Exam 4 Flashcards
immunology, cancer, aging, exercise, Mike young
Anatomical and chemical barriers
continuous
-physical barrier-
ex. Mucus
saliva
stomach acid
tears
skin
Intrinsic
Immediate
-Intrinsic-
ex. Autophagy
Apoptosis
MicroRNAs
CRISPRs
Innate
Minutes/hours
-Innate-
(not specific to the pathogen)
ex. Natural killer cells
Complement
Antigen-presenting cells
Neutrophils
Cytokines
Natural killer cells
Activated by cytokines, recognize changes in cell surface, secrete perforins (poke holes in cell membranes) and granzymes (activate apoptosis). Kill tumor cells and infected cells
Complement system
series of serum proteins that help in later (antibody) responses
*helps the movement
Neutrophils
Initial response to pathogens, induce inflammation (but need to go away first)
Cytokines
Stream of info to the rest of the immune system abt what kind of pathogen they have been exposed to
(specific: interferons)
Acquired immunity
Hours/days
-adaptive-
-very specific to pathogen-
ex. T cells
B cells
T cells
(Cytotoxic B cells) destroy infected cells (important for intracellular pathogens)
intracellular
B cells
Induce and mature plasma cells to make antibodies and those will circulate and destroy pathogens
Bacterial, too big to get in
what’s the only immune defense thats available after an organism is exposed to a pathogen?
Innate immune response
Adaptive response takes…?
a week to produce antibodies
Innate/Adaptive system differences
Both derive from hematopoietic stem cells:
Origin:
Innate= Myeloid linage Characteristics: Non-specific, rapid.
❄︎Components: Physical barriers, cellular components (e.g., phagocytes), soluble factors.
❄︎Recognition: Pattern recognition receptors (PRRs) detect pathogen-associated molecular patterns (PAMPs).
❄︎Response: Triggers inflammation, phagocytosis, and activation of immune cells.
❄︎Memory: Lacks immunological memory; response does not improve upon repeated exposure
Adaptive= Lymphoid linage
❄︎Characteristics: Antigen-specific, slower.
❄︎Components: Lymphocytes (B cells, T cells), NK cells.
Recognition: Specific recognition of antigens presented by antigen-presenting cells.
❄︎Response: Tailored response including antibody production, cytotoxic T cell activation, and immune cell coordination.
❄︎Memory: Develops immunological memory for faster and stronger responses upon re-exposure.
Antigen
Substance that is capable of stimulating an immune response.
Foreign antigens and autoantigens
Interferons
type of cytokine that protects cells from damage and death, but they do not play a major role in pathogen clearance
Phagocytes (macrophages, dendridic cells)
Internalize dead cells, cell debris, pathogens, including viral proteins.
*Activated by cytokines
*can present antigens on the cell surface
Granulocytes (neutrophils, eosinophils, basophils, mast cells)
Neutrophils usually the first innate cells recruited to infection site, they have phagocytic activity
Innate immune system mechanism
Pathogen- (cut/mosquito)–>
pattern recognition receptors (will recognize patterns of pathogens that are different from ours) –>
cytokines will be produces and will activate
–>
our innate response–>
Interferons create an antiviral state by shutting down ____and ____. Not specific to pathogen, so the response need to be____
transcription; translation; short lived
Sentinel cells
They patrol all our tissues, looking for signs of change
*Dendritic cells, macrophages, NK cells
Tnf-⍺
early warning signal in the innate immune response, and causes inflammation
step by step inflammation
❁Pathogen will induce an innate immune response, which will lead to the production of cytokines.
❁Those cytokines will induce inflammation, antipathogen state thru interferons and signal to sentinel cells that something is wrong.
❁They will move to the site of pathogen and mature and engulf debris, including pieces of the pathogen and present those short peptides or antigens, on cell surface.
❁Through inflammation, they will be able to migrate through lymph nodes, where they will talk to cells to adaptive immune response (immature T and B cells) and will signal to them that there is a big problem (takes several days)
when cells are expressing antigens on MHC class I molecules, this is recognized by what type of cells
NK cells and T cells
When are NK cells ONLY active
when MHC class I is not present