Zusammenfassung der Ressource
Immunology
- Vaccination
- Features of a successful vaccination
program
- Few side-effects
- Means of producing, storing
and transporting available
- Means of administering
vaccine available
- All vulnerable population vaccinated
- Problems with controlling cholera
- Intestinal disease- not easily
reached by immune system
- Antigenic variability
- Mobile populations spread cholera
- Principles
- Weakened/mutated
pathogen injected
- Stimulates immune response and production of antibodies
- Immunological memory - faster
response to future infections
- Ethics
- Use of animals in
development of
vaccines
- Could have
side-effects/cause
disease
- Human trials
- Problems with
controlling TB
- HIV - more people with
impaired immune systems
- Body kills bacterium
before antibodies produced
- Ageing populations - older people have
weaker immune systems
- Antibodies
- Proteins synthesised
by B cells
- Quaternary structure: two heavy
chains and two light chains
- Held together by disulfide bonds
- Variable and constant regions
- Antigen-binding sites:
antigen-antibody complex is formed
- Monoclonal antibodies: produced from a
single clone of B cells
- Formed by hybridisation with
cancer cells
- Number of useful functions
- Immunoassay (e.g.
pregnancy testing kits)
- Cancer treatment
- Transplant surgery
- B cells and cell-mediated
immunity
- 1. B cells take up suface antigens of pathogens
and present them on the membrane
- 2. Activated T helper cells bind to antigens
and activate the B cells
- 3.B cells divide by mitosis and specialise into one of
two types of cells:
- Plasma cells produce antibodies.
- Agglutination (clumping) of pathogens
facilitates phagocytosis
- Cause lysis of pathogens
- Memory cells store an immunological
memory of the antigen.
- Secondary immune response:
greater and faster antibody production
- Phagocytosis: the non-specific
immune response
- 1. Macrophage attracted
to pathogen by
chemoattractants
- 2. Macrophage binds to
pathogen and engulfs it,
forming a phagosome
- 3. Lysosome fuses with
phagosome to form a
phagolysosome
- 4. Digestive enzymes break
down the pathogen
- T cells and cell-mediated
immunity
- T cells mature in the thymus gland.
- T cells carry out cell-mediated immunity:
- 1. Pathogens invade
body/ingested by phagocytes
- 2. Phagocyte presents antigens on its cell
membrane
- 3. T cells have complementary
receptors which bind to the antigens
- 4. The T cell then divides rapidly by
mitosis.
- Roles of cloned T cells
- Developing into memory cells for
faster secondary response
- Stimulating phagocytosis
- Producing interleukins, which
stimulating B cells to divide
- Killing infected cells
- Perforin makes holes in cell
membrane of infected cells - they
become freely permeable and die