Immunology Board Study 2015

Front 1

What is the difference between natural vs. acquired immunity

Back 1

a. Natural immunity is present without prior exposure to an antigen
2.

Front 2

Name the native defensive mechanisms

Back 2

a. Intact skin and mucous membranes, normal microbial flora, fatty acids in the skin, acid in the stomach, mucociliary apparatus in trachea, enzymes in intestinal fluid saliva or tears, coughing, vomiting, sneezing, diarrhea, fever, complement, phagocytic cells (neutrophils , monocytes or macrophages, eosinophils, basophils (mast cells)), natural killer cells, acute phase proteins
3.

Front 3

What are examples of acquired immune defense

Back 3

a. Antibodies produced by B lymphocytes, cell mediated immunity with cytotoxic T cells and cytokines produced by t cells
4.

Front 4

What is passive immunity

Back 4

a. Form of acquired immunity in which patient receives antibodies or lymphocytes from another individual (colostrum is an example)
5.

Front 5

What are the only cells in the body highly capable of highly specific antigen recognition

Back 5

a. B and T lymphocytes
6.

Front 6

How does a mast cell help prevent against parasites

Back 6

a. IgE becomes bound to parasite and mast cell recognizes the IgE and binds, thereby releasing granules that have histamine, serotonin, and vasoactive amines increasing blood flow and attracting eosinophils
7.

Front 7

What roles do macrophages play in immunity compared to neutrophils

Back 7

a. Respond to more than just bacterial infections and are present in fungal and viral infections, trap and process antigens for presentation to T lymphocytes
b. Live longer than neutrophils and repair their membranes and replenish enzymes
c. Produce cytokines
8.

Front 8

What are the three types of lymphocytes

Back 8

a. B, T, and NK cells
9.

Front 9

What is the role of natural killer cells

Back 9

a. Kill virus infected cells and cancer cells (non self cells) without prior exposure to infectious diseases. Can appear like large granular lymphocytes on cytology. Also kill antibody coated antigens
10.

Front 10

Where all do lymphocytes circulate

Back 10

a. B and T cells circulate through blood and lymph tissues (live for several months and can circulate back and forth)
11.

Front 11

What kind of antigens can T cells recognize

Back 11

a. Only small peptide antigens presented on major histocompatibility complexes
12.

Front 12

Name the components of the classical pathway of complement activation

Back 12

a. Presence of IgM or IgG bound to antigen and C1-C4 which once combined, produce C4b,2b,3b which is called C5 convertase
13.

Front 13

What is the alternative pathway

Back 13

a. Alternative way for activating complement that is activated by some microbial surfaces in the absence of antibody involving four proteins: Factors B and D, properdin, and C3; end product is C3bBb3b which converts C5 into C5a and C5b
14.

Front 14

What is the membrane attach complex

Back 14

a. C5b,6,7,8,9 (activated when C5b binds to cell membranes) which can produce holes in membranes
15.

Front 15

Which components of the complement pathway are considered anaphylatoxins

Back 15

a. C3a, C4a, C5a
16.

Front 16

Which component is a strong chemoattractant for neutrophils

Back 16

a. C5a
17.

Front 17

What keeps the complement system from overreacting

Back 17

a. Activated enzymes have short half life; host cells that inactivate the C3b that is produced at a slow, constant rate
18.

Front 18

How long do neutrophils survive for

Back 18

a. 8 hours in blood, 1-2 days in normal tissue and minutes to hours at sites of inflammation
19.

Front 19

What are the main types of intracellular structures that neutrophils have

Back 19

a. Multiple lysosomes (Function is to fuse with phagosome); glycogen granules
20.

Front 20

What adherence protein allow neutrophils to slowly roll along endothelium and marginate

Back 20

a. L-selectins
21.

Front 21

What protein causes the neutrophil to stop rolling and to stick tightly to endothelial cells

Back 21

a. Beta integrins
22.

Front 22

Without the help of antibody or complement, what kind of bacteria can neutrophils phagocytize

Back 22

a. Those with a more hydrophobic membrane than their own
23.

Front 23

What receptors does a neutrophil membrane have

Back 23

a. Fc receptor for antibody and C3b receptor for complement (attach and phagocytize opsonized particles)
24.

Front 24

What are the two types of killing mechanisms used by neutrophils

Back 24

a. Nonoxidative- not need oxygen to kill and use enzymes and cationic antibacterial substances(less bacteria are killed by this especially if have thick capsule)
b. Oxidative – use oxygen (oxidase system generates superoxide, hydrogen peroxide, hydroxyl and aldehydes)”oxidative burst”
25.

Front 25

What is myeloperoxidase

Back 25

a. Enzyme used by bacteria that catalyzes reaction to make hypochloroud acid (bleach)
26.

