Introduction to General Immunology, Slides of Immunology

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Introduction to

General Immunology

Course Code and Number: PHG 231 Dr. Masood Alam Khan, PhD Dr. Syed Imam Rabbani, PhD Dept. Pharmacology and Toxicology, QU [email protected]

Immune system

Cells, organs and molecules responsible for immunity constitute the immune system

Immune response

Collective response of immune system to foreign substances Immunology

Immunity

Specific defensive response when a host is invaded by foreign organisms or other foreign substances

Immunology is the study of the components

and functions of the immune system

Terminologies used in Immunology

PRINCIPAL FUNCTION OF THE

IMMUNE SYSTEM

• (^) To protect humans from pathogenic microorganisms
• (^) Pathogenic microorganisms (Pathogens)
  • (^) Microorganisms capable of causing infection and/or disease
• (^) Infection
  • (^) Ability of pathogen to enter the host, multiply and stimulate an immune response
• (^) Disease
  • Clinical manifestations associated with infection

Immune responses Nonspecific Defense Mechanisms Specific Defense Mechanism s 1 st line of defense 2 nd line of defense 3 rd line of defense

• (^) Intact skin
• (^) Mucous membranes and their secretions - (^) Phagocytic white blood cell - (^) Inflammation and fever - (^) Antimicrobial substances (complement system ‘C’, interferon) - (^) Specialized lymphocytes : B cells and T cells - Antibodies

Other mechanisms of defense:

Physiological variables:

1. pH of our environment
2. Temperature of our environment Chemical defenses: Nitric oxide, enzymes, proteins

Summary of Non-specific host defenses Type Mechanism Anatomic barriers Skin Mechanical barrier retards entry of microbes. Acidic environment (pH 3–5) retards growth of microbes. Mucous membranes Normal flora compete with microbes for attachment sites and nutrients. Mucus entraps foreign microorganisms. Cilia propel microorganisms out of body. Physiologic barriers Temperature Normal body temperature inhibits growth of some pathogens. Fever response inhibits growth of some pathogens. Low pH Acidity of stomach contents kills most ingested microorganisms.

The Immune system: divided in to 2 branches

1. The Innate Immune System: a general

response to anything other than recognized “self cells”.

2. The Adaptive Immune System: a specific

counter-assault against a “known foreign” invader [previously recognized]

What Happens During an Infection?

Innate Immune system

The troops are called to battle against: 1.Injury and Infection 2.Macrophages slip between cells (Extravasation) to arrive at the site 3.Cytokine chemicals attract other cells (Chemotaxis) 4.Histamine chemicals dilate blood vessels to make access easy to the site of infection or injury (Vasodilation)

Phagocytes: These cells have ability to engulf the foreign invaders particularly micro-organisms 1.Macrophages 2.Neutrophils 3.Monocytes They release cytokines that increase immune response to pathogens

Vaccine and vaccination