lecture 1 - introduction to immunology Flashcards
what are PRRs
Pattern Recognition Receptors (PRRs)
These are of two types: PAMPs – Pathogen-Associated Molecular Patterns
DAMPs – Damage-Associated Molecular Patterns
B cell antigen receptors bind to…
intact antignes
T cell receptors are made from …
two protein chains one alpha one beta
T cell receptors bind to
‘processed’ antigen fragments presented at cell surfaces
outline the features of strategy one on how cells use receptors to recognize danger
Molecular patterns
Hundreds of receptors
Germ-line encoded
outline the features of strategy two on how cells use receptors to recognize danger
Precise molecular structure
Millions of receptors
Generated by random recombination of gene segments
give examples of pamps
unmethylated cpg motifs, envelope glycoproteins, peptidoglycans
What does the innate immune response do?
destroys invading nucleic acids (e.g. viruses) in the cytoplasm
activates inflammatory pathways, signals for recruitment of immune system cells to sites of damage/infection
elicits type 1 interferons, for anti-viral defence
describe what is meant by clonal selection
Each lymphocyte carries a single, unique antigen receptor due to random genetic recombinations occur within each cell among multiple copies of immunoglobulin gene segments (B cells) or TCR gene segments (T cells).
There are millions of lymphocytes in the body, and thus millions of different antigen receptors.
Lymphocytes that meet an antigen they recognize will proliferate and survive.
The huge majority of lymphocyte clones will die out.
How does the immune response actually clear a pathogen?
Cytotoxic T lymphocytes (CTLs) kill infected cells
Antibodies bind to pathogens: the complex is destroyed or ingested by cells.
what is an antigen
a molecule that is recognised and bound by antibodies or T cells.
what is an immunogen
antigens that can initiate an immune response.
what is a antibody
an immunoglobulin molecule in the blood and body fluids which binds specifically to an antigen
