Micro Study Guide Flashcards
Define Immune Response
Overall actions and interactions of the immune system to provide immunity beginning w/ host/foreign encounter and leading to cellular/chemical defensive actions.
How much of blood is RBCs?
How much of blood is WBCs?
4-6mill/mcL
4500-11000/mcL
Basophils respond to ? and make up __%
Eosinophils respond to ? and make up __%
Neutrophils respond to ? and make up __%
B- inflammatory .5-1%
E- allergic 1-5
N- inflammatory 45-75%
How fast do neutrophils mature?
How long do they circulate?
Where do the adhere to and wait?
10^10/day
circ for 6-10hrs
adhere to endothelium
Monocytes mature into ? 2 cells?
What signals do they respond to?
What % of blood do they make up?
macrophages and dendritic
inflammatory
2-8%
What are the 3 types of lymphocytes?
How fast do they mature?
How long do they circulate before adhering and waiting?
T B NKC
10^9
Completes cycle in 1-2 days
1% circulate, the rest adhere to blood/lymph vessels
What is the largest of the phagocytic cells?
Macrophages- monocyte->macrophage (10x bigger)
major phagocytic role, lower numbers
Broad specificity allows major line of defense against microbes or abnormal host cells
What is the function of the lymph nodes?
Lymph fluid carrying Ags and APCs through nodes and encounter/activate pre-committed lymphocytes
Respond to local and regional infections
What is the function of the spleen?
Blood-borne antigens and APCs travel through organ where they encounter/activate pre-committed lymphocytes.
Responds to systemic infections.
What are the MHC complexes?
Proteins on surface of blood/tissue cells that identify cells as belonging to a specific individual.
Recognition of self vs non-self
What are the two classes of MHC complexes?
1- one aa chain, on almost every cell in body
II- two aa chains, only on certain cells of immune system. Particularly dendritic, macrophage and B cells
How do MHC complexes recognize cells?
Antigens recognized by T cells when presented to MHC molecules
What are the main characteristics of the dendritic cells?
Specialized cells predominantly located in tissues exposed to external environment and participate in initiating antigen recognition and immune responses
List 6 places where dendritic cells can be found and the names of those cells
Langerhans- skin Intestine- various Alveolar macrophage- lung Kupffer cells- liver Microglial cells- brain interdigitating- lymph nodes/spleen
Major characteristics of antigens?
What is their chemical nature?
What are their typical minimal size?
foreign substance which stimulates an immune response when introduced to the body and reacts/ binds with antibodies or T cell receptors.
Protein w/ complex 3D configuration
Molecular weight usually greater than 10,000
What is an epitope?
What determines their quality?
Specific part of immunogen that determines the exact antibody to produce.
Portion of Ag that binds w/ antibody or TCR
Different epitopes ( even on same Ag) will produce different antibodies
Quality determined by exposure and 3D shape
Define antibody
Characteristics of antibody
immunoglobulin, 20% of plasma proteins
antigen-specific glycoprotein
Y shaped w/ Fab and Fc sites
A D E G M
What is the role of the Fab site?
antigen specific
specific site attachment assists w/ inactivation
“lock and key” specificity for specific antigen
How many Fab sites per immunoglobulin molecule?
How many Fc sites?
2 Fab per monomeric molecule
1 Fc- binds to phagocyte
Major characteristics and differences of Innate and Adaptive responses?
Innate: non-specific, general recognition, inflammatory
Adaptive: specific response w/ chemicals and cellular actions
Innate: physical and chemical barriers, phagocytosis
Adaptive: T cells, B cells, memory
Describe phagocytosis
antigenic substance is engulfed and digested by WBC
macrophage or neutrophil
chemotaxis- C5a
Adhere, Ingest, Digest
What are the significant surface molecules on T cells and what are their roles?
CD3- identifies mature cell
CD28- receives activation signal
CD40 receptor
LFA-1- adhesion mol of T cells
What are the significant surface molecules of B cells and what are their roles?
CD40- binds w/ receptor on T cell
CD19,20,21- identification
CD80/86- when acting as an APC
Where do T cells mature and concentrate?
Where do B cells mature and concentrate?
T- Thymus->nodes
B- marrow-> peripheral lymph tissues (spleen, MALT, nodes, marrow)
Define APC
What do they produce?
Cell that binds antigen to specific receptors on surface
Places some digested antigen on MHC-II
Presents it to Helper T Cells
Produce IL-1 and IL-12
What are the 3 types of APCs
Where are they found?
What are their surface proteins?
What are their roles/activities?
macrophage- blood/lymph vessel, MHC-II, captures WHOLE microbes w/ phagocytosis, digests and presents
dendrite- MHC-II, captures material, processes and presents
B cell- CD40, CD19,20,21 and CD80/86, captures “digested” material via antigen specific BCRs and presents
What are the primary cells of cell mediated immunity response?
