I1 - Intro to Immunology Flashcards
What is Immunology?
Study of physiological mechanisms that humans and other animals use to defend from invading organisms -Bacteria -Fungi -Viruses -Parasites -Toxins
What is Edward Jenner (1790) known for?
Smallpox eradication. Developing Vaccination.
When was smallpox eradicated?
1980
What is Paul Ehrlich (1864-1915) known for?
Worked with Koch. Proposed concept of RECEPTORS (which we now know as antibodies) secreted by immune cells in response to foreign antigens (“magic bullets”). Developed anti-toxin (diphtheria) and haemolysis.
What was elie Metchnikoff (1845-1916) known for?
Discovering phagocytosis (larvae of starfish, similar process to WBCs
What are the stages of Phagocytosis? What is it?
- Chemotaxis and adherence of microbe to pahgocyte 2. Ingestion of microbe by phagocyte 3. Formation of a phagosome 4. Fusion od the phagosome with a lysosome = Phagolysosome 5. Digestion of microbe by enzymes 6.Formation of residual body containing indigestible material 7. Discharge of waste materials. Allows breaking up of molecules and education of immune cells
What was Sir Frank Macfarlane Burnet (1899-1985) known for?
Clonal selection theory to explain tolerance. Discovery of acquired immunological tolerance.
What is tolerance?
When the immune system ignores a foreign body
What were Benacerraf, Dausset and Snell known for?
Discovered genes regulating immune responses (now known as Major Histocompatibility Antigens MHC or HLA)
What were Milstein, Jerne and Kohler known for?
Monocolonal antibodies. Many new monoclonal drugs: Perception (HER2), Remicade, Avastin. Humanised antibodies now transforming therapy for many diseases (e.g. Rheumatoid Arthritis, Macular Degeneration and Cancer)
What does any immune response involve?
- RECOGNITION of the pathogen - Mounting a REACTION against it to eliminate it
What are the two types of immune response that defend against infection?
-NATURAL/INNATE (non-adaptive) immunity -ACQUIRED/SPECIFIC (adaptive) immunity
What is an antigen?
Any molecule that binds to immunoglobulin or T Cell Receptor and MHC Molecules
What are the genes that regulated immune responses?
MHC - Major Histocompatibility Antigens (called HLA - the Human Leukocyte Antigen - in humans)
What is a pathogen?
A microorganisms that can cause disease
What is an Antibody (Ab)
A Secreted Immunoglobulin (Ig)
Define vaccination
Deliberate induction of protective immunity to a pathogen
What are cytokines?
Soluble mediators of inflammation
Define ‘Immunization’
The process by which a person is made able to resist infection
How many stages can response to infection be divided into?
3 - The first 2 reply on activation of the innate immune system. Innate Immunity (immediate, 0-4hrs) Early Induced Response (early, 4-96hrs) Adaptive Immune Response (late, >96hrs)
What are the stages of the immediate response (0-4hrs) to infection?
Infection Recognition by preformed, non specific effectors Removal of Infectious Agent
What are the stages of the Early (4-96hrs) response to infection?
Infection Recognition of Microbial-associated molecular patterns Inflammation,recruitment and activation of effector cells Removal of Infectious Agent
What are the stages of the Late (>96hrs) response to infection?
Infection Transport of antigen to lymphoid organs Recognition by naive B and T cells Clonal Expansion and differentiation to effector cells Removal of infectious agent
What is adaptive immunity?
This occurs later and results in the clonal expansion of antigen-specific lymphocytes
What are the features of the innate immune response?
Rapid Non-specific First Line of Defence Not Enhanced by repeated exposure
What are the features of the Adaptive Response?
Slow Specific Second Line of Defence Enhanced by Repeated Exposure
What are the Stages of Infection and the protection at each stage?
Adherence to epithelium - Normal flora, Local Chemical Factors, Phagocytes (especially in lung) Local Infection, Penetration of Epithelium - Wound healing induced antimicrobial proteins and peptides, phagocytes and complement destroy invading microorganisms. Local Infection of Tissues - Complement, cytokines, cheekiness, Phagocytes, NK cells Activation of macrophages Dendritic cells migrate to lymph nodes to initiate adaptive immunity Adaptive Immunity - Infection cleared by specific antibody, T-cell dependent macrophage activation and cytotoxic T cells
What are the natural BARRIERS to infection?
Skin, Mucosal epithelial surface of respiratory GI and Urogenital tracts