Any process that stops, prevents, or reduces the frequency, rate, or extent of antigen processing and presentation of peptide antigen via MHC class II.
Synonyms:
exact_synonym:
down regulation of antigen processing and presentation of peptide antigen via MHC class II; downregulation of antigen processing and presentation of peptide antigen via MHC class II; negative regulation of peptide antigen processing and presentation via MHC class II
narrow_synonym:
inhibition of antigen processing and presentation of peptide antigen via MHC class II