Week 2 - Study Guide Flashcards
Immunity
Immune system has two intrinsic defense systems:
- Innate (nonspecific) (born with)
- Adaptive (Specific) (exposed to)
Innate Defense System
- Set of structures and Functions born with
- Nonspecific - born with
Meaning - they do not help learn anything - they only do what their specialized functions are for our entire life. - They do not change
- They do not get better
- Just keep doing what they do
Adaptive Immune System
- Exposed to
- About what we are exposed to during our life – we get sick, Fight, get better, remember it
- Some interconnection between innate functions and adaptive functions
Bacteria are the most common pathogens and typically cause illnesses by 2 names:
- Endotoxins
- Exotoxins
Endotoxins –
Components of bacterial cell wall
Bacteria are cellular - group -
- Prokaryotic cell
- simple and small
- No nucleus
- No organelles
- Have genetic material
- Makes ATP
Viruses are not cellular –
- Without a host cell, they cannot do anything
- Viruses enter the Host
- Take over the cell
- Commandeer the cell metabolism
– Use our structures to replicate their genetic material
– And create products of themselves over and over again.
– so much that they grab components (our cell membranes)
– then deplete our resources and damage our cell membranes. (toxin build-up)
– until our cells literally die
Death due to rupture
and
Release of viral particles
Innate Defenses are highly connected
(Born With)
Non-Specific - provide protection that is not selective
SURFACE BARRIERS -
Inhibit entry of most microorganisms
1. Skin
2. Mucus membranes, hair, & cilia
Mucus- pH balance
Catch irritants
3. and their secretions and contain antibacterial toxins
Oil, sweat, enzymes, acids
4. Keratin - resistant to weak acids and bases, bacterial enzymes, toxins
5. Tears - contain antimicrobial enzyme - Lysosome
Mucous membranes line our hollow tubes:
digestive, urinary, respiratory, reproductive
INTERNAL DEFENSES
1. Phagocytes
2. NK cells
3. Inflammation
4. Antimicrobial proteins
5. Fever
Adaptive Defenses are highly connected
(Exposed to)
Provides specific protection
and
generally requires a First-time exposure
Humoral Immunity
B cells
Cellular Immunity
T cells
Internal Defenses - Cells and Chemicals
Necessary of microorganisms invade deeper tissues:
NonSpecific
- Phagocytes
- NK - Natural Killers
- Fever
- Inflammatory Responses:
Macrophages, mast cells, WBCs, inflammatory chemicals - Antimicrobial Proteins (2)
Complement proteins & Interferons
Phagocytes are WBCs and come in different forms - what is the most common
Macrophages
Macrophages
- Found in all organs
- Engulf particles by cellular eating - it pulls in what it is eating and creates a phagosome.
- Phagosome with the lysosome of the phagocyte - breaks down the nasty
- and release back into the interstitial fluid
- will be picked up
- and filtered out by the kidney
Phagosome
is a vesicle that fuses with the lysosome of the phagocyte
Macrophages recognition of pathogen:
Aided by
Recognition of Pathogen- Aided by:
1. Complement
OR
2. Antibody marking
Providing a binding site for Phagocyte
Antibodies are part of which immune process?
the Adaptive Immune Process.
We have better immune functions because of this interconnection:
- Possible interaction between:
Phagocytes * Complement proteins - Both are Innate - Antibodies are adaptive
Natural Killer cells (NK)
Innate cells (born woth)
- type of Lymphocyte
- Large
–Target our damaged cells - Target and induce the process of APOPTOSIS in cancer cells and virus infected cells
When - our cells our infected, potentially have damage
Apoptosis -
Programmed cell death`
Complement proteins
flag invaders
innate
assist adaptive immunity
Nonspecific
includes barriers - skin, mucous & more
Innate - born wot it
Specific
Adaptive - exposed to
- Complement proteins - flag invaders
- Generalist Phagocytes engulf invaders & commnuicate to specialist
- Specialist WBCs (T & B cells) learn to fight invaders and produce armies and munitions for future battles (memory cells)
MHC
- genes that allows us to have our own specific antigens
AND - Recognize the difference between our cell markers, the antigens, and Foreign cell markers.
