Utrecht University (logo) (logo)
Universitair Medisch Centrum Utrecht (logo)
You are here: Home > Education > Master > Research projects > UMC Utrecht > Rheumatology > Radstake7

Targeting ERAP for precision medicine in HLA-class I associated ocular autoimmunity

Tuesday 7 July 2015

Targeting ERAP for precision medicine in HLA-class I associated ocular autoimmunity
Dr. Jonas Kuiper / Prof. Tim Radstake/ Prof. Joke de Boer

The goal of this project is to identify the contribution of ERAP1-ERAP2 to the generation of pathogenic peptides presented by HLA-B27 and HLA-A29 in ocular autoimmune diseases and beyond.
Emerging data from genome-wide studies revealed unequivocal evidence for a key role of ERAP1 and ERAP2 genes in HLA-class I-associated ocular autoimmune diseases or Uveitis (HLA-B27-associated uveitis, ankylosing spondylitis (AS) and BehÁetís disease). Recently, we discovered strong association for ERAP2 in HLA-A29-associated birdshot chorioretinopathy (BSCR), another archetypal form of HLA-class I uveitis. ERAP enzymes in the cell are jointly responsible for trimming peptides for presentation by HLA-class I to T cells, thus have a critical role in the regulation of immune responses. However, very little is understood about their mechanism of action. The goal of this project is to identify the contribution of ERAP1 and ERAP2 to the generation of peptides presented by HLA-B27 and HLA-A29 and assess whether inhibition of ERAP decreases their presentation by HLA. This project is unprecedented in that it directly translates emerging genome-wide association findings into key disease mechanism and provides straightforward rationale for using selective ERAP inhibitors as the first precision medicine approach for treatment of HLA class I-associated uveitis and other auto-immune diseases. The project proposal was awarded the Bayer Ophthalmology Research Award 2015.
Our previous work has demonstrated that B cells have good expression HLA class I, ERAP1, ERAP2, making this cell type excellent for studying the HLA-ERAP axis. Currently, we have overexpressed ocular proteins in B cells of HLA-A29+ or HLA-B27+ patients that carry disease relevant polymorphisms of ERAP1 and ERAP2. This approach includes patient cells, thus conserving canonical antigen processing, so we are able to characterize in detail the uveitis-associated peptides that are clinically relevant.

Objectives to be reached during the internship
Step1: Establish ERAP1/ERAP2 disease relevant models (using CRISPR/Cas9 editing) in patient cell lines expressing candidate autoantigens

Step2: Identification of peptides presented by HLA-B27 and HLA-A29 that are specifically generated by ERAP1 and ERAP2

CRISPR/Cas9 editing will be used to alter ERAP1/ERAP2 expression and activity. HLA-A29 and HLA-B27 proteins will be isolated by immune-affinity chromatography. Peptides will be eluted from HLA for analysis by on-line nano-HPLC-tandem mass spectrometry in the lab of van Veelen (LUMC) that developed this technique for in-depth identification and quantification of peptides from B cells.
During the internship, the student will be directly supervised by dr. Kuiper (post-doc, head of Ophthalmo-Immunology unit in Prof. Radstake group) and daily lab-support by Sanne Hiddingh. The student will take advantage by a young and enthusiast group focusing on the emerging field of ERAP in HLA-associated autoimmunity, with a long-standing technical and clinical expertise.
The project involves the implementation of delicate molecular biology techniques, including CRISPR/Cas9 editing, immune-affinity chromatography and high-throughput technology. The maximal accuracy and commitment to the project are therefore required and only highly motivated students will be considered.

CRISPR/Cas9 editing, Viral transduction, Western blot, flow cytometry, ELISA, DNA sequencing, B and T cell-culture, immune-affinity chromatography, mass-spectrometry
Duration: 6 or 9 months

Dr Jonas Kuiper, J.J.W.Kuiper@umcutrecht.nl