1: The Human Immune System: Innate Immunity Flashcards
candida albicans
eukaryote model organism
causes most infections of humans
part of normal flora
Saccharomyces cerevisiae
brewers yeast- fungi... EUKARYOTE fermentation leads to ethanol production wine beer, leaving of bread (from CO2 production) Non-pathogen usually model organism
Saccharomyces cerevisiae as a model organism
sexual AND asexual reproduction budding division secretion cell division eukaryotic cell signaling short division time
Break down of Immunity
Innate Immunity: First and Second lines of defense
Adaptive immunity: Third line of defense
Innate immunity:
born with it. it grows, but DOES NOT ADAPT
what is it that is making us feel ill?
immune responses
Innate immunity: First Line of Defense
intact skin
mucous membranes and secretions
normal microbiotia
Innate immunity: Second Line of Defense
Phagocytes (neutrophuls, eosiophils, dendrtic cells, macrophages)
Inflammation
Fever
Antimicrobial substances
Adaptive Immunity
Adapts over time. Able to learn
Adaptive Immunity: Third Line of Defense
specialized lymphocytes: T and B cells
antibodies
the goal of the immune system
to prevent pathogens and cultivate normal flora
antigens (general)
molecular patterns. can be proteins, carbs, lipids etc
have epitopes
epitope
part of antigen
specific patterns recognized by immune system
subset of atigens
PAMPs
Pathogen Associated Molecular Patterns
not found in normal human body… like LPS
sometimes called MAMPs (microbe)
innate immunity
Receptors types for PAPMs
Toll Like Receptors (TLRs) and Pattern Recognition Receptors
why call them MAMPs/
include ALL microbes, not just pathogens
Cytokines and chemokines
lingo of the immune system why you feel sick small diffusable chems/peptides used in cell communication immunostimulatory immunosuppressive
immunostimulatory
pro-inflammatory
immunosuppressive
anti-inflammatory
antibody
PROTEIN secreted by B cells
specifically bind to an epitope
ADAPTIVE immune response
recognize epitopes on antigens from previous disease
recognizes just one epitope
Antigen
protein or other NOT FROM HOST
recognized by immune system
one antigen can have multiple epitopes
Epitope
amino acid sequence or structure recognized by SPECIFIC immune cell
how vaccines work
inject antigen into body
immune response stimulated
antibodies respond to antigen
may be many different responses to same antigen
pattern recognition receptors
the way macrophages sense the world
macrophages on and off
resting macrophage until activated… good
internal changes turn it on… like kicking a beehive
nonspecific responses… kills everything around it, self or non-self
TLR-2
Gram Positive Bacteria: PEPTIDOGLYCAN
TRL-4
LPS of Gram Negative Bacteria
LPS Receptor (CD14)
LPS of Gram Negative Bacteria
Scavenger receptor
non-self carbohydrages
parasites
glucan receptor
parasites
mannose receptor
parasites
What DON’T macrophages recongize
viruses!
what do macrophages kill
Cells, any cell around it
goal: cellular pathogens
Toll Like Receptors (TLRs)
receptors in HOST CELLS bind to non-host moelcs signal cell to start immune response First recognition of pathogens different TLRs activate in response to different ligands PAMP
TLRs and viruses
recognize dislocalized nucleotides like:
double stranded RNA in cytosol
neuclic acids in endosome
So What do TLRs recognize?
bacteria, fungi (yeasts), viruses
Cytokines… in the overall process
after TLRs activate, signaling occurs
protein secretion, activation of immune cells, migration to infection site/proliferation of immune cells
cytokines… what they do
signaling molecs that transmit immunological information
Pro-inflammatory
Anti-inflmmatory
Pro-inflammatory
activate immune cels like macrophages and stim innate AND adaptive immune cells to migrate to site of disturbance
Anti-inflmmatory
turn of activated cells
after pathogens dealt with, these chems stop more damage from occuring. ends inflammatory response
Skin
keep stuff out.
Dead cells… non-vital cells
Keratinocytes
most outer layer. dead cells
epidermis
squamous cells
makes cells that turn into keratinocytes
dermis
blood vessils, follicles
immune functions of skin
low pH?
subum: skin oil. has antimicrobial peptides
physical barrier
perspiration: lysozymes
lysozyme
enzyme to cultivate bacteria
digests peptidoglycan
Mucus Membranes
surfaces exposed to bacteria
soft/live barrier.
where are most infections?
through skin. but they go away quickly
where are most illnesses?
mucous membranes
What is mucus made of?
glycoprotein
What makes mucus?
goblet cells
amount of mucus made is proportional to bacteria present (including normal flora)
ciliated cells
move mucus towards exits
epithelial cells
digestive tract and respiratory tract (connected) urogentical tract (not connected)
Mucus membrane secretions
saliva gastric juice vaginal secretions atimicrobial peptides mucus
saliva
pH of 6.55-6.85
lysozyme
gastric juice
pH of 1-3
digestive enzymes
PPIs stop acid secretion in stomach. but this has little effect on immune system
bile acids break up fats
vaginal secretions
glycogen broken down to lactic acid by Lactobacillus acidophilus
this DECREASES pH, prevents yeast
antimicrobial peptides
lysozyme
small proteins made by body that kill some bacterial species
Innate immunity 1.5: Bloodborne Immunity
Complement System (w. 30 peptides) Cellular immunity: WBCs, innate and adaptive immunity
Inflammation
process of body responding to activation of INNATE receptor
due to release of cytokines from surveillance cells
systematic inflammation
feeling ill, all over body
local inflammation
like a pimple. rednesss at one spot recruitment of WBCs pus clearance repair
Vasodilation
opeing of capillaries. Process:
- infiltration of fluid
- swelling
- heat
Phagocyte Micgration and Inflammation
chemotaxis of phagocytic cells
macrophages and PMN
WBCs that swallow stuff
they follow chemokines
Tissue repair
after inflammation
platelet repair
Fever
systemic response to cytokines where core temp is raised
can keep certain pathogens from reproducing.
can be good or bad
