Any process that activates or increases the frequency, rate, or extent of antigen processing and presentation of antigen (peptide or polysaccharide) via MHC class II.
Synonyms:
exact_synonym:
positive regulation of peptide or polysaccharide antigen processing and presentation via MHC class II; up regulation of antigen processing and presentation of peptide or polysaccharide antigen via MHC class II; upregulation of antigen processing and presentation of peptide or polysaccharide antigen via MHC class II
narrow_synonym:
activation of antigen processing and presentation of peptide or polysaccharide antigen via MHC class II; stimulation of antigen processing and presentation of peptide or polysaccharide antigen via MHC class II