Half-life in serum for IgG
Half-life in serum for IgM
Half-life in serum for IgA
Half-life in serum for IgD
Half-life in serum for IgE
In regions of inflammation how do IgG move?
these monomer antibodies readily cross the walls of blood vessels and enter tissue fluids
What is the predominant type of antibody involved in response to ABO blood group antigens?
IgM causes clumping of the cells
What does the detection of IgG mean?
may indicate that immunity against a particular pathogen was acquired in the more distant past
the study of reactions between antibodies and antigens
is the generic term for serum because it contains Ab
are serum proteins
a mature B cell that has left the bone marrow but has not yet encountered its specific antigen
• gamma (γ) globulin
is serum fraction containing Ab
Differentiation of T cells and B cells
Both cells then migrate to lymphoid tissues, such as the lymph nodes or spleen
Name4 Bacterial Antigens
What is a bacterial H-antigen?
How does a bacterial K-antigen present?
How does a bacterial O-antigen present?
• lipid and polysaccharide; found in the outer membrane of
How does a bacterial M-antigen present?
protein; mediates attachment to epithelial cells of the host
and helps resist phagocytosis
Description of a general Structure of Antibodies
4 peptide chains
- 2 heavy
- 2 light
• 2 antigen binding
• flexible hinge regions
• constant region (Fc)
Attachment of epitopes on bacteria and antibodies
What are top arrows pointing to?
Antigen binding sites
What are middle arrows pointing to?
The class involved in the immune response depends on 3 things.
- the type of foreign antigen
- the portal of entry
- the antibody function needed
the relative amount of Ab in serum
How long are there no detectable antibodies after initial contact with antigen?
4 to 7 days
What is the first antibody titer produced? second?
first IgM followed by IgG peaks at 10 to 17 days (primary response)
When does 1° response to an antigen occur?
after initial contact with Ag
When does 2° (memory) response to an antigen occur?
after second exposure and is more rapid and greaater in magnitude
Functions of antibodies
*Bacterium "tagged" with Antibodies for macrophages, eosinophil and natural killer (NK) cells
*coating antigen with antibodies
*the process by which a pathogen is marked for ingestion and
destruction by a phagocyte.
*blocks attachment of toxins
*blocks adhesion of bacteria and viruses to mucosa
defends a cell from an antigen or infectious body by
inhibiting or neutralizing any effect it has biologically
foreign antigens that are processed by and then expressed on the surface of cells that have been invaded by intracellular pathogens such as viruses
Reduces the amount of infection units to be dwelt with
*the clumping of cells such as bacteria or RBCs in the
presence of an antibody that binds multiple particles and joins
them, creating a large complex.
Causes immflammtion and cell lyses
*the binding of active serum complement to an antigen-antibody pair.
a protein-degrading enzyme secreted by the bound NK cell which enters the pore made by the perforins. Inside the enemy cell, the granzymes destroy cellular enzymes and induce apoptosis (programmed cell death)
TH1 (T helper cell 1)
respond to most bacterial and viral
pathogens; activate macrophages, activate CTLs
TH2 (T helper cell 2)
respond to parasites and involved in
allergies; activate B cells
Tregs ( T regulatory cells)
regulate T cell responses, can put the "brakes" on the immune response
*primary function is to combat autoimmunity by suppressing T cells that escape deletion in the thymus without the necessary "education" to avoid reacting against the body's self
Two main antibody-producing T cell.
dendritic cells and macrophages
act as sentinels in tissues enguld invading microbes, degrade them and trnsfer then to lymph nodes for display to T cells located there
important for innate immunity and for ridding the body of worn out blood cells and other debris
Humoral (Antibody-mediated) immune system
control of freely circulating pathogens and depends on B cells
Natural Killer cell
lyse virus-infected cells, tumor cells, and parasites. They kill cells that do not express MHC class 1 antigens
Cellular (Cell-mediated) immune system
control of intracellular pathogens, depends on T cells to eliminate intracellular pathogens, tumor cells, nonself
• named after their ability to "interfere" with viral replication within
• activate immune cells, such as natural killer cells and
• increase recognition of infection or tumor cells by up-regulating
antigen presentation to T lymphocytes
• increase the ability of uninfected host cells to resist new infection
• about 10 distinct IFNs have been identified in mammals
• have been exploited to treat autoimmune diseases such as
multiple sclerosis (MS)