Post on 17-Dec-2015
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Acquired Immunity• Natural Immunity
– Acquired as part of normal life experiences
• Artificial Immunity – Acquired through vaccination
• Active Immunity – Results when a person is challenged with Ag that stimulates production of Ab– Memory
• Passive Immunity – Preformed Ab are donated to an individual– Acts immediately but is short term– No memory
• Breast feeding• Gamma globulin• Monoclonal antibodies
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Vaccines• Provide an antigenic stimulus that does not cause disease
– Attenuated strain• Tissue culture or unnatural / unusual host• Hypovirulent
– Dead whole cells or inactivated viruses• Heat, formalin, UV irradiation
– Purified antigen subunits from cells or viruses– Surface antigens produce via rDNA technology– DNA vaccines
• Produces long lasting protective immunity• Edward Jenner (page 476)
– www.sc.edu/library/spcoll/nathist/jenner2.html– Cowpox – Smallpox
• Variola – Controlled experiments
• Vaccinia virus– Cultured cow pox virus for many years
• Small pox eradicated in 1973
Why did the vaccinia viruswork?
Immunization using a closely related, less pathogenic organism to give protection against a more pathogenic one.
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Vaccination Success•Small pox
• 2 million people a year died from small pox until 1967 • The World Health Organization initiated an immunization campaign that eradicated small pox in 12 years
•Poliomyelitis (polio)
• This virus attacks the motor neurons of the brain and spinal cord• Causes paralysis and death• Immunization campaigns since the 1950s have virtually eradicated polio in developed countries
www.who.int/immunization_safety/en/www.cdc.gov
news.bbc.co.uk
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• Haemophilus influenzae type b – Mistakenly believed to have
caused influenza – Type b strains accounted for
majority of bacterial meningitis
• Meningitis, pneumonia, and epiglottitis
• Was the leading cause of bacterial meningitis of children 5 years or younger– 1/200 children contracted Hib– Incidence has decreased 99%
since the vaccine was introduced
www.cdc.gov
20,000 cases per year in the early 1980’s
1,247 in 2000
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Vaccines cause diseaseDisease is no longer a threat in my countryCost of vaccination Difficulty reaching vaccination centerNot recommended by my physicianSafety concerns
Side effectsSIDS
Autism Depress the immune system
Mercury PoisoningReligious beliefs
www.who.int/immunization_safety/aefi/immunization_misconceptions/en/index.html
Herd ImmunityProtection from a disease among unvaccinated individuals occurs when 90% of a population is immunized.
% depends on the disease & vaccine
Content and Design Attributes of Antivaccination Web Sites Robert M. Wolfe, MD; Lisa K. Sharp, PhD; Martin S. Lipsky, MD
JAMA 2002 287:3245-3248.
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Polio Outbreak Occurs Among Amish Families In Minnesotaby David BrownWashington Post Staff WriterOctober 14, 2005The first outbreak of polio in the United States in 26 years occurred earlier this fall in an Amish community in central Minnesota, state and federal health officials reported yesterday. Four children have been infected with the virus, although none has become paralyzed. The Amish typically decline to vaccinate their children. The last large outbreak of polio occurred in numerous Amish communities in several states in 1979.Fears Rising Over Measles Outbreaks by ROBERT A. HAMILTONSTATE health officials are preparing for what they fear could be ''a major outbreak'' of measles when students who attend Boston University return home next week for spring break. Last week, a measles case was reported in Fairfield, an 18-year-old Boston University freshman who returned home eight days ago with cold symptoms and by Tuesday was in the hospital. ''We expect a lot more students will be returning to Connecticut next week, for the spring break,'' the program director of the state immunization program, Dr. Charles H. Alexander, .
