Immunology Flashcards
Where are antibodies found and what’s their function ?
They are proteins founds in the serum
They are produced after they come into contact with an antigen and bind specifically to the antigen
B cells secrete them (as antibodies are on the surface, B cells use them as an antigen receptor )
What are CD79?
Transmembrane molecules that transduce activation signals to the B cell and are required for the expression of membrane iG
B cell markers.
In antibodies there are how many types of heavy chains?
5 types of heavy chains (made of 450-600 amino acid)
The type of heavy chain determines the antibody class (isotype)
2 types of light chain: Kappa or lambda (made of 230 amino acids)
What is the main antibody in the secondary immune response?
IgG-
Transferred across the placenta to prove immunity in neonatal life
Activated complement classical pathway
Acts as opsonin by cross linking immune complexes to F.C. receptors on neutrophils
What Is complement?
Group of molecules found in the serum whose role is to control inflammation
Remove immune complexes
Lysis of pathogens or cells sensitised by antibody
What is cytokines?
Signalling proteins which signal between cells of the immune system ( interleukins, interferons, tumour necrosis factors, transforming growth factors, colony stimulating factors
What are interferons?
Group of molecules that limit the spread of viral infections
There’s 3 types-
IFN-a and IFN-b are produced by white blood cells and fibroblasts
IFN-y produced by activated T cells and natural killer cells
What kind of proteins do interferons make?
Interferons from activated or virally infected cells bind to receptors on nearby cells causing them to make antiviral proteins
What do antiviral proteins do?
Limit viral replication
Many are inactivated and become activated in infected cells by contact with viral products
Activated viral proteins-
Block protein synthesis
Cause mRNA degradation (reduce viral protein synthesis)
What are the primary lymphoid organs of the immune system?
Bone marrow and thymus.
Where are B and T cells formed/B cells develop?
Bone marrow (primary organ)
Where do T cells develop and become trained so they don’t recognise self-antigens ?
Thymus (primary gland) (tolerant)
What happens in the secondary organs?
Organs in which mature lymphocytes recognise antigen
What are the characteristics of secondary lymphoid organs ?
Lymphoid
