Microbiology And Immunology 6400 Oral Intermicrobial Interactions Practice Test

Pattern recognition receptors in the oral epithelium that detect microbial components include Toll-like receptors on the cell surface and in endosomes, which recognize a range of bacterial PAMPs such as lipopolysaccharide, lipoproteins, and flagellin. When these receptors bind their ligands, they activate signaling pathways that drive inflammatory cytokine production and antimicrobial peptide release, helping the epithelium mount a rapid defense against invading microbes. Cytosolic NOD-like receptors sense intracellular bacterial components, like peptidoglycan fragments, and can form inflammasomes that activate caspase-1 to produce inflammatory cytokines such as IL-1β. This complements surface and endosomal sensing by detecting microbes that have breached the cell membrane, reinforcing the antimicrobial response. Together, these two families are central to detecting microbial components in the oral mucosa. In contrast, G protein-coupled receptors are not primary microbial pattern-recognition receptors, RIG-I-like receptors focus on viral RNA, and Nuclear receptors respond to host-derived ligands rather than direct microbial PAMPs.