A HISTORICAL PERSPECTIVE OF IMMUNOLOGY
- Immunity is the state of protection against foregin pathogens or substances
(antigens)
- Immunis (latin) - “exempt”
- Observations of immunity go back over 2000 years - in 430 BC, a plague
occurred in Athens where those who had recovered could safely nurse the
currently ill
- Immunity can be generated without inducing disease through vaccination
- Vaccination prepares the immune system to eradicate an infectious agent
before it causes disease
- Common vaccines include rabies vaccine and smallpox vaccine
- Chinese and Turks recorded the first attempts to induce immunity
- Was against smallpox
- Involved inhaling or inserting dried crusts from smallpox pustules into
small cuts in the the skin - variolation
- Edward Jenner developed the first vaccine in 1798 using cowpox pustules
- Pasteur developed the idea of an attenuated vaccine using heat treatment of
the rabies virus
VACCINATION AND IMMUNITY
- Goal of vaccination is to expose the individual to a pathogen in a safe way,
allowing the immune cells to respond and developing and honing a strategy to
fight this pathogen or others that are similar
, - Can produce extremely specific and long-lived memory cells
- Efficiency of vaccine depends on mutation and evolution rate of the virus
- HI virus mutates rapidly so developing a vaccine is difficult
- Rabies virus mutates slowly so one vaccine can be used to protect an
individual for decades
- Herd immunity - a critical mass of people acquires protective immunity either
through vaccination or recovery from infection and can serve as a buffer for
the rest
- Susceptible and non immune individuals can benefit from pervasive immunity
of their neighbours
- Eradication of a disease and end of universal vaccination can have a
downside
- Number of people with no immunity to the disease will begin to rise
- Herd immunity ends
- A weaponized version of the disease can be used as a potential
bioterrorism threat
HUMORAL AND CELLULAR COMPONENTS OF IMMUNITY
- Full immune response requires both cellular and humoral immunity
- Humoral immunity combats pathogens via antibodies
- Antibodies are produced by B cells
- Can be transferred between individuals to provide passive immunity
- Humoral immunity involves the soluble component that could neutralise or
precipitate toxins and could agglutinate bacteria
- Immunoglobulin is a fraction of this serum - contains active molecules called
antibodies
- Antiserum - antibody-containing serum fraction from a pathogen-exposed
individual
- Passive immunity includes the use of immune serum containing antibodies
against snake or scorpion venom to treat victims of certain poisonous bites or
stings
- Passive immunity is short lived and limited as the cells that produce these
antibodies are not being transferred
- Natural infection or administration of a vaccine is said to produce active
immunity
- Cell-mediated immunity involves primarily lymphocytes
- These can eradicate pathogens, clear infected self-cells or aid other
cells in inducing immunity
- Is a type of white blood cell
- Humoral and cell-mediated immunity relies on surface receptors (B- and T-
cell receptors)
- Receptors are randomly generated by gene segment rearrangements in B
and T cells
, - B cells that encounter an antigen produce the antibody specificity of their cell
membrane immunoglobulin
- Antigen - any substance that elicits a specific response by B or T lymphocytes
- Released B cells are called antibodies
- T-cell receptors bind specific peptides presented by MHC molecules
- Cellular immunity is imparted by T cells and the antibodies produced by B
cells confer humoral immunity
MAMMALIAN IMMUNE RESPONSE
- Pathogens - organisms that cause disease
- Pathogens fall into 4 main categories
- Viruses
- Bacteria
- Fungi
- Parasites
- Immune responses are quickly tailored to the type of organism involved and
depend on the structure of the pathogen and its location i.e. intra- or extra-
cellular
- Some areas are “off limits” to the immune system because an immune
response could do more damage than the pathogen e.g. the eye or CNS
,
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller ejnotes. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.51. You're not tied to anything after your purchase.