Peripherin Is a Relevant Neuroendocrine Autoantigen Recognized by Islet-Infiltrating B Lymphocytes

Abstract

Most of our knowledge of the antigenic repertoire of autoreactive B lymphocytes in type 1 diabetes (T1D) comes from studies on the antigenic specificity of both circulating islet-reactive autoantibodies and peripheral B lymphocyte hybridomas generated from human blood or rodent spleen. In a recent study, we generated hybridoma cell lines of infiltrating B lymphocytes from different mouse strains developing insulitis, but with different degrees of susceptibility to T1D, to characterize the antigenic specificity of islet-infiltrating B lymphocytes during progression of the disease. We found that many hybridomas produced mAbs restricted to the peripheral nervous system (PNS), thus indicating an active B lymphocyte response against PNS elements in the pancreatic islet during disease development. The aim of this study was to identify the autoantigen recognized by these anti-PNS mAbs. Our results showed that peripherin is the autoantigen recognized by all anti-PNS mAbs, and, therefore, a relevant neuroendocrine autoantigen targeted by islet-infiltrating B lymphocytes. Moreover, we discovered that the immune dominant epitope of this B lymphocyte immune response is found at the C-terminal end of Per58 and Per61 isoforms. In conclusion, our study strongly suggests that peripherin is a major autoantigen targeted during T1D development and poses a new question on why peripherin-specific B lymphocytes are mainly attracted to the islet during disease.

Proteomic characterisation of pancreatic islet β-cells stimulated with pancreatic carcinoma cell conditioned medium

“…Boitard et al proposed peripherin to be an auto-antigen related to type 1 diabetes (T1D) in 1992, though previous studies had shown that islet-infiltrating T-cells are major effectors of β-cell damage in type 1 diabetes, and these T-cells progressively destroy islet β-cells over a long, protracted period of insulitis; they doubted whether peripherin was the target of the T-cell immune reaction. Recently, Puertas et al 25 characterised the antigenic specificity of peripherin during T1D progression and suggested that peripherin-specific B lymphocytes might be attracted to the islet during disease. Carrillo et al 26 further demonstrated that anti-peripherin B lymphocytes are positively selected in the course of T1D development in NOD mice.…”

In Vivo Detection of Peripherin-Specific Autoreactive B Cells during Type 1 Diabetes Pathogenesis

“…Cells were incubated with octamers at a final concentration of 8.5 μg/ml in FACS buffer (PBS/5% FCS) for 15 min on ice. For inhibition studies, A g7 /PRPH 467-507 C octamers were preincubated overnight with mAb 228 E1 at 4°C before cell staining (10). For PRPH C B cell distribution studies and co-staining of additional cell surface markers of islet-resident B cells, FITC-labeled anti-B220 or CD19 as well as PE-Cy5-labeled anti-CD3, anti-CD11c and anti-F4/80 (dump channel) were used.…”

“…About half of the B cell hybrids generated in this study recognized the peripheral nervous tissue (9). It was subsequently suggested that all neuronal-reactive B cells recognized the C-terminal portion of peripherin (PRPH), a cytoskeleton class III intermediate filament protein expressed in neuroendocrine tissues (10). These findings confirmed previous observations of anti-PRPH antibodies (Abs) in NOD mice (11, 12).…”

“…With a single exception, in the study of the Verdaguer group all anti-PRPH B cell hybridomas originating from islet-infiltrating B cells from NOD and related mouse strains recognize PRPH 61 and PRPH 58, but not PRPH 56 (10). All 3 isoforms are composed of an N-terminal head, a central rod as well as a C-terminal tail sequence.…”

The Long and Winding Road to Understanding and Conquering Type 1 Diabetes

“…One issue that is not discussed but is important to appreciate is that most intra-islet B cells, at least in NOD mice, do not recognize antigens targeted by islet-associated T cells or T1D-associated antibodies. Rather, most of these intra-islet B cells recognize antigens expressed exclusively by the peri-islet Schwann cell, such as peripherin (Carrillo et al, 2005;Puertas et al, 2007). Immune targeting of the pancreatic glia has been implicated in the genesis of T1D (Tsui et al, 2008), and it is therefore possible that these autoreactive B cells contribute to this process.…”