Podcast
Questions and Answers
Which cellular structure is responsible for proteolytically generating peptide fragments of proteins displayed by class II MHC molecules?
Which cellular structure is responsible for proteolytically generating peptide fragments of proteins displayed by class II MHC molecules?
What type of T cell is activated by the proteasomal processing pathway?
What type of T cell is activated by the proteasomal processing pathway?
From where are the proteins found in late endosomes and lysosomes largely derived?
From where are the proteins found in late endosomes and lysosomes largely derived?
Which pathway ensures that CD4+ T lymphocytes will be able to recognize antigens from microbes originally present outside the APC?
Which pathway ensures that CD4+ T lymphocytes will be able to recognize antigens from microbes originally present outside the APC?
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Which type of cells can present ingested antigens on class I MHC molecules to CD8+ T lymphocytes?
Which type of cells can present ingested antigens on class I MHC molecules to CD8+ T lymphocytes?
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What happens if peptides weakly bind to class I major histocompatibility complex (MHC) molecules?
What happens if peptides weakly bind to class I major histocompatibility complex (MHC) molecules?
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Which type of T cells recognize Class I MHC-peptide complexes?
Which type of T cells recognize Class I MHC-peptide complexes?
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What is the process called when dendritic cells present ingested antigens on class I MHC molecules to CD8+ T lymphocytes?
What is the process called when dendritic cells present ingested antigens on class I MHC molecules to CD8+ T lymphocytes?
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Where are antigenic peptides generated and bound to class I MHC molecules?
Where are antigenic peptides generated and bound to class I MHC molecules?
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What is the role of CD4+ helper T cells in the immune response?
What is the role of CD4+ helper T cells in the immune response?
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Which type of antigens can dendritic cells ingest and transport into the cytosol for processing?
Which type of antigens can dendritic cells ingest and transport into the cytosol for processing?
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Which type of T cells are presented with endocytosed protein antigens in the MHC pathway?
Which type of T cells are presented with endocytosed protein antigens in the MHC pathway?
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Where are antigens destined for presentation via the Class II MHC pathway usually internalized from?
Where are antigens destined for presentation via the Class II MHC pathway usually internalized from?
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How are cytosolic proteins tagged for degradation in proteasomes?
How are cytosolic proteins tagged for degradation in proteasomes?
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What happens to antigens destined for presentation via the Class II MHC pathway once they are internalized?
What happens to antigens destined for presentation via the Class II MHC pathway once they are internalized?
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What is the term for the initiation of CD8+ T cell responses to antigens in organ transplants and some intracellular microbes?
What is the term for the initiation of CD8+ T cell responses to antigens in organ transplants and some intracellular microbes?
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Where do the peptides generated by proteasomes bind to newly synthesized MHC class I molecules?
Where do the peptides generated by proteasomes bind to newly synthesized MHC class I molecules?
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What is the function of tapasin in the MHC class I pathway?
What is the function of tapasin in the MHC class I pathway?
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How are peptide-MHC complexes recognized by CD4+ helper T cells?
How are peptide-MHC complexes recognized by CD4+ helper T cells?
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Which molecular pump transports peptides generated by proteasomes into the ER?
Which molecular pump transports peptides generated by proteasomes into the ER?
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What is the function of tapasin in relation to class I MHC molecules?
What is the function of tapasin in relation to class I MHC molecules?
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What stabilizes newly synthesized class I MHC molecules in the ER initially?
What stabilizes newly synthesized class I MHC molecules in the ER initially?
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Which type of T cells recognize peptide-MHC complexes on the cell surface?
Which type of T cells recognize peptide-MHC complexes on the cell surface?
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What is the main function of proteasomes in the MHC pathway?
What is the main function of proteasomes in the MHC pathway?
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Which mechanism allows for preferential loading of high-affinity peptides onto class I MHC molecules?
Which mechanism allows for preferential loading of high-affinity peptides onto class I MHC molecules?
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What is the role of chaperones in the stabilization of class I MHC molecules?
What is the role of chaperones in the stabilization of class I MHC molecules?
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Where are high-affinity peptides preferentially loaded onto class I MHC molecules?
Where are high-affinity peptides preferentially loaded onto class I MHC molecules?
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Where are Class II MHC molecules synthesized?
Where are Class II MHC molecules synthesized?
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What is left in the peptide-binding cleft after the degradation of the invariant chain?
What is left in the peptide-binding cleft after the degradation of the invariant chain?
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Which protein facilitates the exchange of CLIP with other peptides in the vesicles?
