Immediate Immunity: Barriers and Soluble Effectors I Flashcards
What is innate immunity?
A generalized host defense mechanism that continuously acts from the start of an infection and does not adapt to a specific pathogen or generate immunologic memory
What are the two components of the innate system?
- Immediate
2. Induced
What are the 2 components of Immediate innate immunity?
- Barriers
2. Soluble Effectors
What are the types of Barriers in Immediate induced Immunity?
- Mechanical
- Chemical
- Microbiological
What are the soluble effectors of Immediate innate immunity?
- Complement
2. Antimicrobial Peptides
What are the 2 components of Induced innate immunity?
- Cells
2. Cytokines
What are the cells of induced innate immunity?
- Neutrophils
- Monocytes
- Macrophages
- Dendritic cells
- NK cells
- Mast cells
- Eosinophils
- Basophils
What are the cytokines in induced innate immunity?
- Interleukins
- Chemokines
- Growth Factors
Innate immunity is a system of _______ _______
Pattern recognition
Types and composition of extracellular and cell surface _______, _________, and ______ activate specific immune respones
- Proteins
- Carbohydrates
- Lipids
What are effector processes?
The things that kill pathogens and cells
What are 2 classes of molecular patterns/
- Pathogen Associated Molecular Patterns (PAMPs)
2. Damage-Associated Molecular Patterns (DAMPs)
Name 4 things involved in the PAMPs
- Lipopolysaccharide
- Flagellin
- Mannose sugars
- Unmethylated CPG DNA
Name 3 things involved with the DAMPs
- Heath shock proteins
- Fibronectin
- Chromatin
What are the mechanical components of the skin that make it a barrier?
- Epithelial cells joined by tight junctions
2. Longitudial flow of air or fluid
What are the Chemical aspects of the skin as a barrier?
- Fatty Acids
2. Beta-defensins, Lamellar bodies, Cathelicidin
What are the microbiological aspects of the skin as a barrier?
Normal microbiota
What are the mechanical aspects of the gut as a barrier?
- Epithelial cells joined by tight junctions
2. Longitudinal flow of air or fluid
What are the chemical aspects of the gut as a barrier?
- Low pH
- Enzymes (pepsin
- Alpha-defensins (cryptdins)
- RegIII (lecticidins)
- Cathelicidin
What are the Microbiological barrier aspects of the gut?
Normal Microbiota
What are the mechanical barriers of the lungs?
- Epithelial cells joined by tight junctions
2. movement of mucus by cilia
What are the chemical barriers of the lung?
- Pulmonary surfactant
- Alpha-defensins
- Cathelicidin
What are the Microbiological barriers of the lung?
Normal Microbiota
What does opsonization mean?
Basically to be covered and coated
What are the mechanical barriers of the Eyes, nose, and oral cavity?
- Epithelial cells joined by tight junctions
2. Tears and Nasal Cilia
What are the chemical barriers of the eyes, nose, and oral cavity?
- Enzymes in tears and saliva (lysozome)
- Histatins
- Beta-defensins
What are the microbiological barriers of the eyes, nose, and oral cavity?
Normal microbiota
Mechanical barriers prevent _________
Infiltration, they physically block pathogens
T/F Barriers are passive
FALSE
Mucosal cells produce ______ barriers
chemical
_________ are integrated into barriers
Specialized immune tissues like Lymphoid tissues
Cells within the stratum granulosum have lamellar bodies T/F
TRUE
Chemical Barriers act on pathogens in what two ways?
- Isolation and physical removal
2. Targeted destruction
T/F Lymphoid tissues are more structured than lymph nodes
FALSE, they are less structured
Can localized B and T cell activation happen in lymphoid tissues?
Yes
Every mucosal tissue has some form or capacity of what two things?
- Secretion
2. Motility
What does secretion do?
Traps pathogens
What does motility do?
Removes pathogens from mucosal surfaces
What cleaves peptidoglycans?
Lysozyme
What are the most common Chemical barriers?
Peptides and proteins
T/F Lipids and carbohydrates are never considered Chemical barriers
False
Defensins are ______ and ______
- Chemical Barriers
2. Soluble Effectors
What are defensins released by?
Immune and barrier cells
Lysozymes specifically target which type of bacteria?
Gram +
because they have exposed peptidoglycan
Slide 9 table
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What are the two different classes of defensins?
Alpha and Beta
What produces Alpha defensins?
Neutrophils (predominately)
Paneth cells do a little bit
What produces Beta defensins?
- epithelial cells
- Most mucosal surfaces in the body
What are the two major things that defensins do?
- Disrupt pathogen membranes
2. –
How do defensins disrupt pathogen membrane?
