FINAL IMMUNITY DECK Flashcards
Location of molecules on the complex between a dendritic cell and a cytotoxic T cell?
Part binding to the dendritic cell = MHC class I molecule
Side chain co receptor on the left = CD8
Part bound to cytotoxic T cell = T cell receptor
Location of molecules on the complex between a helper T cell and a dendritic cell?
Part binding to the dendritic cell = MHC class II molecule
The co receptor side chain = CD4
Part bound to cytotoxic T cell = T cell receptor
Helper T cells and Cytotoxic T cells are derived from which pluripotent cell found in the bone marrow?
Haematopoietic stem cell
To which immune cell lineage do Helper T cells and Cytotoxic T cells belong?
Lymphoid
The other types are B cell or natural killer cells
Name the two other immune cell lineages derived from the Haematopoietic stem cell?
Myeloid and erythroid
Seven cell types belonging to the innate immune system?
Mast cells, dendritic cells, neutrophils, macrophages, NK cells, eosinophil,
basophils
Where is the Fab domain, the Fc domain, the heavy and light chains, the VH and VL regions of the Fab domain on an IgG immunoglobulin molecule?
Fab domain = top half of the Y
Fc domain = bottom half of the Y
Heavy chain is top part of arm of Y
Light chain is lower part of arm of Y
The VH region is the very top of the arm on the heavy region in the fab domain
The VL is the very top of the light chain in the fab domain
What is opsonisation?
Opsonisation is the deposition of molecules on the surface of a cell, enhancing uptake by phagocytes
Name the 2 types of soluble host molecule involved in opsonisation
Complement (C3b) and antibody
How is the bacterium B. pseudomalleu arable to avoid opsonisation?
Polysaccharide capsule blocks opsonisation
What is ADCC?
antibody dependent cell mediated cytotoxicity
Which class of immunoglobulin is involved in parasite immunity and binds to the FcεR1 receptor on the surface of Mast cells, basophils and eosinophils leading to degranulation?
IgE
What’s the molecular formula of IgE?
ε2κ2 or ε2λ2
Activating Fc receptors signal through which immune cell-activating motif?
ITAM (Immunoreceptor Tyrosine-Based Activating Motif)
A linear polysaccharide chain indicates a bacteria will have what types of surface structures?
Capsular polysaccharide and lipopolysaccharide
What molecule anchors bacteria surface structures?
Lipid A
How and where might the DNA be modified in mammalian DNA?
The CG motif may be methylated
How does this modification affect the interaction of DNA with cells bearing Toll-like receptor 9?
Only un-methylated CG motifs are recognised by TLR9
Pattern recognition molecules in the host can be categorised as cell-associated or soluble, Name a class of cell-associated pattern recognition molecules?
Toll-like receptors, NOD-like receptors, C-type lectin receptors, scavenger receptors, or N-formyl met-leu-phe receptors
How might the extracellular domain of Toll-like receptors be modified to recognise different molecules?
By the insertion of amino acids and/or glycosylation
what is the function of the MD-2 accessory factor?
To bind to lipid A of lipopolysaccharide
Give an example of a toxoid vaccine?
Tetanus
List disadvantages of formaldehyde toxoids
Must balance cross-linking with retention of antigenic structure
Batch-to-batch variation
Reversion
Requires pure toxin as the starting point, therefore need to grow the pathogen and purify and handle the toxin
What is antigenic mimicry and an example?
Many pathogenic bacteria are able to avoid the induction of an adaptive immune response
This is done by the bacteria have surface molecules that resemble the molecules on the
surface of host cells
Neisseria menigitidis - sialic acid or Streptococcus pyogenes - hyaluronic acid