead to widespread autoimmunity?

In the context of tumor immunology, if cancer cells downregulate MHC class I expression to evade CD8+ T cell recognition, what compensatory mechanism might they exploit to simultaneously avoid NK cell-mediated killing?

An experimental drug inhibits the function of cathepsin S specifically within dendritic cells. What downstream effect would MOST directly compromise the adaptive immune response?

A hypothetical virus inhibits ERAP1 and TAP function in infected cells. What combined immunological consequence would MOST significantly impair the host's ability to mount an effective CD8+ T cell response?

If a novel pathogen evolved to disrupt the interaction between HLA-DM and MHC class II molecules, but only in B cells, what specific immunological defect would MOST likely manifest?

In a scenario where a cell expresses functional MHC class I molecules, but is completely deficient in beta-2 microglobulin, what cellular interaction would be MOST directly affected?

Given the role of autophagy in antigen presentation, what is the MOST likely mechanism by which a tumor cell might exploit defects in autophagy to evade immune surveillance by T cells?

Consider a novel therapeutic strategy that involves engineering dendritic cells to express a constitutively active form of ERAP1. What is the MOST likely outcome of this modification on antigen presentation?

A new viral strain expresses a protein that directly binds and inhibits the function of tapasin. What is the MOST likely mechanism by which this viral protein interferes with antigen presentation?

In the context of MHC genetics, what evolutionary advantage is MOST directly conferred by the high degree of polymorphism observed in HLA genes within a population?

How does the phenomenon of 'cross-dressing' MOST directly enhance the priming of naive CD8+ T cells during a viral infection?

If a patient has a mutation that results in the complete absence of functional HLA-DO, what specific aspect of MHC class II antigen presentation would be MOST affected?

In a scenario where a virus significantly downregulates the expression of both MHC class I and MIC molecules on infected cells, which two immune cell populations would be MOST directly impaired in their ability to respond to the infection?

To elicit a robust CD8+ T cell response against a specific tumor antigen, which of the following vaccine strategies would be MOST effective in ensuring efficient presentation on MHC class I molecules?

If a new drug specifically blocks the function of calnexin, which of the following processes involved in MHC class I antigen presentation would MOST immediately be inhibited?

What is the MOST likely functional consequence of a mutation affecting the peptide-binding groove of an MHC class I molecule, rendering it unable to bind any peptides?

Consider an individual with a genetic defect resulting in non-functional non-classical MHC Ib molecule HLA-G. Which of the following immune responses would MOST likely be affected?

Within the framework of adaptive immunity, what is the MOST accurate interpretation of the term 'MHC restriction' in the context of T cell activation?

A researcher is investigating a novel compound that selectively enhances the stability of peptide-MHC class I complexes on the cell surface, but only for specific viral antigens. This enhancement would MOST directly amplify which of the following immune functions?

A cell is genetically engineered to be completely unable to acidify its endosomes. Which of the following immunological processes will be MOST directly impaired as a result?

Consider a newly identified pathogen that triggers a potent inflammatory response, leading to increased expression of both MHC class I and class II molecules. What is the MOST likely underlying mechanism driving this upregulation?

If a novel immunotherapeutic agent selectively ablates HLA-DO function within antigen-presenting cells, but without affecting HLA-DM activity, which of the following immunological consequences is MOST likely to occur?

A research team engineers a recombinant virus expressing a novel protein that competitively binds to the peptide-loading groove of MHC class I molecules with extremely high affinity, preventing the binding of endogenous peptides. Which of the following strategies would MOST effectively restore MHC class I-mediated antigen presentation?

In a hypothetical scenario, a population of antigen-presenting cells is engineered to express a mutant form of tapasin that retains its ability to bind MHC class I molecules and other components of the peptide-loading complex (PLC) but is incapable of undergoing conformational changes required for optimal peptide loading. What is the MOST likely immunological consequence?

A researcher is investigating a novel mechanism of immune evasion employed by a specific intracellular bacterium. They discover that the bacterium secretes a protein that selectively inhibits the function of Rubicon-like autophagy regulator (RUBCN) specifically within dendritic cells (DCs). What is the MOST likely consequence of this bacterial interference on antigen presentation and adaptive immunity?

A research scientist generates a line of mice with a targeted mutation in the gene encoding cathepsin S, specifically designed to abolish its enzymatic activity only within dendritic cells (DCs). Following immunization with a protein antigen, which of the following outcomes is MOST likely observed in these mice compared to wild-type controls?

A novel viral strain exhibits a unique immune evasion strategy by expressing a modified ubiquitin ligase that specifically targets and ubiquitinates newly synthesized MHC class II molecules within antigen-presenting cells, leading to their proteasomal degradation prior to peptide loading. Which of the following cellular compartments would exhibit the MOST significant accumulation of ubiquitinated MHC class II molecules in these cells?

Consider a scenario in which a research team discovers a novel variant of HLA-DM that exhibits a significantly enhanced affinity for binding CLIP-MHC class II complexes but is severely impaired in its ability to release once peptide loading is complete. What is the MOST likely immunological consequence of this altered HLA-DM function?

A research group generates a mutant cell line lacking the ER-resident protein RTN4 (Reticulon 4), known for its role in shaping ER morphology. Considering RTN4's function, which aspect of MHC class I antigen presentation would be MOST directly affected in these cells?

Following exposure to a novel environmental toxin, a patient exhibits a selective defect in the expression of non-classical MHC class Ib molecule HLA-G. Given the known functions of HLA-G, which of the following immunological consequences would be MOST likely observed in this patient?

In a study analyzing the consequences of interallelic conversion within the MHC locus, researchers identify a novel recombinant allele exhibiting a mosaic structure derived from two distinct HLA-B allotypes. This recombinant allele displays a unique peptide-binding motif characterized by enhanced affinity for peptides containing a specific non-canonical amino acid. What is the MOST likely functional consequence of this novel peptide-binding specificity?