APC- macrophage, dendritic
T Cells- Cytotoxic and Helper
NKCs
What are the primary cells of humoral immunity?
APCs- Dendritic, macrophage or B Cells
Activated Helper T Cells
B Cells activated -> Ig production
What is the key composition and activities of the helper T Cells?
CD3 and CD4 Recognizes Ag on MHC-II of APC TCR->epitope on APC MHC-II ICAM-1 w/ LFA-1 CD28 w/ CD80/86 IL-1 initiates growth of T Cells
List the characteristics of TH1?
antigen specific local inflammatory response
amplifies CTL response
Promotes macrophage/neutrophil phagocytosis
Down regulates further TH2 cells
List the characteristics of TH2?
Antigen specific immunoglobulin response
Recruit/activate B Cells
Enhances mast/baso/eosinophils attack
Down regulates further TH1 development
Describe the composition and activities of CTLs?
CD8 and LFA-1 surface proteins
Req’s IL-2 from activated helper T Cell
Recognizes Ag bound to MHC-1 of host target cell
(virus, intracellular bacteria, parasites, cancer, transplanted tissues)
Reqs LFA-1 and ICAM-1 contact
CD8 not fully activated until “immunological synapse” is formed
Destroys w/: Serglycin, perforin, granzymes
Describe passive immunity
Results from transfer of pre-formed Igs or cells from a donor to the host
Host immune system does NOT participate
short lived
No memory cells produces
Describe active immunity
Direct stimulation of host’s immune system
Long lasting effects
Memory cells produces
Describe events and speed of secondary response?
Rapid and highly specific by hosts immune system that has been previously encountered (Memory T or B Cells)
Ig attach and neutralize/opsonize Ag (phagocytosis)
APCs present Ag to T/B memory cells
CD4 activate B cells
CD8 inhibit/kill Ag
CD4 activate B cells->plasma cells-> IgG
Some non-memory T cells are activated and repeat primary response
Describe events and speed of primary response?
events in host immune system during a first time exposure
Innate tries, APCs present, no recognition
T cells activated, CD4 activate B cells/CD8 cells
B cells differentiate->plasma cells and produce IgM
Memory T and B cells formed
Which Ig can cross the placenta?
IgG
Which Ig’s activate complement?
M and G
What Ig’s have a potential opsonizing effect?
How do they accomplish this?
M- enhances ingestion of target cells by phagocytes
G- enhances phagocytic effectiveness
What Ig provides protection for mucosal areas?
IgA
Which Ig is elicited by parasitic infections?
IgE
Which Ig is produced in the greatest concentration?
IgG- 80-85% 1000mg/dL
Which Ig is produced in first sequence from plasma cells?
IgM
Which Ig provides major protection during primary response?
During secondary?
IgM
IgG
Describe IgE’s function on a mast cell during allergic responses?
IgE binds tightly w/ surface receptors on mast cell
antigen reacts w/ IgE causing cell to dump histamines/chemical mediators
Describe composition and activity of NKCs
What enhances them?
CD16 and CD56, NO CD3
Does not require MHC-I or II presentaiton
Binds to surface proteins and carbohydrates on Fc of Ig
Kills virus infected host and tumor cells
Enhanced by IL-2 and IF
Define opsonization
What are the opsonization molecules?
attachment of Ig molecules to surface of antigen to mark for rapid phagocytosis and increasing phagocytic adherence
IgG IgM C3b
IgM size Fab sites Timing of production Lifespan Concentration Function
Largest 970kD 10 binding sites First to appear after initial exposure 5 days 120mg/dL (5-10%) Major product of primary response Enhances phagocytic ingestion Bloodstream defender Activates compliment
IgG size Fab sites Timing of production Lifespan Concentration Function
Smallest 150kD
4 subclasses
Several days after Primary/very soon during Secondary Re
Longest- 23 days
1000mg/dL 80-85%
Major protection secondary response
High Ag concentration before IgG formation
Protects against circulating viruses and bacteria, neutralizes toxins
Protects fetus
Activates complement
IgA size Fab sites Timing of production Lifespan Concentration Function
Medium- dimer 400kD
dimer
soon after stimulation, serum levels increase w/ delay
6 days
200mg/dL 15%
Secretory IgA defense through secretions, doesn’t activate complement due to poor Fc binding
May enhance nonspecific defenses (inflammation and phagocytosis)
IgD size Fab sites Timing of production Lifespan Concentration Function
small 180 kD
monomer
Surface receptor on B Cells- initiates immune response
NOT synthesized by plasma cells, directly as surface molecules
IgE size Fab sites Timing of production Lifespan Concentration Function
medium monomer produced at first encounter of antigen shortest, 1.5-2 days lowest 0.05mg/dL Major Ig of allergic reactions, increased w/ parasitic infections Binds w/ mast cells, immediate contact hypersensitivity No complement activation
In humoral response, ____-lymphocytes are activated to differentiate into ____ and produce ____
B-> plasma cells-> IgM/IgG
What is the overall role of Cell Mediated Immunity
antigen specific protection against intracellular viruses/bacteria, parasites, fungi, tumors and transplanted organs through killing function of T and NK lymphocytes
What are memory cells?
