Eating habits - 10th set Flashcards
b anthracis is encoded by…(you know already)
plasmid DNA (virulence plasmid). it is a 3 part toxin, all 3 parts must be present together for biological action of toxin.
3 parts of anthrax
protective antigen, lethal factor, and the edema factor. protective antigen portion used in vaccine preparation
protective antigen - anthrax (lars sub - front door)
2 subunits, binds to receptors, anthrax receptor not meant for toxin, small subunit gets separated from rest of protective antigen. subunit now assembles with subunits and forms a channel. edema factor and lethal factor taken inside cell in endosomal vessel. copies for a multi-subunit structure. when taken inside there will be proton pumping, which acidifies the lethal and edema factor to come out in cytoplasm.
anthrax - disregulates….(ex - lars milk)
the calmodulin. ex. organ transplant, given immunosuppressant drugs, some target calmodulin.
edema factor is (anthrax) (lars edna- corner)
inactive until it reaches cytoplasm. binds to calmodulin. activates adenylyl cyclase, induces runaway cAMP. leades to loss of electrolytes, water.
lethal aspect - anthrax (3)
3 factors
anthrax creates a…(edema factor) (h20)
hypertonic environment and then h2o is pulled out of cell. this is why its so deadly like a drowning victim
lethal factor - anthrax (Lars skull/chemo- corner)
protease split regulatory pathway components that promotes growth and proliferation. inhibits chemokine (is the trafficking agent - attracts defense cells) production, can’t call for help and recruitment of defense cells. MAP kinase messed up - leads to cell death, necrosis.
botulism - type of toxin
Toxin belongs to AB toxin
botulism has the least impact on…
intestines.
highest botulism - which state
Alaska - homemade meat smoked over flame after tightening both ends. cuts off oxygen supply.
SNARE (nfl)
soluble NSF attachment receptor protein
NSF (botulism marmalade)
N ethyl maleimide sensitive fusion protein
death from botulism is due to…
failure of the diaphragm muscles there is no contraction. signals to heart muscle stops and brain doesn’t get normal signals.
death from tetanus
also called tetanospasm - death is due to respiratory failure. the diaphragm is locked in. jaw muscles in a contraction. this leads to spastic paralysis
action of tetanus (gabe)
it inhibits release of the inhibitory neurotransmitter, GABA (gamma amino butyric acid) and glycene. breaks down snare protein and no relaxation. it chews up V snare protein, not released at neuromuscular junction.
Clostridium tetanus is…
non-invasive.
tetanus vaccine is a…(bee)
vaccine with an inactivated toxin. it then creates memory b and t cells.
cholera ToxR - allows for rapid…
sensing and activation of pathogenic functions. It is able to detect acidity and elevated temperature ( signs of host digestive system)
Cholera toxin is an…
enterotoxin - it is secreted by V. cholerae
V. cholerae 0139
bengal strain. bengal is more virulent, there is no effective vaccine against this evolving strain
cholera encoded by..
phage genome
cholera outside the body..
doesn’t secrete the toxin.
causes cholera to release toxin
acidity and heat
cholera is an…(type of toxin AND)
AB toxin (its a multimeric toxin)
cholera action (chiq gang)
Membrane receptors are ganglioside receptors on the intestinal epithelial cells. B part binds, and there are subunits 1A and 2A.
Cholera toxin modifies G protein (Chiq A jeans - bed)
and A part causes ADP ribosylation. G protein controls activation of adenylate cyclase - ATP to cAMP. then build up of cAMP in cell. Then Ca++, Na+, K+, Cl- all opened up, and get into intestines and creates hypertonic environment. draws water out of the cells, leads to diarrhea. A subunit adds to G protein and locks it in. adenylate cyclase is constantly activated
after cholera modifies G protein…(camp first- kitchen counter)
increases cAMP, activates kinase, A phosphorylates. CFTR (Cystic fibrosis transmembrane conductance regulator) transports chloride ions across ; water follows - becomes hypertonic environment.
superantigens are…(backyard)
exotoxins. trying to scavenge for iron (tampons)
1st line (SML SBM)
SSMMBL
includes skin, mucous (physical), lysozyme (chemical), acidic ph of stomach. genetic barrier (some only infect ppl, some only animals), normal microflora.
2nd line of defense (NMP IF)
NMP IF
phagocytosis (neutrophils, macrophages), fever, inflammation
3rd line of defense
adaptive immunity - B cells (lymphocytes) and T lymphocytes.
