Innate and Adaptive Immunity Part 2 Flashcards
what are the components of GALT
Peters patches (PPs) and isolated lymphoid follicles constitute the major part of GALT, but the appendix is also included
what are the components of NALT?
in humans, NALT consists of the lymphoid tissue of waldezyers pharyngeal ring, including the adenoids (the unpaired nasopharyngeal tonsil) and the paired palatine tonsils, scattered isolated lymphoid follicles may also occur in nasal mucosa
rodents lack tonsils, but do have paired
NALT structures dorsally in the floor of the nasal cavity and also salivary glands
what are the components of BALT
not generally detectable in normal lungs of adult humans
waldeyers ring
an interrupted circle of protective lymphoid tissue at the upper ends of the respiratory and alimentary tracts
composition of saliva (9)
~99% water Na K Ca Mg bicarbonate proteins enzymes muffins nitrogenous products such as urea and NH3
types of saliva (3)
serous
mucos
mixed serous and mucos
serous saliva is the main product of the
parotid glands
mucos saliva is the main product of the
minor glands
mixed serous and mucos saliva is the main product of the (2)
sublingual and submandibular glands
functions of saliva (6)
lubrication and protection buffering action and clearance maintenance of tooth integrity antibacterial activity taste and digestion saliva production is 750-1000 mL/day
where is GCF secreted
into the space (gingival sulcus) between the surface of the toot hand the free margin of the epithelium lining the gingiva
how much GCF is secreted a day
1-2 mL /day
functions of GCF (4)
cleansing the sulcus
improve adhesion of the epithelium to the tooth surface
antimicrobial properties
antibody defense of the gingiva
how many proteins and peptides detected in the proteome of saliva?
> 2000
200 proteins are secretions of
major glands (parotid, submandibular, and sublingual)
secretions of the major glands include (6)
alpha-amylase mucins histatins statherin salivary cystatins PB peptide
the remaining 1800 proteins include (2)
alpha defensins
beta thymosins
what is the major fraction of salivary proteins?
proline rich proteins (PRPs)
20-30% of total
PRPs are highly
phosphorylated, some
where is the highest concentration of PRPs found?
in parotid saliva
> 20 PRPs are (2)
acidic
basic
glycosylated
acidic PRPs (3)
10-40 kDa
N terminal region contains high % of acidic GAs (ex. asp glu)
bind bacteria
basic PRPs (3)
60-70 kDa
high content of basic Was (ex. arg, his, lys)
bind fungi and viruses
glycosylated PRPs (1)
bind bacteria and virus
PRPs help exclude
microbes from surfaces and clear from oral cavity
alpha-amylase
major digestive enzyme (glycoside hydrolase)
alpha-amylase catalyzes breakdown of
starch into sugars (di, tri-saccharides)
alpha amylase acts on
alpha-1,4 glycosidic bonds
alpha amylase optimum pH is
6.7-7
antimicrobial properties of alpha-amylase (4)
Binds bacteria, (pili involved in bacterial adhesion); promotes clearance from oral cavity to GI tract (e.g., Streptococcus gordonii, S. mitis, S. crista, S. anginosus)
Direct inhibitory effect on certain bacteria; powerful selective inhibitor of Neisseria gonorrhoeae
Binds bacterial lipopolysaccharide (LPS)
May inhibit virus (equine & porcine rotaviruses)
cystatins are what kind of inhibitor
cys protease inhibitors
block bacterial and parasitic protozoan proteases
how many cystatins are present in saliva?
7
A, B C, D, S, SA, SN
highest concentrations of cystatins are found in — and lowest in —
highest: submandibular saliva
lowest: parotid saliva
which cystatins inhibit bacterial growth?
