1.B Flashcards
Are inflammation and immunity the same thing?
no, however they are intertwined
Where do all blood cells come from?
pluripotent hematopoietic stem cells
What is hematopoiesis?
the production of all the cellular components of blood and plasma
precursor is pluripotent hematopoietic stem cells
When HSCs are exposed to cytokines and stromal cells, what can they differentiate into?
megakaryocytes—>platelets
erythrocytes
leukocytes—>lymphocytes, granulocytes, monocytes, macrophages, neutrophils, eosinophils
What is an antigen?
any substance that induces the immune system to produce antibodies against it
What is a pathogen?
an organism that causes disease
What is a phagocyte?
a type of cell capable of engulfing and absorbing bacteria or other small particles
What is innate immunity?
the host defence mechanism that are immediately available on exposure to pathogens
always present
first responders that are constantly surveying
What are the cell types of innate immunity?
granulocytes
mononuclear phagocytes
natural killer cells
dendritic cells
What is the function of granulocytes?
first cells to arrive at the site of injury
have granules in their cytoplasm
they engulf and kill pathogens with their granules that can kill a pathogen or enhance immune response
What are examples of granulocytes? Something about each of them?
neutrophils: phagocytize microbial invaders
eosinophils: phagocytize parasites, boost immune response
mast cells: histamine release, located in mucous membranes
basophils: similar to mast cells, boost immune response
What type of membrane are you likely to find mast cells? What are some examples of this?
mucous membranes exposed to environment
ex: nose
What are examples of mononuclear phagocytes?
monocytes
macrophages
How does a monocyte become a macrophage?
monocytes circulate in blood and then migrate to tissue, once in tissue they grow into a macrophage
What is the function of mononuclear phagocytes?
engulf and eliminate pathogens, dead cells, and cellular debris
release pro-inflammatory molecules to recruit more cells to the site of injury
What are natural killer cells?
cytotoxic lymphocytes that target tumor and virus-infected cells (not a specific antigen)
they recognize abnormal expression of surface molecules on DAMAGED cells
What is the main function of dendritic cells?
stimulate the adaptive immune response
immature dendritic cells capture pathogens via phagocytosis
mature dendritic cells present antigens to T-cells
What is the adaptive immune system?
the acquired immune system (antigen specificity)
more complex due to antigen processing and recognition
What are the two major cells of the adaptive immune system?
B and T
Describe the process that B cells undergo when they encounter a pathogen.
naive B cell encounters a pathogen and binds to it with its immunoglobulin
B cell multiplies
B cell differentiates into plasma cells or memory B cells
What do plasma cells do?
short-lived and secrete antibodies to respond to the specific pathogen
What do memory B cells do?
long-lived and responsible for a quick secondary response of the pathogen
Describe how T-cells function.
they express receptors that only recognize antigens that are expressed by dendritic cells or any other antigen presenting cell (don’t respond independently, pathogen has to be identified by someone else)
What are the three types of T cells?
cytotoxic CD8+ (destroy infected host cells)
helper CD4+ (secrete cytokines to enhance other cells)
memory T cells (long lived and mount quick response)
True or false: memory T cells do not persist for years and take a long time to mount an immune response
cap
they persist for years and mount a quick response
Are antibodies and immunoglobulins free floating or part of the membrane?
antibodies=free floating
immunoglobulins=part of the membrane (transmembrane domaine)
What is the lymphatic system?
the network of vessels through which lymph drains from the tissues into the blood
it collects fluid that leaks out of blood vessels and brings this fluid to a secondary lymphoid tissue such as a lymph node where the fluid gets filtered and then returned to the bloodstream
Which direction does the lymphatic system go?
upward
Do B and T cells travel in the lymph or blood?
both
What is the role of primary lymphoid organs?
lymphocyte maturation and development
In which tissue does lymphocyte maturation and development occur?
bone marrow and thymus
B cells: develop+mature in bone marrow
T cells: originate in bone marrow, mature in thymus
What guides the maturation of lymphocytes?