B lymphocytes that remember antigen exposures for quick response upon future encounters
How are Cytotoxic T Cells activated?
What connections are required?
How do they protect the body from invaders?
IL-2 from activated Helper T cell
Reqs contact between MHC-1 and TCR/ LFA-1 and ICAM-1 forming immunological synapse
Destroys invaders by GPS method
What is meant by antigenic group and how are they distinguished?
organisms w/ major antigen that may be common to more than one species of the genus
Designated by capital letters
What is meant by antigenic type?
organisms w/ common specific antigen to limited/related organisms (membranes of an antigenic group)
Designated by numbers
Describe the major shapes and arrangements of bacteria cells
Coccus
Bacillus- coccobacillus, coryneform/diaphtheroid, pleomorphic
Spirochete
What are the major cell arrangements?
single- no arrangement pairs- one plane, daughter cells chains- one plane, end-to-end clusters- 3 planes, grapes palisades- picket fence, bacilli only
What are the major components of bacterial cytoplasm?
What is the overall function of the components?
comp: cell sap and genetic material
function: metabolism and reproduction
What are the major components of bacterial cytoplasm membrane and what are the overall functions?
8-10% of cell’s dry weight
phopholipid bilayer- affect movement through membrane
proteins- porins and enzymes
What is the overall function of the bacteria cell wall?
shape/rigidity
protection
attachment to tissues
antibody attachment site
Endospores are found in the cytoplasm of Gram-______ bacteria
Pos
What is the “mucoid” slimy layer surrounding bacterial cell walls?
What is it’s function
capsule
Resist phagocytosis
Hide surface antigens
Assist w/ attachment (dental plaque)
What are the thread like structures on the exterior of bacteria?
What is their composition and function?
Flagellum
Proteins
Motility towards FAVORABLE conditions
Describe components and structure of a Gram-Pos cell wall
Peptidoglycan layer (60-80%)- N-acetylgucosamine and N-acetylemuramic acid, cross linked w/ peptide chains
Teichoic acid- glycerol/ribitol w/ phospholipid bridges
Protein inclusions- less frequent in Gram Neg
Describe the components and structure of Gram-Neg cell wall
peptidoglycan- 10-20%
lipoprotein- creates periplasmic space
Outer membrane
What makes up the outer membrane of a Gram-Neg cell all?
Phospholipid bilayer
Pore proteins
lipopolysaccharides- O antigen and site of Lipid A
define colony
clump of few million bacteria from same origin
Most medically significant bacteria will reproduce ever ___-___ min
30-60min
15-30hrs for some
Rapidly growing bacteria can produce millions w/in 18-24hrs
Describe the types of O2 utilization?
aerobic- 21%
microaerophilic- reduced O2 5-10%
anaerobic- no O2
facultative- either will do
What are the optimal temps, pH, humidty and CO2 ranges for growth of typical medically significant bacteria?
34*C
6.8-7.4pH
60-80% humidity
most don’t require increased CO2, some need 5-7% CO2
Major characteristics of “atypical” bacteria?
Why are these significant in lab diagnosis?
Metabolically limited
modified cell wall
complicated/modified reproduction
Reqs living host or highly enriched media
Mold cells are __-cellular and a mass is called _____.
Reproductive forms grow on what structures?
multi-cellular
mycelium
Spores on reproductive hyphae
____ growth reqs a media similar to bacteria but with ABX to inhibit bacteria
Fungi
What type of organism is a virus?
Size?
Reproduction?
Obligate, intracellular parasite
18-300 nm (0.018-0.3um), some 14,000nm in length
Reqs host metabolic processes
What is the inner most structure of a virus?
What is it composed of?
What is it’s function?
Core
DNA or RNA
Genetic info
What is structure found on exterior of only some viruses?
What is it’s composition and function?
Envelope
lipid bilayer and glycoprotein spikes
protection, attachment, antigens during infection, site for antibody attachment
Describe the major steps of the virus infection
Attachment Penetration/uncoating Eclipse/synthesis Maturation Release
What are the growth conditions and time required for virus replication?
living cell required
isolation time: 2-28 days
what are the means of locomotion for protozoa
amoebae- pseudopdia (false feet)
flagellates- flagella
ciliates- cilia
apicocomplexans (sporozoans) non-motile when mature
what are the characteristics of the major morphological stags of protozoa?
