ANTIGEN Flashcards
Macromolecules that is capable triggering an adaptive
immune response by inducing formation of antibodies or
sensitized T- cells of an immunocompetent host
Immunogen
Can evoke an immune response
Immunigen
• Substance that reacts with antibody or sensitized T cells but
may not evoke an immune response
• Can only bind sensitized T cells or antibody, not capable of sensitizing T and B cells (no reaction)
Antigen
Ability to induce a humoral and/or cell-mediated immune
response
Immunoginecity
Ability to combine specifically with the final products of the
immune response
Antigenicity
What are the final products of antigenicity?
secreted antibodies and/or surface
receptors on T-cell
What are the factors influencing the immune response?
Size
Foreignness
Chemical composition and molecular complexity
Adjuvants
Route, Dose, Timing
This is the ability of the person to mount an immune response
Immunocompetent
Coupled with a certain receptor
Antigenicity
their immune system is not completely developed
Neonates
Pediatricians monitor closely neonates that get sick from ___________ old
0-3
months
the immune system won’t work well if the body
does not receive the enough nutrition that it needs (especially
here in the Philippines and children
Malnutrition
What are the routes of inoculation?
Intravenous
Intradermal
Subcutaneous
Oral contact
This is inoculated into the vein.The fastest route of entry of an immunogen because it will
enter directly into the bloodstream
Intravenous
This is inoculated into the skin.
Intradermal
This is inoculated beneath the skin / tissue.
Subcutaneous
What is the primary organ to fight off the immunogen in an intravenous route?
Spleen
What is the example of subcutaneous?
Local lymph nodes
Linked to MHC (Major Histocompatibility Complex) and to
receptors generated during T and B lymphocyte development
Genetic capacity
system of genes that code for cell surface molecules that
play an important role in antigen recognition
MHC (Major Histocompatibility Complex)
What is the MW of the best immunogens?
100,000 Daltons
This route of inoculation has a stronger stimuli than subcutaneous.
Intradermal
What is the rule of thumb of macromolecular size?
the greater the molecular weight, the more
potent the molecule to induce an immune response
Lymphocyte capable of reacting with self- antigen is normally eliminated. Will determine if the antigen foreign or self
. Should be eliminated because it is a self-antigen
Foreignness
Which are the best immunogens?
Proteins
Which is the 2nd best immunogen?
Polysaccharides
This is the least immunogenic and must be attached to a carrier particle before being an
immunogen.
Lipid and nucleic acids
These are antigenic determinants and are molecular shapes or configurations that are
recognized by B or T cells
Epitopes
Immunologically active regions of an immunogen that bind to
antigen-specific membrane receptors on lymphocytes or to
secreted antibodies
Epitopes
amino acids following one another on a single chain
SEQUENTIAL OR LINEAR EPITOPES
results from the folding of one chain or multiple chains,
bringing certain amino acids from different segments of a
linear sequence or sequences into close proximity with each
other so they can be recognized together
CONFORMATIONAL OR DISCONTINUOUS EPITOPE
Small organic compound that are antigenic but not
immunogenic
Haptens
reactions that we
observe in the serology laboratory indicating an
antigen-antibody reaction
Precipitation/ agglutination
What should a hapten do to become a complete antigen/immunogen?
they should be
coupled to a carrier
Who wrote the specificity of the serological reaction?
Karl Landsteiner
He discovered that antibodies not only recognize chemical
features such as polarity, hydrophobicity, and ionic charge,
but the overall three-dimensional configuration is also
important. Immunized rabbits with haptens attached to a carrier
molecule.
Karl Landsteiner
• Substances that are administered with an immunogen that
increase the immune response in order to provide immunity
to a particular disease
• Used to make vaccine
Adjuvants
This is an example of Adjuvants used to complex with the
immunogen to increase its size and to prevent a rapid escape
from the tissues
Aluminum salts
• Antigens that belong to the host
• Do not evoke an immune response under normal
circumstances
• The only problem that will occur is that if the lymphocytes
don’t have the capability of discriminating self from non-self
Autoantigens
• From other members of the host’s species
• Human to human
• Capable of eliciting an immune response
Alloantigens
From other species such as other animals, plants or
microorganisms
Heteroantigens
• hetereoantigens that exist in unrelated plants or animals
• Either identical or closely related in structure so that
antibody to one will cross- react with antigen of the other
Heterophile antigens
