Oral Presentation HUPO 2019 - 18th Human Proteome Organization World Congress

Affinity proteomics for array based profiling of autoantibody repertoires (#24)

Peter Nilsson 1
  1. Div Affinity Proteomics, Dept Protein Science, SciLifeLab & KTH Royal Institute of Technology, Stockholm, Sverige

The quest to find novel disease associated autoantigens could and should lead to increased understanding and also enhance the long term possibilities to develop drugs for diagnosis, treatment and monitoring of progression. In order to contribute to this, we utilize in-house developed affinity proteomics resources and technologies for high-throughput and highly multiplex array-based profiling of proteins and autoantibody repertoires in CSF and plasma within a range of inflammatory, neurodegenerative and/or psychiatric disorders as well as within healthy individuals.

The general understanding of the global reactivity patterns in the human autoantibody repertoires is still at an early phase. More and more diseases and conditions are speculated to have autoimmune components but very few novel targets are clearly associated to disease conditions.

We are utilizing a unique resource of affinity reagents created within the Human Protein Atlas (HPA, www.proteinatlas.org). HPA has generated more than 42 000 unique protein fragments of in average 80 amino acids and the atlas currently contains protein expression and localization data for 26 000 antibodies targeting 17 000 human proteins.

Through a combination of various planar and bead-based microarray formats, including an array with 42 000 protein fragments representing 19 000 unique proteins, assays are set up for untargeted screening of autoantibody repertoires and targeted protein profiling and verification assays. The latter part utilizes a suspension bead array format with magnetic color-coded beads functionalized with either antibodies to generate protein profiles from labeled samples or antigens to capture autoantibodies. This format enables the analysis of up to 384 samples in parallel on 384 antigens or antibodies.

Within a large effort of neuroproteomic profiling in large numbers of both plasma and CSF samples are we comparing and exploring the global autoantibody repertoires as well as protein profiles of brain associated proteins. The focus is on the analysis of samples from patients with frontotemporal dementia, amyotrophic lateral sclerosis, multiple sclerosis, Alzheimer’s disease and psychiatric disorders.

We see in general a large degree of heterogeneity between individuals and within diseases and also often relatively high numbers of antigens targeted by each individuals repertoires of IgGs, which is also the case for healthy individuals. There is certainly a need for careful and extensive characterization of identified autoantigens in order to understand the disease associated mechanisms.

  1. http://www.publicationslist.org/nipe