IgG,ADE antibodies

Question 1

what are the different functions of IgG antibody

Answer 1

agglutination, complement system activation, foetal immune response, neutralisation, opsonisation and NKC activation

Question 2

describe IgG role in foetal immune protection

Answer 2

they are transported across the placenta, directly into the foetal blood circulation

Question 3

describe process of neutralisation by IgG and IgA antibodies

Answer 3

this is when the antibodies prevent viruses infecting host cells, either by interfering with virus binding receptors, blocking entry to cell etc.

Question 4

describe the process of opsonisation by IgG antibodies

Answer 4

phagocytes express a type of Fc receptor that binds to IgG chain, opsonisation enhances phagocytosis by coating pathogens in opsonins

Question 5

what are the functions of the IgD antibody

Answer 5

in membrane-bound form serves as receptor for B cell activation, function of secreted form is not well understood and is found at very low conc. on blood

Question 6

what is the function of IgA antibodies

Answer 6

in monomeric form(in serum), function = neutralisation

in dimeric form(in secretory fluids), function = neonatal defence and neutralisation

Question 7

describe how IgA antibody is involved in neonatal defence

Answer 7

they are transported into colostrum/breast milk, to protect GI tract of neonates(baby/infant)

Question 8

what is the function of IgE antibodies

Answer 8

they can trigger allergic responses, eg asthma, allergy, anaphylaxis