Antigens: types and features Principles of antigen recognition by T and B cells Antigen Presenting Cells
Jan 21, 2016
Antigens: types and features
Principles of antigen recognition by T and B cells
Antigen Presenting Cells
ANTIGENS
DEFINITIONS
Antigen
Immunogen
Hapten
Carrier
Epitope or antigenic determinant
ANTIGEN
Molecule that binds antibody or T cell receptor
IMUNOGEN
antigen that induce immune response
IMMUNOGENICITY
Depends on
characteristics of the immunogene
biological system
route of administration
IMUNOGENICITY characteristics of the immunogene
Phylogenetic distance
Molecular size
Chemical composition and heterogeneity
proteins > carbohydrates, lipides, nucleic acids
Physical appearance
particulated > soluble
denatured > native
IMUNOGENICITY characteristics of the biological system
Genetic bacground
– species
– individual
Age
IMUNOGENICITY administration of the antigen
amount
optimal
route
subcutaneous > intravenous > peroral
adjuvant
substancee that stimulates immune
response to the antigen
HAPTEN
small molecule that can not elicit an immune response by itself. It can elicit an immune response only when attached to a large molecule – carrier.
CARRIER
Macromolecule that enables induction of immune response directed to the attached hapten.
ANTIGENIC DETERIMINANTE or EPITOPE
Part of the antigen that binds specific antibody or T-cell receptor
Antigenic determinantes of the proteins
linear
conformational
aminoacidlinear determinant
conformational determinante
Principles of antigen recognition by T- and B-lymphocytes
Antigens recognized by B-lymphocytes are
Proteins (linear and conformational determinants), carbohydrates, nucleic acids etc.
Native and processed
Soluble and membrane
Antigens recognized by T-lymphocytes are
Peptides
Linear determinants
On the cell membrane within groove of self MHC molecule
ANTIGEN-PRESENTING CELLS
Figure 8-14
Ralph Steinman
Dendritc cells
Nobel prize for medicine 2011