Front 26

What are the primary lymphoid organs for T and B cells

Back 26

a. T cells=thymus
b. B cells= bone marrow
27.

Front 27

What are considered secondary lymphoid organs

Back 27

a. Lymph nodes, spleen
28.

Front 28

Where are most B lymphocytes concentrated in a lymph node

Back 28

a. Outer cortex and medulla
29.

Front 29

Where are T cells concentrated in a lymph node

Back 29

a. Paracortical region
30.

Front 30

What are the two major classes of T cell receptors

Back 30

a. Alpha and beta T cells (most abundant)
b. Gamma and delta T cells
31.

Front 31

What proteins do T lymphocytes recognize on antigen-presenting cells

Back 31

a. MHC I and MHC II
32.

Front 32

What enables the T lymphocytes to recognize the MHC I and II

Back 32

a. CD4+ (helper functions) and CD+8 (Cytotoxic) coreceptor proteins
33.

Front 33

What are the coreceptor proteins for B cells

Back 33

a. CD19 and CD21 (can bind to complement)
34.

Front 34

What is an epitope

Back 34

a. Part of the antigen binding site; complementary structure on the receptor that binds the epitope is the paratope; variable binding affinity between the two; held together irreversibly with covalent bonds
35.

Front 35

What are the four basic mechanisms by which diverse receptor genes may be produced

Back 35

a. Genetic rearrangement, junctional diversity, somatic mutation, combination diversity
36.

Front 36

What are the three segments found on genes for light chain of B cells and alpha chain of the T cell

Back 36

a. V, J, C
37.

Front 37

What are the four segments found on the genes for heavy chains of B cells and the beta chain on the T cell

Back 37

a. V,D,J, C
38.

Front 38

Where does clonal expansion of lymphocytes take place

Back 38

a. Secondary lymphoid tissues
39.

Front 39

What is the difference between professional antigen presenting cells and other cells such as epithelial and B lymphocytes

Back 39

a. Professional APC are cells that are always capable of presenting antigens to T cells whereas others are not capable of doing this under resting conditions
40.

Front 40

What types of antigens are generally involved with endogenous pathway of antigen processing

Back 40

a. Viruses; MHC I; can be expressed on in nearly all tissue
41.

Front 41

What types of antigens are generally involved with exogenous pathway of antigen processing

Back 41

a. Bacteria; MCH II; can be expressed only in cells of the immune system
42.

Front 42

What is a costimulatory signal

Back 42

a. Second signal that activates lymphocytes (both secondary and primary signals are required for activation) (secondary to the primary signal which is the binding of the antigen to the antigen receptor). T cells= CD28 and CTLA4; Dendritic cell=B7 (CD80 and CD86 are two types of B7 molecules)
43.

Front 43

Which cells generally serve as costimulators for B lymphocytes

Back 43

a. T helper lymphocytes
b. B cell stimulation is generally through binding of CD40 molecule
44.

Front 44

What are superantigens

Back 44

a. Bacteria or viruses that activate multiple clones of T lymphocytes; do not bind to conventional antigen-binding site of TCR; must be presented bound to MHC II molecules
45.

Front 45

What is the difference between central and peripheral tolerance

Back 45

a. Central tolerance is when self-reactive lymphocytes are deleted from the lymphocyte pool and peripheral tolerance is when self-reactive lymphocytes become anergic (nonfunctional) likely because of lack of a co-stimulatory molecule but they remain in the lymphocyte pool but can react to other antigens
46.

Front 46

What are the basic units of all antibodies

Back 46

a. Heavy, light chains (two of each) which make up constant, variable, and hypervariable regions
47.

Front 47

What is the “fab” portion of an antibody

Back 47

a. The ends of the “fork” on either side of the Y that bind antigens
48.

Front 48

What is the “fc” portion

Back 48

a. Contains region that determines the antibody class
49.

Front 49

Which antibody is considered to the be most abundant class of antibody

Back 49

a. IgG
50.

Front 50

Which antibody is the most abundant in colostrum

Back 50

a. IgG
51.

Front 51

Which antibody is produced the earliest in the first time an individual is exposed to an antigen

Back 51

a. IgM
52.

Front 52

Which antibody is the largest

Back 52

a. IgM
53.

Front 53

What is a J chain

Back 53

a. Bonds that closes a circle of 5 subunits of the IgM
54.

Front 54

What is the predominant IgA in external secretions (milk, saliva, tears) as well as mucosal surfaces

Back 54

a. IgA
55.

Front 55

Which other immunoglobulin has a J chain

Back 55

a. IgA when it is in mucosal surfaces
56.

Front 56

What is secretory component

Back 56

a. Protein that protects IgA from digestion by enzymes
57.

Front 57

What is IgD

Back 57

a. Immunoglobulin that mainly serves as an antigen receptor and may play a role in inducing tolerance to self antigens during development; short half life and readily degraded
58.

