The Acute Phase Response

• Activated in response to “alarm” cytokines:IL-1, IL-6.

• Enhances host resistance, minimizes tissue injury, promotes resolution and repair of inflammatory lesion.

The Inflammatory Response

• Produced through:(I) Ab Independence(a) Tissue Injury(b) Alternate complement pathway(II) Ab Dependence(a) Classical complement(b) Mast cell degranulation

Mediators of Inflammation

Mast Cell Mediators

Chemokines`

• Function: Stimulates chemokinesis and chemotaxis (a chemotactic cytokine.)

• Two types: – C-C (produced mainly by activated T cells -

acts mainly on subsets of m/p’s and TH cells). e.g. RANTES

– C-X-C (produced mainly by m/p’s, endothelial cells, fibroblasts - acts mainly on neutrophils). e.g. IL-8

The Complement Pathway

Biological Functions of Complement

Biological Functions of Macrophages

• Phagocytosis• Antigen-presenting

cell• Cytokine production

Innate vs Acquired Immunity

Innate-Adaptive Immunity

The Antiviral Response

Fc Receptors

Antiviral Immunity

TNF

Delayed-Type Hypersensitivity I

T Cell Receptor

Mechanism of T Cell Triggering

Successful Effector Cell Stimulation Requires Accessory Molecules

TH1 vs TH2

TH1 vs TH2