humoral immunity Flashcards
What is the major effector molecules of the humoral immune response?
Antibodies (immunoglobulins)
The two antigen recognition molecules are?
Antibodies and T cell antigen receptor
What are the 5 classes (isotypes) of immunoglobulins?
IgG, IgA, IgM, IgD, IgE
All immunoglobulins include…?
Fab, 2 light chains and 2 heavy chains.
What class is the predominant antibody in normal human serum?
IgA
What class is the predominant antibody isotype in seromucous secretions?
IgA
What class is the first immunoglobulin produced in a primary response to an antigen?
IgM
What class is an antigen-specific receptor on mature B cells?
IgD
What class mediates immediate hypersensitivity reactions?
IgE
Why is antibodies known as adapter molecules?
Can neutralise toxins, opsonise and activate the complement system
How can we produce millions of antibodies?
Variability in the antigen-binding fragment (Fab) region
Random selection and gene recombination
Mutations (specifically somatic hypermutation)
Class switching (rearrangement of VDJ genes)
What is neutralisation?
Prevention of bacterial adherence
What is opsonisation?
process by which a microorganism is coated by serum components, thereby enhancing recognition and ingestion by phagocytic cells
What is the complement activation?
Enhancement of osponisation, phagocytosis recruitment and direct lysing of bacteria
What are the 3 main ways in which antibodies participate in host defence?
Neutralisation
Osponisation
Activation of complement system
