IMM250H1 Study Guide - Midterm Guide: Cytoplasm, Bacteroidetes, Aspirin

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Published on 25 Feb 2015
School
UTSG
Department
Immunology
Course
IMM250H1
Professor
IMM250 MIDTERM NOTES
LECTURE 1 - THE IMMUNE SYSTEM, A HISTORICAL PERSPECTIVE
Immunology: The study of the immune system
The immune system: a system if cells, tissues and their soluble products that recognize, attack, and
destroy entities that can endanger our health if and when they enter our bodies
Immunity: the quality or state of being immune; a condition of being able to resist a particular disease
The Black Death/Bubonic Plaque shaped how we think of pandemics
oResponsible for killing 30-60% of all Europeans from 1350-1400
oEurope’s population did not recover until 1550
oPlague was thought to spread through trade routes; migrations to cities resulted in further
disease propagation
oRats carried the fleas which harbored the bacteria
oFarmers were affected by the disease and therefore food supplies were cut off, causing
starvation
oMongol Empire collapsed in Central Asia as a result of the black death
oIn the absence of a mechanism, superstitious views dominated
oCivic services were shut down and to keep up peasants were further taxed; peasant revolt in
1371; education and architecture put on hold
oSurvivors of the Black Death may have had immunological advantage
oSurvivors may have benefited from greater resources due to the mass deaths
2000 BC: The Babylonian Epic of Gilgamesh
oAccounts of disease and pestilence
oUnderstood that disease came upon a population and wrecked havoc
oAn early connection between contagion and immunity
oThucydides , Ancient Greek general and historian reported the concept of immunity after
exposure to disease during a plague outbreak in Athens in 430 BC
Term immunity not yet used, no concept of causes of disease
oProcopius , a scholar in 6th century Roman Empire, made another recorded observation relevant
to disease resistance after witnessing a horrific plague
Term immunity not yet used, no concept of causes of disease
oGiralamo Fracastro , in 1500 Italy, studied epidemic diseases or “contagion” and witnessed the
Black Death in Europe
First time the term “immune” is used
oBelieved they were caused by invisible atoms/seeds that could travel great distances to infect
people (this was false)
We understood at this point that if we survived a disease, we would become immune
What doesn't kill us makes us stronger
Imbalance of humors thought to cause disease (ex// too phlegmatic, not choleric enough, etc.)
What caused disease and immunity still unknown in the 1500s
Treating diseases thought to be dependent on the imbalance of “humors(“humor” = medieval term for
body fluid)
Smallpox: one of the greatest plagues known to civilization
oHighly contagious, causes fever and eruption of small fluid-filled vesicles on the skin (pocks)
oAmong oldest known infectious enemies
oOften killed of the population
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oSurvivors were scarred and often blinded
The practice of variolation: “The Royal Experiment”
oIn the 1700s in Europe up to 400k people a year were dying of smallpox
oVariolation: Started in China (1000 AD), picked up by English royalty
oInoculation of someone with material from a smallpox (variola) pustule to produce immunity to
the disease
oIn 1721 England, urging by Lady Mary Wortley and others resulted in variolation of her own
daughter and members of the royal family
oBecame common amongst upper classes
oBut, variolation remained hazardous: use of virulent strains resulted in disease and even death
(not enough control)
Moving away form variolation:
oEdward Jenner , 1800 - the father of immunology
oHis theory: exposure to harmless, related cowpox protects against smallpox
oNoted that milkmaids don’t often contract smallpox and theorized they were immune
oInoculated 8 year old James with the pus from the cowpox blisters from Sarah Nelmes (a
milkmaid who caught cowpox from the cow Blossom)
oJenner then exposed James to variolation and he did not develop symptoms  immunity
Further advances in immunization would require an understanding of mechanisms
oStill no understanding of germs or infectious disease
oStill no understanding of immune responses
oNo progress in immunization against other diseases
The Germ Theory of Disease
o1880s: Louis Pasteur, Robert Koch and others began to isolate and characterize organisms that
could only be seen under a microscope
oThese medical scientists were the ‘fathers of microbiology
1884: Koch proposed the Germ Theory of Disease:
oMicrobes are organisms too small to be seen by eye, and some cause illness, which are called
‘pathogens’
oMicrobes include bacteria, viruses, parasites, fungi
oA given pathogen causes a specific illness
oEx// he found that anthrax was caused by a bacteria he named Bacillus anthracis
Koch’s postulates establish a cause-and-effect relationship between a microbe and a disease
1) The microorganism must be found in abundance in all organisms suffering from the disease, but