T lymphocytes - organ transplant - adaptive immunity
MHCs have to be compatible
B cells have…(joseph)
BCRs - they recognize and phagocytose antigens directly.
short circuits T cell activation
Superantigens
Superantigens best described as….(super T2)
viral / bacterial proteins (toxins) that binds simultaneously to portion of T cell receptor and to MHC class II molecules
Consequence of super antigens (super t-rex guest room)
activates T cells irrespective of their antigenic specificity- activated T cells secretes large amount of cytokines TNF α and IL-1. Results in systemic reactions including fever, systemic clotting activation, shock etc
Superantigens are..(eyes)
cytotoxins -they don’t enter the target cells
superantigens v. regular antigens (%)
Conventional antigen less than 0.01% T cells responds
Super antigen more than 5% T cells popul responds
class II MHC molecules located on.. (class 2 - DMB)
DMB
dendritic cells, macrophages, and B cells. display antigen to helper T cells
Exogenous superantigen (genous - dissolve in beaker)
SOLUBLE proteins secreted by bacteria (exotoxins)
Endogenous superantigen (dodge the membrane)
are MEMBRANE proteins coded by some viruses that infects mammalian cells
How superantigens benefits pathogen? (super - hallway)
No clear answer; nonspecific T cell activation may slow down response that would otherwise restrict colonization. Cytokine outbursts disrupts cells and microenvironment for productive defensive response would have eliminated pathogen.
induces T cell tolerance for the pathogen
Endotoxins - location
lipid A portion of outer membrane LPS of Gram negative sps - released upon cell damage and cell wall breakage
botulism - B part (bot - car)
attaches to specific receptor on motor nerve endings
botulism - A part (bot - cat tree)
enters inside cytoplasm, becomes protease or active peptidase enzyme that chews up a vesicle protein (snare protein). It is responsible for attachment to cytoplasmic membrane
botulism - ach not…
released, so muscle can’t contract.
cholera - B part enters the…(chiq - throw B at aiden- microwave)
epithelial and activates adenylyl cyclase in an indirect way. once it’s activated, it converts atp in cAMP. then all electrolytes come into lumen and creates hypertonic and water follows electrolytes
botulism targets…(junction)
the neurons at the neuromuscular junction and inhibits the release of excitatory neurotransmitter ach, so the muscle is always relaxed, which leads to flaccid paralysis.
all endotoxins produce the same…
signs and symptoms, though to different degree (irrespective of the microbe) - symptoms include………………………………………………………. - endotoxins have the same mode of action, irrespective of the species
V and T snare (botulism)
V snare is vesicle snare. T is target snare. they induce exocytosis
cholera ToxR - NH2 (transcript - swimming)
- NH2 part reaches cytoplasm - NH2 terminal domain binds to DNA sequence as a transcriptional activator. in turn, activates cholera toxin gene expression as well as other virulence factors
sensor in cholera (X-tran)
is called cholera toxR. It’s an integral membrane protein on the bacterial surface
MHC
major histocompatibility antigens.
MMTV (endogenous) (dodge MMTV)
retroviral protein expressed on infected cell surface following genome integration Mouse Mammary Tumor Virus
ex of exogenous superantigens (genous - bathroom)
agent of bacterial toxic shock (TSST of S. aureus) a few food poisoning enterotoxins secreted by Gram (+) ve bacterias. Mycoplasma arthridis supernatant ( MAS)
AB toxins
cholera and botulism anthrax
AB parts of anthrax
two enzymes, edema factor and lethal factor are the A component. Protective antigen is the B component
honey
often times honey is contaminated with botulism spores. that is why children are not given honey.
mycoplasma arthriditis - (exogenous super antigen)
infected rodents, rats cause arthritis
diptheria enters…
the cell via receptor-mediated endocytosis but the toxin is released only after passage through the Golgi system
super antigens binds to (TLC)
TCR component and MHC on the antigen presenting cells (APC) bypassing conventional antigen processing and MHC loading.
MHC - 2 types
class 1 and class 2
class 1 - MHC (history)
only present in all nucleated cells of the body, exception is RBC. No MHC on RBC
class 2 - MHC (2nd class can’t enter - only surface)
is present only on surface of APCs. (antigen presenting cells)
APCs are…(think presenting)
B cells, macrophages, dendrites
APCs display both…(2 histories)
MHC class 1 and class 2.
T cell recognizes…(pep histo class)
displayed peptide from MHC II
superantigens bind to…
MHC and T cells simultaneously. short circuits activation of T cell.
T cells secrete…(NFL)
TNF a and IL-1 - all pro-inflammatory cytokines
superantigens - shock is (definition - super shock)
a sudden drop in blood pressure due to vasodilation
cytokine storm can cause
death
superatigens cause
DIC
superantigens are incorporated into…
mammal DNA and is displayed on cell surface. this is how it disrupts T cells.
superantigens are…(super retro)
retroviruses
staph is a..(super staph)
superantigen
part of anthrax used for vaccine
protective antigen
