lecture 9 multiple chocie quiz- immunology

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Which cell surface proteins play a central role in presenting peptides to CD8+ T cells?

Rotes of antigen entry

MHC class I molecules (correct)

Dendritic cells

MHC class II molecules

What is the main role of MHC class II molecules?

Code for alpha and beta chains

Activate CD4 T lymphocytes

Present peptides to CD8+ T cells

Present peptides from extracellular proteins to CD4+ T cells (correct)

What is the significance of the peptide-binding cleft in MHC molecules?

Contains polymorphic amino acids (correct)

Influences the MHC shape and chemical properties

Identifies specific amino acid residues

Activates CD8+ T cells

Which type of T cells do MHC class I molecules present peptides to?

CD8+ T cells Signup and view all the answers

What is the role of MHC molecules in antigen presentation?

Influence the peptide-binding specificity Signup and view all the answers

What is the primary function of Class I MHC molecules?

Presenting peptides derived from intracellular proteins to CD8+ cytotoxic T lymphocytes Signup and view all the answers

Which type of T cells recognize Class II MHC molecules?

CD4+ helper T cells Signup and view all the answers

What is the significance of MHC haplotypes in immune responses?

They play a role in the diversity of immune responses and disease susceptibility Signup and view all the answers

Which region of MHC molecules are encoded by polymorphic genes?

Antigen-binding regions critical for presenting a diverse range of peptides to T cells Signup and view all the answers

What do Class II MHC molecules primarily present?

Peptides derived from extracellular proteins to CD4+ helper T cells Signup and view all the answers

Which class of MHC molecules presents peptides derived from intracellular proteins to CD8 T cells?

Class I Signup and view all the answers

In the context of MHC, which cells interact with peptides presented by MHC Class II molecules?

CD4+ T cells Signup and view all the answers

What is the main role of MHC Class II molecules in antigen presentation?

Present peptides from extracellular proteins to CD4 T cells Signup and view all the answers

Which gene loci were initially identified through research on tissue transplantation and encode for MHC proteins?

Human Leukocyte Antigen (HLA) complex Signup and view all the answers

What is the significance of matching MHC alleles between the donor and recipient in tissue transplantation?

Increases transplant success by reducing risk of rejection Signup and view all the answers

Which type of cells primarily express Class II MHC molecules?

Dendritic cells, macrophages, B cells Signup and view all the answers

What is the main role of Class I MHC molecules in the immune system?

Expressed on the surface of all nucleated cells Signup and view all the answers

What is the significance of matching MHC alleles in transplantation?

Essential for reducing the risk of rejection Signup and view all the answers

What do Class II MHC molecules present peptides derived from?

Extracellular proteins Signup and view all the answers

Where are Class I MHC molecules expressed?

On the surface of all cells except erythrocytes Signup and view all the answers

Which type of T cells are primarily involved in cell-mediated immune responses against infected or abnormal cells?

CD8+ T cells Signup and view all the answers

What is the role of Class II MHC molecules in the immune response?

Regulate immune responses Signup and view all the answers

Which type of proteins do Class I MHC molecules primarily present peptides from?

Proteins from infected cells Signup and view all the answers

What is the main function of dendritic cells in antigen presentation?

Activate CD8+ T lymphocytes Signup and view all the answers

What structural feature of MHC molecules allows them to present a wide range of peptides to T cell receptors?

Peptide-binding cleft Signup and view all the answers

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. Signup and view all the answers

Which type of T lymphocytes interact with Class I MHC molecules to present intracellular peptides?

CD8+ cells Signup and view all the answers

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. Signup and view all the answers

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. Signup and view all the answers

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. Signup and view all the answers

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. Signup and view all the answers

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. Signup and view all the answers

Which cell surface proteins play a central role in presenting peptides to CD4+ T cells?

Class II MHC molecules Signup and view all the answers

What is the role of dendritic cells in antigen capture and presentation?

Capturing antigens, processing them, and presenting them to T cells Signup and view all the answers

How do MHC cell surface proteins activate CD4+ T lymphocytes?

By presenting peptide antigens to TCRs on CD4+ T cells Signup and view all the answers

In which cellular compartment are peptides loaded onto Class II MHC molecules?

Endosomal compartments Signup and view all the answers

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. Signup and view all the answers

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. Signup and view all the answers

What initiates immune responses following interaction between MHC-bound peptide antigens and T cell receptors?

T cell activation Signup and view all the answers