Immunology Flashcards
Why do warm blooded, long lived animals require complex immune defenses?
infectious agents such as bacteria can divide rapidly in warm blooded creatures
How many bacteria are there in the world?
4-6x10^30
What is the difference between gram positive and gram negative bacteria
gram positive has a thick layer of peptidoglycan, while gram negative does not
Describe the innate immune response
rapid response (min to hrs) limited variability of effector mechanisms nonspecific no memory (no maturation of repeated response)
describe the adaptive immune response
slow response (days to weeks)
B cells and T cells are highly selective
specific
memory, maturation of secondary response
neutrophil morphology and effector function
polymorphonuclear, phagocytosis and digestion of microbes
eosinophils morphology and effector function
polymorphonuclear, allergic reactions and defense against helminths
basophils morphology and effector function
polymorphonuclear, allergic reactions
mast cells morphology and effector function
polymorphonuclear, allergic reactions
monocytes morphology and effector function
mononuclear, circulating macrophage precursors
macrophages morphology and effector function
mononuclear, phagocytosis and digestion of microbes, antigen presentation
How does immune responses of the innate immune system provide natural immunity against microorganisms?
phagocytosis and intracellular killing
recruitment of other inflammatory cells
presentation of antigens
_________ include neutrophils, monocytes and tissue macrophages, eosinophils and natural killer (NK) cells which are _______
leukocytes, lymphocytes
What is the pattern recognition receptor of gram positive bacteria?
TLR2
What is the pattern recognition receptor of gram negative bacteria?
TLR4
TLR1:TLR2 heterodimer ligand
lipopeptides, GPI
TLR1:TLR2 heterodimer microorganism recognized
bacteria, parasites
TLR1:TLR2 heterodimer cells carrying receptor
monocytes, dendritic cells, eosinophils, basophils, mast cells
TLR1:TLR2 heterodimer cellular location of receptor
plamsa membrane
TLR2:TLR6 heterodimer ligands
lipoteichoic acid, zymosan
TLR2:TLR6 heterodimer microorganisms recognized
gram positive bacteria, yeasts (fungi)
TLR2:TLR6 heterodimer cell carrying receptor
monocytes, dendritic cells, eosinophils, basophils, mast cells
TLR2:TLR6 heterodimer cellular location of receptors
plasma membrane
TLR3 ligand
double stranded viral RNA
TLR3 microorganisms recognized
viruses
TLR3 cells carrying receptors
NK cells
TLR3 cellular location of receptor
endoscopes
TLR4: TLR4 heterodimer ligand
lipopolysaccharide
TLR4: TLR4 heterodimer microorganism recognized
gram negative bacteria
TLR4: TLR4 heterodimer cells carrying receptors
macrophages, dendritic cells, mast cells, eosinophils
TLR4: TLR4 heterodimer cellular location of receptor
plasma membrane
TLR5 ligand
flagellin
TLR5 microorganisms recognized
motile bacteria having a flagellum
TLR5 cells carrying receptors
intestinal epithelium
TLR5 cellular location of receptor
plasma membrane
TLR7 ligand
single stranded viral RNAs
TLR7 microorganism recognized
viruses
TLR7 cells carrying receptor
plasmacytoid dendritic cells, NK cells, eosinophils, B cells
TLR7 cellular location of receptor
endosomes
TLR8 ligand
single stranded viral RNAs
TLR8 microorganisms recognized
viruses
TLR8 cells carrying receptor
NK cells
TLR8 cellular location of receptor
endosomes
TLR9 ligands
unmethylated CpG-rich DNA
TLR9 microorganisms recognized
bacteria
TLR9 cells carrying receptors
plasmacytoid dendritic cells, B cells, eosinophils, basophils
TLR9 cellular location of receptor
endosomes
TLR10 homodimer and heterodimers with TLR1 and 2 ligand
unknown
TLR10 homodimer and heterodimers with TLR1 and 2 microorganisms recognized
unknown
TLR10 homodimer and heterodimers with TLR1 and 2 cells carrying receptor
plasmacytoid dendritic cells, basophils, eosinophils, B cells
TLR10 homodimer and heterodimers with TLR1 and 2 cellular location of receptor
unknown
REVIEW COMPLEMENT AND INNATE IMMUNE RESPONSE
on slides
_______ are the first cells to arrive at the site of tissue damage in the innate immune response
neutrophils
activation of neutrophils leads to what?
