Features of the pathways of Ag processingFeatures of the pathways of Ag processingFeatureFeature Class II MHC PathwayClass II MHC Pathway Class I MHC Class I MHC

PathwayPathwayCompositionCompositionof MHCof MHC

Types of APCTypes of APC

Responsive T cellResponsive T cell

Source of AgsSource of Ags

Enzymes responsibleEnzymes responsibleFor peptide degradationFor peptide degradation

Molecules involved inMolecules involved inTransport of peptides andTransport of peptides andLoading of MHC moleculesLoading of MHC molecules

Features of the pathways of Ag processingFeatures of the pathways of Ag processing

FeatureFeature Class II MHC Pathway Class II MHC Pathway Class I MHC Class I MHC PathwayPathway

CompositionComposition alpha/beta chainsalpha/beta chains alpha/beta 2-malpha/beta 2-mof MHCof MHC

Types of APCTypes of APC DC, MO, B cells (endothelial) DC, MO, B cells (endothelial) All nucleatedAll nucleated

Responsive T cellResponsive T cell CD4 T cellsCD4 T cells CD8 T cellsCD8 T cells

Source of AgsSource of Ags ExogenousExogenous EndogenousEndogenous

Enzymes responsibleEnzymes responsible Endosomal and lysosomalEndosomal and lysosomal Cytosolic Cytosolic For peptide degradationFor peptide degradation proteasesproteases proteasomeproteasome

Molecules involved inMolecules involved inTransport of peptides andTransport of peptides and Invariant chain (Ii), HLA-DMInvariant chain (Ii), HLA-DM TAPTAPLoading of MHC moleculesLoading of MHC molecules

Kuby Figure 8-8Viral immune evasion