Innate Immunity Overview

Question 1

How do phagocytic cells identify pathogens?

Answer 1

They recognize pathogen-associated molecular patterns (PAMPS) and damaged/necrotic self, damage-associated molecular patterns (DAMPS)

Question 2

What are some examples of Pattern Regonition Receptor?

Answer 2

Toll-like receptors, Lectin, NOD-like receptor, RIG-like receptor

Question 3

Where can Toll-like receptors be found?

Answer 3

On the cell membrane, in endosomes, or in the cytoplasm?

Question 4

What is TL-1, 2 responsible for?

Answer 4

Recognizes several bacterial and parasitic glycolipids and peptidoglycans

Question 5

What is TLR3, TLR7, and TLR8 responsible for?

Answer 5

Responsible for viral single-stranded and double-stranded RNAs. Since this acts on RNA, the TLR is in an endosome

Question 6

What is TLR4 responsible for?

Answer 6

Recognizing bacterial LPS (endotoxin)

Question 7

What is TLR5 responsible for?

Answer 7

Regonizing bacterial flagellar protein called flagellin

Question 8

What is TLR9 responsible for?

Answer 8

Recognizing unmehtylated CpG DNA that is abundant in microbial genomes. Found in endosomes

Question 9

What is the interferon system and what is it used for?

Answer 9

Component of innate immune defense which is used against intracellular viruses

Question 10

What are the components of the Innate Immunity?

Answer 10

Host barriers; Enzymes in epithelial and phagocytic cells; Inflammation-related serum proteins; antimicrobial peptides on the surfaces of t cells within phagocyte granules; phagocytic cells identifying PAMPS and DAMPS; cell receptors that sense micro-organisms and signal a defensive response; complement; acute inflammation; pro-inflammatory cytokines, NK cells, mast cells and other granulocytic cells

Question 11

Neutrophil cell type and function?

Answer 11

WBC Granulocyte; Engulf bacteria and fungia, oxidative burst

Question 12

Monocyte/Macrophage cell type and function?

Answer 12

WBC Mononuclear; Engulf bacteria, fungi, and cellular debris, produce cytokines, antigen processing

Question 13

Eosinophil cell type and function?

Answer 13

WBC Granulocyte; Associated with allergic response and parasitic infection (helminthic)

Question 14

Basophil cell type and function?

Answer 14

WBC Granulocyte; Associated with hypersensitivity and release histamine

Question 15

Mast cell type and function?

Answer 15

Bone marrow derived cell; Granules contain vasoactive amines like histamine, proteases kill bacteria

Question 16

Natural killer cell type and function?

Answer 16

WBC Lymphocyte; Recognizes stressed or infected cells and kills them by secreting macrophage-activating cytokine INF-gamma

Question 17

Dendritic cell cell type and function?

Answer 17

Bone marrow derived; Phagocytosis, APC, initiation of T-cell responses. Immunosurveillance. They are less phagocytic than neutrophils and macrophages and do more consuming through endocytosis

Question 18

These cells secrete granules that contain granyzme and performin and cell surface receptors for IgG

Answer 18

Natural killer cells

Question 19

How are follicular dendritic cells different than normal dendritic cells?

Answer 19

Follicular dendritic cells are more adept at trapping antigens and presenting them to B cells while Dendtritic cells are very efficient at present antigen to T cells

Question 20

What are some examples of Pattern Associated Molecular Patterns?

Answer 20

Bacterial peptidoglycan, Lipoportein, LPS, Bacterial flagellin, lipotechoic acid, viral envelope proteins

Question 21

Where is interleukin-6 found and what are its targets?

Answer 21

Found in macrophages, endothelial cells, T-cells; Targets are the liver for synthesis of acute-phase proteins and B-cells for proliferation of antibody-producing cells

Question 22

Where is Interleukin-1 found and what are its targets?

Answer 22

Found from macrophages, endothelial cells, and some epithelial cells; Recruits neutrophils. Targets are endothelial cells for activation of inflammation and coagulation. hypothalamus during fever, liver for synthesis of acute phase proteins, T-cells for Th17 deifferentiation

Question 23

What are acute phase reactants? What is the chief stimulator in the production of most acute-phase proteins?

Answer 23

During the acute phase response, usual levels of various proteins by homeostatic mechanisms change. These changes are thought to contribute to host defense and other adaptive capabilities. These proteins are Acute Phase Reactants; They are largely stimulated by Interleukin-6. The other implicated cytokines influence subgroups of acute-phase proteins

Question 24

What might change the concentration of acute-phase proteins?

Answer 24

Infection, trauma, burns, surgery, tissue infarction, various immunologically medicated inflammatory conditions, advanced cancer

Question 25

Where are the majority of these acute-phase proteins produced and how are they defined?

Answer 25

They are produced by hepatocytes and are labeled as acute-phase proteins if their levels increase/diminish by 25% during inflammatory disorders.

Question 26

What are some examples of acute-phase reactants?

Answer 26

1) C-reactive protein 2) Serum amyloid A (SAA) 3) Complement components 4) Haptoglobin and hemopexin 5) Hepcidin 6) Fibrinogen

Question 27

Describe the role of the APR, C-reactive protein

Answer 27

C-reactive protein: Promote recognition and elimination of pathogens and enhance clearance of necrotic and apoptotic cells. Pro-inflammatory effects include activation of complement system and induction in monocytes of inflammatory cytokines

Question 28

Describe the role of the APR, Serum amyloid A (SAA)

Answer 28

Serum amyloid A (SAA): Proteins influence cholesterol metabolism during inflammatory states

Question 29

Describe the role of APR, complement components

Answer 29

Complement components: serve pro-inflammatory roles, including chemotaxis, plasma protein exudation at sites of inflammation, and opsonization of infection agents and damaged cells

Question 30

Describe the role of APR, Haptoglobin and hemopexin

Answer 30

Haptoglobin and hemopexin: Antioxidants that protect against reactive oxygen specieis by removing iron-containing cell-free hemoglobin and heme, respectively from the circulation

Question 31

Describe the role of the APR, Hepcidin

Answer 31

Hepcidin: Can contribute to decreases in serum iron by release intestinal iron absorption and impairing the release of Iron from macrophages. Bacteria love iron, so if you decrease it, they won’t replicate as much.

Question 32

Describe the role of the APR, Fibrinogen

Answer 32

Fibrinogen: Influences would healing. Causes endothelial cell adhesion, spreading, and proliferation, which is critical to repair