What is presented on MHC class II molecules?
Having MHC class II molecules present proper peptides that are bound stably is essential for overall immune function. Class II molecules interact mainly with immune cells, like the T helper cell (CD4+). The peptide presented regulates how T cells respond to an infection.
What role to MHC II molecules play in antigen presentation?
Antigen presentation with MHC II is essential for the activation of T cells. Antigen-presenting cells (APCs) primarily ingest pathogens by phagocytosis, destroy them in the phagolysosomes, process the protein antigens, and select the most antigenic/immunodominant epitopes with MHC II for presentation to T cells.
Where do the peptides presented by MHC class II molecules come from?
MHC class II presentation MHC class II molecules bind to peptides that are derived from proteins degraded in the endocytic pathway. MHC class II complexes consists of α- and β-chains that are assembled in the ER and are stabilised by invariant chain (Ii).
Where are antigens loaded into MHC class II complexes?
endosomes
Antigenic fragments and self-peptides are loaded onto MHC class II molecules in late endosomes or MHC class II containing compartments (MIICs).
What antigens are presented by MHC II?
MHC class II binds antigenic peptides that are generated by proteolysis of self and non-self proteins in endosomes and lysosomes, and ‘presents’ them to antigen-specific CD4+ T cells3.
Where are class II MHC molecules found quizlet?
Class II MHCs are found on antigen-presenting cells and present antigens to CD4 positive T cells.
What is MHC presentation?
Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity. Prior to presentation, peptides need to be generated from proteins that are either produced by the cell’s own translational machinery or that are funneled into the endo-lysosomal vesicular system.
How do MHC class I and MHC class II antigen presentation differ?
MHC class I glycoproteins present endogenous antigens that originate from the cytoplasm. MHC II proteins present exogenous antigens that originate extracellularly from foreign bodies such as bacteria. MHC Class II presents 14-18 amino acid peptides.