Antigen Processing and Presentation by MHC on Professional APCs

Play an AI-generated podcast conversation about this lesson

Which cells are the most efficient antigen presenting cells (APCs)?

B lymphocytes

Macrophages

Dendritic cells (correct)

Langerhans cells

Where are dendritic cells primarily located?

In the liver

In the bloodstream

In the bone marrow

Under the skin and mucosa (correct)

What is the role of dendritic cells in the immune response?

Storing antigens for future use

Processing and presenting antigens to activate T cells (correct)

Producing antibodies

Destroying pathogens directly

How do protein antigens bind to MHC molecules on APCs?

By endocytosis Signup and view all the answers

Where do dendritic cells transport captured foreign antigens for presentation to naive helper T cells?

To local lymph nodes Signup and view all the answers

Which type of antigens require antigen processing and conversion to peptides for binding to MHC molecules on APCs?

Exogenous antigens Signup and view all the answers

Which of the following is true about the MHC-II pathway?

The invariant chain (Ii) temporarily occupies the peptide binding groove. Signup and view all the answers

Which type of antigen-presenting cells can process extracellular antigens for MHC class I presentation via cross-presentation?

Dendritic cells Signup and view all the answers

What is the source of protein antigens presented by MHC class II molecules?

Mainly exogenous proteins taken up by endocytosis Signup and view all the answers

Which pathway is particularly important for activating CD8+ T cells to respond to virus-infected cells, tumor cells, and dying cells?

Cross-presentation pathway Signup and view all the answers

Which type of antigens are processed and presented by all nucleated cells?

Endogenous antigens Signup and view all the answers

Which pathway involves the use of autophagy to gain access to lysosomal degradation for antigen loading?

Both MHC-II and cross-presentation pathways Signup and view all the answers

Which cells are considered professional antigen-presenting cells (APCs)?

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

In the MHC-I pathway, what is the source of the endogenous antigens that are processed and presented?

Viral proteins and tumor antigens generated within the cell Signup and view all the answers

What is the role of TAP proteins in the MHC-I pathway?

They transport the peptides from the cytoplasm into the endoplasmic reticulum Signup and view all the answers

In the MHC-II pathway, how are exogenous antigens processed and presented?

Exogenous antigens are taken up by endocytosis, degraded in the lysosome, and the peptides are loaded onto MHC-II molecules Signup and view all the answers

What is the role of CD8+ T cells in the immune response?

CD8+ T cells bind to the MHC-I/peptide complex and directly kill the infected or transformed cell Signup and view all the answers

How are MHC-I molecules assembled and transported to the cell surface?

MHC-I molecules are synthesized by ribosomes on the rough endoplasmic reticulum, assembled in the ER lumen, and then transported through the Golgi to the cell surface Signup and view all the answers