Immune System Flashcards
Lymphocytes and Monocytes(macrophages)
Most important leukocytes ( WBCs) that deal with immunity
3 Main Lymphocytes
T-cells (80%). B-cells (15%), NK cells (5%)
These cells mature in thymus
T cells
make antibodies; turns into plasma cells & produces antibodies
B cells
attack/destroy bacterial cells that can be viral or cancerous, etc
NK cells
Monocytes become
macrophages (big eaters/ phagocytic)
Agents that can produce diseases are
Pathogens
Actively seek pathogens
Wandering Macrophages
Phagocytize pathogens that come to them
Fixed macrophages
Examples of macrophages that can be found in CNS, lungs & liver
microglia, alveolar , and hepatic macrophages
Skin and mucous membranes considered
1st line of immune defense
2nd line of defense are Innate aka
NON specific
3rd line of Immune Defense are Adaptive aka
Specific
Innate/nonspecific/ external/ mechanical barrier
skin- keratin roughness makes breach difficult, releases acid to kill bacteria, makes peptides to kill microbes
Innate/Non Specific/ Mechanical External barrier
mucus membrane- traps microbes; makes lysosomes that destroy bacterial cell walls
INNATE/ NON SPECIFIC- PROTECTIVE PROTEINS are
interferons and complement (system)
This innate/ non specific / protective proteins interferon …
alert system for neighboring cells, helps protect from infection, activates NK cells & macrophages
Innate/NonSpecific Protective protein complement system
group of 30+ proteins involved in resistance & adaptive immunity
4 functions/ Mechanism of complement include
Inflammation, Immune Clearance, Phagocytosis, Cytolysis
3 routes of Complement Activation
Classical , Alternative & Lectin pathways
Complement proteins cause mast cells and basophils
to secrete histamine, resulting in inflammation
Popular vasodilator
Histamine
Immune Clearance main principle
is to clear foreign antigens from blood
How does immune system work?
C3 binds to RBCs that travel to spleen where macrophages break off & eat up foreign antigens from blood stream
Phagocytosis is a process
that makes foreign cells more appetizing. complement binds to bacteria cell & macrophage will eat it up
Classical pathway requires
anti body presence
Steps of Classical pathway
Antibody-antigen complex forms, antibody changes shape, C1 binds to antibody to begin complement fixation
cell splitting and killing process is known as
cytolysis
complement proteins form ring in membrane of target cells causing cytolysis
MAC- membrane attack complex
Complement cannot
phagocytize itself
complement by itself
can kill cells
has ability to kill multi types of cells; releases perforins that perforate membrane
NK Cells
How NK cells operate as protective cells
Pokes hole in cell, secretes granzymes to kill cell from inside out, the macrophages comes clean up cell
Innate/ Non Specific/ Protective Processes include
Fever & inflammation
Abnormal elevation of body temperature that presents when fighting infection; promotes interferon activity
fever; febrile; pyrexia
4 Cardinal signs of inflammation
Redness, Swelling, Pain, Heat
Inflammation is caused by
release of cytokines (a protein that regulates immunity & inflammation)
Inflammation prevents
spread of pathogens
How does inflammation stop spread of pathogens?
Fibrin surrounds outside to contain infection; heparin stays inside to prevent clotting & to get blood cells and antibodies in
Enemy of bacteria that accumulates at site of injury & quickly phagocytizes bacteria
Neutrophils
Respiratory burst is when
neutrophils secrete “clorox” which “kills everything”
Chemotaxis is
movement in response to chemicals
diapedesis is
passage of blood through an intact vessel
Adpative immunity is
HIGHLY SPECIFIC
two forms of adapative immunity include
Cellular (t cells) & Humoral ( antibodies)
How does Cellular Adaptive immunity work?
Lymphocytes directly attack foreign cells
How does Humoral Adaptive immunity work?
It is mediated by antibodies, and the antibodies sets up pathogens to be destroyed by something else. (antibodies cannot kill cells)
Humoral Adaptive Immunity only works
outside of cell/ extracellular pathogens
Natural Active Immunity
standard response to infection; production of antibodies from natural exposure to antigen
Artificial Active Immunity
production of antibodies as result of vaccine; induced
Natural Passive
temporary immunity resulting from antibodies produced from another person (mama to fetus)
Artificial passive
temp immunity from injection of antibodies from another persona/ animal. (snake bites, rabies)
active immunity
body makes antibody/ immune response
passive
we’re “passed”/ “given” antibody/ immune response
antigen
anything that triggers an immune response
Lymphocyte that is non specific/ innate
NK Cells
Lymphocyte that is adaptive/ specific
T cells & B cells
in order for T cell to recognize antigen
antigen must be presented with an MHC (major histocompatibility protein”
Our bodies make T cell receptors and antibodies
randomly
What happens if t cell receptors/ antibodies recognize self?
They will attack each other and result in autoimmune disease
How are t cell/ antibody lymphocytes handled in early development?
These cells are either killed or put to sleep (energy)… hopefully they do not wake up :)
What are Professional Antigen Presenting Cells?
These are presentation of antigens that originate OUTSIDE of the cell; ex: bacteria cells
Examples of APCs
macrophages, B-cells, dendritic, reticular cells
Cells that are capable of immune response in nucleated cells & their MHC protein
Cytotoxic T-cell, MHC-1; presentation of antigen that originates from within APC
Cells that are capable of immune response in antigen presenting cells & their MHC protein
T-Helper cell; MHC-2; antigens that originate outside of APC
Tcell+ Ag (antigen) =
NOTHING
Tcell + Ag/MHC=
BINDING
Ab+Ag=
BINDING
What is being matching when searching for organ donor compatibility?
MHC proteins
Cytotoxic T cells (CD8)
KILLs cells/ similar to NK cells
Helper T cells (CD4)
Activate immune system; releases cytokines and interleukins
Regulatory Tcells (CD4)
inhibits/limits immune response
Memory Tcells
memory in cellular immunity; triggered/fight when cells are reactivated
How are antibodies involved in Humoral immunity?
B cells produce antibodies, which binds & tag antigens for later destruction
Do antibodies require MHC to recognize antigens?
no, t cells receptors require MHC.
How does the humoral immune response work
B cells have antibodies on their surface. Some turn into plasma cells, which secretes antibodies and allowed them to fulfill antibody mediated attack mechanisms.
How many antibodies can plasma cells produce? what is their life span?
plasma cells can produce 2k per second & have 4-5 day lifespan
Can antibodies kill cells?
No.
Antibody mediated attack mechanisms include
Neutralization, Complement fixation, Agglutination, Precipitation
Where antibodies mask pathogenic portion of antigens
Neutralization
antibodies bind to antigen, antibody changes its shape, complement binds to antibody resulting in protective mechanisms aka classical pathway
Complement fixation
binding to multiple cells to immobilize them
aggulutination
antibody antigen complex forming, precipitates to then be phagocytized or removed by immune clearance
precipitation
How long until antibody response from initial exposure
2 weeks
How long for antibody response once re exposed
1-2 days