Antigens and antibodies Flashcards
What are the group of chemicals (polysaccharide, protein etc) that the adaptive immune system recognizes?
Epitopes or determinants
What accounts for the adaptive immune system’s specificity?
Lymphocyte having cell membrane receptors that distinguish between epitopes
How many specificities does each lymphocyte have?
One!!
What accounts the in lowered response time of a secondary infection/immunological memory?
Immunologic memory is due to the presence of memory cells.These cells are more sensitive to stimulation by antigen than are antigen-naive lymphocytes
What are the three factors that abate the immune response?
- Removal of antigen (no further stimulation)
- Death of activated lymphocytes
- Regulatory immune system
What phospholipid is the marker for cell death?
Phosphatidyl serine on the outside of a cell membrane
How are autoimmune diseases brought about?
When immune cells that are specific for self proteins do not undergo apoptosis during development
What is immunogenicity?
The property of a molecule that allows it to induce an immune response.
What are adjuvants?
Chemicals that prolong another molecule’s (like antigen) retention in the body so that a more vigorous immune response can occur
What is antigenicity?
The property of a molecule that allows it to react with an antibody.
What are haptens?
Small molecules that cannot induce antibody formation but can react with antibody that is specific for it, (i.e. it must be coupled to a carrier molecule in order to induce antibody formation. Therefore, an hapten is an antigen, but not an immunogen).
What molecular weight is the dividing line between immunogenic and less immunogenic immunogens?
Molecules of >10,000 molecular weight are the best immunogens
The (BLANK) complex the molecule, the more capable it is to be an immunogen.
More
Where does immunogne processing occur?
In phagocytes
What are the areas of the immunogen that are easy to reach and generate a strong immune response called?
Immunodominant areas
What are the five features of immunogens that give them a strong immune response?
- Size
- Internal complexity
- Degradability
- Foreignness
- Accessibility
What are linear determinants?
Epitopes that are formed by adjacent amino acids
What are conformational determinantss/epitopes?
are composed of amino acid residues from different parts of the protein that are brought together in space.
T lymphocytes can only recognize what type of determinant (linear or conformational)?
Linear
What are neoantigens?
new antigens” formed by proteolysis, phosphorylation, or exposure of new determinants through the interaction with foreign antigens
Most antigens that the body is exposed to are of what type of chemical (polysaccharide, proteins, lipids, etc.)?
Proteins
Where are antibodies found?
- Surfaces of B lymphocytes
2. Blood plasma/tissue fluids
How many specific antibodies can any given B cells have?
Just one
What are the two types of immunoglobin that B lymphocytes contain/
IgM and IgD
B lymphocytes have both IgG and IgM immunoglobin. What, therefore, must occur if a B cell needs to produce antibodies of another isotype?
Isotope switching
Blood plasma and tissue fluids contain large amounts of antibody that has been secreted from what cell type?
Plasma cells
True or false: The antibodies produced by plasma cells have only minor changes compared to the immunoglobin that is present on the plasma cells surface
True
What immunoglobin type are found on the surfaces of mast cells? What type of antibodies do these capture?
IgE–capture soluble antibodies
True or false: Secretory fluids such as mucus and milk contain do NOT antibody
False
What is antiserum?
Antibody-containing serum.
What is serum?
the fluid portion of the blood after the cellular elements have clotted
What are polyclonal antiserums?
A population of antibodies which (collectively) can bind to more than one particular antigen, since each antibody will bind different antigens
What are monoclonal antiserums?
antiserum that contains antibodies which bind to only one specific antigen
What is an antibody titer?
the reciprocal of the last dilution of antiserum that still yields a demonstrable antibody binding reaction
What are the three bands into which antibodies separate into when undergoing electrophoresis? In which band are most found?
Alpha
Beta
Gamma–most found
True or false: the term “immunoglobin” is synonymous with “antibody”.
True
What are the two major components that antibodies are made of (hint, there are two pairs of these general structures)?
Light chains
Heavy chains