innate immunity

Question 0

Collectins

Answer 0

enhances macrophage phagocytoisis, specific to lung epithelia and lung infection.
epithelial derived chemical

Question 1

What are the biochemical barriers of innate immunity?

Answer 1

Lysozyme- sweat, tears saliva
Epithelial derived chemicals-
*Cathlicidin, *defensin, *collectins, *resin like molecule *Bacterial Inducing Protein, * Antimicrobial Lectins.
Bacterial Derived Chemicals- natural flora produce chemicals such as ammonia, indols and phenols

Question 2

resin like molecule

Answer 2

intestinal goblet cell, against helminths

epithelial derived chemical

Question 3

BPI- Bacterial permeability inducing protein

Answer 3

reacts with lipopolyscharide on the gram negative cell wall
stored in nuetrophil and intestinal epithelium
epithelial derived chemical

Question 4

Antimicrobial lectins

Answer 4

effective against gram positive bacterium in the intestinal epithelium.
epihelial derived chemical

Question 5

Cathelicidins and Defensin

Answer 5

toxic to bacteria, fungi and virus classes,
produced by monocytes, macrophages and neutrophils.
epithelial derived chemicals, polypeptides

Question 6

Plasma protein systems

Answer 6

compliment cascade
kinnin cascade
clotting cascade
*consist of multiple proteins in the blood, many of which are enzymes (inactive as proenzymes) activated by the products of tissue damage or infection

Question 7

Compliment cascade

Answer 7

classical pathway- antibodies and antigen
lectin pathway- bacterial carbohydrates
alternative: activated by gram negative bacteria and fungus

all converge at C3.

Question 8

Clotting Cascade

Answer 8

plasma and fibrin
-prevents spread of infection to surrounding tissue
-traps microorganism for cleansing by macrophage and neurophils
-forms clot to stop bleeding
-provided framework to heal
converge at factor X-> common pathway to clot.

Question 9

Plasma Kinin system

Answer 9

augments inflammation
produces Bradykinin: dilation of blood vessles, acts with prostiglandin to stimulate nerve endings -> pain.
muscle contraction, slower and more prolonged for later phases of inflammation

Question 10

how are the protien plasma systems correlated?

Answer 10

very interconnected, each stimulates the other,
example=many enzymes exist to inhibit and control the inflammatory response. like C1 esteraseinhibits C1-C3, also clotting and kinnin.
genetic defect here, hereditary angioendema=hyper-activation of bradykinin thus vacular permiability.

Question 11

tissue injury or infection stimulates what? innate.

Answer 11

chemical and cellular reaction

vascular responce

Question 12

what are the cellular mediators of inflammation?

Answer 12

Luekocytes.

granulocytes and monocytes (macrophages)

Question 13

what is a granulocyte?

Answer 13

is a cellular mediator of inflammation.
are circulating WBCs
neutrophils, eosinophils, basophils
inconstant contct with endothelium
cytoplasm contains many enzymes.

Question 14

what is an innate immunity cell receptor?

Answer 14

PRRs- pattern recognition receptors, on infectious agents and thier products (PAMPS) found on cells that interact with the environment.
TRLs- toll like receptors, recognize PAMPs on microorganisms cell wall
Compliment receptors
scavenger receptors

Question 15

Compliment receptors

Answer 15

found on many receptors of both innate and acquired responces, macrophages, basophils neutrophils, eosinophils, mast cells and plateletes,
a PAMPs

Question 16

Scavenger receptor

Answer 16

is a PAMP.
found primarily on macrophages and facilitate phaygocytosis
associated with vascular damage-> HDL, acetylated LDL, oxidized LDL (these are damaged lipoproteins.

Question 17

mast cell

-what is it?-where located?- whats its job?

Answer 17

initiates the inflammatory responce
located in the epithelia, especially those connected to environment.
bags of granuals
what innitiates?- injury, chemical agent, IgE of acquired immunity, TRL activation by bacteria or virus.

Question 18

PAMP

Answer 18

pathogen associated molecular patterns

Question 19

degranulation

Answer 19

occurs within the mast cell, releases histamine, cytokine, chemotactic factors, within seconds

Question 20

what are the effects of histamine?

Answer 20

temporary and rapid constriction of large vessels and dilation post capillary beds, increase vascular permiability
effects are due to H1-proinflammatory or H2- antiinflamatory

Question 21

what else do mast cells do?

Answer 21

synthesis new cell mediators:

leukotrienes, prostiglandins, platelet activation facotors.

Question 22

luekotrienes.

Answer 22

similar to histamine with a later and longer action. (smooth muscle contraction and vascular perimability)

Question 23

prostiglandins

Answer 23

increase vascular permiability, neutrophil chemotaxis, induce pain.
can inhibit histamine action by releasing lysosomal enzymes from nuetrophils.

Question 24

platelet activating factor

Answer 24

also produced by monocytes, neutrophils, endothelial cels and platelets (but mostly by mast cells).

• endothelial cell retraction,
• increase permeability - leukocyte adhesion -platelet activation.

