Immunity: Part III

Innate Immunity: Further body defenses

• Natural killer (NK) cells:

– Patrol the body and attack virus-infected body cells and cancer cells (IMMUNGOLOGICAL SURVEILLANCE)

– Trigger apoptosis in the cells they attack

NK Cells video clip

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

Antimicrobial Proteins

• Numerous proteins function in innate defense

– By attacking microbes directly or by impeding their reproduction

• Interferons

• Complement System

-Small proteins produced in response to viruses or cancer cells.-Cytokines-Stimulate the actvities of macrophages and NK Cells-Interferon therapy

interferon clip

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Complement proteins

Group of proteins normally present in blood in inactive state

Complement cascade• Important mechanism of action for antibodies• Causes cell lysis by permitting entry of water through a

defect created in the plasma membrane

Also perform other functions • attracting immune cells to a site of infection • activating immune cells• marking foreign cells for destruction• increasing permeability of blood vessels

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc.

Complement Cascade

complement cascade

complement system

Signs:

• Redness

• Swelling

• Heat

• Pain

Purposes of Inflammation

• To perform a temporary repair at the injury site and prevent access of additional pathogens

• To slow the spread of pathogens from the injury site

• To mobilize a wide range of defenses that can overcome the pathogens

• To aid in permanent tissue repair (REGENERATION)

Mast cells & Basopils

Notes Handout

Events in Inflammation

Inflam resp video (short)

Inflam resp video (long)

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Inflammatory Response

Fever = the maintenance of a body temp >37.2ᵒC (99ᵒF)

Hypothalamus

Pyrogens – endogenous vs. exogenous

Fever

Pros• Increases rate of metabolism• Cells move faster

(phagocytes)• Enzymatic reactions

proceed more quickly (lysozymes)

Cons• High fever can damage

physiological systems– Nausea– Disorientation– Hallucinations– Convulsions– Brain damage (@42ᵒC)