39 Questions
Which cell surface proteins play a central role in presenting peptides to CD8+ T cells?
MHC class I molecules
What is the main role of MHC class II molecules?
Present peptides from extracellular proteins to CD4+ T cells
What is the significance of the peptide-binding cleft in MHC molecules?
Contains polymorphic amino acids
Which type of T cells do MHC class I molecules present peptides to?
CD8+ T cells
What is the role of MHC molecules in antigen presentation?
Influence the peptide-binding specificity
What is the primary function of Class I MHC molecules?
Presenting peptides derived from intracellular proteins to CD8+ cytotoxic T lymphocytes
Which type of T cells recognize Class II MHC molecules?
CD4+ helper T cells
What is the significance of MHC haplotypes in immune responses?
They play a role in the diversity of immune responses and disease susceptibility
Which region of MHC molecules are encoded by polymorphic genes?
Antigen-binding regions critical for presenting a diverse range of peptides to T cells
What do Class II MHC molecules primarily present?
Peptides derived from extracellular proteins to CD4+ helper T cells
Which class of MHC molecules presents peptides derived from intracellular proteins to CD8 T cells?
Class I
In the context of MHC, which cells interact with peptides presented by MHC Class II molecules?
CD4+ T cells
What is the main role of MHC Class II molecules in antigen presentation?
Present peptides from extracellular proteins to CD4 T cells
Which gene loci were initially identified through research on tissue transplantation and encode for MHC proteins?
Human Leukocyte Antigen (HLA) complex
What is the significance of matching MHC alleles between the donor and recipient in tissue transplantation?
Increases transplant success by reducing risk of rejection
Which type of cells primarily express Class II MHC molecules?
Dendritic cells, macrophages, B cells
What is the main role of Class I MHC molecules in the immune system?
Expressed on the surface of all nucleated cells
What is the significance of matching MHC alleles in transplantation?
Essential for reducing the risk of rejection
What do Class II MHC molecules present peptides derived from?
Extracellular proteins
Where are Class I MHC molecules expressed?
On the surface of all cells except erythrocytes
Which type of T cells are primarily involved in cell-mediated immune responses against infected or abnormal cells?
CD8+ T cells
What is the role of Class II MHC molecules in the immune response?
Regulate immune responses
Which type of proteins do Class I MHC molecules primarily present peptides from?
Proteins from infected cells
What is the main function of dendritic cells in antigen presentation?
Activate CD8+ T lymphocytes
What structural feature of MHC molecules allows them to present a wide range of peptides to T cell receptors?
Peptide-binding cleft
What is the primary difference in the expression pattern of Class I and Class II MHC molecules?
Class I MHC molecules are expressed on professional antigen-presenting cells, while Class II MHC molecules are expressed on almost all nucleated cells.
Which type of T lymphocytes interact with Class I MHC molecules to present intracellular peptides?
CD8+ cells
What is the role of dendritic cells in the context of antigen capture and presentation?
Dendritic cells express Class II MHC molecules and capture extracellular antigens to present to T cells.
What feature distinguishes the peptide binding cleft of Class I MHC molecules from that of Class II MHC molecules?
The peptide binding cleft of Class I MHC molecules contains polymorphic amino acids, while that of Class II MHC molecules does not.
Which statement accurately describes the cellular distribution of Class I and Class II MHC molecules?
Class I MHC molecules are expressed on professional antigen-presenting cells, while Class II MHC molecules are expressed on almost all nucleated cells.
What distinguishes the peptide binding cleft of Class I MHC molecules from Class II MHC molecules?
Class II MHC cleft is open at both ends, while Class I MHC cleft is closed at one end.
How do peptides typically enter the endoplasmic reticulum (ER) for binding with Class I MHC molecules?
They are transported directly from the cytoplasm into the ER.
Which cell surface proteins play a central role in presenting peptides to CD4+ T cells?
Class II MHC molecules
What is the role of dendritic cells in antigen capture and presentation?
Capturing antigens, processing them, and presenting them to T cells
How do MHC cell surface proteins activate CD4+ T lymphocytes?
By presenting peptide antigens to TCRs on CD4+ T cells
In which cellular compartment are peptides loaded onto Class II MHC molecules?
Endosomal compartments
Why is the peptide-binding cleft of MHC molecules considered highly polymorphic?
It can adapt and bind a wide variety of peptide sequences due to its variability.
What happens when peptide antigens are presented on the cell surface for recognition by T cell receptors on CD8+ cytotoxic T cells?
T cell activation and initiation of immune responses occur.
What initiates immune responses following interaction between MHC-bound peptide antigens and T cell receptors?
T cell activation
Learn about the importance of MHC molecules as key antigens in tissue transplantation, their polymorphic nature, and how mismatched MHC alleles can lead to transplant rejection.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
