Medical Immunology Fever and Inflammation

What role do Interleukin-1(IL-1) and TNF-α have in fever formation?

They induce prostoglandin synthesis in the hypothalamus

Where does prostaglandin synthesis occur?

In the hypothalamus

Where is IL-1 released from?

Macrophages

Where is TNF-alpha released from?

Macrophages, tissues, and T-cells

What role do prostaglandins play in fever formation?

They produce micro-contractions of muscles that increase body temperature

What happens to the blood when the body has a fever?

It shifts from the surface of the body to the interior

Why does the body induce fever?

To disrupt the function of viral and bacterial proteins

Label this part of prostaglandin synthesis

Phospholipase A2

Label this part of prostoglandin synthesis

Arachidonic Acid

Label this part of prostoglandin synthesis

Lipoxygenase

Label this part of prostoglandin synthesis

Leukotrienes

Label this part of prostaglandin synthesis

Bronchoconstriction and asthma

Label this part of prostaglandin synthesis

Cyclooxygenase

Label this part of prostaglandin synthesis

Prostaglandins

Label this part of prostaglandin synthesis

Thromboxanes

Label this part of prostaglandin synthesis

Fever and inflammation

Label this part of prostaglandin synthesis

Blood clots

Label this part of prostaglandin synthesis

Phospholipids

Label this part of prostaglandin synthesis

Disruption of lipid bilayer causing the release of phospholipids

How does acetaminophen help with a fever?

It inhibits cyclooxygenase, the enzyme that produces prostaglandins

What are the functions of inflammation?

To get cells of the immune system to the site of an extravascular injury, prevent spread of toxins, and promote healing

Diseases that cause _______ often have a suffix of “-itis”

Inflammation

Local manifestations of inflammation

Pain, swelling, warmth, redness

Systemic manifestations of inflammation

Fever, leukocytosis, malaise, loss of function

Who first responds to the inflammatory response?

Mast cells

How do mast cells respond to foreign organisms invading the body?

They release chemicals (histamines, prostaglandins, serotonin, and leukotrienes) to attract phagocytes (neutrophils then macrophages)

What causes heat release?

Vasodilation

What causes pain?

Vasodilation and release of vasoactive and chemotactic factors

What causes redness?

Vasodilation

What causes swelling?

Increased permeability and neutrophil emigration

What is the effect of prostaglandins, leukotrienes, and histamines on the body?

They cause blood vessels to widen and the flow of blood to increase

What causes vasodilation?

Release of prostaglandins and histamines

Outcome of vasodilation

Swelling, redness and pain

Histamine, bradykinin, PGE2

Vasodilation and swelling

TNF-α, Interleukin-1, PGE2

Endogenous Pyrogens

What are endogenous pyrogens?

chemical mediators that cause fever

Leukotrienes, C5a (complement)

chemotaxis

What is chemotaxis?

Attraction of white blood cells to infection

What is a complement?

Chemical mediator that actively destroys viruses and bacteria, initiates inflammation

How does a complement become active?

In response to antibodies IgG and IgM bound to surface of bacteria, directly activated when it encounters bacteria

What is the classical pathway to complement activation?

Antibody binds to bacteria, complememnt binds to antibody which is on bacteria

Which immune system uses the classical pathway of complement activation?

Adaptive

What is tehe alternative pathway to complement activation?

Complement proteins bind to LPS (surface molecules) on bacteria

What is the MBL pathway to complement activation?

MBL binds to carbohydrates on bacteria

Whihch immune system uses the alternative pathway?

innate

Which immune system uses the MBL pathway?

Innate

What is the ultimate goal of ALL activation pathways?

to make the membrane attack complex

How does the membrane attack complex kill microbes?

Lysis