COVID Flashcards
What is the mortality rate of SARS-COVID-2
3-4%
what are the 3 main spike proteins on covid?
S (spike), M(matrix) , E (envelope)
what does the S spike do?
binds membranes - target for antibodies
what does the E spike protein do?
responsible for infectivity
what does the M spike protein do?
helps E form the envelope and is the most abundant
whats the N protein?
Helical nucleocapsid - single strand + charge
what does covid bind to in lungs ?
pheumocyte, ACE2 receptor ( angiotensin converting enzyme)
whats TMPRSS2 ?
host cell serine protease - cuts off S protein and enables binding
what are the two ways covid can enter the cell?
engulfed or fusion
what ultimately gets released from host cell?
virions
what is triggered first in the immune response?
innate
what happens to interferons ?
they get suppressed or delayed
what causes the innate response to be unbalanced?
the cytokine storm - hyper reaction
whats lymphophenia ?
low levels of lymphocytes
why is lymphophenia common in covid?
reduces bone marrow production of immune cells
what do elisa tests do ?
see if there are any specific IgG or M antibodies
what happens to cd4/8 numbers in mild covid ?
numbers decrease
what happens in a mild covid response?
damaged epithelial cells send out cytokines which trigger macrophages to come
what happens in server covid ?
more inflammatory cytokines, increase of interleukin 6, decreases of interferon gamma which normally helps with viral infections
what is ARDS ?
acute respiratory disease syndrome
how do T cell precursors know what to differentiate into ?
due to the cytokines present which influence which one to turn into
what does a high amount of IL-6 AND TGF beta cause T cells to turn into?
TH17
what does TH17 produce?
IL-6 AND IL17
what does the low levels of TH - gamma do ?
reduce the chance of TH1 cells being produced
what does TH17 do ?
increases neutrophil production - unnecessary as it would be more beneficial to have CD8 cells
how does the IL6 signalling work ?
need both the IL6 and GPL30 subunits to be phosphorylated (JAK and STAT pathways ) in order to transduce signal
where is the IL6 found ?
in neutrophils and alveolar cells
what does anti IL6 receptor antibody do?
binds therefore blocks receptor
whats mass cytomometry ?
mix of flow cytonomy and mass spectrometry
what may explain why there is such a var in covid genes activated and responses
SNP - single nucleotide polymorphism’s - genetic , ethnic
what is dexamethasone ?
corticosteroid, anti inflammatory drug
how does dexamethasone work?
steroid is hydrophobic and passes through cell membrane, binds to steroid receptor. the steroid receptor is then free from the H chaperone protein to bind to specific gene regulatory seq. these can up/down regulate gene transcription