Oral Immunity & Host Defenses Flashcards
(29 cards)
What does an accumulation of dental plaque induce?
inflammatory response in gums -> inflammation in pulp may lead to abscess & root canal
*dental diseases result from imbalance between oral commensal bacteria and immune responses
What is the general concept of host defenses?
in oral cavity it consists of both mucosal and systemic immune systems
What are the physical barriers in oral cavity?
epithelial cells with tight junctions, basement membrane below
What is in saliva to help protect against microbes?
mucins, a & B defensins, protease inhibitors, lysozyme, lactoferrin, peroxidases
What is the enamel pellicle?
protects teeth from demineralization & friction, however contributes to plaque formation, made of mucins, secretory IgA and other proteins
In MALT, what does secretory IgA in saliva do?
neutralize toxins & pathogens, binds pathogen and transported through lamina propria by M cells to induce an immune response
In MALT, what is homing?
activated lymphocytes enter circulatory system -> enter infected mucosa
What is the Systemic Immune System of Oral Immunity composed of?
leukocytes in pulp and gingival crevice, lymph
How is the inflammatory response induced when caries approach pulp?
neutrophils enter pulp from blood -> B cells migrate into pulp -> inflammation helps prevent damage to pulp -> abscess or lesion forms
What is the importance of the gingival crevice?
it is the major site where leukocytes enter saliva (in gingival crevicular fluid)
How does gingival crevicular fluid function in response to plaque?
after leukocytes from MALT, is part of systemic system so it mixes with the mucosal system (saliva), increases flow and changes composition, increase leukocytes within gingival sulcus (especially neutrophils)
How can pathogens be classified?
where infection occurs
Recovery and resistance requires what type of immunity?
acquired, although responses may differ
Can a wrong immune response be lethal?
yes, especially T cell response
Where are extracellular pathogens found?
within body fluids or attached to epithelial cells
Where are intracellular pathogens found?
cytoplasm or vesicles
What are the four types of pathogens?
bacteria, fungi, virus, parasite
What are the defenses against bacteria?
neutralizing antibodies prevent attachment, opsonization of pathogen, classical complement pathway, neutralizing antibodies against bacterial toxins, activation of macrophages by Th1 CD4+ T cells, cytotoxic CD8+ T Cells kill infected cells
What type of pathogens are viruses?
extracellular before infecting, then intracellular
How are virus infections categorized?
acute infection, latent with reactivation, chronic
What is the defense against acute virus infection?
viruses eliminated, cell mediated immunity is important for recovery, antibody stops virus from spreading and may render host resistant to reinfection
What is the defense against latent virus infections with reactivation?
virus persists in latency, cell mediated immunity clears infected cells, as well as antibodies prevent spreading when reactivation does occur
What is the defense against chronic virus infections?
virus not eliminated nor latency, disease may be limited by immune response
What are the categories of fungal infections?
cutaneous, systemic