Pleomorphic
trophozoite- active and pathogenic
cystic- dormant and benign
what are the two protozoa reproduction types?
schizogony
conjugation
characteristics of trematodes
flukes- leaf shaped one body part, non-segmented 500um-60mm partial alimentary monoecious
characteristics of cestodes
tapeworms multiple body parts, segmented 2mm-12m no alimentary monoecious
characteristics of aschelminthes
nematodes (true roundworms) unsegmented and cylinder 300um-1m complete alimentary dioecious
List the differences between TH1 and TH2 activation?
What products are secreted for each and the event at the end of each cascade?
TH1- inflammation response, enhances CTL, enhances phagocytosis, inhibits TH2 (IL-2, IFN, TNF)
TH2- immunoglobulin response, activates B cells, increases BEM response, inhibits TH2 (IL-4,5,6,10)
What is the location of Lipid A and the O Antigen?
Gram Neg cell wall
O antigen= cell wall antigen
what structure do macrophages grow/use to engulf microbes?
pseudopods
Which phagocytic microbe will eat until its death resulting in pus?
Which immune response is pus included under?
neutrophil
Innate / humoral
Why do some bacteria need increased CO2 levels?
use CO2 as a pH buffer
What 3 cells can become memory cells?
B lymphocytes
Helper T Cells
Cytotoxic T Cells
What is the lysogenic cycle unique to?
dormant cycle of virus w/in a BACTERIA cell
lytic cycle= animal
what are the spikes on the outer viral envelope made of?
glycoproteins
What is the difference of LFA-1 and LFA-3?
Where are they found?
LFA-1: T cell binding
LFA-3: binding molecule of CD2
Define class switching
gene rearrangement leading to expression of new HEAVY chain class (IgM->G or A) without altering specificity (Fab) of the Ig
List two examples of obligate intracellular parasites?
Atypical bacteria
Viruses
What is the most potent activation signal for a B cell?
CD40 binding w/ CD40R on T Cell
Typical bacteria cell size
1-6um length
.5-.8um diameter, most 1-2um
Dimensions of staphylococcus
Bacillus
Pasteurella
These bacterias are all examples of what type of bacteria?
Staph- 1um
Bacillus- 1 x 1.3um
Pasteurella- 0.2-0.7um
Typical Bacteria
Atypical bacteria cell size
0.1-0.3
Yeast cell size
4-15um diameter
Mold cell size
Mold spore size
cell- 2-15um
spore- 1-10um
Virus particle sizes
180300nm, some 14000nm length
Protozoa size
2um - 1mm
Helminthes include what organisms
Aschelminthes include what organisms
Platyhelminthes (flatworms)- trematodes (flukes) cestodes (tapeworms)
nematodes- true round worms
An antigenic determining site may also be known or called ?
epitope
trematode size
500um-60mm
cestode size
2mm-12m
aschelminthes size
300um - 1m
Lymphocytes are differentiated by ?
Clusters of differentiation
Viral envelope proteins act in what purpose/function?
antigens
TRF, IL-4 and IL-6 are involved with what type of immunity?
humoral
Lymphocyte with immune tolerance leads to ?
autoimmunity
Phagocytosis belongs to what type of immunity process?
innate- humoral
What makes IL-12?
macrophages
What makes IL-10?
TH2
After presenting Ag to next step, APCs will perform what function?
activate lymphocytes
Antigens stimulates an immune response when introduced to the body and react/bind with ____ or _____
Ab
TCRs
MHCs and recognition of self vs non self all rely on the presence/absence of what type of molecule?
proteins
During phagocytosis foreign material is engulfed and digested within what part of the cell?
phagolysosome
Immune tolerance is a result of ___ _____?
immune tolerance
CD80/86 used to be what molecules?
B7-1 and B7-2 on B cells
what are the key words on how APCs work when defining dendritic, macrophage and B Cell?
Dendritic- captures then presents
Macrophage- engulfs
B cell- captures digested material
lymphokines are produced by _____
monokines are produced by _____
lymphocytes
macrophages
Macrophage Attracting Factor comes from what cells?
T Cells
Superantigen production brings in IF-y, what cell makes it?
T cells
Common B cell activating agents are ? 3
bacteria
virus
foreign RBC proteins
What happens if an antigen is T cell independent?
B cell is directly activated, causes:
weak CD4 activation
IgM ONLY production
no memory cell formation
Opsonization/C3b may also increase dendritic cells located where?
kupfer cells in liver
Define clonal selection
T/B cells engage Ag and are cloned