respiratory bursts and release of granules
______ engulf organism by phagocytosis and release many inflammatory mediators
macrophages
review mechanisms of phagocytosis
slide 20
______ is a cytokine of both innate and adaptive immunity
IFN-gamma
TNF principal source
macrophages, T cells
TNF principal cellular targets and biological effects
endothelial cells: activation neutrophils: activation hypothalamus: fever liver: synthesis of acute phase proteins muscle, fat: catabolism many cell types: apoptosis
Interleukin (IL-1) principal source
macrophages, endothelial cells, some epithelial cells
Interleukin (IL-1) principal cellular targets and biological effects
endothelial cells: activation
hypothalamus: fever
liver: synthesis of acute phase proteins
chemokine principal cell source
macrophages, endothelia cells, T lymphocytes, fibroblasts, platelets
chemokine principal cellular targets and biological effects
leukocytes: chemotaxis, activation
IL-12 principal cell source
macrophages, dendritic cells
IL-12 principal cellular targets and biological effects
NK cells and T cells: IFN-gamma synthesis, increased cytolytic activity
T cells: Th1 differentiation
Type I IFNs (alpha and beta) principal source
alpha: macrophages
beta: fibroblasts
Type I IFNs principal cellular targets and biological effects
all cells: antiviral state, increased class I MHC expression NK cells: activation
IFN-gamma principal cell source
NK cells, T lymphocytes
IFN-gamma principal cellular targets and biological effects
activation of macrophages
stimulation of some antibody response
IL-10 cell source
macrophages, endothelial cells, T cells
IL-10 principal cellular targets and biological effects
macrophageS: inhibition of IL-12 production, reduced expression of costimulators and class II MHC
IL-6 cell source
macrophages, endothelial cells, T cells
IL-6 principal cellular targets and biological effects
liver: synthesis of acute phase proteins
B cells: proliferation of antibody-producing cells
IL- 15 cell source
macrophages, other
IL-15 principal cellular targets and biological effects
NK cells and T cells: proliferation
IL-18 cell source
macrophages
IL-18 principal cellular targets and biological effects
NK cells and T cells: IFN-gamma synthesis
What is an important bride between innate and adaptive immunity?
pathogen recognition through PRRs which causes activation and maturation of antigen presenting cells (APC). APC processed antigen is presented to naive T cells and then secreted cytokines asset development maturation of T cell
What immunity is a B cell and what is its function?
adaptive, humoral immunity
What immunity is a plasma cell and what is its function?
adaptive, Ab-producing cell
What immunity is a T cell and what is its function?
adaptive, cell mediated responses
What immunity is a NK cells and what is its function?
innate, anti-viral and anti bacterial
Describe cell mediated immunity
mediated by thymus dependent lymphocytes called T lymphocytes
describe humoral immunity
mediated by antidotes produced by B lymphocytes
______ lymphocytes develop from precursors during lifetime
B
all _____ lymphocytes are generated in the thymus during fetal stage
T
describe TH1 cells
produced IFN-gamma that activates macrophages to destroy microbes
describe TH2 cells
produce IL-4, 5, 10
describe cytotoxic T lymphocytes (CTLs)
kill host cells that are haboring infectious microbes in the cytoplasm
where are MHC class 1 expressed
all nucleated cells of body, including professional APCs
where are MHC class 2 expressed
professional APC only
CD4 and CD8 bind ___ on APCs
MHC molecules (not Ag!)
T cell receptors has two binding chains alpha and beta, that do what?
bind Ag
What does the Ag interact with on the class II MHC molecule
alpha1 and beta1 domains
what does the Ag interact with on the class I MHC molecule?
alpha1 and alpha2 dominos
What are the properties of MHC molecules?
codominant expression: both paternal alleys of each MHC gene are expressed
polymorphic genes: many different alleys are present in the population
MHC expressing cell types
costimulation of what is required in the activation of CD4 T cells?
B7-CD28 costimulation
If IL-12 is produced by macrophages and DCs what happens
TH1 cells differentiate
if no IL-12 is not produced by what is made?
Th2 cells
What part of the Ab confers Ag recogniton
variable region, F(ab’) 2
what part of the Ab interacts with cell surface receptors
constant region, Fc
IgA function
mucosal immunity, neontal passive immunity
IgD function
naive B cell Ag recognition
IgG function
oposination, complement activation, antibody dependent cell mediated cytotoxicity, neonatal immunity, feedback inhibition of B cells
IgM function
naive B cell antigen receptor, complement activation