L3 Vaccination & T cell activation

Question 1

What does TCR (T cell receptor) need in order to recognise antigens?

Answer 1

• short peptides
• MHC molecule

TCR only recognises antigen with short, “chopped” up peptides that is displayed on MHC molecules on an APC

Question 2

What are MHC molecules

Answer 2

they are proteins involved in display of Ag to T cells. It helps to check similarity between donor and recipient genes in transplantation –> accept or reject the donor’s genes?

Question 3

TCR
BCR
MHC
APC

Answer 3

TCR: T cell receptor
BCR: B cell receptor
MHC: major histocompatibility complex
APC: antigen presenting cell

Question 4

naïve* T cells

Answer 4

T OR B cells that have never responded to their antigen.

Question 5

Is a DC displaying an antigen to a T cell enough to activate the T cell?

Answer 5

No, naïve* T cell activation requires 2 signals.
Signal 1 = T cell receptor binding MHC- Ag peptide
Signal 2 = Costimulatory signal

Question 6

R-nought

Answer 6

the basic reproduction number prior to vaccination and immunity;
avg no. of ppl who WILL BE infected by 1 infectious person in a completely SUSCEPTIBLE population.

Question 7

DC-mediated T cell activation needs two signals. Signal 2 is dependent on what?

Answer 7

innate activation pathways

and the presence of infection.

Question 8

R effector

Answer 8

value of changing
levels of susceptibility (i.e. vaccination levels or numbers already infected),
and behaviour that reduces or increases transmission (i.e. social distancing, mask wearing, rioting)

Question 9

The aim is to reduce R effector below ___, so that incidence gradually declines

Answer 9

Below 1

Question 10

what is the main target for vaccine development in covid-19?

Answer 10

the spiked protein, as antibodies will block viral entry into cells