Lecture 6: Immunoglobulins Flashcards
what makes antibodies and B cell receptors
B cells
BCRs are membrane bound versions of ?
antibodies
antibody structure
Y shape
composed of 4 peptide chains joined by disulfide bonds
- 2 identical heavy chains
- 2 identical light chains
- each chain has variable and constant regions
what amino acid sequences are the constant region of the light chains encoded by
Kappa (60%) and Lambda (40%)
how do B-cell lymphomas present on light chains
marked by increased frequency in one type of light chain
What is an epitope?
the sequence or region of an antigen that is recognized by the immune system
what are the 5 classes of antibodies? (based on the constant region of heavy chain)
Immunoglobulin M - IgM
IgD
IgG
IgA
IgE
(there are subclasses within groups ex: IgG1, IgG2, IgA1, etc)
What are hypervariable regions within an antigen
regions of extensive variability in amino acid sequence that determines antibody specificity
do all species have all classes of antibodies ?
naur
Different heavy chain ______ define antibody class
isotopes
what element of an antibody determines its class
heavy chain
what differences exist in antibody structures
- the location of disulfide bonds
- different carbohydrates are linked
what is the first class of antibodies produced by B cells after their activation
IgM
what is the most abundant class of antibody
IgG
how many isotopes does IgG have and how do they differ?
Four (IgG1-4)
they differ based on the structure of their hinge
what class of antibodies can be found in blood and tissue during the immune response?
IgG
what does IgG interact with to activate complement?
C1
*IgG4 does NOT activate complement
what is the only class of antibodies that transfers across the placenta?
IgG
*IgG1 is best
what is opsonization
the process of targeting pathogens for destruction by phagocytes
what cell types are involved in mobilizing cells to the site of infection
Mast cells and basophils
what is the effect of the activation of Mast cells and Basophils
the release of granules including histamine