Front 58

What are the functions of helper T cells

Back 58

a. Secrete cytokines (IL-1,2,4,5) when they are presented with antigens, modulate immune response, direct B lymphocytes to produce effective and large amounts of antibody (without helper T cells, the B lymphocytes would likely only generate limited quantities of low affinity IgM antibodies. Stimulate NK cells to be more efficient at killing with IL-2. Macrophages stimulated by interferon gamma made by Th-2 helper
59.

Front 59

Which types of T helper cell will likely be involved in bacterial or viral infections

Back 59

a. Th1; activation of macrophages and NK cells are major producers of IL-12 and IFN gamma which promote differentiation of Th1
60.

Front 60

Which types of T helper cell will likely be involved in parasitic infections

Back 60

a. Th2; mast cells which produce IL-4 produces differentiation of Th2
61.

Front 61

How are Cytotoxic T cells different from NK cells

Back 61

a. Have more specialized targeting and destroy cells in an antigen-specific manner. NK cells detect cells that have stopped doing what they are supposed to do (express MHC class I) and cytotoxic T cells recognize cells that have started doing something they are not supposed to be doing (express foreign proteins)
62.

Front 62

What are the two ways that cytotoxic T cells kill cells

Back 62

a. Perforin mediated pathway (granules in cytoplasm release and create channels in the cell membrane) and FAS mediated pathway (FAS is a molecule that is related to TNF expressed on lymphocytes and on liver, heart, and lung cells and when activated cause CTL to induce apoptosis)
63.

Front 63

How are NK cells different from B and T cells

Back 63

a. Do not circulate back and forth from blood to tissue; do not have receptors that recognize certain antigens. Do have CD16 molecules on surface however and they do not undergo clonal expansion after being exposed to an antigen
64.

Front 64

What is antibody dependent cell mediated toxicity

Back 64

a. When natural killer cells utilize antibody binding to attach to target cells
65.

Front 65

What is lymphokine activated killer cell

Back 65

a. Natural killer cell that is activated by IL-2 or other lymphocyte derived cytokine (also responsive to IFN alpha and beta)
66.

Front 66

What are gamma/delta T lymphocytes

Back 66

a. T lymphocytes residing on mucosal epithelial surfaces (t-cell receptors are different from the more common alpha/beta T lymphocytes)
67.

Front 67

What are intraepithelial lymphocytes

Back 67

a. Specialized T lymphocytes in the epithelium of mucosal surfaces; play a role in surveillance, homeostasis, and regulation of immune responses at mucosal surfaces; many of which are gamma/delta forms, they express CD4 and CD8
68.

Front 68

What is lymphocyte homing

Back 68

a. Where a lymphocyte’s behavior changes after encountering an antigen. It no longer circulates as widely and is likely to stay in the area where it first encountered the antigen
69.

Front 69

What are addressins

Back 69

a. Molecules expressed on blood vessel endothelia that mediate tissue specific homing of lymphocytes
70.

Front 70

What are characteristics for a secondary antibody response

Back 70

a. Subsequent exposure to antigen produces a more rapid and more effective antibody response than the first antigen exposure; B lymphocytes undergo class switching to produce antibodies of isotypes other than IgM; Antibodies produced in secondary responses have higher affinity than do those produced in primary response
71.

Front 71

Which cell marker is heavily involved in class switching

Back 71

a. CD40
72.

Front 72

What is a type I hypersensitivity and what cells are involved

Back 72

a. Allergic type response and involves IgE, mast cells, and basophils, immediate response that can involve hives, wheals, respiratory disease, and gastrointestinal dysfunction
73.

Front 73

What is the theory behind hyposensitization therapy

Back 73

a. Used to be thought that it induced IgG so that IgG could bind the antigen first but now thought that it helps stimulate production of interferon from macrophages (interferon inhibits differentiation and function of Th2 which are the lymphocytes that stimulate mast cells)
74.

Front 74

What cells are involved in type II hypersensitivities

Back 74

a. IgG and antigens (most common antigen is the RBC); can involve complement, IMHA is the most common example of this
75.

Front 75

What is the difference between Type II and Type III hypersensitivity

Back 75

a. Type III hypersensitivity the antigen-antibody complexes (still IgG) are soluble and can adhere to endothelial cells in capillaries or accumulate in tissues, damage is still mediated by complement like in type II reactions
76.

Front 76

Describe a type IV hypersensitivity

Back 76

a. Mediated by T lymphocytes, not b lymphocytes, often delayed due to nature of T cells. Examples are tuberculin reactions or contact hypersensitivity
77.

Front 77

What are the two most important cytokines that macrophages produce

Back 77

a. IM-1 and TNFalpha which activate fibroblasts; mediate fever, induce changes in protein production by the liver (acute phase proteins such as serum amyloid A, CRP, and serum amyloid P)