Immune Responses in Periodontal Disease Flashcards
(15 cards)
What are the key immune and defense mechanisms involved in periodontal pathogenesis?
- Innate Immunity: Immediate, nonspecific defense against pathogens.
- Adaptive Immunity: Specific immune responses to antigens.
- Saliva: Contains antimicrobial proteins and enzymes.
- Epithelial Tissue: Acts as a physical barrier.
- Gingival Crevicular Fluid: Contains immune cells and antibodies for protection.
What are the two main types of immunity in periodontal defense?
- Innate Immunity: Nonspecific defense mechanisms, including barriers like skin and mucosa.
- Adaptive Immunity: Antigen-specific responses that target particular pathogens.
What are the main components of innate immunity?
- Barriers: Skin, mucosa, stomach acid.
- Immune Cells: Neutrophils and macrophages that kill pathogens.
- Antimicrobial Molecules: Lysozymes and peptides.
- Receptors: Toll-like receptors that detect pathogens.
- Antigen Presentation: Activates adaptive immunity.
What are the primary components of adaptive immunity?
- Recognition of specific pathogens at species and strain levels.
- Cellular Immune Response: Targets intracellular pathogens (e.g., viruses) using T cells, macrophages, and NK cells.
- Humoral Immune Response: Targets extracellular pathogens (e.g., bacteria) using B cells that produce antibodies.
What are the main types and roles of host-derived inflammatory mediators?
Types: Cytokines, Prostaglandins, Enzymes (e.g., Matrix Metalloproteinases, MMPs)
Roles:
- Protective: Kill bacteria and neutralize antigens.
- Destructive: Induce inflammation that can cause tissue damage.
What roles do cytokines play in periodontal disease?
- Act as messengers, binding to receptors to initiate signaling.
- Function locally and are short-lived in tissues.
- Proinflammatory and anti-inflammatory
- Regulate immune responses and tissue destruction.
What are the main cytokines in the Interleukin-1 family and their roles?
- IL-1α: Promotes bone resorption; produced by macrophages and neutrophils.
- IL-1β: Key proinflammatory mediator, up-regulates inflammation.
- IL-18: Similar to IL-1β, activates neutrophils.
- IL-1Ra: Acts as an antagonist, inhibiting IL-1α and IL-1β effects.
What role does TNF-α play in periodontitis?
- Increases neutrophil activity and osteoclast development.
- Stimulates MMP secretion and endothelial selectins for leukocyte recruitment.
- Limits tissue repair and promotes apoptosis in fibroblasts.
What is the function of Interleukin-6 in periodontal disease?
- Stimulates bone resorption and osteoclast development.
- Regulates B cell and T cell differentiation.
- Secreted by T cells, B cells, macrophages, keratinocytes, and fibroblasts.
What role do chemokines play in periodontal inflammation?
- Act as chemoattractants for leukocytes during infection.
- Essential for neutrophil recruitment and migration to sites of infection.
- Influence osteoclast activity and bone resorption.
What are the key anti-inflammatory cytokines involved in periodontal health and what are their roles?
- IL-4: Regulates adaptive immunity.
- IL-10: Immunosuppressive, produced by Tregs.
- IL-1Ra: Blocks IL-1 effects, anti-inflammatory.
- IL-1F5: Antagonises the inflammatory effects of IL-1β and LPS
- TGF-β: Promotes repair and regeneration, regulates immune response.
What is the role of prostaglandins in periodontal disease?
- Derived from arachidonic acid through COX-1 and COX-2 pathways they promote inflammation and bone resorption.
** PGE₂ is critical for vasodilation, cytokine release, and osteoclast activation.
What are Matrix Metalloproteinases (MMPs) and their role in periodontitis?
- Enzymes that degrade structural proteins like collagen
- Produced by neutrophils, fibroblasts, macrophages, osteoclasts.
- In periodontitis, MMP-8 and MMP-9 are elevated, contributing to tissue destruction.
How are MMPs inhibited?
- α1-antitrypsin and α2-macroglobulin (liver-produced inhibitors)
- Tissue inhibitors of metalloproteinases (TIMPs)
- Tetracyclines (e.g., doxycycline)
How does host susceptibility affect periodontal disease progression?
- Hyperresponders: High inflammatory response → more tissue breakdown.
- Hyporesponders: Low inflammatory response → less tissue breakdown.
- Genetic differences influence individual susceptibility.