Question 25

Cells that are phagocytes

Answer 25

neutrophils, monocyte/macrophages, and dendritic cells

Question 26

neutrophils

Answer 26

predominant in early inflammation
attracted by bacterial protiens, compliment factos, chemotactic factors
short lived, become pus.
Neutrophils, along with two other cell types; eosinophils and basophils (see below), are known as granulocytes due to the presence of granules in their cytoplasm, or as polymorphonuclear cells (PMNs) due to their distinctive lobed nuclei. Neutrophil granules contain a variety of toxic substances that kill or inhibit growth of bacteria and fungi. Similar to macrophages, neutrophils attack pathogens by activating a respiratory burst. The main products of the neutrophil respiratory burst are strong oxidizing agents including hydrogen peroxide, free oxygen radicals and hypochlorite. Neutrophils are the most abundant type of phagocyte, normally representing 50 to 60% of the total circulating leukocytes, and are usually the first cells to arrive at the site of an infection.[5] The bone marrow of a normal healthy adult produces more than 100 billion neutrophils per day,

Question 27

macrophages

Answer 27

big eaters, large and slow, 3-7 days after neutrophils, most effective bacterial eaters, plays a role in adaptive immunity with receptors,
also produces cytokines to call in other cells to fight.

Question 28

eosinphils and basophils

Answer 28

encounter, basophils releasing histamine are important in defense against parasites, and play a role in allergic reactions (such as asthma).[3] Upon activation, eosinophils secrete a range of highly toxic proteins and free radicals that are highly effective in killing bacteria and parasites, but are also responsible for tissue damage occurring during allergic reactions. Activation and toxin release by eosinophils is, therefore, tightly regulated to prevent any inappropriate tissue destruction.[5]

Question 29

dendritic cells

Answer 29

Dendritic cells (DC) are phagocytic cells present in tissues that are in contact with the external environment, mainly the skin (where they are often called Langerhans cells), and the inner mucosal lining of the nose, lungs, stomach, and intestines.[2] They are named for their resemblance to neuronal dendrites, but dendritic cells are not connected to the nervous system. Dendritic cells are very important in the process of antigen presentation, and serve as a link between the innate and adaptive immune systems.

Question 30

natural killer cells

Answer 30

does not directly attack invading microbes but destroy compromised host cells, such as tumor cells or virus-infected cells,

Question 31

neural regulation of inntate immuntiy

Answer 31

The innate immune response to infectious and sterile injury is modulated by neural circuits that control cytokine production period. The Inflammatory Reflex is a prototypical neural circuit that controls cytokine production in spleen.[12] Action potentials transmitted via the vagus nerve to spleen mediate the release of acetylcholine, the neurotransmitter that inhibits cytokine release by interacting with alpha7 nicotinic acetylcholine receptors (CHRNA7) expressed on cytokine-producing cells.[13] The motor arc of the inflammatory reflex is termed the cholinergic anti-inflammatory pathway.

Question 32

Cytokines

Answer 32

Cytokines (Greek cyto-, cell; and -kinos, movement) are a broad and loose category of small proteins (~5–20 kDa) that are important in cell signaling. They are released by cells and affect the behavior of other cells, and sometimes the releasing cell itself. Cytokines include chemokines, interferons, interleukins, lymphokines, tumour necrosis factor but generally not hormones or growth factors (despite some terminologic overlap). Cytokines are produced by a broad range of cells, including immune cells like macrophages, B lymphocytes, T lymphocytes and mast cells, as well as endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell.[1][2][3]

They act through receptors, and are especially important in the immune system; cytokines modulate the balance between humoral and cell-based immune responses, and they regulate the maturation, growth, and responsiveness of particular cell populations. Some cytokines enhance or inhibit the action of other cytokines in complex ways.[3]

They are different from hormones, which are also important cell signaling molecules, in that hormones circulate in much lower concentrations and hormones tend to be made by specific kinds of cells.

They are important in health and disease, specifically in host responses to infection, immune responses, inflammation, trauma, sepsis, cancer, and reproduction.

Question 33

chemokines

Answer 33

The major role of chemokines is to act as a chemoattractant to guide the migration of cells. Cells that are attracted by chemokines follow a signal of increasing chemokine concentration towards the source of the chemokine. Some chemokines control cells of the immune system during processes of immune surveillance, such as directing lymphocytes to the lymph nodes so they can screen for invasion of pathogens by interacting with antigen-presenting cells residing in these tissues. These are known as homeostatic chemokines and are produced and secreted without any need to stimulate their source cell(s). Some chemokines have roles in development; they promote angiogenesis (the growth of new blood vessels), or guide cells to tissues that provide specific signals critical for cellular maturation. Other chemokines are inflammatory and are released from a wide variety of cells in response to bacterial infection, viruses and agents that cause physical damage such as silica or the urate crystals that occur in gout. Their release is often stimulated by pro-inflammatory cytokines such as interleukin 1. Inflammatory chemokines function mainly as chemoattractants for leukocytes, recruiting monocytes, neutrophils and other effector cells from the blood to sites of infection or tissue damage. Certain inflammatory chemokines activate cells to initiate an immune response or promote wound healing. They are released by many different cell types and serve to guide cells of both innate immune system and adaptive immune system.