Quiz 3 - German - Intro To Immunology Flashcards
What are the 5 roles of the immune system?
Kill or control pathogens
Control disease
Repair tissue damage
Organ development
Maintain organ integrity and function
How do pathogens directly damage tissues? 3 ways.
Exotoxin production
Endotoxins
Direct cytoplasmic effect - Viruses
How do pathogens indirectly damage tissues?
Immune complexes
Anti-host antibody
Cell-mediated immunity
*Bystander tissue can be harmed during degranulation
What is an exotoxin?
Pathogen-secreted toxin
What is an endotoxin?
Toxic pathogen-component
What are 4 challenges that pathogens present to the immune system?
Form diversity
Life cycle diversity
Diverse routes of infection
Rapid, targeted response over a broad domain
T/F - Pathogens often infect multiple body compartments.
TRUE
What pathogen has a “comet” actin tail and also overwhelms the host’s nitric oxide production?
LISTERIA MONOCYTOGENES
Tell me 4 things about the innate immunity.
Rapid response (Hours)
Fixed
Limited number of specificities
Constant during response
Tell me 4 things about the adaptive immune response.
Slow response (days to weeks)
Variable
Numerous highly selective specificities
Improve during response
The innate and adaptive immune systems’ final goal is what?
Destruction of pathogens
________ ________ form the bridge b/t innate and adaptive immune responses.
Dendritic cells
What are 4 cells in the innate immune system?
Neutrophil
Eosinophil
Basophil
Monocyte
What are 2 cells in the adaptive immunity?
B cell
T cell
What are primary lymphoid organs?
Where immune cells originate and develop
- Bone marrow
- Thymus
What are secondary lymphoid organs?
Where adaptive immune responses are initiated
-Where naive and mature B and T cells reside
—Lymph nodes
—Spleen
—Lymphatic system
—Organ-specific lymph node-like tissues
Immune cells use the ___________ and __________ systems to reach tissues.
Cardiovascular
Lymphatic
Mature lymphocytes route to get to tissues.
After maturity, sometimes 12-24 hrs in a lymph node, it will leave via the lymphatic system, drain into the heart via venous return, by pumped out of the heart into arteries and go to the tissue
What is lymph?
Interstitial fluid that drains into the lymphatic system
- Cells
- Pathogens
- Waste
What is the lymphatic system?
Large duct network
Is flow of lymph unidirectional?
YOU BET IT IS!
How is the flow unidirectional?
Valves
Smooth muscle
Pressure gradient
Drains into the venous system
T/F - Lymph nodes allow lymphocytes to browse drainage.
TRUE
What is the generalized response to infection? 3 stages
Immediate innate (Most frequent, least specific)
-0-4hours
—Very minor tissue damage is repaired
Induced innate (Medium frequency, medium specificity)
-4 hours to 4 days
—Minor tissue damage soon repaired
Adaptive (Least frequent, most specific)
-4 days until pathogen defeated
—Major tissue damage is gradually repaired
What are 3 things in the immediate innate system?
Barriers
Antimicrobial peptides
Complement
What is the inflammatory response?
Bacteria introduced, which activate resident effector cells to secrete cytokines
Vasodilation and increaed vascular permeability allow fluid, protein, and inflammatory cells to leave blood and enter tissue
Infected tissue becomes inflamed, causing redness, heat, swelling, and pain
What is the induced innate immune response?
Large reserves of neutrophils are stored in the bone marrow and are released when needed to fight infection
They travel to infected tissue where they engulf and kill bacteria
They then die in tissue Andre are engulfed and degraded by macrophages
What are three primary antigen presenting cell types?
Dendritic cells
Macrophages
B lymphocytes
What are antigens?
Small, components of bacterial proteins
The adaptive immune response in a draining lymph node. What happens?
Pathogens interact with B and T cells in lymph nodes
These cells are activated - they drain out to vasculature - and go to injury site
*Body creates a lot of B and T cells
Antigen presentation activates what?
Lymphocytes
Antigen-receptor binding and co-stimulation of T cell by what?
Dendritic cell
B cells and T cells have a lot of receptors, for what purpose?
To bind antigens and activate and go thru clonal selection.
What is clonal selection?
The lymphocytes that most readily bind to the antigen presented, get a secondary signal from the dendritic cells and rapidly replicate.
T and B cells have specific ______ to remember pathogens.
MEMORY
T/F - Lymphocyte antigen specificity improves over time.
TRUE
What do T cells do?
Kill pathogenic self cells and regulate the immune response
CD8 T cells do what?
CYTOTOXIC
These will recognize complex of viral peptide with MHC Class I and kills infected cell
*Almost all cells in the body have MHC I
What do CD4 T cells do?
They are REGULATORS
*They go on to activate B cells and they drive the innate immune system to become more active or resolve the activation of the innate system
**MHC Class II
What do B cells do?
Produce antibodies
What does an activated B cell do, generally?
Forms numerous plasma cells
*Can respond to large things like pathogens and small things like toxins
T/F - B cells produce plasma cells.
TRUE
What do plasma cells do?
Secrete antibodies
*Antibodies are targeted against a single antigen
What is opsonization?
The coating of antibody on a pathogen
Once opsonized, what happens to a pathogen?
Can be engulfed and degraded or trigger the complement system to kick in
Innate immune response is what?
Inflammation
Complement activation
Phagocytosis and destruction of pathogen
*Happens immediately and can be days in it’s duration of response
What is the adaptive immune response? (Hours to days)
Hours to Days
- Interaction b/t antigen-presenting dendritic cells and antigen-specific T cells
- Recognition of antigen
- Adhesion
- Co-stimulation
- T-cell proliferation and differentiation
- Activation of antigen-specific B cells
What is the adaptive immune response? (Days to weeks)
- Formation of effector and memory T cells
- Interaction of T cells with B cells, formation of germinal centers
- Formation of effect B cells (plasma cells*) and memory B cells
- Production of antibody
What is the adaptive immune response? (A few days to weeks)
- Emigration of effector lymphocytes from peripheral lymphoid organs
- Effector cells and antibodies eliminate the pathogen
What is the adaptive immune response? (Days/wks- Lifetime)
Days to weeks - Lifetime
- Maintenance of memory B cells and T cells
- High serum or mucosal antibody levels
- Protection against reinfection
T/F - Immune response can be helpful and harmful.
TRUE
- Positives: Protective immunity, organ acceptance, tolerant of self cells, tumor immunity
- Negatives: Autoimmunity (Diabetes), organ transplant rejection, allergy to innocuous substances, cancer
