What is the best description of an infectious agent?
An organism that can replicate inside the host and cause a host reaction to its products
An organism which lives in co-existence with the host
An organism which is immunogenic
Advantages of infecting a host to a pathogen are:
P provision Travel
Disadvantages are:
Host driven mechanisms encountered
True or false?
The response of the innate immune system is the same every time
The first encounter of the adaptive immune system is very rapid.
The innate immune system has a memory property.
What are some physical barriers of the innate immune system?
Lysozyme
Hydrochloric acid
Ciliated epithelia
Epidermis
Which of these options summarises lysozymes action?
Cleaves the NAG-NAM carbohydrates in Gram positive bacterial cell walls
Generates hypothiocyanite anion which inhibits glucose transport by oxidation
Chelates iron, preventing growth and oxidation
Chelates Ca2+ and Zn2+
Induce pore formation
Which of these options summarises lactoperoxidase's action?
Which of these options summarises lactoferrin's action?
Which of these options summarises calprotectin's action?
Which of these options summarises defensin action?
Which of these options summarises histatin action?
Which is a function of mucins?
Glycoproteins which lubricate and hydrate the mucosal surfaces. This traps and prevents admission of bacteria to the mucosa.
Bind to bacterial adhesins causing bacterial clumping for removal
Which is a function of salivary agglutinin?
Defensins are...
Serine proteases
Cationic peptides
Cysteine deaminases
What feature of defensins allows them to become inserted in the lipid bilayer?
They are amphipathic
They are cationic peptides
They have cysteine rich regions in their amino acid sequence
Defensins, cathelicidins and histatins are antimicrobial peptides all secreted by...
Epithelial cells
Phagocytes
Epithelial cells and Phagocytes
What does NAG mean in the context of lysozyme?
N-acetylglucosamine
N-acetylmuramic acid
Non agglutinating glycoprotein
N-acetylcysteine
What does NAM mean in the context of lysozyme?
What linkage is cleaved between NAG-NAM carbohydrates by Lysozyme?
B-1,4
A-1,6
B-1,2
Lysozyme is more effective against gram negative bacteria since they do not have a layer of LPS covering the peptidoglycan NAG-NAM carbohydrates in their cell wall structure
Histatins are produced by
The major salivary glands
Dendritic and Natural killer cells
Histatins are predominantly active against
Fungi
Viruses
Bacteria
Histatins are particularly rich in...
Histadine
Cysteine
Serine
Defensins
Calprotectin depletes iron availability.
Lactoferrin produces hypothiocyanite which oxidises glucose transport carriers therefore reducing bacterial glucose uptake
Chromogranin A and Thrombospondin 1 give rise to cationic peptides. They interact better with plant/animal cells than bacterial surfaces.
Cystatins are
Cysteine protease inhibitors
Cysteine protease
Serine protease inhibitor
What is gingipains?
Cysteine protease inhibitor
Serine protease
SLP1 is a
Serine protease inhibitor (inhibit neutrophil elastase)
Serine protease (cleave neutrophil elastase)
Cysteine protease (cleave neutrophil granules)
Cystatins and Von Ebner's protein are both cysteine protease inhibitors
Cystatins, Von Ebners protein and SLP1 are all cysteine protease inhibitors
Which scavenges peroxidation products?
Von Ebners protein
SLP1
Cystatins
Toll like receptors react to...
PAMPs
DAMPs
Antigens
NOD-like receptors detect intracellular virus RNA
NOD-like receptors detect intracellular pathogen peptidoglycan
NOD-like receptors detect intracellular pathogen p
RIG-1 like helicase detect intracellular R
NLRP family of proteins are nod like receptors with pyrin associated with them
The inflammasome is important in cleaving cytokines and contributes to their short half life
NLRP3 is the only NLRP protein to form inflammasomes
What are the components of the typical inflammasome?
Caspase 1
NLRP3
Adaptor protein
TLR
Activation of toll like or nod like receptors results in what?
Transcription factor activation and subsequent pro-inflammatory cytokine production
Inflammasome cleavage of pro-cytokines
Exocytosis of active pro-inflammatory cytokines
Which of these are serum proteins?
Acute phase proteins
Complement
Interferons
Cytokines
Chemokines
Which of these are tissue factors?
Acute phase proteins are produced by the
Liver
Spleen
MALT
Peyer's patches
C reactive protein is a protein made by h
C reactive protein activates...
Complement cascade
Promotes phagocytosis
IL-10 to suppress inflammation
CRP is said to act like a primitive antibody since it activates complement and induces more phagocytosis
Interferons are proteins
Type 1 interferons are...
Alpha
Beta
Gamma
Type 2 interferons are...
How do interferons function?
Prevent viral replication
Increase display of viral particles to the immune system
Promoting phagocytosis
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