introduction to immunology - week 1 Flashcards
what is the main function of the immune system
the immune system has to defend against a wide range of hostile pathogens
what were the early vaccination strategies
- Edward Jenner in 1798, noted milkmaids who contracted and recovered from cowpox were immune to severe smallpox
He inoculated fluid from cowpox pustules to offer protection against smallpox.
Edward Jenner used pus (which he took from a dairy maid that contracted cowpox from a cow) as a vaccine for an 8-year-old James Phipps in 1798.
-Louis Pasteur observed that weakened pathogenic strains could provide protection against aggressive disease.
in 1891, Pasteur administered his first vaccination on a young boy named Joseph who got multiple rabid dog bites and the boy lived.
what is Elie Metchnikoff’s do
Metchnikoff observed, described and named the process of phagocytosis, which is ingesting foreign matter by white blood cells.
what is Paul Ehrlich’s side-chain theory
a variety of receptors (side-chain receptors) are expressed in blood cells which could bind to pathogens and inactivate them.
interaction between receptor and pathogen induces the cell to produce and release more of these receptors.
Ehrlich invented the term antigen.
an immune response is provoked if any substance is recognised as foreign by the immune system.
what is the definition of immunogenicity and reactivity
immunogenicity - the ability to provoke an immune response
reactivity - the ability to react with antibodies or T cells
what is the Host-Pathogen interaction
its a fine balance between the fighting force of immune system and virulence of a disease
what affects the outcome of the pathogen and host interaction
what affects the pathogen is:
- mechanisms of pathogenicity
- immune escape mechanisms
- number of pathogens
what affects the host:
- genes regulating immune response
- health of host
what are the primary organs
the primary organs are where immune cells are formed or matured, these include:
- bone marrow
- thymus
what are the secondary organs
the secondary organs are where immune cells work
for example, the spleen where blood-borne diseases occur
where do the cells of the immune system develop
the cells of the immune system develop from a stem cell in the bone marrow
what cells are in natural immunity and specific immunity
the cells in natural immunity are:
- Granulocytes, which include:
> neutrophils
> eosinophils
> basophils
- monocytes
- natural killer cells
the cells in specific immunity lymphocytes are:
- T lymphocytes
- B lymphocytes
what are neutrophils
they are
inflammatory cells,
first on the scene
phagocytes
what are monocytes/ macrophages
they are
wound-healing cells
opsonisation
antigen-presenting cells
phagocytosis
what are eosinophils
they are increased in allergy response
they produce major basic proteins that are toxic to helminth
what are basophils/ mast cells
they are increased in allergy response
inflammatory cells
what activities do activated complement proteins engage in
-they engage in the inflammatory response
- they adhere to microbial surfaces to attract phagocytes
- they puncture holes in the cell membrane so water can flood in and bust the cell
- they help clear antibody-antigen complexes that could otherwise cause inflammatory damage to tissues.
what are the 2 arms of adaptive immunity
- humoral which is involved in the production of antibodies by activated B cells
- cell mediators which involve activated T-cells
what are the 2 types of T-cells
1 - cytotoxic T cells which kill infected host cells
2 - helper T cells with the production of cytokines promote:
> antibody production of B cells
> activate macrophages to kill intracellular pathogen like phagocytosis
what is innate immunity
innate immunity is:
- epithelial barriers
- anti-microbial peptides
- phagocytes
- complement system
- acute phase reactants
- natural killer cells
what is adaptive immunity
adaptive immunity relies on the function of T and B lymphocytes:
- B cells produce antibodies
- T cells can either kill (cytotoxic), help or suppress
what do cytokines do
cytokines are immunological ‘hormones’ and they do the following:
- stimulate the immune system
-regulate immune system activities
-activate inflammatory cells
-stimulate the production of different blood types in bone marrow
-anti-viral activity
- inhibit certain cell types, e.g. tumours
what are active and passive immunity
active immunity
immunity following the disease or vaccine
passive immunity
immunity donated from another individual, e.g. mother to fetus
what is B-lymphocyte and T-lymphocyte receptor
B-lymphocyte
their antigen receptor is on the cell surface and is membrane-bound immunoglobulin.
plasma cell release immunoglobulin into the body fluids.
T-lymphocyte
the T-cell receptor recognises the antigen
The T-cell receptor is membrane-bound but is not secreted into body fluids.
what are the 4 properties (4 R’s) of specific immunity
the 4 R’s of specific immunity are:
- recognition of the foreign antigen
- response, which is provoked by highly specific antigens, then mounted for elimination
-remembers
immunological memory is built through multiple exposures to the same antigen
-regulates
once the infection load is reduced, the immune response diminishes
what happens in innate immunity (0-4h)
infection by pathogen –> action of innate effectors ( innate effectors are immune cells and soluble molecules involved in the immune response) –> removal of pathogen
what happens in early induced response (4-96h)
infection by pathogen –> recruit innate effectors –> activation of innate effectors –> removal of pathogen
