Inflammation, Complement, and Natural Killer Cells

Rubor

Redness, erythema

Calor

Heat

Tumor

Swelling, edema

Dolor

Pain

When are cytokines produced in small amounts?

Injured tissue

When are cytokines produced in large amounts?

Phagocytes and lymphocytes

How does chemokine CXCL8 cause inflammation?

Gradient leads to neutrophil migration, neutrophils produce large amounts of CXCL8, producing even more neutrophils

How do proinflammatory cytokines IL-1, IL-2 and TNF-alpha lead to inflammation?

Vascular permeability: swelling, reddening and heat

How do proinflammatory cytokines affect blood vessels?

Keep pathogens out of blood vessels

What are pyrogens?

Fever inducing organisms

Examples of endogenous pyrogens (3)

IL-1, IL-2, TNF-alpha

Example of exogenous pyrogens

Lipid A on LPS

How are pathogens affected by the shift in temperature during a fever?

Reduces bacterial growth rate

What is the limiting nutrient in the body?

Iron

How does fever affect iron production?

Fever stimulates production of transferrin which binds iron

How many complement proteins are there in blood

9

Which complement protein is the most influential?

C3

Which proteins (3) are involved in recognizing bound antibody in the classical complement pathway?

C1q, C1r, C1s

Which fragment is involved in cleaving C2 and C4 in the classical complement pathway?

Complex

Which proteins are involved in cleaving C3 in the classical complement pathway?

C2a and C4b

Which protein is involved in cleaving C5, and forming MAC in the classical complement pathway?

C3b

What is MAC and what does it do?

Molecular associated complex, poke holes in the membrane and kills bacteria

Is complement more effective against gram negative or gram positive bacteria?

Gram negative

What is the alternate function of C3b?

Opsonization

What part of the phagocyte attaches to C3b?

C3 receptor protein (C3R)

What is the role of C3a and C5a as chemokines?

Act as chemoattractant and recruit pathogens

What granulocytes does C3a and C5a interact with?

Mast cells, neutrophils, eosinophils

What is the result of the interaction between granulocytes and C3a and C5a?

Mast cells degranulate, release proinflammatory histamines

Why are C3a and C5a called anaphylatoxins?

Too much can cause anaphylaxis

What is the lineage of Natural Killer Cells?

Lymphoid

Are NKC associated with innate or adaptive immunity?

Innate

Which cell surface proteins do NKC interact with?

Stress recognition and MHC1 recognition receptors

If a cell presents a self-peptide of MCH1 what will the NKC do?

Nothing

What does “license” mean in the case of a cell presenting a self-peptide of MCH1?

The NKC allows the other cell to live if it has a normal MHC1

How do virus infected (and tumor) cells differ from healthy cells in regards to MHC1 and stress proteins?

Have reduced levels of MHC1 and they express stress proteins

What are perforins?

Forms a pore in cell membranes

What are granzymes?

Enter the cell and cause apoptosis

What is apoptosis?

Genetically encoded death sequence

How do interferons prevent viral infection?

Infected cells produce a large amount of INF alpha and INF beta which simulates production of antiviral proteins in healthy cells

Are interferons virus specific or host specific?

Host specific