Exam Flashcards
Describe an experiment to test the effect of a JAK inhibitor on IFN activation in vitro. What materials are needed and what is the readout method?
Culture PBMCs with a JAK inhibitor. THe readout is IFN stimulated gene expression or IFN protein, although gene expression is better since there are so many IFN subsets that an easy way to test for all of them is quite difficult in a protein array.
Give three different reasons why you expect more of these inhibitors as treatment for IFN positive systemic autoimmune diseases than from antibodies blocking the cytokine IFN type I.
- Antibodies blocking IFN type 1 are unlikely to block all different subtypes
- small molecule inhibitors are cheaper and can be taken orally as opposed to those blocking IFN type 1 itself, since it needs to be injected.
- JAK inhibitors are more upstream and also block signal transduction of other cytokine receptors
Decribe in the correct order the 4 steps of ADCC by which anti-TPO autoantibodies cause thyroid tissue damage in Hashimoto’s thyroiditis.
- TPO is expressed by thyrocytes. Autoantibodies bind to TPO.
- NK cells interact with the FC-receptor of these antibodies through cross-linking
- NK cells are then activated and degranulate
- The thyrocyte undergoes apoptosis and is destroyed
Name four (4) cells in the bone that are important for bone formation/remodeling and what are their functions?
Hematopoetic stem cells - progenitors of osteoclasts
Mesenchymal stem cells - progenitors of osteoblasts, adipocytes and chondrocytes
osteoblasts - bone formation
osteoclasts - bone resorption
Osteocytes - mechanosensing of microfractures
Implantation of a blastocyst is required for a successful pregnancy.
How would you set up a study in an animal model to find out the contribution of dendritic cells to a successful implantation?
cd11c DC deletion and study a number of successful pregnancies in comparison with wildtype
An endometrial biopsy during non-pregnant conditions makes the uterine wall receptive for blastocyst implantation. What mechanism is underlying this observation?
The biopsy induces an inflammatory response, which is important for blastocyst implementation
Mention 2 different mechanisms of how HLA-G induces tolerance in pregnancy
NK cells are induced into a tolerogenic state, leading to production of anti-inflammatory cytokines and growth factors
DC maturation stop
Mention 2 properties of trophoblasts that contribute to tolerance development from the mother towards the fetus?
They lack MHC II
They have a variable expression of MHC I
They express HLA-G
IFN activation plays a role in the pathogenesis of systemic autoimmunity.
Put the following terms that are involved in the IFN activation pathway in the right order and explain the process.
-Expression IFN
-pDC
-activation TLR7 and 9
-BAFF
-IFN induced gene expression
-immune complexes
-TLR7 and TLR9 are somehow induced in pDC which leads to the expression of IFN. This causes monocytes to produce BAFF, which activates B cells to differentiate into plasma cells and leads to the production of auto-antibodies, immune complex formation and that in turn activates TLR7 and TRL9 again.
Give two arguments supporting the relevance of IFN activation in the pathogenesis of systemic autoimmunity.
(1) There is a correlation with disease activity and auto-antibodies compared to healthy individuals, and (2) injection of IFN leads to the development of systemic autoimmunity.
Graves’ ophthalmopathy is an extrathyroidal complication of Graves’
disease. Which autoantibody type contributes to the development of Graves’
ophthalmopathy?
Auto-antibodies against TSH receptors. These receptors are also expressed in orbital fibroblasts and leads to adipogenesis, causing inflammation and accumulation of fat in the orbital cavity, resulting in the characteristic bulging of the eyes.
HLA class I genes are extremely polymorphic. For instance, hundreds of different HLA-A alleles have been identified. Although HLA class I genes consist of 8 exons, especially polymorphisms in two of these exons are responsible for this highly polymorphic character.
Which specific protein domains of an HLA-class I molecule are encoded by these exons?
Exons 2 and 3 encode the alpha1 and alpha 2 domains, respectively
What is the molecular impact of the polymorphisms in these exons?
The alpha1 and alpha2 domains together form the peptide binding cleft. Polymorphisms in exons 2 and 3 are thus responsible for the amino acid variability in the peptide binding cleft and thus determine which peptides can be presented by HLA I molecules to T cells.
Fetal trophoblasts and uterine NK cells have an optimal make up for tolerance induction.
List the following characteristics that contribute to tolerance induction under fetal trophoblasts or uterine NK cells:
-derived from local hematopoietic precursor
-production IL-10
-secretion HLAG
-expression inhibitory receptors
-lack of MHC II expression
-secretion proangiogenic factors
-transfer immunoglobulins
-HLA-C expression
Fetal trophoblasts:
-secretion of HLA-G
-lack of MHC II expression
-transfer immunoglobulins
-HLA-C expression
uterine NK cells:
-derived from local hematopoetic precursor
-production of IL-10
-expression of inhibitory receptors
-secretion of proangiogenic factors
Why is CRISPR/CAS9 much more useful than using restriction enzymes to create cell lines with mutations in specific genes?
It is possible to target one specific gene with the CRISPR/Cas9 system, while restriction enzymes cut many times in the genome. Therefore, it is not possible to target one specific gene with restriction enzyme digestion.
