Intro to Immunology Flashcards
allergy
overreaction to harmless materials
autoimmune
attacking healthy “self” cells
Link between innate and adaptive systems
dendritic cells (innate) can phagocytosize a microbe and then present an antigen to the adaptive system
When does adaptive immunity kick in?
takes a couple of days
Location of innate immune system
periphery tissue
Location of adaptive immune system
lymph nodes + spleen
Antigen presenting cells
Dendritic, macrophages and B-cells
normal tissue can present antigens as well
Humoral immunity
part of adaptive immunity
acts on extracellular pathogens
vaccines use memory of humoral immunity
What should you associate with humoral immunity?
B-cells and antibodies
Cell-mediated immunity
T-cells
acts on intracellular pathogens
new exposure to virus
What are intracellular pathogens?
TB and listeria
Helper T-cells
involved in activating macrophages, killer T-cells
active B-cells (this is a biggy)
release cyotkines
increase inflamattion
How are B-cells activated?
activated by helper T-cells
What is an activated B-cell called?
plasma cell
now, cell can secrete antibodies
B-cells function
antigen presenting or antibody producing
can recruit phagocytes or complement system
Regulatory T-cells
help avoid damage of healthy cells
prevent overactivation of immune system
Cytotoxic T-cells
attack cells that express microbial antigens
(pathogens have already been phagocytized and now antigens are presented)
When does immune system kick in?
after a pathogen has already entered a tissue
what is first immune cell to work in innate immunity? why?
macrophages
since they can live in tissues for long periods of time
Where are neutrophils?
they normally circulate in the blood for a couple days
they need to be recruited to site of infection
PAMPs vs. DAMPS
pamps are pathogen associated patterns
damps are “danger” or “self” associated patterns
What recognizes PAMPs?
pattern recognition receptors
examples of PRRs
TLR-4 and mannose receptors
What does TLR-4 bind?
LPS on gram neg. bacteria
Where are PRRs located?
membrane, endosome or free-floating in cytoplasm
what are 2 things triggering PRRs can do?
activated NF-kB or produce interferons
2 distinct pathways
NF-kB
causes inflammation
interferons
antiviral state
4 main effects of activated PRRs
phagocytosis
recruit more cells through chemokines
trigger inflammation through cytokines
release O2 / nitrogen which is directly toxic
Cytokines
trigger inflammation
What is one specific thing cytokines trigger?
increased vascular permeability to allow leukocytes to enter tissues
What cell is responsible for chemokine and cytokine secretion?
macrophages
chemokine
recruits more cells
What cell is responsible for generating reactive oxygen species?
neutrophils
what cell is responsible for generating reactive nitrogen species?
macrophages
what attracts neutrophils to infected tissue?
cytokines
what do endothelium cells produce to slow leukocytes down?
adhesion molecules
selectin + integrin
3 stages of attracting leukocytes
rolling
adhesion
extravasation (out of blood)
What are the 3 main cytokines?
IL - 1
IL - 6
INF- alpha
What does fever do?
slows rate of viral and bacteria DNA replication
What are MHC receptors?
they are present on all cells
if they aren’t present, the immune system knows to attack
