Immunology

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Immunology
Immunology is the study of our protection from
foreign macromolecules or invading organisms and 
our responses to them.
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History

• Concept first recorded in Athens, 430 BC. Those
  who recovered from Plague could attend the sick
  without relapsing.
• Chinese and Turks made crude attempts to achieve
  immunity from smallpox by inhaling dried crusts
  from pustules of the disease.
• Technique, called variolation, was improved by
  Edward Jenner in 1798. He used cowpox pustules
  to immunize a boy against smallpox.
• Louis Pasteur gave the first true vaccine about
  100 years later. The rabies vaccine was given to
  the boy, Joseph Meister, who had been repeatedly
  bitten by a rabid dog.

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Two Parts of the Immune Response

• Innate (non-specific) Immunity
• Basic, first line defense
• Immediate maximal response
• Non-specific with no permanent immunity

• Acquired (specific) immunity
• Complex, highly specific defense
• Delayed time until maximal response
• Specificity, diversity, memory, self/non-self
  recognition

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• Innate (non-specific) Immunity

Skin Unbroken skin is an effective physical
barrier to invasion
Secretions Mucus keeps passages moist and traps
organisms. Mucus is continually swallowed and
taken to the stomach where acid destroys most
invaders. Sweat, tears, and saliva all contain
Lysozome which breaks down bacterial cell walls.
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Innate (non-specific) Immunity

• Phagocytosis phagocytes are white blood cells
  that circulate in the blood engulfing pathogens.
  Macrophages (shown here) are large phagocytes.

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Innate (non-specific) Immunity

• Inflammatory Response
• Marked by four symptoms redness, swelling,
  pain, increased temperature

• 1.When injury occurs, damaged cells release
  histamine.
• 2.This functions as a beacon for phagocytes to
  migrate to the injured area and begin ingesting
  pathogens.
• Phagocytes release a hormone that acts on the
  hypothalamus, instructing it to increase body
  temperature. Temperature serves as a defense by
  interfering with pathogen metabolism.
• Pain encourages protection of damaged area.

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Innate (non-specific) Immunity

• Complement a set of plasma proteins that
  function in non-specific and specific immunity.
  Complement proteins circulate in the plasma in an
  inactivated state. Contact with a pathogen or
  with antibodies can activate other complement
  proteins, leading to a cascade of immune
  responses. The complement cascade can result in
  lysis of the pathogen, increased phagocytosis,
  and initiation of the inflammatory response.
  Complement can target bacteria, protists, and
  viruses.