Innate Immune System

external barriers

what is the 1st line of defense?

macrophage, neutrophil, dendritic cell

name the 3 phagocytic cells of innate immunity

neutrophil

most common leukocyte

basophils, mast cells

2 pro-inflammatory cells of innate immunity

histamine, heparin, eicosanoids

3 chemicals released by pro-inflammatory cells

eicosanoids

which chemical released by basophils and mast cells is described below:

promotes further inflammation

histamine

which chemical released by basophils and mast cells is described below:

increases vasodilation and capillary permeability

heparin

which chemical released by basophils and mast cells is described below:

anticoagulant

neutrophils

__ are the most numerous leukocyte and first responders to site of injury; act as weaker macrophages

phagolysosome

in phagocytic cells, when the intake vesicle fuses w/ the lysosome, a __ is formed

The following occurs during __.

1. Intake vesicle fuses with lysosome forming phagolysosome

2. Digestive enzymes break down unwanted substances

3. Degraded residue is released by exocytosis

dendritic

__ cells destroy antigens, then present the remaining fragments on their surface to T-cells (APC cells)

• initiates adaptive immunity

inflammation

Basophils and mast cells promote __.

phagocytic

macrophages, neutrophils, and dendritic cells are __

basophils

__ are most rare leukocyte (less than 1% of circ. Leukocytes)

mast cells

__ __ reside in connective tissue, mucosa, internal organs

chemotaxis

pro-inflammatory cells like basophils and mast cells release __ chemicals, which attract immune cells

eicosanoids

__ released from the plasma membrane of pro-inflammatory cells promote further inflammation

natural killer

__ __ cells are apoptosis-inducing cells that target unhealthy/unwanted cells

natural killer

__ __ cells form in bone marrow, circulate in blood, and accumulate in secondary lymphoid structures

• perform immune surveillance

natural killer

__ __ cells perform immune surveillance

natural killer

__ __ cells destroy virus-infected cells, bacterial-infected cells, tumor cells, and cells of transplanted tissue

natural killer

__ __ cells kill by releasing cytotoxic chemicals such as perforin and granzymes

perforin, granzymes

natural killer cells kill by releasing cytotoxic chemicals such as __ and __

perforin

name the cytotoxic chemical described below:

creates a transmembrane pore in the unwanted cell

granzymes

name the cytotoxic chemical described below:

enter transmembrane pore and cause apoptosis of the cell

eosinophils

which cell attacks multicellular parasites?

second

macrophages, neutrophils, and dendritic cells are part of the __ line of defense

innate

macrophages, neutrophils, and dendritic cells are part of __ immunity

second

basophils and mast cells are part of the __ line of defense

innate

basophils and mast cells are part of __ immunity

second

natural killer cells are part of the __ line of defense

innate

natural killer cells are part of __ immunity

second

eosinophils are part of the __ line of defense

innate

eosinophils are part of __ immunity

eosinophils

__ degranulate (perforins) and participate in immune responses of allergy/asthma

eosinophils

pattern recognition receptors (toll-like) receptors on the surface of __ bind to patterns on a m/o’s surface

eosinophil

which cell type would respond to a parasitic worm?

antimicrobial proteins

__ __ are molecules that destroy cell membranes, impact metabolism, and sequester nutrients

destroy cell walls/membranes

defensins, cathlecidins, protegrins, and lysozymes are anti-microbial proteins that __

defensins

which anti-microbial proteins impact metabolism?

lactoferrins

which anti-microbial proteins sequester nutrients?

interferons

__ are a type of cytokines that non-specifically interfere w/ the spread of intracellular pathogens

interferons

types of __ include IFN-a, IFN-B, and IFN-g

IFN-a, IFN-b

which type of interferons are produced by leukocytes and virus-infected cells?

IFN-a, IFN-b

which type(s) of interferons;

1. bind to neighboring cells

2. trigger the synthesis of enzymes that destroy viral nucleic acids

3. inhibit the synthesis of viral proteins

IFN-a, IFN-b

which type(s) of interferons stimulate NK cells to destroy virus-infected cells?

