Anoctamin 2 identified as an autoimmune target in multiple sclerosis

Abstract

Multiple sclerosis (MS) is the most common chronic inflammatory disease of the central nervous system and also is regarded as an autoimmune condition. However, the antigenic targets of the autoimmune response in MS have not yet been deciphered. In an effort to mine the autoantibody repertoire within MS, we profiled 2,169 plasma samples from MS cases and population-based controls using bead arrays built with 384 human protein fragments selected from an initial screening with 11,520 antigens. Our data revealed prominently increased autoantibody reactivity against the chloridechannel protein anoctamin 2 (ANO2) in MS cases compared with controls. This finding was corroborated in independent assays with alternative protein constructs and by epitope mapping with peptides covering the identified region of ANO2. Additionally, we found a strong interaction between the presence of ANO2 autoantibodies and the HLA complex MS-associated DRB1*15 allele, reinforcing a potential role for ANO2 autoreactivity in MS etiopathogenesis. Furthermore, immunofluorescence analysis in human MS brain tissue showed ANO2 expression as small cellular aggregates near and inside MS lesions. Thus this study represents one of the largest efforts to characterize the autoantibody repertoire within MS. The findings presented here demonstrate that an ANO2 autoimmune subphenotype may exist in MS and lay the groundwork for further studies focusing on the pathogenic role of ANO2 autoantibodies in MS.multiple sclerosis | autoimmunity | autoantibodies | protein microarrays | affinity proteomics

Clonal Evolution of Autoreactive Germinal Centers

“…We further validated our findings in nucleolar ELISA-type assays (Figure S3F). The analysis was extended and refined by screening with autoAg arrays (Ayoglu et al, 2016), where each clone was assayed against 241 Ags (227 unique targets) and 30 controls (10 unique antibodies) (Table S3), and overall, results were congruent with the HEp-2 and nucleolar ELISA results (Figure S3G–K). The 564 clone, 564 UCA, G4_G22, and UCA GC2 were strongly reactive with single-stranded (ss)DNA (Figure S3H).…”

“…Autoantigen arrays were generated and assays on the arrays were performed as described previously (Ayoglu et al, 2016). Unless stated otherwise in Table S3, 6 µg of each Ag and a three-point dilution series of control mouse and anti-mouse antibodies (0.25, 1, 4 µg) were diluted in PBS and transferred into 3 × 96-well plates.…”

Tolerogenic Dendritic Cells Generated with Tofacitinib Ameliorate Experimental Autoimmune Encephalomyelitis through Modulation of Th17/Treg Balance

“…Furthermore, the major barrier of tolDC-mediated immunotherapy in autoimmune diseases was the identification of autoantigen loaded onto the tolDCs [36]. Although the search for autoantigen in patients with multiple sclerosis has been ongoing for decades and several proteins have been postulated to be potent autoantigens, such as α B-crystallin [37], anoctamin 2 [38], and KIR4.1 [39], the exact target autoantigen of MS remains unclear. The breakthrough in searching for specific autoantigens in patients with MS has been an urgent need for clinical and preclinical translation of tolDCs-based therapies.…”

AAgAtlas 1.0: a human autoantigen database

“…Using bead-based arrays, Ayoglu et al . profiled the sera from multiple sclerosis patients with 11 520 proteins and identified Anoctamin 2 as an autoimmune target in multiple sclerosis (14). In addition, some tumor AAgs might be ideal targets for targeted immunotherapy such as p53, HER2 and NY-ESO-1 (15,16).…”