Immuno - Lymphocytes (Intro)

Question 1

What is the difference between innate and adaptive immunity in terms of the development of receptors involved?

Answer 1

INNATE - Receptors that recognize pathogen are germline encoded. ADAPTIVE - Receptors that recognize pathogens undergo V(D)J recombination during lymphocyte development.

Question 2

What is the difference between innate and adaptive immunity in terms of response to pathogen?

Answer 2

INNATE - Nonspecific. Occurs rapidly ( minutes to hours); ADAPTIVE - highly specific, refined over time. Develops over long periods; memory response faster and more robust

Question 3

What is the difference between innate and adaptive immunity in terms of types of cells involved?

Answer 3

INNATE - Consists of neutrophils, macrophages, monocytes, dendritic cells, natural killer cells (lymphoid origin), and complement. ADAPTIVE - Consists of T cells, B cells, and circulating antibody.

Question 4

What does MHC stand for? What are the types of MHC? What encodes them? What function does they serve?

Answer 4

MHC = major histocompatibility complex; MHC I and II; Encoded by human leukocyte antigen (HLA) genes; Present antigen fragments to T cells and bind TCR

Question 5

What are the genes that code for MHC I versus MHC II?

Answer 5

MHC I = HLA-A, HLA-B, HLA-C; MHC II = HLA-DR, HLA-DP, HLA-DQ

Question 6

What does MHC I versus MHC II bind?

Answer 6

MHC I binds TCR and CD8; MHC II binds TCR and CD4

Question 7

Where is MHC I versus MHC II expressed?

Answer 7

MHC I is expressed on all nucleated cells (i.e., not expressed on RBC); MHC II is expressed only on antigen-presenting cells (APCs)

Question 8

What is the difference between MHC I versus MHC II in terms of how antigen is loaded?

Answer 8

MHC I = Antigen peptides loaded in RER after delivery via TAP peptide transporter; MHC II = Antigen is loaded following release of invariant chain in an acidified endosome.

Question 9

Which type of MHC mediates viral immunity?

Answer 9

MHC I

Question 10

Which type of MHC pairs with Beta2-microglobulin? What function does this pairing serve?

Answer 10

MHC I pairs with Beta2-microglobulin (aids in transport to cell surface)

Question 11

Draw a visual of MHC I, labeling the following: (1) Peptide-binding groove (2) alpha (3) Beta2-microglobulin (4) Cell membrane.

Answer 11

See p. 194 in First Aid for first visual on right

Question 12

Draw a visual of MHC II, labeling the following: (1) Peptide-binding groove (2) alpha (3) Beta (4) Cell membrane.

Answer 12

See p. 194 in First Aid for second visual on right

Question 13

Which disease is associated with HLA subtype A3?

Answer 13

Hemochromatosis

Question 14

Which diseases are associated with HLA subtype B27?

Answer 14

Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, Reiter’s syndrome; Think: “PAIR”

Question 15

Which disease is associated with HLA subtype DQ2/DQ8?

Answer 15

Celiac disease

Question 16

Which diseases are associated with HLA subtype DR2?

Answer 16

Multiple sclerosis, hay fever, SLE, Goopasture’s; Also Celiac disease associated with DQ2/DQ8

Question 17

Which diseases are associated with HLA subtype DR3?

Answer 17

Diabetes mellitus type I, SLE, Graves’ disease

Question 18

Which diseases are associated with HLA subtype DR4?

Answer 18

Rheumatoid arthritis, diabetes mellitus type I

Question 19

Which diseases are associated with HLA subtype DR5?

Answer 19

Pernicious anemia –> B12 deficiency, Hashimoto’s thyroiditis

Question 20

With what HLA subtype is Hemochromatosis associated?

Answer 20

A3

Question 21

With what HLA subtype are the following diseases associated: Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, Reiter’s syndrome?

Answer 21

B27; Think: “PAIR”

Question 22

With what HLA subtype is Celiac disease associated?

Answer 22

DQ2/ DQ8

Question 23

With what HLA subtype are the following diseases associated: Multiple sclerosis, hay fever, SLE, Goopasture’s?

Answer 23

DR2

Question 24

With what HLA subtype are Diabetes mellitus type I, SLE, and Graves’ disease associated?

Answer 24

DR3

Question 25

With what HLA subtype are Rheumatoid arthritis and Diabetes mellitus type I associated?

Answer 25

DR4; think: "there are 4 walls in a rheum"

Question 26

With what HLA subtype are Pernicious anemia --> B12 deficiency and Hashimoto's thyroiditis associated?

Answer 26

DR5

Question 27

With which 2 HLA subtypes is diabetes mellitus type I associated? What other diseases are associated with these 2 HLA subtypes?

Answer 27

DR3 - Graves' disease, SLE; DR4 - Rheumatoid arthritis

Question 28

What function do Natural killer cells serve and via what mechanism(s)?

Answer 28

Use perforin and granzymes to induce apoptosis of virally infected cells and tumor cells

Question 29

What is unique about Natural killer cells in terms of its classification/role?

Answer 29

Only lymphocyte member of innate immune system

Question 30

Which cytokines enhance the activity of natural killer cells?

Answer 30

IL-2, IL-12, IFN-beta, and IFN-alpha

Question 31

In what 2 contexts are natural killer cells induced to kill?

Answer 31

Induced to kill when exposed (1) to a nonspecific activation signal on target cell and/or (2) to an absence of class I MHC on target cell surface

Question 32

What are the 3 major functions of B cells?

Answer 32

(1) Recognize antigen - undergo somatic hypermutation to optimize antigen specificity (2) Produce antibody - differentiate into plasma cells to secrete specific immunoglobulins (3) Maintain immunologic memory - memory B cells persist and accelerate future response to antigen

Question 33

What are the 4 major functions of T cells?

Answer 33

(1) CD4+ T cells help B cells make antibody and produce cytokines to activate other cells of immune system. (2) CD8+ T cells kill virus-infected cells directly (3) Delayed cell-mediated hypersensitivity (type IV) (4) Acute and chronic cellular organ rejection

Question 34

What function(s) do CD4+ T cells serve?

Answer 34

CD4+ T cells help B cells make antibody and produce cytokines to activate other cells of immune system.

Question 35

What function do CD8+ T cells serve?

Answer 35

CD8+ T cells kill virus-infected cells directly

Question 36

With what type of hypersensitivity are T cells involved?

Answer 36

Delayed cell-mediated hypersensitivity (type IV)

Question 37

What function do T cells serve that is relevant to transplantation?

Answer 37

Acute and chronic cellular organ rejection

Question 38

To which type of immunity do physical barriers apply? Give 2 examples of such barriers.

Answer 38

Innate immunity; epithelial junctions, mucus

Question 39

What are secreted proteins in innate versus adaptive immunity?

Answer 39

INNATE: lysozyme, complement, CRP, defensins; ADAPTIVE: immunoglobulins

Question 40

What are key features of pathogen recognition for innate versus adaptive immunity?

Answer 40

INNATE - Toll like receptors (TLRs): pattern recognition receptors that recognize pathogen-associated molecular patterns (PAMPs). Examples of PAMPs include LPS (gram negative), flagellin (bacteria), ssRNA (viruses); ADAPTIVE - Memory cells: activated B and T cells; subsequent exposure to a previously encountered antigen => stronger, quicker immune response