Week 2 Practise Questions L4-6 Flashcards
What is the main difference between Toll-like receptors (TLRs) and NOD-like receptors (NLRs)?
Former associated with membranes, latter cytoplasmic
What is extravasation?
Movement of cells (and large molecules) out of blood into tissues during inflammation
How do Type I interferons affect viral replication?
Induce expression of endonuclease that degrades viral RNA + protein kinase that phosphorylates an initiation factor needed for protein translation
What are the functions of the Fab and Fc regions of antibodies?
Antigen recognition (Fab) and effector (i.e antigen elimination) functions (Fc)
How do the immunoglobulin classes differ from one another?
Differ in the constant region of the heavy chains (and in effector functions)
What 3 main discoveries were made from the sequencing of myeloma proteins?
V and C regions, homology regions, hypervariable regions were identified
What is a CDR and why is it important?
Complementarity Determining Region - corresponds to hypervariable “loop”, main region involved in antigen recognition
How do soluble and membrane-bound forms of antibody differ?
Soluble antibodies have hydrophilic C terminus, whereas membrane forms have a hydrophobic C terminus (for insertion in lipid bilayer). Membrane forms are usually IgM and/or IgD and monomers.
What is the disease SCID and how does it arise?
Severe combined immunodeficiency disease can arise due to mutations in the RAG genes; B and T cell receptor genes cannot undergo rearrangement. Patients are unable to produce functional B and T cells i.e. no adaptive immunity.
What is the greatest source of antibody diversity?
Junctional diversity (where the somatically recombined genes join).
How do you think patients with AID deficiency would be affected?
Lack of class switching from IgM and no somatic hypermutation i.e. lacking effector functions associated with classes other than IgM and no affinity maturation.
