overview of immune response Flashcards
innate immune response
first response. within a few hours. more broad, helps train adaptive immune response
adaptive immune response
immunological memory. reacts much later than innate. very specific for certain pathogens. makes antibodies
why are there more cell types for innate immune response
because each type attacks a different type of pathogen
adaptive immune response cells
b cells and t cells(natural killer t cells and lymphocytes are both)
after birth _____ occur in the bone marrow
hematopoiesis
three types of cells made from hematopoiesis
platelets, red blood cells and white blood cells (myeloid and lymphoid)
types of granulocytes (innate)
neutrophils
basophils
eosinophils
neutrophils
most abundant leukocyte, 1st responders
basophils
for inflammation and allergic response
eosinophils
compare parasitic infections and allergic response
types of phagocytes (myeloid lineage)
monocytes
macrophages
conventional dendritic cells
monocyte
phagocytosis, differentiate into macrophages or dendritic cells when they enter tissues
macrophages
phagocytic cells that reside in all tissues. clear away debris. antigen presenting cells
dendritic cells
similar to macrophages can activate naive t cells. good at antigen processing
Mast cells
(not a granulocyte) involved in defense against parasitic worms and allergic response
lymphoid lineage cells
t lymphocytes*
b lymphocytes*
natural killer cells
*- invovoled in adaptive immune response and are antigen specific
t lymphocytes
cytotoxic (CD8), helper (CD4) and suppressor/regulatory
b lympohcytes
differentiate into plasma cells . antibody production
natural killer cells
involved in innate immune response, not antigen specific.
antigen (Ag)
molecule capable of inducing an immune response
antibody (Ab)/ immunoglobulin
protective protein made by B cells that recognize 1 specific antigen
how does the cell secrete signaling molecules
cytokines and chemokines- movement towards a source
most activation of receptors are
external
the cytoplasmic domains gets
signally cascade going
steps in cell signaling
- ligand binds to a receptor and intracellular domains aggregate
- phosphorylation of protein tyrosine kinases
- protein tyrosine kinases initiate a series of phosphorylation and dephosphorylation events leading to
protein tyrosine kinases can initiate events that lead to
- release of cellular mediators (Ca2)
- actin rearragenment
- transcriptional activation leading to production of target proteins
cytokines
group of secreted proteins that are involved in regulating the innate and adaptive immune response
3 different organizations of lymphoid tissue
- follicle (organized clusters)
- patch (many follicles grouped)
- organ ( groups of follicles that are encapsulated)
primary lymphoid tissue vs secondary lymphoid tissue
primary- thalamus and bone marrow
secondary- everything else (lymph nodes, spleen MALT tissue and SALT)
the thymus is involved in
t cell differenation and maturation
types of mucosa-associated lymphoid tissue (MALT)
NALT (nasopharynx)
BALT (bronchial)
GALT (gut)
lymph
fluid collected from interstitial fluid that empties into lymphatic vessels (10%of fluid that wasn’t reabsorbed in the veins)
lymph arrives to the organ via the _____ and exits the organ via the ______
afferent lymphatic vessel; efferent lymphatic vessel
can find lymphoid follicles (B Cell)
in smaller vessels of arterioles
what happens during an infection
antigens are presented to all t cells in an organ. if this t cell is for the specific antigen it becomes activated. if not then it continues to travel to other lymph organs to find the correct t cell for the antigen
innate immunity can be triggered by
infectious or non infectious materials
types of innate mechanisms
inducible vs non0inducilbe
examples of non-inducible
physical: skin, mucus, commensal bacteria or
Chemical: lysozyme (tears_ and antimicrobial peptides (alpha and beta defense’s and cathelicidin)
what do antimicrobial peptides do
create holes in bacterial membranes and help maintain mucus levels
examples of inducible
(must be turned on)
innate immune cells: neutrophils, macrophages, dendritic cells, mast cells, NKC
neutralizing antibodies: secretory IgA
most importnatn non inducible barrier
skin and GI covering
how do we activate innate immune cells
they can recognize non self cells and danger signals through the recognition of certain PATTERNS and they look for damage to the body
PAMPs (pathogen associated molecular patterns) for bacterial cells
lipopolysaccharide, peptidoglycans, CpG DNA, and flaggelin
PAMPs for virus
double stranded RNA and single stranded RNA
PAMPs for fungi
chitin and zymosan
DAMPs
damage- associated molecular patterns
examples of DAMPs
- complement products (C3b, C4b)
- reactive oxygen intermediates (h2O2, OH< O2-)
- stress induced molecules (heat shock proteins, hyaluronic acid fragments, chaperone proteins)
- metabolic products- ATP, potassium, uric acid, cholesterol, saturated fatty acids)
- nucleic acids (mRNA histones)
- exogenous substances (alum, silica, asbestos)
why are metabolic products and nucleic acids considered DAMPs
because they shouldn’t be found on the outside of the cells so this tigers immune response
Pattern recognition receptors can be ____ or ____
cel- associated or unassociated with cell
toll like receptors
TLR are membrane bound pattern receptors . highly expressed in dendritic cells, monocytes, neutrophils
TLR2
bacterial peptidoglycans
TLR4
LPS (lipopolysacchrides)
TLR5
bacterial flagellin
TLR7 and 8
ssRNA
activation of TLR leads to
- DC maturation
- Stimulation of antigen presentation
- phagocytosis
- Cellular activation
- Production of pro inflammatory cytokines/chemokines
NOD-like receptors NLRs
regonzie both PAMP and DAMP
free cytoplasmic receptors . this activation can also lead to apoptosis
inflammasomes
large complexes of NLRs. leads to caspase 1 activation
toll-like receptors and ______ often work together
NOD-like receptors
RIG receptors
retinoid acid inducible gene-1 receptors.
- cytoplasmic receptors
- recognize VIRAL RN
activation of RIG receptors leads to
production of antiviral proteins (interferon alpha and beta)
CLRs
c-type lectin receptors
lectin
proteins that bind to carbohydrates . pathogens often use them to bind to a target cell
CLRs recognize carbohydrate based ____?
DAMPs and PAMPs
what are group I and II of CLRs
group I- mannose- HIV, m. tuberculosis dengue fever
group II- asialoglycoprotein- bacteria, yeast, ticks, viruses
scavenger receptors
bind to lipids, can be from host or foreign
Collectins
collagen domain fused to a lectin domain. upon biding their ligand they can activate complement, do phagocytosis, agglutination
where are collectins found
in the blood
complement activation (C3)
serum based mechanism to destroy pathogens no cells involved just 30 proteins
what happens during complement activation
pathogen destruction, pathogen opsonization(aids phagocytosis), clearance of immune complexes (Ab-Ag), creation of peptides to help inflammation
3 ways to activate complement
classical pathway (antibodies), lectin pathway(mannose binding lectin), or alternative pathway(microbe) . all lead to LYSIS OF MICROBE
other roles for C3b
solubilization of immune complies and virus neutralization
macropinocytosis
engulfment of unwanted fluid and macromolecules; creates macropinosome
clathrin-mediated endocytosis
receptor mediated macropinocytosis; created clathrin-coated vesicles
ways of killing microbes during phagocytosis
ROS, NO and lysosomal enzymes
inflammation
necessary process to eliminate foreign substances and repair damaged tissue