should not be found in healthy animals
2) The microorganism must be isolated from a diseased organism and grown in pure culture
3) The cultured microorganism should cause disease when introduced into a healthy organism
4) The microorganism must be re-isolated from the inoculated, diseased experimental host and
identified as being identical to the original specific causative agent
Only one that isn’t true - some pathogens develop quicker and can look different
oEx// The flu:
1) If we have the flu, we should find the influenza virus in us
2) Virus can be cultivated
3) If given, virus will cause disease
4) The given virus should be the same disease if extracted
But, some pathogens will mutate so 4) is not 100% true
Microbiology and immunology became related fields of study
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Contagious diseases like Black Death and smallpox were understood to have infectious causative
agents that could be isolated and characterized
oEx// bubonic plague caused by the bacteria Yersinia pestis, smallpox caused by the virus Variola
major
Suggested the state of ‘immunity’ that allowed people to be exempt from disease was due to a
response that an individual made to the associated microorganism  an immune response
Pasteur extended the immunization approach of Jenner
oImmune response made by an individual to the relatively weak cowpox virus protected them
against the related but highly virulent smallpox virus
oNot all germs and bacteria have a similarly related “cousin” that can be used to immunize
humans (as with cowpox and small pox)
oPasteur’s question: Is there a way to take the original pathogen and modify it to then use it for
immunization?
oModifying it to make us less likely to become sick: attenuation
Saves time to find some other cousin
oDiscovered this by accident while culturing cholera
oTechnician let the culture spoil; bacteria overgrew and died
oPasteur kept the bacteria and used it as a vaccine and immunized chickens
oSimilarly for other diseases, inoculation with a weakened or
‘attenuated’ form of the causative microbe would not cause disease
but could protect the recipient against future exposure to the natural
form of the microbe
oAlso used the same principle to immunize sheep against anthrax and
humans against rabies
oCalled the approach ‘vaccination’ to honor Jenner’s seminal work with
cowpox (‘vacca’ is Latin for ‘cow’)
oVaccinations are born
The advent of vaccines meant that many infectious diseases could now be controlled
Late 1800s: vaccines against smallpox, cholera, typhoid, plague
oBefore 1800's all about chance and hope not to die of disease
oNow we have more control; only allows immunity to a specific pathogen
1900 – 2000: 25 more vaccines developed for various infectious diseases
Importance of vaccination
oSmall pox vaccination started in 1796
oIn 1979 WHO declared virus had been eradicated because of the vaccine
oCost of smallpox eradication: $300 million
oIn 1985, as a result of money saved on prevention and treatment efforts, the U.S. estimates that
it recoups its investment in smallpox eradication every 26 days
oVaccinations have nearly eliminated diseases that were once common among children
(measles, mumps, diphtheria, etc.)
Numbers start to creep up again due to parents who choose not to vaccinate children
Older children infect children who have been unable to get their vaccination
oApproximately 5 in 400,000 children born in Canada each year will experience a severe reaction
to a vaccine
oMMR (Measles Mumps Rubella) vaccine is the most controversial. A small study of less than
20 children examined a link with autism. This study has been since thoroughly debunked
Innate immunity: one organism can deflect another organism
Variolation VS. Vaccination
-Variolation: refers SOLELY to the
inoculation of SMALLPOX
-Vaccination: inoculant material is NOT a
viral human pathogen
-This can still facilitate a small reaction
(like fever) as we see today but we don't
succumb to disease
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Document Summary

Lecture 1 - the immune system, a historical perspective. Immunology: the study of the immune system: the immune system: a system if cells, tissues and their soluble products that recognize, attack, and destroy entities that can endanger our health if and when they enter our bodies. 1371; education and architecture put on hold: survivors of the black death may have had immunological advantage, survivors may have benefited from greater resources due to the mass deaths. , ancient greek general and historian reported the concept of immunity after. Term immunity not yet used, no concept of causes of disease: procopius to disease resistance after witnessing a horrific plague. , a scholar in 6th century roman empire, made another recorded observation relevant. Term immunity not yet used, no concept of causes of disease: giralamo fracastro. , in 1500 italy, studied epidemic diseases or contagion and witnessed the.

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