C and S
which sustains bind bacteria and bacterial LPS? (2)
SN and S
cystatins are also likey to exert
antiviral effects
mucins
High molecular weight, heavily glycosylated proteins
mucins are produced by
epithelial tissues
mucins are secreted onto
mucosal surfaces or as component of saliva
mucins bind to
pathogens are part of the immune system
mucins prevent
adherence of oral microbes to the enamel pellicle and inhibits their growth, reducing caries
mucins form
viscous coating on epithelial surfaces
microbes excluded from the surface due to
steric hinderance from the dense glycostlation layer
MG1 is produced in the
submandibular gland for
MG1 function
barrier protection
MG@ is produced in
acini of submandibular and labial glands
MG2 interacts with – and promotes
streptococci
promotes their aggregation
statherin size and # of residues
5.4 kDa (43 residues)
statherin is a (3) phosphoprotein
tyr
gluc
pro-rich
statherin inhibits
precipitation of calcium phosphate salts from saliva
statherin is critical for
remineralization of teeth
statherin binding of bacteria likely leads to
aggregation and clearance towards the stomach
histatins size
small, 7-38 aa
histatins are rich in
His-rich
cationic peptides
histatins are secreted by (3)
parotid
SL
SM glands
histatins broad spectrum properties (3)
antibacterial
antifungal
antiviral
histatins act on
microbial membranes
primary function of salivary antibodies
inactivate bacteria, fungi, viruses & microbial toxins via binding and/or agglutination
salivary antibodies are constitutively excreted into
saliva
2 major antibody classes
secretory immunoglobulin A (sIgA) immunoglobulin G (IgG)
secretory immunoglobulin A (sIgA) (4)
a) 90-98% of salivary Ab
b) dimeric or polymeric
c) produced by salivary gland
d) 15% derived from serum; monomeric
immunoglobulin G (IgG) (3)
a) 1-10% of salivary Ab
b) monomeric
c) serum derived
there is a small fraction of (3) salivary antibodies
IgM
IgD
IgE
Serum derived IgG & monomeric (non-secretory) IgA enter oral cavity via (3)
GCF
mucosal transudate
ultrafiltration through the SG acini
salivary defenses (3)
cationic, lys containing peptides
alpha-defensins
beta-defensins
alpha-defensins (4)
HNP1, HNP2, HNP3, HNP4
alpha-defensins are produced by
neutrophil granulocytes
beta-defensins (4)
hBD1, hBD2, hBD3, hBD4
beta-defensins are produced by
mucosal cells
both alpha and beta defensins are present in (4)
whole saliva
GCF
broad antibacterial, antifungal & antiviral activities
also various immune activator & modulatory activities, incl. induction of cytokines & chemoattraction for immature dendritic & memory T-cells
Fordyce’s granules
they are sebaceous glands containing lipid. - a normal phenomenon not an infection,
Fordyce’s granules have been linked to
hyperlipidemia
where was the term antibody was coined
by Emil von Behring and Shibasaburo Kitasato in 1890. They discovered that the serum of vaccinated individuals contained substances that specifically bound to relevant pathogens
The diversity of lymphocyte antigen receptors is generated by
somatic gene-segment rearrangements
antibody diversity light chains (2)
V (variable region) and J (joining segment)
Κ light chain gene cluster is on
Cs 2
λ light chain gene cluster is on
Cs 22
heavy chains (5)
α, δ, ε, γ, and μ
heavy gene are on
Cs 14
35 VLκ genes X 4 JLκ genes =
140 κ chain variable region genes
3o VLλ genes X 5 JLλ genes =
150 λ chain variable region genes
Total of — different light chains
290
Heavy Chains
100 VH genes X 23 DH genes X 6 JH genes = 13,800 chain variable regions
Total binding specificities:
290 X 13,800 = 4,002,000
In additional junctional diversity caused by addition or removal of nucleotides between the different gene segments increases the specificity of the variable region to
10^10 !!!
Antigens are molecules recognized by the
immune response
Specific regions within antigens that antigen receptors bind are known as
epitopes
complement
its role in “complementing” the antibacterial activity of antibodies was discussed in a previous lecture
Complement can also be activated early in infection in the absence of
antibodies
It now appears that complement first evolved as part of the innate immune system, where it plays an important role in (2)
coating pathogens and facilitating their destruction