Humoral Body Fluids -
Plasma
Interstitial Fluid
Not specifically inside the cell
Lymphocytes
T & B cells
Effectors =
Plasma cells & fight right away
Take action
Memory =
Fights future battles with the same foe
Walk thru the steps in Antibody-Mediated Immunity
AKA - Humoral
Targeting stuff not inside the cell - plasma, interstitial fluid
All about B cells and Antibody-Mediated Immunity
T cells hanging out in the background
- Bacteria enters
- APCs (Antigen Presenting dendritic cell) phagocytize
- Non-infected agent is presented
- Helper Ts activated
- Helper Ts selected
- Helper Ts bind with B cell
- Activated B cell stimulated by helper T cell
- Selected B cell forms clones - mitosis
- B cell makes plasma and memory cells
- Plasma cells produce antibodies
- Bacteria disabled by antibody
causing more phagocytosis
APCs. -
Antigen Presenting Cells
Presenting piece of the antigen
to communicate to
Naive cells
Walk Thru steps in Cell-Mediated Immunity
Targets things inside the cell
Example HIV
- Virus enters
- APCs (Antigen Presenting dendritic cell) phagocytize
- Non-infected agent is presented
- Helper Ts activated & cloned (mitosis)
- Cytotoxic T activated but waits for go signal
- Effector Helper Ts send cytokines
- Activated cytotoxic T cell clones (mitosis)
- Activated Cytotoxic T cell produces Memory and effector T cells
- Effector cytotoxic T performs apoptosis like a Natural Killer cell - (program cell death)
- Cell self destructs
HIV example - cell-mediated immunity
What kills an AIDS patient? - weakened immunity - secondary issues
What type of WBC do they monitor in HIV patient? – T cells
What issue with the T cells? no communication
W/O T cells? You never get the cytokine - the communication is affected - will not be able to create effectors or memory cells.
Cannot do teh final step
Primary Response to 1st exposure - lag time
Lag 3-6 days
Max - [plasma antibosy] ~10 days and declines from there
Secondary response - timing
(Booster shot or natural exposure)
Sensitized memory cells responds in hours - much faster
Much higher [antibody] peaks 2-3 days
Greater antibody affinity to antigen (better - learn for next time)
[antibody] can remain high for much longer
Acquired Immunity
Active - antigen-induced
(you did the work). -
Natural or Artificial
Vaccines – Killed, weakened, inactive toxins (not a cellular component), antigens only (extracted)
Long Term - body did the work (from our won memory cells, antibodies - learned to fight)
Passive - antibodies only
(did not do the work)
Did not learn how to fight those pathogens
gained from some other source
Nonhuman source or mother
Immediate protection
SHortterm - body did NOT do the work
Occurs during development
Antibodies - placenta
breast feeding
Exotoxins
Proteins secreted by bacteria
Macrophages
found in all organs -
engulf particulates with pseudopods
Pseudopds
fake arms to engulf
Phagosome
produces vesicle – fuse with lysosomes to break down the nasties
Recognition of pathogen aided by
complement protein OR antibody marking
Flag antigens - pathogens for destruction
Coordinates activity with WBCs
Natural Killers
Target & Induce apoptosis - -program cell death - in cancer and virus-infected cells
Inflammation
Solution to Pollution is dilution
- mobilizes resources
- Immobilize, dilute toxins
- Activate clotting proteins
- Repair
Inflammation
Histamines
Vasodilation & capillary Permeability
Inflammation
Prostaglandins
- Vasodilation & capillary Permeability
- Induces Pain
- Chemotaxis - release chemical to attract WBCs to come and fight injury
Inflammation
Complement proteins
- Mark invaders (for destruction)
- Enhance inflammation
Inflammation
Lymphokines
Chemotaxis - release chemical to attract WBCs to come and fight injury
Cardinal signs of inflammation
- Redness
- Heat
- Swelling
- Pain
Cardinal signs of inflammation
Redness
Send more blood to area - appears red
Vasodilation
Increased metabolic rate of cells
Cardinal signs of inflammation
Heat
Send more blood to area not only appears more red but also heats up due to blood being warm
Blood holds heat
Vasodilation
Increased metabolic rate of cells
Cardinal signs of inflammation
Swelling
Swelling - edema
Leakes protein-rich fluid in tissue spaces (interstitial fluid) & Water follows
Possible temporary limitation of joint movement
Cardinal signs of inflammation
Pain
Swelling pinches nerve endings and induces pain
Possible temporary limitation of joint movement
Inflammation:
Some specific Inflammatory Mediators
-
Histamines & Kinins
- Vasodilation
- capillary permeability
-