interleukins
What is the role of secondary lymphoid organs?
where mature lymphocytes interact with antigen presenting cells (where antigen is presented to mature lymphocytes)
What are some examples of secondary lymphoid organs?
spleen, lymph nodes, tonsils, appendix
What is the significance of a swollen lymph node?
infection
Describe lymphocyte recirculation
- B and T cells develop in bone marrow and thymus—>enter blood stream
- when they reach secondary lymphoid organ, they enter it (antigen detected=stays and activates, no antigen=re-enter bloodstream0
- allows continuous monitoring for infection
What is an auto-immune disorder?
the immune system has identified something as an antigen that it shouldnt
What is typically the treatment for autoimmune disorders?
anti-inflammatories
immuno-suppressants (sometimes)
True or false: antimicrobial treatment revolves around specific immune cells
cap
it revolves around specific micro-organisms
What are the two mechanisms by which bacteria can cause disease?
rapid growth
releasing a toxin
How are antibiotics classified?
medicinal chemistry structure
mechanism of action
What is a bactericidal antibiotic?
an antibiotic that kills/destroys the bacteria
What is a bacteriostatic antibiotic?
an antibiotic that slows down the growth of bacteria, it helps the immune system dispose of the bacteria
Give an example of a health condition where a bacteriostatic antibiotic would not be effective.
an immunosuppressed patient
Differ broad-spectrum and narrow-spectrum antibiotics.
broad-spectrum are effective against a wide variety of bacteria, narrow-spectrum are effective against very specific bacteria
True or false: pencillins and beta-lactams are different things
false, they are the same
What is an easy way to identify an antibiotic being a penicillin?
it ends in “-cillin”
What do penicillin’s target? How do they do this?
they disrupt bacteria cell walls (bactericidal)
they bind to the penicillin-binding protein which weakens the cell and then fluid enters
What component of a penicillin is necessary for their activity?
beta-lactam ring
What is a bacteria’s natural defence to penicillin?
beta-lactamase
Which antibiotic is good for fighting penicillin resistance? Which component of the drug allows for this?
Amoxiclav (amoxicillin+clavulanic acid)
clavulanic acid inhibits beta-lactamase
What type of drug is cyclosporine? What is its common usage?
immuno-suppressant
transplants
True or false: cyclosporine is very specific
false, it suppresses the entire immune system
What type of drug is methotrexate? What does it target?
immuno-suppressant
targets DNA synthesis, repair, and cellular replication (actively proliferating cells)
What are some conditions where methotrexate is used?
rheumatoid arthritis
psoriasis
Crohns disease
What is meant by “blocking”?
binding to a receptor with no biological response
How do antihistamines work?
they block histamine receptors
no effect on histamine release
What is histamine?
a bioactive amine packed in dense intracellular granules
Where are H1 receptors?
smooth muscle of vascular tissue, bronchial tree, digestive tract, nasal glands
Which histamine receptor are we targeting for allergies?
H1
What are some characteristics of 1st gen antihistamines? Some examples?
block H1 receptors, short acting, drowsiness, work fast, used to treat allergic response, sedation
diphenhydramine (Benadryl) and chlorpheniramine
What are some characteristics of 2nd gen antihistamines? Some examples?
block H1 receptors, long acting, less sedating, takes longer to start, taken daily
cetirizine (Reactine), loratidine (Claritin), desloratidine, fexofenadine
True or false: there are allergy medications specific to certain allergies such as cats, dogs, grass, etc
false, they are all H1 receptor blockers
True or false: natural killer cells will target a specific antigen
false, they target tumour and virus-infected cells
What is the MOA of cyclosporine? How is this useful for patients with transplants or autoimmune disorders?
it targets IL-2, which is an interleukin important in B and T cell proliferation and maturation
preventing the maturation of B and T cells leads to less immune cells that can attack the foreign organ in a transplant or less immune cells that are self-attacking in an autoimmune disorder
