GI Immunology Flashcards
what is the largest immunological organ in the body
- GI tract
is IL-10 immunoreactive or immunosuppressive
- immunosuppressive
is TGF-Beta immunoreactive or immunosuppressive
- immunosuppressive
which proinflammatory cytokines that can cause disease are produced by dendritic cells
- IL-6
- IL-12
- IL-23
which proinflammatory cytokines that can cause disease are produced by activated T cells
- TNF-alpha
- IFN-gamma
- IL-17
GALT favors tolerance or reactivity
- tolerance
GALT protects against which intestinal disorders
- food allergy
- celiac disease
- IBD
two methods of GALT antigen uptake
- antigen sampling by M cells and dendritic cells in Peyer’s Patches
- soluble antigen uptake directly by dendritic cells
the importance of oral exposure to antigen
- oral exposure is preset to tolerance
tolerance is mediated by which cells
- T cells
the majority of immunoglobulin secreting cells are located where
- the GI tract
in the GI tract, which immunoglobulin is synthesized most
- IgA
IgA+ plasma cells develop where
- Peyer patch germinal centers
IgA is secreted how
- as a dimer
role of epithelial cells with IgA
- add a secretory component
importance of IgA with added secretory component
- highly resistant to proteolytic enzymes
what is the most common primary immunodeficiency
- IgA deficiency
common symptoms of IgA deficiency
- chronic diarrhea
- ulcerative colitis
- Chron’s disease
- recurrent oral and mucosal infections
antigen feeding and oral tolerance is more mediated by which antibody?
- IgA
what is the importance of regulatory T cells
- immunomodulatory
- tone down inflammatory response
defects in regulatory T cells can cause
- IBD
importance of GALT T cells in HIV infection
- lots of GALT T cells depleted early in HIV infection
what is the site within the GI tract that harbors the greatest number of microbes
why?
- large intestine
- pretty low acidity
which microorganisms are found in the upper/lower GI tract
- upper - aerobic
- lower - anaerobic
streptococci is found where in the GI
tract
- stomach
candida is found where in the GI
tract
- stomach
helicobacter is found where in the GI
tract
- stomach
E. coli is found where in the GI
tract
- small intestine
enterococci is found where in the GI
tract
- small intestine
bacteroides is found where in the GI
tract
- large intestine
bifidobacteria is found where in the GI
tract
- large intestine
clostridia is found where in the GI
tract
- large intestine
relationship between microflora function and CNS function
- healthy microflora, healthy CNS
flagella are important for
- locomotion
pili are important for
- adherence
what does bacterial flaggelin (FliC) do
- stimulates innate immune response
- protects mice from rotavirus infection
Rag-1 is important for
- immunoglobulin and T-cell receptor gene rearrangements
- recombining activating genes (RAG)
which is most important immune mechanism for bacterial protection from viral infection
- TLR signaling
structure of C. diff
- spore-forming bacterium
spores of C. diff
- not metabolically active
- extremely stable
function of Peyer’s patches
- coordinates immune responses
what is a tolerogenic immune response
- immune system initiates anti-inflammatory response
IL-10 is secrete by
- regulatory T cells
