Exploration of high-density protein microarrays for antibody validation and autoimmunity profiling

Protein fragments are used within the Human Protein Atlas project for the generation of antibodies, these fragments have also been utilized for the validation of the antibodies on antigen microarrays.

All antibodies produced by the Human Protein Atlas have been validated for target recognition on antigen microarrays comprising of their target antigen and 383 other protein fragments. In total over 42.000 protein fragments have been arranged in sets of 384. These antigen microarrays can be used for general analysis of affinity binder profiling and for autoantibody profiling of biofluids, and the sets of 384 antigens can be combined in to larger sets of antigens. Large-scale arrays of 11.520 and 21.120 antigens have recently been produced by scientist from the Human Protein Atlas in an attempt to increase the throughput of the antigens that can be screened simultaneously.

The large-scale arrays have been utilized for profiling the antigen interactions of 48 Human Protein Atlas antibodies and for profiling the autoantibody repertoire in human plasma from patients with Secondary Progressive Multiple Sclerosis.

The study showed that the antigen microarrays used during the validation of the Human Protein Atlas antibodies gave a good indication of the general reactivity of the antibodies that were investigated, and several possible autoimmune targets that could be relevant in a Multiple Sclerosis context were identified.

A comparison between the Human Protein Atlas arrays and commercially available HuProt (CDI Laboratories) protein microarray, comprising approximately 17.000 full-length proteins, showed that the two different platforms generated complementary information. This gives the scientist at the Human Protein Atlas an in-house generated platform that extends their ability to profile samples beyond what is commercially available.

The findings demonstrate that these large-scale antigen arrays offer a unique opportunity to investigate the interactions of interesting affinity binders, thus making them a useful tool in the validation of affinity binders to possible biomarkers, and for investigating the diversity of the autoantibody repertoire in body fluids from patients with disease with possible autoimmune components.

The current goal is to combine all antigens produced by the Human Protein Atlas into one large antigen microarray to enable complete simultaneous high-throughput profiling of affinity binders and biological samples on all antigens available in the Human Protein Atlas.

Read the full article about the large scale protein microarray that has been used for antibody validation and autoimmunity profiling here.

Also read our blog post on Investigating autoantibody reactivity in lungs.