Exam 2: Memory and Human Microbiome Flashcards
What is the longest lived Abs? how long do they live? What does this mean to us?
IgG; live for a month or two
therefore, Abs must be made continuously to confer the immunity
What three kinds of B cells are made when B cells are activated from initial invader?
- Short-Lived Plasma Cells
- Long-Lived Plasma Cells (memory cells)
- Central Memory B Cell (memory cell)
Where are short-term and long-term plasma cells produced?
in lymphoid follicles of secondary lymphoid organs
Where do short-term plasma cells travel?
Where do long-term plasma cells travel?
short-term–> to bone marrow and spleen
long-term–> to bone marrow
What type of B cell produces incredible amounts of anitbodies and live only for a few days?
Short-lived plasma cells
What type of B cells continuously produce modest amount of antibodies and provide “life-long antibody protection”?
long-lived plasma cells
What type of B cell slowly proliferates and maintains a pool of themselves and replace the long-lived plasma cells which die from old age?
Memory B stem cells and maintain a pool of Central memory B cells
If an invader is encountered a second time, when cells will quickly proliferate and making more short-lived plasma B cells?
Memory B stem cells (Central memory B cells)
Overall, what do these cells do?
- Short-lived B cell
- Long-lived B cell
- Central Memory cell
- massive Ab production and dies after a few days
- modest Ab production and always active
- Stem cell to replace–> long-lived B cells and short-lived B cells
how does B cell memory relate to primary and secondary Ab responses?
1st time–> delayed a bit and IgM is more prominent at start
2nd time—> Ab’s made right away much more, esp. IgG
T cell memory is similar to B cell memory, what are the three kinds of T cells that can be made?
- Effector T cells
- Memory Effector T cells
- Central Memory T cells
After activation of T cells, what do they do?
proliferate (10,000 fold)
What type of activated T cell will travel to battle site and fight, and most die of apoptosis after a few days?
Effector T cells
What type of activated T cell will travel to battle site and remain there and can stay there for at least 10 years?
Memory Effector T cells
What type of activated T cell will stay in secondary lymphoid organs and bone marrow? What do they do during a subsequent attack?
Central Memory T cells
quickly activate and proliferate (mostly into Effector T cells) and go to the battle site
During subsequent infections, how come we usually don’t even know we have been infected?
- more T and B cells specific to invader
- memory B and T cells are easier to activate
- Memory B cells are upgraded versions–> Somatic Hypermutation and Ab class has been pre-determined and better suited for invader
How is innate memory different than adaptive memory?
Innate–> born w/ in; is static; essentially all humans have SAME innate memory
Adaptive–> expandable; remembers invaders met; UNIQUE to each human
T/F. No two humans have the exact adaptive memory, but they do essentially have the same innate memory.
TRUEEE
What is CAR T cells and how do they work?
form of immunotherapy using specific altered T cells to fight Cancer
– sample patients blood and use their T cells and modify them to produce CARs on surface (chimeric antigen receptors)
What is the microbiome?
collection of microbes in and on us
- on skin and line GI tract
What percentage of us are human and what is microbial cells?
10% human
90% microbial
(or 1% human genes and 99% microbial genes)
Where do we find most gut microbes?
in the large intestine
How much of our fecal material is microbial stuff?
about 1/2
What cell types does out gut microbiome consist of?
- bacteria
- viruses
- fungi
- protozoa
How do our colonocytes (cells from the colon) get most of there energy?
microbes digest fiber into short chain fatty acids (SCFA) and these SCFA provide up to 80% of the energy for colonocytes
How do we digest a long of our carbohydrates if many plant carbohydrates are “humanly” indigestible (fiber)?
enzymes from our microbiome degrade them providing nutrients
provide up to 10% of calories
When it comes ti C diff Infections, what have been some well documented ways to help these individuals?
fecal microbiota transplant (FMT)
Does the gut communicate with our brain?
yes, communication b/w grain-gut-enteric microbiota
connections b/w reduced anxiety, stress, depression
What did germ free mice demonstrate? What reversed this?
germ free–> social avoidance
a fecal transplant reversed that
The interface b/w the gut lumen and tissue is potentially inflammatory and we need to control this, what impact may the gut microbiota have on our immune system function?
short chain fatty acids and butyrate–> cause production of Treg cells (which help turn down immune response)
What are foods we can eat that promote a good flora?
prebiotics
What are live microorganisms that we can swallow that can benefit to the host?
probiotics
Is a mix or single species better when it comes to probiotics?
mix
What type of foods naturally contain good bacteria?
fermented foods
What are five reasons why the microbiome is important?
- competes with pathogens
- produces vitamins we absorb
- digest indigestable foods
- provides energy source for intestinal cells
- talk to immune system to prevent over-rxn and allow symbiosis
What are non-inflammatory macrophages and how do they help us “deal with” microbiota?
in lamina propria
don’t release a great deal of cytokines
deal with normal microbiota and “small attacks”
What antibody is important for the GI tract and regulating all the microbes? How?
Secretory IgA–> specifically designed for mucosal surfaces
- can bind invaders in lamina propria and escot them back into lumen
- don’t cause inflammation (IgA isotype doesn’t bind to and activate immune cells)
What is on guard along entire GI tract and deal with invaders quickly, reducitn inflammation?
Macrophages, lyphocytes, DCs, and IgA
“educated” B and T cells
Where do DCs and lymphocytes that are activated in mesenteric lymph nodes and lamina propia tend to go?
they stay there
What is the default setting in the intestinal system?
anti-inflammatory
What do intestinal epithelial cells produce that promotes development of pTregs?
TGFbeta
What will pTregs produce that help create an anti-inflammatory env. in the intestinal system?
IL-10 and TGFbeta
What does normal microbiota produce that promotes formation of pTregs?
short-chain fatty acids
What do DCs have that bind specific commensal bacteria? What do they produce?
TLRs
DCs produce cytokines that CALM the immune response
What do TLR5 on DCs detect in the lumen?
flagella and pathogens
DC’s produce _____ which drives ____ development.
IL-6
Th17
What are DCs constantly doing in the GI tract?
sampling the lumen directly
