Download Helper T cells

What do these
three pictures
have in common?
11.1: ANTIBODY
PRODUCTION &
VACCINATION
Any protein identified
as not self is known as
an antigen
BLOOD TRANSFUSION RECAP
http://learn.genetics.utah.edu/content/inheritance/blood/
http://highered.mheducation.com/sites/0072495855/student_view0/chapter21/
animation__cytotoxic__type_ii_hypersensitivity_.html
SPECIFIC IMMUNE RESPONSE
Also known as challenge and response.
Challenge - antigen on the invading pathogen
Response – immune response
Lymphocyte
General term for a WBC
Macrophage
WBC that engulf and digest
Helper T cells
Cytotoxic T cells
B cells/plasma cells
Clonal selection
STEP 1: MACROPHAGE
Engulf invading pathogen, digest and display antigen on their
surface.
This is now an
Antigen presenting cell
STEP 2: HELPER T CELLS
Helper T cells (lymphocyte) bind to antigens presented by the
macrophages
Signaling proteins stimulate the
replication of B cells (lymphocyte)
STEP 3: CYTOTOXIC T CELLS
Cytotoxic T cells bind to antigens presented on the surface of infected
cells and produced toxins which kill the infected cell.
STEP 4: B CELLS
Mature B cells (once activated by helper T cells) are known as plasma
cells.
B cells produce antibodies
Antibodies bind to antigens
so macrophages can easily
identify and destroy them.
STEP 5: MEMORY B CELLS
Not all B cells become plasma cells (and then produce antibodies)
some become memory cells that can survive for decades.
If a person is re-exposed to a antigen, there is a swifter/stronger
immune response aka secondary immune response.
HTTP://HIGHERED.MHEDUCATION.COM/SITES/0
072495855/STUDENT_VIEW0/CHAPTER24/ANI
MATION__THE_IMMUNE_RESPONSE.HTML
ROLES OF ANTIBODIES
Opsonization
Making the pathogen more visible.
Neutralization of virus &
bacteria
Can prevent viruses from binding to potential host
cells.
Neutralization of toxins
Also capable of binding to toxins, preventing the
toxins from causing more harm.
Activation of complement In other words, antibodies can swarm the
membrane of a pathogen, eventually causing
holes/pores in the membrane leading to lyse (cell
destruction).
Aggutination
Antibodies causing pathogens to ‘stick’ together
meaning they cannot enter cells and are easier to
digest.
The principles of immunity
Challenge and response
Immunity can only be developed once the immune
system has been challenged by an antigen
Clonal selection
As described on previous slides, immune system selects
and clones the most appropriate B lymphocyte cell
Memory cells
Provide long term immunity. Can only produce memory
cells after primary infection.
• Production of memory
cells
• Long-term immunity
• Acquiring antibodies from
another organism e.g.
• Mother  foetus, through
placenta. Memory cells are not
transferred.
• Antibodies from colostrum,
again no memory cells
transferred
• Injection via antisera (blood
serum with high antibody conc.)
IMMUNITY
We acquire immunity only when we either have the antibodies
capable of recognizing specific antigens or the memory cells
to produce the required antibody.
Figure 9, page 470 shows the difference between a primary
and secondary immune response. Sketch this graph and
describe what it shows.
VACCINATIONS
Vaccines contain antigens which trigger immunity but do not
cause the disease.
Vaccines usually contain a weakened (attentuated) version of
the pathogen or a derivative (something similar) with the same
antigen to stimulate a primary immune response.
https://www.youtube.com/watch?v=jJwGNPRmyTI
http://www.historyofvaccines.org/content/timelines/all
HISTAMINES
Histamine is a chemical produced by mast cells & basophils in
response to infection.
Histamine causes small blood vessels to dilate and become
‘leaky’  increasing the number of immune cells in a specific
area.
To lessen the affects of an allergic response – antihistamines can
be taken (allergy pills)
http://highered.mheducation.com/sites/0072507470/student_v
iew0/chapter22/animation__ige_mediated__type_1__hyperse
nsitivity__quiz_1_.html
USES OF MONOCLONAL ANTIBODIES
Complete activity, pg. 475, to explain how monoclonal
antibodies are used in pregnancy tests.
EPIDEMIOLOGY
The study of the distribution, patterns and causes of
disease.
http://www.who.int/entity/gho/en/
Look at the data for malaria, TB, polio or any
other disease that interests you. Are there any
trends you can see?
QUIZ NEXT CLASS
6.3, 11.1