IMMUNOCHEMISTRY 1

Question 1

immune reponses are specific for distinct antigen
epitope is that part of the antigen specifically recognized by antibodies

Answer 1

specificity

Question 2

immune system can discriminate at least 10 to the 9th antigenic determinants or epitopes

due to variability in the structures of the antigen-binding sites of lymphocyte receptors for antigens

Answer 2

diversity

Question 3

exposure of the immune system to a foreign antigen enhances its ability to respond again to that antigen

secondary immune responses are usually more rapid and larger

Answer 3

memory

Question 4

all normal immune responses wane with time after antigen stimulation

results from the elimination of the stimulus for lymphocyte activation since the immune response functions to eliminate the antigen

Answer 4

self-limitation

Question 4

ability to distinguish between foreign antigens and self antigen

tolerance is immunologic unresponsiceness

autoimmune diseases are due to abnormalities in the maintenance of self-tolerance

Answer 4

discrimination of self-from nonself

Question 5

signposts that serve to alert the immune system if foreign material is present inside a cell

Answer 5

Major Histocompatibility Complex

Question 6

highly polymorphic genes are located on ________ and are called human leukocyte antigen (HLA)

traditionally divided into classes I, II, and III

Answer 6

Chromosome 6

Question 7

Located in surfaces of all nucleated cells

Answer 7

Class I molecules

Question 8

found on antigen presenting cells (B lymphocytes, macrophages and dendritic cells)

Answer 8

CLASS II molecules

Question 9

class I molecules have one alpha chain encoded by the genes ________________ and a small invariant chain the _______________

Answer 9

Genes HLA, B or C
Beta 2 microglobulin

Question 10

__________________ have receptors for the class I MHC proteins (CD8)

Answer 10

cytotoxic T lymphocytes

Question 11

the alpha and beta chains of class II molecules are encoded by genes __________

Answer 11

genes HLA-DR, DP, DQ
(D-region)

Question 12

_______________ have receptors for class II MHC proteins (CD4)

Answer 12

Helper T cells

Question 13

______________ (e.g. from antigens are formed from the degradation of cytosolic proteins (“self” pathogen and tumour derived proteins in the cytoplasm)

Answer 13

peptides

Question 14

in an APC newly synthesized MHC class I molecules bind to ____________ which retains them in a partially folded state in the ER

Answer 14

calnexin

Question 15

calnexin is then replaced by __________ and _____________ to keep the MHC complex in its properly folded state

it binds to TAP 1 and TAP 2 via tapasin

Answer 15

calreticulin and tapasin

Question 15

antigens are inhaled, ingested or introduced beneath the skin

Answer 15

exogenous antigens

Question 16

___________- is engulfed by endocytosis

Answer 16

antigen

Question 17

phases of immune response

Answer 17

cognitive phase
activation phase
effector phase

Question 18

binding of foreign antigens to specific receptors on mature lymphocytes that exist prior to antigenic stimulation

B-lymphocytes express antibody molecules on their surfaces that can bind foreign antigens
T-lymphocytes express receptors that recognize short peptide sequences in protein antigens

Answer 18

cognitive phase

Question 19

sequence of events induced in lymphocytes as a consequence of specific antigen recognition

lymphocytes: undergo 2 major changes which are proliferate and differentiate

Answer 19

activation phase

Question 20

stages when lymphocytes specifically activated by antigens perform the functions that lead to the elimination of the antigen

participation of non-lymphoid cells (neutrophils)
substances - complement and cytokines

Answer 20

effector phase

Question 21

cells involved in innate immunity

Answer 21

phagocytes (macrophages, eosinophils, neutrophils)

Question 22

soluble mediators in innate immunity

Answer 22

macrophage derived cytokines

Question 23

cells involved in adaptive immunity

Answer 23

lymphocytes

Question 24

soluble mediators in adaptive immunity

Answer 24

lymphocyte derived cytokines

Question 25

3 forms of complement system activation

Answer 25

classical alternative mannose-binding lectin

Question 26

the ______________ for activating complex system is triggered when an antibody-antigen complex binds to and stimulates the protease activity of factor C1

Answer 26

classical pathway

Question 27

the classical pathway for activating complex system is triggered when an antibody antigen complex binds to and stimulates the protease activity of factor ______

Answer 27

C1

Question 28

C5b protein combines with complement factors C6, C7, C8, and C9 to form ______ which kills bacterial invaders by binding to and opening a pore in their plasma membrane

