Cellular Components

Question 1

Innate immunity COMPONENTS

Answer 1

Neutrophils, macrophages, monocytes, dendritic cells, natural killer (NK) cells (lymphoid origin), complement, physical epithelial barriers, secreted enzymes

Question 2

Innate immunity MECHANISM

Answer 2

Germline encoded

Question 3

Innate immunity RESISTANCE

Answer 3

Resistance persists through generations; does not change within an organism’s lifetime

Question 4

Innate immunity RESPONSE TO PATHOGENS

Answer 4

Nonspecific
Occurs rapidly (minutes to hours)
No memory response

Question 5

Innate immunity SECRETED PROTEINS

Answer 5

Lysozyme, complement, C-reactive protein (CRP), defensins

Question 6

Innate immunity KEY FEATURES IN PATHOGEN RECOGNITION

Answer 6

Toll-like receptors (TLRs): pattern recognition receptors that recognize pathogen-associated molecular patterns (PAMPs) and lead to activation of NF-κB. Examples of PAMPs include LPS (gram ⊝ bacteria), flagellin (bacteria), nucleic acids (viruses).

Question 7

Adaptive immunity COMPONENTS

Answer 7

T cells, B cells, circulating antibodies

Question 8

Adaptive immunity MECHANISM

Answer 8

Variation through V(D)J recombination during lymphocyte development

Question 9

Adaptive immunity RESISTANCE

Answer 9

Microbial resistance not heritable

Question 10

Adaptive immunity RESPONSE TO PATHOGENS

Answer 10

Highly specific, refined over time

Develops over long periods; memory response is faster and more robust

Question 11

Adaptive immunity SECRETED PROTEINS

Answer 11

Immunoglobulins

Question 12

Adaptive immunity KEY FEATURES IN PATHOGEN RECOGNITION

Answer 12

Memory cells: activated B and T cells; subsequent exposure to a previously encountered antigen p stronger, quicker immune response

Question 13

MHC I LOCI

Answer 13

HLA-A, HLA-B, HLA-C

MHC I loci have 1 letter

Question 14

MHC I BINDING

Answer 14

TCR and CD8

Question 15

MHC I STRUCTURE

Answer 15

1 long chain, 1 short chain

Question 16

MHC I EXPRESSION

Answer 16

All nucleated cells, APCs, platelets

Not on RBCs

Question 17

MHC I FUNCTION

Answer 17

Present endogenously synthesized antigens (eg, viral or cytosolic proteins) to CD8+ cytotoxic T cells

Question 18

MHC I ANTIGEN LOADING

Answer 18

Antigen peptides loaded onto MHC I in RER after delivery via TAP (transporter associated with antigen processing)

Question 19

MHC I ASSOCIATED PROTEINS

Answer 19

β2-microglobulin

Question 20

MHC II LOCI

Answer 20

HLA-DP, HLA-DQ, HLA-DR

MHC II loci have 2 letters

Question 21

MHC II BINDING

Answer 21

TCR and CD4

Question 22

MHC II STRUCTURE

Answer 22

2 equal-length chains (2 α, 2 β)

Question 23

MHC II EXPRESSION

Answer 23

APCs

Question 24

MHC II FUNCTION

Answer 24

Present exogenously synthesized antigens (eg, bacterial proteins) to CD4+ helper T cells

Question 25

MHC II ANTIGEN LOADING

Answer 25

Antigen loaded following release of invariant chain in an acidified endosome

Question 26

MHC II ASSOCIATED PROTEINS

Answer 26

Invariant chain

Question 27

A3 Disease

Answer 27

Hemochromatosis

Question 28

B8 Disease

Answer 28

ADDISON disease, MYasthenia gravis, GRAVEs disease (don’t Be late(8), dr. ADDISON, or else you’ll send MY patient to the GRAVE)

Question 29

B27 Disease

Answer 29

Psoriatic arthritis, Ankylosing spondylitis, IBD-associated arthritis, Reactive arthritis (PAIR. Also known as seronegative arthropathies)

Question 30

DQ2/DQ8 Disease

Answer 30

Celiac disease | I ate (8) too (2) much gluten at Dairy Queen

Question 31

DR2 Disease

Answer 31

MULTIPLE sclerosis, HAY fever, SLE, goodPASTURE syndrome (MULTIPLE HAY PASTURES have DiRt)

Question 32

DR3 Disease

Answer 32

``` diabetes mellitus type 1, SLE, graves disease, hashimoto thyroiditis, addison disease ``` (2-3, S-L-E)

Question 33

DR4 Disease

Answer 33

RHEUMatoid arthritis, diabetes mellitus type 1, addison disease (There are 4 walls in a “rheum” (room).)

Question 34

DR5 Disease

Answer 34

Hashimoto thyroiditis | Hashimoto is an odd doctor (DR3, DR5).

Question 35

Natural killer cells

Answer 35

Use perforin and granzymes to induce apoptosis of virally infected cells and tumor cells enhanced by IL-2, IL-12, IFN-α, and IFN-β

Question 36

B cells Major functions

Answer 36

Humoral immunity Recognize antigen: undergo somatic hypermutation to optimize antigen specificity. Produce antibody: differentiate into plasma cells to secrete specific immunoglobulins. Maintain immunologic memory: memory B cells persist and accelerate future response to antigen

Question 37

T cells Major functions

Answer 37

Cell-mediated immunity. CD4+ T cells help B cells make antibodies and produce cytokines to recruit phagocytes and activate other leukocytes. CD8+ T cells directly kill virus-infected cells. Delayed cell-mediated hypersensitivity (type IV). Acute and chronic cellular organ rejection

Question 38

Positive selection

Answer 38

Thymic cortex. T cells expressing TCRs capable of binding self-MHC on cortical epithelial cells survive.

Question 39

Negative selection

Answer 39

Thymic medulla. T cells expressing TCRs with high affinity for self antigens undergo apoptosis or become regulatory T cells. Tissue-restricted self-antigens are expressed in the thymus due to the action of autoimmune regulator (AIRE); deficiency leads to autoimmune polyendocrine syndrome-1

Question 40

Macrophage lymphocyte interaction

Answer 40

Th1 cells secrete IFN-γ, which enhances the ability of monocytes and macrophages to kill microbes they ingest. This function is also enhanced by interaction of T cell CD40L with CD40 on macrophages

Question 41

Cytotoxic T cells

Answer 41

Kill virus-infected, neoplastic, and donor graft cells by inducing apoptosis. Release cytotoxic granules containing preformed proteins (eg, perforin, granzyme B). Cytotoxic T cells have CD8, which binds to MHC I on virus-infected cells.

Question 42

Regulatory T cells

Answer 42

Help maintain specific immune tolerance by suppressing CD4 and CD8 T-cell effector functions. Identified by expression of CD3, CD4, CD25, and FOXP3. Activated regulatory T cells (Tregs) produce anti-inflammatory cytokines (eg, IL-10, TGF-β).

Question 43

IPEX (Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked) syndrome

Answer 43

genetic deficiency of FOXP3 p autoimmunity. Characterized by enteropathy, endocrinopathy, nail dystrophy, dermatitis, and/or other autoimmune dermatologic conditions. Associated with diabetes in male infants