Ch12: Immunity Flashcards
What are the 3 stages of the immune systems?
1) Recognition of non-self cells
2) Activation Phase
3) Effector phase
Describe what occurs in the recognition of non-self cells stage
Pattern recognising receptors (PRRs) recognise microbe associated molecular patterns (MAMPs) of microbes
Where are MAMPs located? And what does their necessity suggest?
These are located on the surface of cells
They are usually vital to the microbes survival SO they are NOT subject to much change (receptors do NOT have to change = more efficient)
What does pneumonic: Pussy rider revolver (PRR) refer to?
Pattern Recognising Receptors
What does pneumonic: major amazing molecular pussy
Microbe associated molecular patterns
What are some examples of common MAMPs? (Hint: for bacterium and virus vectors)
Bacterium: have flagellin (protein)
Virus vectors = have coat proteins + ssRNAs
Describe what occurs in the activation phase:
cells mobilise to fight pathogen:
-When the MAMPs bind to PRRs there is;
- secretion of DEFENSINS –> disrupt cell membrane of pathogen = causing cell lysis and death
- CYTOKINES: bind to surface of pathogen to signal infection + cause further immune response (cascade) = recognised by primary immune system cells
Describe what occurs in the effector phase:
- includes defensins: disrupt cell membrane = cause cell lysis + death
- Macrophages: engulf (phagocytose) pathogens into a vacuole (PHAGOSOME) to mix digestive enzymes + break it down
- Some of these macrophages act as APC (antigen presenting cells), presenting the antigen on their surface to PRIME other immune cells
What part of the immune system are the; recognising, activation and effector phases a part of
INNATE immune system
What can the effector phase activate (different kind of immune system)
Can activate ADAPTIVE immune system
What implies convergent evolution between fungi, plants and animals?
Cell death
Define immune system
natural system of innate + adaptive defences in charge of providing resistance to disease
Define the innate immune system, what kind of response does the 2nd line of defence cause?
1st barrier of defence:
- skin + mucous membranes
Second line of internal defence it activated when the first line is compromised
- Phagocytic cells (macrophages + mast cells) and other non-specific cells + chemicals
- Causes an INFLAMMATORY response
Define the adaptive immune system
3rd line of defence:
- Uses lymphocytes to destroy infection and circulate antibodies
- System needs to be primed (be exposed) to form a memory + produce a stronger attack
Compare innate and acquired immunity
INNATE:
- Non-specific response
- Rapid
- Acute (short-term)
ACQUIRED:
- Specific
- Takes longer
- Long-term
What are some physical barriers in plants
Plants have wax of their epidermis to serve as a barrier as well as bark, they can also have a cuticle layer
Properties of chitin, keratin and mucous
Chitin: exoskeleton serves as support + strength
Keratin: fur, scales = epidermal layer
Mucous: can have antimicrobial properties + trap pathogens;
- in lungs = cilia which push the mucous to the stomach OR removal via coughing
How does the stomach and eyes defend against pathogens
Stomach: acidic environment + digestive enzymes = kill pathogens
Eyes: have eyelids or membranes covering the eye and preventing pathogens from entering - tears also have antimicrobial properties
What do cytokines do?
They attract more immune cells and thus increase inflammation
Define and describe inflammation. What leads this process, and what do they cause?
The isolation of damaged cells to prevent spread of damage
This is led by MAST cells (vertebrates) that release cytokines, attacinting immune cells (which also release cytokines = cascade)
- increasing blood flow to the area of inflammation as blood vessels become more permeable (clots at site = promotes healing
Plant immune response: What are the 3 steps after detection?
When a pathogen breaks the physical barrier, membrane bound pattern recognition receptors detect the flagellin (bacterium) and release immune cells to respond
1) Stomatal closure
2) Produce antimicrobial chemicals
3) Strengthen cell wall
Describe the process of coevolution that occurs between bacterium and plant cells
Bacterium inject cells with EFFECTOR molecules t stop the effect of immune cells (STOP response)
- Plants release RESISTANCE proteins that detect effector molecules + cause pathogen related (fight against) genes to be produced or induce cell death
What is a respond to a herbivore attack that plants have as a defnce?
They release VOLATILES: which attract parasites to kill the herbivores
Define: Cell-mediated Immunity:
adapted cellular response to prevent infection
Explain how Major Histocompatibility class (MHC) cells work with macrophages:
MHCs enter the macrophage and bring the antigen to the cells surface (APC)
How do T cells (Lymphocytes) play a role in acquired immunity? What kind of cells specialise from T cells? What happens when an infection is cleared?
T cells detect the antigen on the APC and undergo mitosis for SPECIALISATION:
Helper T cells: assist in growth and differentiation of cytotoxic T cells
Cytotoxic T cells: kill damaged cells
Memory T cells: for later infection, cells proliferate easier to form cytotoxic T cells
When an infection is cleared: Suppressor T cells prevent further damage to healthy cells (host tissue)
Define humoral immunity
Adaptive respond to pathogens of the humoral fluid (blood + lymph)
Describe the process B cells undertake when they detect antigens:
Detect antigens on surface of bacterial cells:
They proliferate + differentiate into PLASMA cells that produce lots of antigens to fight infection and MEMORY B cells that are able to later recognise reinfection, release small amounts of antibodies + immediately proliferate into PLASMA cells (to produce antibodies)
What are the 3 defence mechanisms of antibodies?
NOC:
1) Neutralisation: antibodies bind to antigens to prevent them from entering + infecting cells
2) Opsonisation: antibodies tag these antigens (antigen-antibody complex) by binding to them, for ENGULFMENT by PHAGOCYTES (macrophages, neutrophils, etc)
3) Complement: activate complement system, where PROTEINS tag antigens which enhances opsonisation + destroys pathogens
