9. recognition of extra-cellular pathogens

Question 1

define antigen

Answer 1

any molecule recognised specifically by lymphocyte or antibody

Question 2

Answer 2

Question 3

TLR what are they

what are they expressed by

function

Answer 3

toll like receptors PRRs expressed by macrophages, dendritic cells

interact with microbial PAMPs- cellular stimulation and generation of immune activity

induces inflammatory cytokine production, express APC molecules needed, activation of T cells

Question 4

types of epitope recognition in antibodies

type of binding with antigen

Answer 4

specific: high affinity

cross reaction: moderate

not specific

non covalent

Question 5

clonal selection

Answer 5

antigen interacts with clones whose surface Ig on B lymphocyte binds with highest affinity

activation of B cells-> proliferation-> some memory cells

Question 6

vaccinations

Answer 6

non-infective forms of microbial agents stimualtes primary response to produce memory cells

Question 7

Answer 7

Question 8

which type of Ig do all mature B cells express? what happens when it is activated by an antigen

Answer 8

IgM

Cµ domains, if activated by antigens they class switch

same specificity (light chains remain the same) but different constant heavy domains Ch

Question 9

Answer 9

Question 10

what do infection induces macrophages release and what does this cause hepatocytes to do?

Answer 10

IL6

hepatocytes produce acute-phase proteins: C reactive protein, mannan binding lectin bind to PAMPs

assists in phagocytosis, opsonisation, activating complement