Humoral (I) Flashcards
What are antibodies also called
Glycoproteins (can be glycosylated)
Immunoglobins (ig)
What sort of antigens attach to antibodies in humoral
Free
Eg carbs, lipids, proteins and nucleic acids (macromolecules)
How are the 4 polypeptide chains linked together in antibodies
Disulfide bonds and non convalent interactions
Where are the N terminal and c terminal
N terminal - variable region
C terminal - constant region
What is the region called where antigen binds (2 identical arms)
Fab region
Where is the FC region
Bottom part (constant)
Which area is antibody cleavage occurring
Hinge region in middle
Fc binding can recruit cells and the c1q activation , how
Through Fc receptors or directly on c1q
What are antigens called with multiple epitopes for binding either different or repeated
Multivalent antigens
What are the 2 types of epitopes called
Linear (continuous)
Conformational (discontinuous interaction with antibody)
Conformational is due to folding of epitopes/antigens
What kinds of forces allow antigen antibody interaction
Non covalent :
Van der waal (hydrophobic) H bonds (electrostatic)
What is the difference between affinity and avidity
Affinity is strength of non covalent forces of a single antibody/antigen bs
Avidity is the combined strength of antibody antigen interaction (multiple binding sites/multivalent/Igm)
How do antibodies neutralise toxins
Prevent the toxin binding to host cell receptors
Toxin is then endocytosed by macrophages
How does opsonisation work directly and indirectly by antibodies resulting in phagocytosis
They can bind to Fc receptors on cells
Or
They can bind specifically to c1q fc globules to increase c3b opsonin which causes opsonisation by binding to c3b receptors
How does ADCC occur via eosinophils/ NK cells
They have fc receptors which antibody coated on the pathogen will bind to
Causes activation of NK/eosinophils to cause extracellular killing eg via perforin or granzymes