Answer 28

membrane attack complex

Question 29

____________, wherein the complexes formed when a complement factor known as mannose binding lectin (MBL) also called mannan binding protein binds bacterial polysaccharides to generate a complex that recruits and activates C4

Answer 29

lectin pathway

Question 30

the complement system can also be activated by __________ in which C3 is activated by direct chemical hydrolysis sometimes referred to as ticking over

Answer 30

alternative pathway

Question 30

differentiation of hematopoietic stem cells is regulates by a set of secreted glycoproteins called _________

Answer 30

cytokines

Question 31

stem cell factor and several colony stimulating factors collaborate with interleukins ___________ to stimulate the proliferation of hematopoetic stem cells in the bone marrow and induce their differentiation into one of several myeloid cell types

Answer 31

Interleukins 1,3,6

Question 32

cytokines includes (I, I, C)

Answer 32

interleukins, interferons, chemokines

Question 33

__________- attract and activate migrating leukocytes to a site of injury or infection

Answer 33

chemokines

Question 34

most cytokines are glycosylated, in general they stimulate both the leukocytes from which they are secreted (____________ signaling) as well as other types of leukocytes (p__________ signalling)

Answer 34

autocrine, paracrine

Question 35

_________ derived their name from their ability to inhibit or interfere with the replication of infecting viruses

Answer 35

interferons

Question 36

___________ derive their name from the cells in which they are synthesized and from which they are secreted

Answer 36

interleukins

Question 37

leukocytes also secrete lipid mediators called _________ produced by the oxidation of arachidonic acid

Answer 37

eicosanoids

Question 38

eicosanoids fall into two broad classes ____________ and ___________

Answer 38

leukotrienes and prostaglandins

Question 39

______________ are characterized by a presence of a set of three conjugated carbon-carbon double bounds several incorporate cysteine into their structure

Answer 39

leukotrienes

Question 40

_____________ were isolated from prostate glands contain 20 carbon atoms and are distinguished by their common 5 membered ring

Answer 40

prostaglandins

Question 41

___________ which is synthesized y decarboxylating the amino acid histidine, is secreted by activated basophils and mast cells

Answer 41

histamine

Question 42

Type of chemokine characterized by an intrachain disulfide bond formed by a pair of conserved cytseine residues possesses a disulfide bond

Answer 42

type c chemokine

Question 42

Small generally 6-10 kDa proteins secreted by activated white blood cells in order to attract additional neutrophils to a site of infection or injury

Answer 42

chemokines

Question 43

type of chemokine one of the additional cysteine residues lies adjacent to the first of the first pair of universally conserved residues

Answer 43

type CC chemokine

Question 44

type of chemokine in types __________- these cysteines are separated by 1 and 3 amino acid residues respectively

Answer 44

type CXC and CX3X

Question 45

type of chemokine largest of the 4 types of chemokines, have a longer C-terminus that includes sites of covalent modification by glycosylation

Answer 45

type CX3C

Question 46

leukocytes can be found throughout the body migrating from the blood to sites of injury or infection in response to chemical signals referred to as ___________

Answer 46

chemotaxis

Question 47

migration out of the circulation takes place via _________ an amoeboid mechanism involving the cytoskeleton mediated contortion of the cell

Answer 47

diapedesis

Question 48

chemotaxis is mediated by g-protein receptors upon ligand binding a signal transduction cascade is initiated in which G proteins activate _________ which hydrolyses phosphatidylinositol 4,5 biphosphate to produce diacylglycerols and the water soluble 2nd messenger IP3

Answer 48

phospholipase C

Question 49

oligomeric glycoproteins whose individual subunits traditionally have been classified as heavy H or light L based on their migration during SDS polyacrylamide gel electrophoresis

Answer 49

immunoglobin

Question 50

type of immunoglobulin main antibody in the secondary response, opsonizes bacteria, making them easier to phagocytose. fixes complement which enhances bacterial killing. neutralizes bacterial toxins and viruses crosses placent

Answer 50

IgG

Question 51

secretory IgA prevents attachment of bacteria and viruses to mucous membranes. does not fix complement

Answer 51

IgA

Question 52

produced in primary response to antigen, fixes complement does not cross placenta, antigen receptor on the surface of B cells

Answer 52

IgM

Question 53

found on surfcaes of b cells where it acts as a receptor for antigen

Answer 53

IgD

Question 54

mediates immediate hypersensitivity by causing release of mediators from mast cells and basophils upon exposure to antigen defends against work infections by causing release of enzymes from eosinophils does not fix complement against helmithic infections

Answer 54

IgE

Question 55

site on the antigen to which an antibody binds

Answer 55

epitope or antigenic determinant