Who Knew The Flu and YOU By Christine
Who Knew? The Flu and YOU! By: Christine Antler and Erin Boyle
COLD FLU Stuffy or runny nose Fever Sneezing Headache Sore Throat Fatigue, extreme exhaustion, weakness Cough
The Influenza Virus
What the heck is a virus? • NOT a bacterium • Very, very small • Simple: genetic material wrapped in protein shell • Must have living cell (host) to survive and replicate
Influenza Structure Hemagglutinin 8 RNA segments Neuraminidase
Influenza Replication HHMI movie http: //www. hhmi. org/grants/lectures/biointeractive/animations /infection/inf_middle_frames. htm
Your Immune System: Under Attack! • Keeps you healthy • Defends ����your against invaders • Can sense what’s normal (self), and what isn’t (non-self)
The Good Guys: B cells
Y Y How the immune system targets influenza Y Y Y Y
Lights Out for Influenza! Y Y Y MACROPHAGE Y Y
Just like an elephant, B cells remember! • Immunity: stronger and faster response
It’s like an Army. . .
Influenza Can Hide From the Immune System! • Influenza alters its spike or knob proteins • Memory B cells can’t recognize it anymore old neuraminidase old hemagglutinin new neuraminidase new hemagglutinin
How Influenza Changes Its Surface Proteins Small Changes = Drift
How Influenza Changes Its Surface Proteins Big Changes = Shift
Influenza Reassortment HHMI movie http: //www. hhmi. org/grants/lectures/biointeractive/animations /subunit/sub_middle_frames. htm
Prevention and Treatment of Influenza
Vaccines. . . Ouch! • Expose immune system to a defective virus or viral component • Immune system responds and is then ready for next infection IMMUNITY
Vaccine Production Live virus is injected into fertilized hen’s egg Virus replicates as embryo develops Virus-containing fluid is harvested from egg
Vaccine Production http: //www. brown. edu/Courses/Bio_160/Projects 1999/flu/vaccin es. html
Killed Vaccines • Also called inactivated vaccines • Virus is killed by injecting a chemical into the egg • Immune system senses virus, but virus is unable to replicate and spread
Live Vaccines • Also called attenuated vaccines • Virus is still alive, but can’t cause disease
Live Vaccines Cont’d Flu. Mist™ nasal spray (under development) • Virus designed to grow best at colder temperatures • Flu virus weakened at body temperature
There must be a better way!!!
Subunit Vaccines • H (spikes) and/or N (knobs) proteins only • ���Genetic engineering: produce H and N proteins using bacteria or yeast • H and N cause immune response
DNA Vaccines H gene (DNA) Inject into human Y Y Human cells produce H protein Immune response to H protein
Why do you need to get a new vaccine every year? Influenza alters its H and N all the time!
Drugs target either H or N and inactivate them
Inhibitors NEURAMINIDASE (N) HEMAGGLUTININ (H) Virus can enter host cells Virus cannot leave host cell - Decreased spread of infection Decreased infection Zanamivir and Oseltamivir Amantadine and Rimantadine
Summary • Influenza uses H and N proteins to infect cells • Body develops immunity after fighting off the virus • Influenza changes its H and N to avoid detection • Vaccines trick body into developing immunity • Antiviral drugs inhibit H and N
References and Resources WEBSITES RELATED TO INFLUENZA: http: //www. niaid. nih. gov/publications/cold/sick. pdf http: //www. med. sc. edu: 85/lecture/images/aviron. jpg http: //www. asap. unimelb. edu. au/hasn/no 32/images/csleggs. jpg http: //www. glycoforum. gr. jp/science/word/gif 0009/gd-a 06 e. jpg http: //medyred. sureste. com/fotos/influenza. jpg http: //www. sciam. com/2001/0201 issue/IMG/working_2. gif http: //rex. nci. nih. gov/PATIENTS/INFO_TEACHER/immune_sys/Title. html http: //www. odomnet. com/vaccines/introduc. htm http: //www. uct. ac. za/depts/mmi/stannard/virarch. html http: //www. niaid. nih. gov/newsroom/focuson/flu 00/background. htm http: //www. brown. edu/Courses/Bio_160/Projects 1999/flu/vaccines. html http: //129. 252. 124. 240: 85/mhunt/flu. htm www. accessexcellence. org/AE/AEC/CC/vaccines_how_why_html
References and Resources WEBSITES RELATED TO INFLUENZA CONT’D: http: //www. tamiflu. com/ http: //www. people. ku. edu/~jbrown/flu. html http: //www. people. ku. edu/~jbrown/virus. html http: //www. cdc. gov/ncidod/eid/vol 4 no 3/webster. htm http: //www. hc-sc. gc. ca/pphb-dgspsp/fluwatch/index. html OTHER WEBSITES: http: //www. allenshea. com/gifs/disguise. gif http: //www. hemophiliagalaxy. com/1_patients/encyclopedia/images/dna. gif http: //pbskids. org/lions/words/images/hen. gi http: //www. army. mil/ http: //www. oaklandzoo. org/atoz/azeleph. html http: //www. leirpoll. com/rubber. htm
References and Resources BOOKS: Textbook of Influenza. K. G. Nicholson, R. G. Webster, and A. J. Hay. 1998. Blackwell Science Ltd. , London. The Invisible Enemy: A Natural History of Viruses. D. H. Crawford. 2000. Oxford University Press, Oxford. The Transmission of Epidemic Influenza. R. E. Hope-Simpson. 1992. Plenum Press, New York.
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