- Electrostatic attraction and the transmembrane electric field bring the defensin in to the lipid bilayer
- Defensins are positively charged and repel each other creating pores in the membrane
What don’t defensins hurt eukaryotic cells normally?
Their membranes have positive proteins in them that repel the defensins
What are other various things that defensins can do?
Slide 11
Beta defensins are constituitively released by what?
Stratified oral epithelium
What secretes Alpha defensins into GCF?
Neutrophils
What does commensal mean?
One organism benefits, the other niether suffers nor benefits
What are the 3 functions of the normal microbiota on our barriers?
- Protective functions
- Structural functions
- Metabolic functions
________ shape local gut flora
Antimicrobial peptides
Commensal flora ______ pathogenic flora
outcompete
What detects commensal vs. pathogenic bacteria and prevents or triggers inflammation accordingly?
Pattern recognition receptors
What do commensal bacteria induce in regards to immune response?
- IgA secretion
2. Antimicrobial Secretion
T/F Dendritic cells constantly browse mucosal flora
TRUE
What is the complement system?
An immune surveillance system of plasma proteins that act in cascades to selectively kill extracellular pathogens and diseased tissue, promote inflammation, clear tissue damage, and regulate tissue homeostasis
What are the 3 classical pathways of the complement system
- Classical Pathway
- Lectin Pathway
- Alternate Pathway
**They were discovered in this order but are activated in reverse order
Where are most complement components made?
The liver
What percent of plasma globulin protein is complement?
15%
What are initiators?
They initiate the complement pathways
What are the initiators of the classical pathway?
Antibody/C1q complexes
What are the initiators of the lectin pathway?
Mannose–binding lectins
What are the initiators of the alternate pathway?
- C3
2. Properdin
Slide 16 proteins
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What are convertase Activators?
Form convertases, which label pathogens/antigens with C3b and C5b
What are Opsonins?
Coat pathogens/antigens and target them for phagocytes
What are anaphylatoxins?
Initiate and promote inflammation
What do membrane attack complexes do?
Form the MAC pore
What do complement receptors do?
Initiate signaling
What do regulators do?
Restrict or halt complement activity
Where are lysozymes located?
Mucosal/glandular secretions like tears, saliva, respiratory tract
Where are lactoferrins located?
Mucosal/glandular secretions like milk, intestine mucus, nasal respiratory and urogenital tracts
Where are defensins located?
Skin, mucosal epithelia like the mouth, intestine, nasal/respiratory tract, and urogenital tract
Where is Secretory leukocyte protease inhibitor located?
Skin, mucosal/glandular secretions like intestines, respiratory, and urogenital tract
Where are S100 Proteins located?
Skin, mucosal/glandular secretions like tears, saliva, tongue, intestine, nasal, respiratory, and urogenital tracts
What are two examples of s100 proteins?
- Psoriasin
2. Calprotectin
Where do you find Cathelicidin (LL37)?
Mucosal epithelia (respiratory tract, urogenital tract)
Where do you find surfactant proteins SP-A, SP-D?
Secrections of respiratory tract, other mucosal epithelia
What are the important types of proteins and peptides?
- Lysozyme*
- Lactoferrin*
- Defensins*
- Secretory leukocyte protease inhibitor
- S100 proteins
- Cathelicidin (LL37)
- Surfactant proteins SP-A, SP-D
What do lysozymes do?
Cleaves glycosydic bonds of peptidoglycans in cell walls of bacteria, leading to lysis
What do lactoferrins do?
- Binds and sequesters iron, limiting growth of bacteria and fungi
- Distrupts microbial membranes
- Limits infectivity of some viruses
What do defensins do?
- Disrupt membranes of bacteria, fungi, protozoan parasites, and viruses
- Additional toxic effects intracellularly
- Kills cells
What do Secretory leukocyte proteases do?
- Blocks epithelial infection by bacteria, fungi, viruses
2. Antimicrobial
What do S100 proteins do?
- Disrups membranes, killing cells
2. Binds and sequesters divalent cations such as manganese ans zinc, limiting the growth of bacteria and fungi
What do Cathelicidins do?
- Disrupts membranes of bacteria
- Additional toxic effects intracellularly
- Kills cells
What do surfactant proteins do?
- Block bacterial surface components
2. Promotes phagocytosis
C3 is cleaved into what two fragments?
C3a and C3b
Is C3a considered the large or small fragment?
Small
Which fragment has enzyme activity, C3a or C3b?
C3b
C3a has not enzyme activity
Is C3a or C3b an anaphylatoxin?
C3a
Which fragment of C3 is involved in signaling activity?
Both C3a and C3b
Which C3 fragment is an opsonin?
C3b
Draw out the Alternative complement pathway
Slide 17
Draw out the Lectin Pathway
Slide 17
Draw out the classical pathway
Slide 17