March 3, 1985 The New York Times
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Serology• A part of immunology
that attempts to detect signs of infection in a patient’s serum – Use Abs that
specifically bind to Ag• Ag-Ab reactions are
visible by– Clumps– Precipitates– Color changes – Release of radioactivity
• The most effective tests have high specificity and sensitivity.
leukocytes
AbsProteinsClotting factorsHormonesNutrientsIons
Clear fluidfrom clottedblood
Isolate Ab from serum
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Agglutination Test
• Ab and Ag from a whole cell crosslink
– Forming complexes that settle out and from visible clumps in the test chamber
Isolate Abs frompatient
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Precipitation Tests
• Soluble Ag is precipitated– Cloudy or opaque
zone– Many variations are
used to maximize this technique
– Measure optical density
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Enzyme-linked immunosorbent assay (ELISA)
• Detect unknown Ag or Ab
• A positive result is visualized when a colored product is released by an enzyme-substrate reaction
Anti-immunoglobulin Ab complexed to an enzyme
conjugate
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Perform a virtual ELISA courtesy of the Howard Hughes Medical Institute www.hhmi.org/biointeractive/vlabs/
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ELISAwww.biology.arizona.edu
Positive Rxn Negative Rxn Positive
Control Negative
ControlPatient A Patient B Patient C
Assay Control
1.689 0.153 0.055 0.412 1.999 0.123
+ is 0.5 or greater
Indeterminate0.300 – 0.495
- is 0.300 or less
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• More sensitive than ELSIA– Less chance of a false +
• Detects specific Ag or Ab proteins in serum• Separates proteins into bands via gel electrophoresis• Protein bands are transferred to a membrane• Specific Abs are used to “probe” the membrane
– Primary Ab are from patient– Secondary Ab
• Anti-immunoglobulin Ab complex to an enzyme – Colorless substrate
• Colormetric
Western Blot Western Blot for a HIV on page 487
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Western Blot for HIVwww.biology.arizona.edu
gp160 viral envelope precursor (env)
gp120 viral envelope protein (env) binds to CD4
p24 viral core protein (gag)
p31 reverse transcriptase (pol)
Serum proteins (virus) separated via electrophoresis.Transferred to a membrane.
The primary Abs from the serum of a patient is added and will react to the HIV proteins (above).
The secondary Ab is an anti-immunoglobulin conjugated to an enzyme. This Ab is specific for the
primary Abs.
A colorless substrate is cleaved if the anti-immunoglobulin conjugated to the primary Ab.
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Band Pattern Interpretation Lane 1, HIV+ serum (positive control) Lane 2, HIV- serum (negative control) Lane A, Patient A Lane B, Patient B Lane C, Patient C
No bands present - Bands at either p31
OR p24 AND bands present at either gp160 OR gp120
+
Bands present, but pattern does not meet criteria for positivity
Indeterminate
Patient A is –Patient B is –Patient C is +
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• Fluorescent Ab (FAbs) either directly or indirectly to visualize cells or cell aggregates
Immunofluorescence
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Monoclonal Antibodies (Mab)• Single specificity antibodies
formed by fusing a mouse B cell with a myeloma cell– A malignant tumor formed by the
cells of the bone marrow
• Used in diagnosis of disease, identification of microbes and therapy
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• Immunize animal• Harvest spleen• Fuse B & myeloma • Hybridoma
• Immortal• Screen hybridomas for Abs directed against antigen of interest
• Hybridomas produce antibody that recognize single epitope• Produce uniform, highly specific Ab in large supply
• Multiple practical applications • Diagnostic tests
• ELISA & Western Blots• Immunosuppressive therapy for transplants
• Prevent action of TC
• Anticancer drugs• Antitoxins• Identify a pathogen• Purification of an important protein
• Precipitate
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ZenapaxPrevent rejection in organ transplantation, especially in kidney transplants.
MylotargAcute myeloid leukemia (AML)
RemicadeAuto-immune disorders like Crohn's disease and rheumatoid arthritis
Target is tumor necrosis factor
RituxanTreat a variety of non-Hodgkin's lymphomas.
Target and destroy non-Hodgkin's lymphoma cells.
Monoclonals on the Market
Herceptin Blocks the effects of the growth factor protein HER2, which transmits growth signals to breast cancer cells.
Causes tumor shrinkage.
Additional information at www.fda.gov