1. The
Immune
System
Some images courtesy of Steve Taylor…Bandung Intl. School
2.
3. PATHOGENS
• The immune system responds to the
presence of proteins not made by the
body.
• These proteins are called antigens.
• An antigen that causes a disease is
called a pathogen.
• Pathogen = disease causing
organism.
6. Method of Transmission
know a disease for each
• Air – “droplets”
• Direct contact – physical contact
• Through food
• Cuts in the skin
• Infected needles
• Blood transfusion
• Animals and Insects
12. Worms
• Worms are usually
ingested as eggs
• Found in minute
particles of feces
• Eggs hatch into larvae
• Can migrate out of the
intestines
13. Antibiotics
• Bacteria vs. Virus
– Act against specific chemicals or chemical
pathways in prokaryotes.
– DO NOT affect Eukaryotic cells.
– Viruses are “intracellular” parasites that
uses the host cell
– Drugs used against them also compromise
human cells (chemotherapy)
19. Second Line of Defense
Counterattack!!!!!...will kill absolutely anything!!!
CELLS THAT KILL INVADING MICROBES:
Phagocytes:
• Recognize chemical receptors on foreign invaders – often
proteins
• Identifies and destroys pathogens: endocytosis: form
vacuole fuse with lysosomes and are digested
• Work in the blood – push through capillaries into tissue
– Work to control infection
– Causes visible inflammation, heat, pus, fever (not over 105)
22. Interferon
• Protein
• Released by cells
infected with
viruses
• Combines receptors
on healthy cells to
produce antiviral
enzymes.
• Inhibit protein
synthesis in viruses
23. Third Line of Defense:
Mounting a Specific Defense!!!!
• The type of WBC that make up the
“specific” immune system:
• Antibodies – specific protein produced by
Lymphocyte:
» T – Cells
» B – Cells
Travel in blood and lymph
Produced in bone marrow
» T – cells mature in the thymus (behind the sternum)
» B – cells mature in bone marrow
• Antigens – foreign substances that
stimulate antibody production
24.
25. T and B Cells
• T Cells – several types
– Activate B cells (t-helper)
– Destroys toxins (t-killer)
– Stops immune response (t-supressor)
• B Cells –
– produces specific antibodies for antigens
Monoclonal Selection
– Production of the same antibody (proliferation)
from the original antigen-antibody complex.
– Can be referred to as “memory cells’
26. Immune System Disorders
AIDS – Acquired Immune Deficiency Syndrome
• Retrovirus – RNA as its genetic material
• RNA is transcribed into DNA
• Reverse Transcriptase
28. HIV
• Human Immunodeficiency Virus
• Attacks “Helper” T – Cells.
• Process:
• T – cells and HIV antigens bind
• HIV virus enters and replicates.
• T – cell ruptures releasing new viruses
• Viruses infect other T – cells
• Virus increases & T cells decrease
• Without Helper T- cells , lymphocytes cannot
form to produce antibodies.
• No Antibodies…the pathogen survives
30. AIDS - transmission
• Sexual relations – all forms
– Transmitted through small tears in soft tissue
• Sharing needles –drug use
• Contaminated blood transfusions
• Accidents
• Tattoos and Piercings
31.
32.
33. HIV DATA - THE WORLD
• Gapminder: Unveiling the bea
34. HIV – Social Implications
• The vast majority of cases are in Africa, with
rapid increases in Asia and Central America
• changes in sexual behavior
• unease over blood transfusions
• ostracizing
• breakdown of family structure
– huge loss in work force
– drugs are available to control effects of HIV, but cost is high
– poor families have limited resources, and are impoverished by
the cost of drugs
• huge drain on medical resources
• poor nations have little drug availability