Prostaglandins
- Vasodilation- capillary permeability
- Chemotaxis (calling other WBCs to the site - backup taxis) - Induces Pain
- capillary permeability
-
Complementary Proteins
- Tag invaders
- lyses
- increase inflammation response
- increase immune response
4, Lymphokines
- chemical that aids in chemotaxis
- initiates it - calls for WBCs to come and help
Inflammation:
Benefits of Edema (4)
- Immobility - immobilize the damaged region
- Dilute Toxins - Get rid of nasty and filter at kidneys
- Activates clotting proteins & - more resources, more chemicals in the area to initiate blood clotting
- Distribute Resources - water everywhere - moves things easily
Two pathways to prolong inflammation
-
Classical Pathway - flagging a cell
Antibodies & complements bind to bacteria & flag it for phagocytosis -
Alternate Pathway - form a pore
Form a pore and insert into cell wall & cause lysis
*Both pathways
1. “CASCADE” -
2. Destroy pathogens
3. Prolong inflammatory response
Interferons. (IFNS)
Activate during viral infection
ALL ABOUT VIRUSES
- Infected cells produce & secrete IFNS and send to neighbors - healthy cell
- gives them the code to fight the infection - preventing viral reproduction
- Activates macrophages & NK cells to target infected cells & possibly malignant cells
Difference between Complement Proteins and Interferons
Complement proteins go after cellular things - bacteria
Interferons - interfere with the viral replication process
Fever
Benefits - metabolism costs - denaturation risk
Increases body temperature
- speeds up metabolism
- Inhibits bacterial reproduction
- Improves lymphocyte activity
- Prostaglandins produce endogenous pyrogens - (go to brain and say turn up the heat
Aspirin interferes with prostaglandin production - fights off the formation of them.
Is a negative feedback loop
Adaptive defenses -
Specific & has a memory
- Antibodies
- Lymphocytes
- Aided by complements & phagocytes
- Must recognize self-antigens
- Amplifies inflammatory response
- Targets infectious agents & abnormal body cells
- Works with complement proteins
- Works best with prior exposure
Cells of the Immune system
Adaptive
1. B Lymphocytes- antibody producers, aids in humoral immunity - antibody-mediated. (things in the body fluids not cells)
- T Lymphocytes - cell-mediated immunity
Innate
1. Antigen-presenting cells (APCs) - do not respond to specific antigens - they are innate.
- Play an essential auxiliary roles in immunity,
- Assisting - help the process - not the ones causing the memory, creating the long term protection
Immunocompetence
-
During maturation -
- Any cells that fail to differentiate between our antigens (self-antigens) and foreign antigens will be destroyed.
- Allows T & B cells to interact with our antigens and should not bind with our antigens.
- *Upon Release - *
- Cell family = 1 receptor + 1 antigen
- Receptors are genetically determined
- Able to recognize & bind to specific antigen
-
Naive (unexposed) B & T cells reside -
- Lymph nodes, spleen, & lymphoid organs
Antigens - 2 types
Complete Antigens
Incomplete Antigens
Complete Antigens
- Hangs out on its own
- Does not need to bind
Proteins, polysaccharides, lipids, & nucleic acids
Stimulates immune cells & Reacts to products of immune response
Incomplete Antigens
(Haptens)
- Chemicals from environment that bind to our proteins and acts like a complete protein
EXAMPLE - poison ivy, animal dander, detergents, & cosmetics
Chemicals on own ok -
On our protein they become a complete protein - attach to our structures - problem
React but do not activate a response directly, but can if attached to body protein
Immunity =
Specificity
Antibodies
Proteins that combine with specific antigens
Constant & variable regions
Y - antibody.
- the fork part is the variable and attaches to foreign substance
- stem is the constant
Antigenic Determinant
Part of the antigen-stimulating immune response
Lock and Key
3 ways antibodies work
- Direct - Antigen binding
- Indirect - Stimulating phagocytosis of antibody-antigen complex
– we called for backup - Indirect - Enhances inflammatory response & activates complements
Transplant Issues =
MHC antigens are unique
- Donor-recipient matching
- Immune suppressing drugs
- Artificial parts benefits…
Allergy =
Reaction not dangerous
- Hypersensitivity to non-pathogenic antigen
But can become dangerous if anaphylactic shock - huge amounts os histamines - dangerous
Autoimmune disease =
Attack self
Genes, infection, antigen & self similarity
Exposed earlier in life
Cytokins
facilitate mitosis