Which protein facilitates the exchange of CLIP with other peptides in the vesicles?
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What type of cells do Class II MHC molecules display peptides to?
What type of cells do Class II MHC molecules display peptides to?
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What type of antigens do Class I MHC molecules bind and display peptides derived from?
What type of antigens do Class I MHC molecules bind and display peptides derived from?
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Where are extracellular microbes typically captured?
Where are extracellular microbes typically captured?
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What type of T cells recognize peptides displayed by Class I MHC molecules?
What type of T cells recognize peptides displayed by Class I MHC molecules?
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Why are T cell-mediated immune responses limited to cell-associated antigens?
Why are T cell-mediated immune responses limited to cell-associated antigens?
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Which compartments facilitate the processing of ingested proteins into peptides?
Which compartments facilitate the processing of ingested proteins into peptides?
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What is the function of CD4+ T cells?
What is the function of CD4+ T cells?
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What is the role of CD8+ T cells?
What is the role of CD8+ T cells?
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Which type of T lymphocytes are responsible for recognizing protein antigens from cytoplasmic microbes?
Which type of T lymphocytes are responsible for recognizing protein antigens from cytoplasmic microbes?
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What pathway do protein antigens from extracellular microbes enter for recognition by T lymphocytes?
What pathway do protein antigens from extracellular microbes enter for recognition by T lymphocytes?
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What determines the immunodominance of some peptides and the inability of some individuals to respond to certain protein antigens?
What determines the immunodominance of some peptides and the inability of some individuals to respond to certain protein antigens?
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What is the role of class I MHC pathway in antigen presentation?
What is the role of class I MHC pathway in antigen presentation?
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How do T cells recognize nonpeptide antigens?
How do T cells recognize nonpeptide antigens?
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In some inbred animals, non-expression of certain class II MHC genes led to their inability to respond to:
In some inbred animals, non-expression of certain class II MHC genes led to their inability to respond to:
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What do protein antigens from cytoplasmic microbes lead to upon recognition by T lymphocytes?
What do protein antigens from cytoplasmic microbes lead to upon recognition by T lymphocytes?
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What is responsible for displaying peptides of protein antigens for immune response generation?
What is responsible for displaying peptides of protein antigens for immune response generation?
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How are small molecules and metal ions recognized by T cells?
How are small molecules and metal ions recognized by T cells?
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What is the role of Class II MHC pathway in antigen presentation?
What is the role of Class II MHC pathway in antigen presentation?
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What are Major Histocompatibility Complex (MHC) molecules responsible for displaying?
What are Major Histocompatibility Complex (MHC) molecules responsible for displaying?
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Study Notes
- The text discusses the importance of linking microbes to specific antigen-processing pathways for effective immune response against intracellular and extracellular microbes.
- Protein antigens from cytoplasmic microbes enter the class I MHC pathway and are recognized by CD8+ cytotoxic T lymphocytes, which kill infected cells.
- Protein antigens from extracellular microbes enter the class II MHC pathway and are recognized by CD4+ helper T lymphocytes, which activate macrophages to destroy phagocytosed microbes and activate B cells to produce antibodies.
- Class I MHC pathway: Antigen presentation to cytotoxic T lymphocytes: cytosolic antigen, antigen presentation, binding to CD8+ T cells, and T cell-dependent effector functions.
- Class II MHC pathway: Antigen presentation to helper T cells: macrophage and extracellular microbe in endosome, binding to CD4+ helper T lymphocytes, release of cytokines, macrophage activation, and B cell antibody secretion.
- Structural constraints on peptide binding to different MHC molecules determine the immunodominance of some peptides and the inability of some individuals to respond to certain protein antigens.
- T cells also recognize and react against small molecules and metal ions in an MHC-restricted manner.
- Some inbred animals did not respond to simple protein antigens due to non-expression of certain class II MHC genes, which were later discovered to be involved in antigen presentation.
- T cells recognize nonpeptide antigens through covalent modification of self peptides or MHC molecules, or noncovalent binding of chemicals to MHC molecules, altering the peptide-binding cleft and displaying foreign peptide-MHC complexes.
- The text answers questions about how rare antigen-specific lymphocytes find antigens and generate appropriate immune responses against extracellular and intracellular microbes by explaining the roles of antigen-presenting cells (APCs) and Major Histocompatibility Complex (MHC) molecules in displaying peptides of protein antigens.
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Description
Test your knowledge about the binding of peptides to class I MHC molecules and their potential to stimulate immune responses. Explore the relationship between peptide binding and the stability of MHC molecules.
