Lymphocytes and APCs

Question 1

how do mature B cells form?

Answer 1

small, naive lymphocytes in G phase become activated to go into G1 for them to divide into clones

Question 2

how can the type and age of lymphocytes be identified?

Answer 2

using monoclonal antibodies as they produce different CD markers at different stages

Question 3

what markers do Th cells have?

Answer 3

CD4

Question 4

what markers do Tc cells have?

Answer 4

CD8

Question 5

what markers do B cells have?

Answer 5

CD21

Question 6

what causes B cells to come out of G0?

Answer 6

an appropriate antigen coming along

Question 7

where are immature T cells found?

Answer 7

produced in the bone marrow and move to the thymus dependant areas of the lymph nodes

Question 8

how is the division of T cells highly selective?

Answer 8

they are presented to self-antigens and if they induce a reaction then they are killed

Question 9

what do Th cells need to be presented with in order to recognise an antigen?

Answer 9

CD4 markers and MHC class II

Question 10

what do Tc cells need to be presented with in order to recognise an antigen?

Answer 10

CD8 markers and MHC class I

Question 11

how is MHC polymorphic?

Answer 11

has multiple alleles on each gene

Question 12

what protein do endogenous antigens associate with?

Answer 12

MHC class I to Tc cells

Question 13

what protein do exogenous antigens associate with?

Answer 13

MHC class II to Th cells

Question 14

how do macrophages present antigens?

Answer 14

by antigen presentation via phagocytosis, combine with MHC class I, as well as presenting to B cells

Question 15

how do dendritic cells present antigens?

Answer 15

trap antigens on their surfaces

Question 16

how do langerhans and interdigitating dendritic cells present antigens?

Answer 16

present antigens with MHC-II to Th cells

Question 17

what cells do follicular dendritic cells present to?

Answer 17

B cells

Question 18

how do B cells present antigens?

Answer 18

B cells can perform the macrophage function and present antigens to Th cells

Question 19

how do B cells activate T cells?

Answer 19

secrete interleukin I

Question 20

what cells is cell mediated immunity effective towards?

Answer 20

intracellular pathogens, cancer cells and transplanted cells

Question 21

how do viruses activate Tc cells?

Answer 21

inject nucleic acid and produce viral proteins which can be inserted into the membrane with MHC-I which is expressed on all body cells

Question 22

how are Tc cells activated by antigen recognition?

Answer 22

the unique TCR binds to antigens with MHC-I only

Question 23

how do macrophages cause co-stimulation?

Answer 23

present antigens with MHC-II to T cells and also secrete IL-I