Cellular and Humoral Immunity

Question 1

Viruses

Answer 1

few molecules, replicate within cells, rapid evolution

Question 2

Bacteria

Answer 2

can live in extracellular space or within cells

Question 3

Large parasites

Answer 3

live within body fluids or within gut - too big to be phagocytosed

Question 4

Unicellular parasites

Answer 4

frequently live inside cells

Question 5

Cellular immunity

Answer 5

immune mechanisms involving direct action of a cell to eliminate a pathogen (includes phagocytosis, NK cells and T cells)

Question 6

Humoral immunity

Answer 6

immune mechanisms which are mediated by factors in the fluids. This includes soluble proteins such as antibodies which bind foreign molecules and the complement system which can form pores in membranes of pathogens

Question 7

Innate immunity

Answer 7

respond within hours, limited and fixed specificity, identical response to primary and repeat infection - alerts adaptive

Question 8

Adaptive immunity

Answer 8

respond within days, highly diverse specificity, repeat response faster than primary - effective cells from first response clonally expand and become memory cells

Question 9

Innate immune cells

Answer 9

macrophages, neutrophils, eosinophils, basophils, mast cells, dendritic cells, NK cells

Question 10

Adaptive immune cells

Answer 10

B cells, T cells

Question 11

TCR/BCR

Answer 11

T/B Cell Receptor, very diverse, random generation by splicing together genes in the DNA

Question 12

Autoimmunity

Answer 12

immune system attacking its own body

Question 13

Lymph node

Answer 13

detects infection of tissue

Question 14

Spleen

Answer 14

detects infection of blood

Question 15

Lymphatic system

Answer 15

route to return fluid from tissues to blood, transports immune cells, pathogens and antigens from tissues to lymph nodes (activates T and B cells) - important in cancer metastasis

Question 16

Lymph composition

Answer 16

like plasma, leukocytes

Question 17

Linking innate to adaptive

Answer 17

innate cells undergo phagocytosis, return to lymph node, naïve T cells recognise MHC molecules, and replicate

Question 18

T/B cell path

Answer 18

naïve T or B cell - Activated/effector T or B cell - Memory T or B cell

Question 19

Antibody

Answer 19

soluble protein that binds foreign molecules (extracellular organisms and toxins), millions of different types, two heavy and two light chains, constant and variable regions, highly specific

Question 20

Antibody isotypes

Answer 20

(eg. IgG, IgM, etc) heavy chain determines class or isotype, light chains are either kappa or lambda

Question 21

Antibody actions

Answer 21

neutralisation, coating virus/bacteria to promote phagocytosis, activating pathways which lyse bacteria

Question 22

Neutralisation

Answer 22

antibody binding to virus can block entry into cells, and can neutralise and precipitate bacterial toxins

Question 23

Immune complex

Answer 23

two antigens bound to an antibody

Question 24

IgM

Answer 24

first class of antibody produced, neutralises and activates complement, 10 binding sites in pentamer form

Question 25

Complement

Answer 25

part of the innate immune system that helps or complements the ability of antibodies and phagocytic cells to clear pathogens from an organism

Question 26

IgG

Answer 26

major Ig in blood, crosses placenta, promotes neutralisation and opsonisation

Question 27

Oponisation

Answer 27

the process by which a pathogen is marked for ingestion and eliminated by a phagocyte

Question 28

IgA

Answer 28

present in tears, saliva, mucous, milk, protects mucous membranes and infants (monomer and dimer forms)

Question 29

IgE

Answer 29

triggers release of histamine from mast cells, allergy and anti-helminth responses (kill parasites)

Question 30

IgD

Answer 30

primarily B cell surface bound, no purpose found

Question 31

Use of antibodies in medicine and science

Answer 31

identify the presence/measure levels of proteins (eg. In serum) examine locations of proteins using flurescently-labelled antibodies and flurescence microscopy identify particular types of cells (by binding to characteristic cell surface molecules) affinity purify proteins (chromatography)

Question 32

Immunoflurescence Microscopy

Answer 32

fluorophore attached to antibody, antibody attaches to antigen, fluorophore emits light when excited by laser

Question 33

ELISA

Answer 33

Enzyme-Linked Immunosorbent Assay: used to detect concentration of a protein within a sample (enzyme added that causes a colour reaction

Question 34

MHC I

Answer 34

binds with CD8, bound peptides derived from intracellular proteins (ie. Viral infection), includes microglobulin and a peptide binding cleft, expressed on all nucleated cells, HLA-A, HLA-B, HLA-C

Question 35

MHC II

Answer 35

binds with CD4, bound peptides derived from extracellular proteins (ie. Extracellular bacteria), expression mainly restricted to B cells, macrophages, dendritic cells, and thymic epithelium, HLA-DR, HLA-DP, HLA-DQ

Question 36

HLA

Answer 36

Human Leukocyte Antigen: the MHC complex in humans, different molecules in different humans, differences cause tissue transplant rejection

Question 37

CD8 (cytotoxic) T cells

Answer 37

kill virally infected or tumour cells, release granules which induce apoptosis

Question 38

CD4 (helper) T cells

Answer 38

activates macrophages, assists B cells in producing antibodies

Question 39

Treg

Answer 39

Regulatory T cells: recognise MHC II and peptide, express CD4 marker, function to suppress immune response

Question 40

NKT cells

Answer 40

Natural Killer T cells: recognise MHC-like molecule called CD1d with bound glycolipid, suppress or promote immunity

Question 41

Gamma delta T cells

Answer 41

associated with epithelial surfaces, recognise MHC-like molecules, suppress immunity and promote wound healing