IFN-g

which type of interferon is produced by t-cells and NK cells?

IFN-g

which type of interferon stimulates macrophages to destroy virus-infected cells?

complement system

the __ __ is a group of > 30 plasma proteins that work w/ antibodies

complement

__ is synthesized in the liver and continuously released in inactive form

enzyme cascade

the complement system is activated via __ __

complement

__ is continuously released inactive by the liver and is activated via enzyme cascade

pathogen

complement activation follows __ entry

classical, alternative, lectin

what are the 3 pathways of complement activation? (CAL)

classical pathway

which complement pathway is described below:

Antibody attaches to foreign substance, then complement binds to antibody

alternative pathway

which complement pathway is described below:

complement binds to polysaccharides of bacterial/fungal cell wall

lectin pathway

which complement pathway is described below:

initiated when mannose-binding lectin binds to mannose

inflammation

which stereotypical response is a local, nonspecific response of vascularized tissue to injury, infection; major response of innate immunity

inflammation

the events of __ are described below

1. Injured tissue, basophils, mast cells, and infectious organisms release chemicals that initiate responses

2. released chemicals induce vascular changes: vasodilation, increased capillary permeability, increased endothelial expression of molecules for leukocyte adhesion

3. leukocyte recruitment: diapedesis, chemotaxis

chemotaxis

leukocytes migrate toward chemicals released from damaged, dead, or pathogenic cells

diapedesis

cells escape blood vessel walls

inflammation

the following vascular changes occur during __

• vasodilation

• increased capillary permeability

• increased endothelial expression of molecules for leukocyte adhesion

exudate

during inflammation, the fluid that moves from blood to the injured/infected area is called __

exudate

__ contains fluid, proteins, and immune cells to eliminate pathogens/promote healing

vasodilation

during inflammation __ brings more blood to the injured/infected area

capillary permeability

during inflammation, the contraction of vessel endothelial cells (opening gaps) increased __ __

fluid reabsorption

the loss of plasma proteins during inflammation decreases capillary osmotic pressure, which then decreases __ __ into the blood

lymphatic capillaries

Extra fluid during inflammation is taken up (“washed”) by __ __ in the area. This allows lymph nodes to monitor the fluid’s contents.

72

Within __ hours inflammation response slows

• macrophages eat bacteria, damaged host cells, dying neutrophils

• tissue repair: fibroblasts form new connective tissue

redness, heat, swelling, pain, loss of function

cardinal signs of inflammation (red hot sweltering peppers laugh)

redness

increased blood flow during inflammation causes __

heat

increased blood flow and metabolic activity during inflammation cause __

swelling

the increase in fluid loss from capillaries during inflammation causes __

pain

fluid loss and chemical irritants (kinins, prostaglandins, m/o secretions) cause the compression of receptors, which then causes __

loss of function

pain and swelling in severe cases of inflammation may cause __ _ __

fever

abnormal body temperature elevation (>37°C)

fever

the release of pyrogens from immune cells or infectious agents causes __

fever

the events of __ include:

1. Pyrogens circulate through blood and target hypothalamus

2. In response, hypothalamus releases prostaglandins

3. Hypothalamus raises temperature set point leading to fever

fever

the benefits of __ include

• Inhibits reproduction of bacteria and viruses

• Promotes interferon activity

• Stimulates capillary permeability

• Increases activity of adaptive immunity

• Accelerates tissue repair

103-104

a high grade fever is between __-__°F

104

a dangerous high-grade fever is over __°F

denaturation

high fevers are dangerous because they cause the __ of proteins

106

irreversible brain damage occurs at fevers greater than __°F

108

death is likely to occur if a fever is >__°F

neutrophils

Which innate cell type is typically the first responder at the site of infection?

innate

the 1st and 2nd lines of defense are part of __ immunity

cytokine storm

life-threatening systemic inflammatory syndromes involving elevated levels of circulating cytokines and immune-cell hyperactivation