humoral immunuty Flashcards
what are the 3 effecor cells
plasma cells
t helper cell
t cytotoxic cells
how are antibodies released
released by plasma cells and they can identify and neaturlsie forgein substances
what can each antibody do?
recognise a specific antigen
where do b cells originate?
bone marrow (BM) (f my baby dad)
outline the steps of the matuearion of b lymphocytes
b progenitor cell (bone marrow)
immature b cell
circulation
peropheral lymphoid organs
mature b cells
what is central tolerance
helps prevent the immune system from attacking the body’s own tissues.
what are the 2 things that part of central tolerance
apoptosis
recpetor editing
what are the perpheial organs
spleen and lymph node
what does central and peripheral aim?
prevent autoimmune reactions mediated by chronic inflammation.
which receptor is repsonsible for antigen recongnition?
b cell
what is a b cell receptor composed off?
immunoglobulin molecules IgM and IgD
what is b cell also known as?
transmembrane receptors
binding of what causes BCR activiation
binding of antigen to the BCR triggers the activation process
what do BCR and antibodies specfically recongise?
specific epitoopes on foreign targets
what is an epitope?
part of an antigen that is recongised by antibodies and b cells
antibodies and epitoopes
Antibodies that can bind to specific surface epitopes on the pathogen and prevent the it from interacting with host cells
this prevents infection of host cells
b cells receptors summarised?
B cells use surface bound antibodies as receptors for antigen
Targets extracellular antigens
BCRs bind intact antigens
Identify linear & conformational epitopes
t cell receptors summarised?
T cells have dedicated transmembrane receptors
T cells have one antigen recognition site
Antigen recognition is MHC dependent
Identify linear peptides
t indepedant activation?
initiated by T- independent antigens e.g. microbial polysaccharides, lipids
result in short lived plasma cells secreting IgMt
T - dependent activation
initiated by T dependent antigens e.g. microbial proteins
result in long-lived plasma cells secreting high affinity IgG/ IgA/IgE
simmarise t indepedant activation?
B lymphocyte activation
Clonal expansion/proliferation
Differentiation
Plasma cells
what is class switching?
Occurs by changing the constant regions of the heavy chains
the specificity of the Igs remains the same
Role of the Fc region on Igs
Fc portion of Igs bind to Fc receptors found on immune cells such as macrophages, dendritic cells
Polyclonal antibodies
Immunochemically dissimilar antibodies that react with different epitopes of an antigen
monoclonal antibodies
Immunochemically identical antibodies that react with the same epitope of an antigen
can monoclonal antobodies be artifcally geneated
yes
summarise celluar immuniuty
can recognise only protein antigens presented as small peptides
recognises antigens presented by APCs with MHC-I/MHC-II molecules
targets intracellular bacteria, viruses, fungi and protozoa
summarise hunoral immunity?
can recognise protein, polysaccharide, phospholipid, nucleic acid antigens
can act against soluble or free intact antigens
targets extracellular bacteria, viruses and toxins
