Immunity and Infection -...
Transcript of Immunity and Infection -...
Immunity and Infection Mr. Nagel
Meade High School
Think…
• What are the sources of illness in living organisms?
• What aspects of your body keep you healthy and resist these infections?
IB Syllabus Statements • 6.3.1
– Define pathogen. • 6.3.2
– Explain why antibiotics are effective against bacteria but not against viruses. • 6.3.3
– Outline the role of skin and mucous membranes in defence against pathogens. • 6.3.4
– Outline how phagocytic leucocytes ingest pathogens in the blood and in body tissues. • 6.3.5
– Distinguish between antigens and antibodies. • 6.3.6
– Explain antibody production. • 6.3.7
– Outline the effects of HIV on the immune system. • 6.3.8
– Discuss the cause, transmission and social implications of AIDS. • 11.1.1
– Describe the process of blood clotting. • 11.1.2
– Outline the principle of challenge and response, clonal selection and memory cells as the basis of immunity. • 11.1.3
– Define active and passive immunity. • 11.1.4
– Explain antibody production. • 11.1.5
– Describe the production of monoclonal antibodies and their use in diagnosis and in treatment. • 11.1.6
– Explain the principle of vaccination. • 11.1.7
– Discuss the benefits and dangers of vaccination.
• http://click4biology.info/c4b/6/hum6.3.htm
Pathogens and Antibiotics
• What makes us sick? – Bacteria, viruses, protists, fungi, parasites
• Why do we use antibiotics? – ANTIBIOTICS: Block metabolic pathways. – Flavors
• Bacteriocidal and Fungocidal (KILL KILL KILL!) • Bacteriostatic and Fungostatic (cease growth)
– Think: “Tactical Nukes” – Why won’t they work on viruses?
Primary Defenses (non-specific)
• Epithelial cells – Skin
• Epidermis (keratin) - surface with tougher cell walls • Dermis – lower layer with hairs, capillaries, and
sensory receptors – Mucous-covered tissue
• Cilia propel mucous from inside the longs to the epiglottis, where it is swallowed and bathed in acid
Secondary (non-specific)
• Phagocytic white blood cells – Macrophages “eat up” invaders (phagocytosis) – Think “Jabba the Hutt”
• Inflammatory Response – Secretion of chemical signals dilates and increases
permeability of capillaries • ex: histamine
– This allows blood clotting factors and phagocytes to respond to the ‘site of activity’
Tertiary Defense (Specific)
• Antigens – foreign molecule eliciting a response from B and T cells (white blood cells) often found on the outside surface of a cell – Ex: Blood types present various antigens
• Antibody (immunoglobulin or Ig) – secreted proteins by B cells in response to foreign molecules (“paint target”) – 2 heavy chains, 2 light chains
http://anthro.palomar.edu/blood/ABO_system.htm
Antibody Creation
• All blood cells come from Bone Marrow – B cells mature in the Bone Marrow – T cells mature in the Thymus
• Antigens stimulate B-cells to secrete additional antibodies AND also to produce Memory B-cells for subsequent infections
P 848, Campbell Biology
H.I.V. and A.I.D.S.
• HIV disables lymphocytes (B and T cells) • No ability to present antigens to T-cells • Immune system does not ‘counter’
infection because it does not believe it is under attack
• AIDS – Acquired (HIV transmission) – Immunodeficient (cannot be resisted) – Syndrome (manifestation of disease varies)
Why should we care about AIDS?
Vaccination – Why?
Odds and Ends
• Blood Clotting – http://users.rcn.com/jkimball.ma.ultranet/Biolo
gyPages/C/Clotting.html • MAB’s (Monoclonal Antibodies)
– http://www.cancer.org/docroot/ETO/content/ETO_1_4X_Monoclonal_Antibody_Therapy_Passive_Immunotherapy.asp
Loose Ends
• Viroids – Raw RNA that attacks plants – Why not animals?
• Prions – Malformed protein that alters surrounding
protein (ie Mad Cow)
Griffith
Hershey/Chase
Transformation/Transduction
• What does it mean to be transformed? – What is a transducer?
• How can information travel from one cell to another, even if it is killed?
• Can viruses be responsible for transferring the information?
• Notation: arg+ trp-
Transduction
• Describe the process of blood clotting. • Outline the principle of challenge and response,
clonal selection and memory cells as the basis of immunity.
• Define active and passive immunity. • Describe the production of monoclonal antibodies
and their use in diagnosis and in treatment. • Discuss the principles of vaccination. • Discuss the benefits and dangers of vaccination.