Lecture 3 - Oral Immunology Flashcards
Name 4 innate process of our oral immunity
- Saliva
- Thick, continually recycling epithelium
- Gingival junctional epithelium –> different = leaky
- Competitive Normal flora
In what 5 ways does Saliva provide oral immunity?
- Constant H2O flush
- Dissolves food
- Buffers (for acids)
- Contains anti-bacterial molecules
- Provides protective oral ‘coating’
Describe how a thick, continually recycling epithelium helps with oral immunity?
- Tough keratin layer with high lipid content
- Tight junctions
- Impermeable
Describe the gingival junctional epithelium.
- Non-keratinized with low lipid content
- Loose junctions
- Allows plasma fluid & inflammatory cells access to mouth
- Leaky!
T or F, Keratinocytes of the junctional epithelium are poorly differentiated and make little keratin, little hydrophobic granular materials, and are loosely linked to each other.
True
Why is it important that the keratinocytes of gingival junctional epithelium are loosely linked to each other?
This allows capillary plasma exudate and migrating PMNs to readily pass into the gingival crevice area = LEAKY!
T or F, Junctional epithelial cells display HLA class II. What does this allow them to do?
True, It allows them to present extracellular antigenic peptides, thereby activating Th cells (T-helper cells)
Junctional epithelial cells, if stimulated by certain microbial products, release what? What will that do?
Release the chemokine IL-8 and numerous other cytokines and chemokines that can activate and stimulate local capillaries, mast cells, and are chemotactic for PMNs
When bacterial infection occurs in mouth and induces a localized inflammatory reaction, what does this cause to happen?
- Causes local edema
- Infiltration by blood leukocytes (PMNs) into and through the junctional epithelium.
- These enter the crevicular fluid, where along with IgG, they help keep the plaque bacteria contained and localized.
Outside of the cervicular space, what plays a major protective factor?
saliva
Saliva contains what immunoglobulin? Does it contain anything else?
Ag-specific sIgA
- Also contains numerous generic, non-Ag-specific, anti-microbial agents (lysozyme)
- It also buffers, dilutes, and washes away toxins and acids that are produced by oral microorganisms.
Neutrophils (PMNs) are produced and matured where?
Bone marrow
What are the major phagocytic cell in the body?
Neutrophils (PMNs)
About 2/3 of blood leukocytes are what?
PMNs
T or F, PMNs are very long-lived cells. In the blood they have a half-life of 6 hours
False, They are very short-lived cells. In the blood they have a half-life of only 6 hours
What is the half life of PMNs that enter tissue
if they enter the tissue, their half life is extended from 6 hours to 1-2 days.
How do PMNs attach to foreign microorganisms?
They use various cell-surface receptors to attach to foreign microorganisms and their products
White PMNs enter the blood stream and go with the flow, they reach a site o inflammation where capillary endothelial cells express what that PMNs can grab onto?
Adhesion molecules (CAMs)
3 Receptor binding triggers for PMNs
- Phagocytosis/Chemotaxis
- Degranulation
- Oxydative Burst
The fluid defenses of the oral cavity include what 2 things?
Saliva and crevicular fluid
What cells mainly make up the crevicular fluid?
PMNs - 90%
Monocytes and IgG cells - 10%
Where does crevicular fluid come from?
from the capillaries below, its antibody levels therefore reflect what is found in plasma: high levels of IgG and low levels of IgA
In contrast to crevicular fluid, Saliva contains large amounts of?
IgA and little IgG. This is because it is a fluid secreted by the body.
- Also contains non-specific anti-microbials (lysozyme), buffers that help maintain the pH.
sIgA is resistant to what?
proteases
What is the secretory component of sIgA?
The secretory component is some of the Fc receptor that remains attached to the IgA when it travels through the cell.
sIgA sticks to what?
Mucins
What can sIgA do?
neutralize viruses/toxins, block colonization of microbes and are resistant to proteases.
