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

Abstract

Summary Autoreactive B cells are essential for the pathogenesis of type 1 diabetes. The genesis and dynamics of autoreactive B cells remain unknown. Here, we analyzed the immune response in the NOD mouse model to the neuronal protein peripherin (PRPH), a target antigen of islet-infiltrating B cells. PRPH autoreactive B cells recognized a single linear epitope of this protein, in contrast to the multiple epitope recognition commonly observed during autoreactive B cell responses. Autoantibodies to this epitope were also detected in the disease-resistant NOR and C57BL/6 strains. To specifically detect the accumulation of these B cells, we developed a novel approach, octameric peptide display, to follow the dynamics and localization of anti-PRPH B cell during disease progression. Before extended insulitis established, anti-PRPH B cells preferentially accumulated in the peritoneum. Anti-PRPH B cells were likewise detected in C57BL/6 mice, albeit at lower frequencies. As disease unfolded in NOD mice, anti-PRPH B cells invaded the islets and increased in number at the peritoneum of diabetic but not pre-diabetic mice. Isotype switched B cells were only detected in the peritoneum. Anti-PRPH B cells represent a heterogeneous population composed of both B1 and B2 subsets. In the spleen, anti-PRPH B cell were predominantly in the follicular subset. Therefore, anti-PRPH B cells represent a heterogeneous population that is generated early in life but proliferates as diabetes establishes. These findings on the temporal and spatial progression of autoreactive B cells should be relevant for our understanding of B cell function in diabetes pathogenesis.

Kinetics of immune cell responses in the multiple low‐dose streptozotocin mouse model of type 1 diabetes

“…Among the main mediators are autoreactive T cells, which infiltrate the islets and induce insulitis . However, innate immune cells such as antigen‐presenting cells or dendritic cells (DCs), neutrophils, macrophages, and B cells are also believed to contribute to insulitis . Diana et al have shown that neutrophils, DCs, and B‐1a lymphocytes initiate an autoreactive response in pancreas of non‐obese diabetic (NOD) mice through pro‐inflammatory mediators such as interferon (IFN)‐ɑ and cathelicidin‐related antimicrobial peptide (CRAMP) during the early development of T1D in young NOD mice .…”

“…[5][6][7][8] However, innate immune cells such as antigen-presenting cells or dendritic cells (DCs), neutrophils, macrophages, and B cells are also believed to contribute to insulitis. 6,7,[9][10][11][12][13][14] Diana et al have shown that neutrophils, DCs, and B-1a lymphocytes initiate an autoreactive response in pancreas of non-obese diabetic (NOD) mice through pro-inflammatory mediators such as interferon (IFN)-ɑ and cathelicidin-related antimicrobial peptide (CRAMP) during the early development of T1D in young NOD mice. 15 Several studies have further confirmed the involvement of innate immune cells in autoimmune diseases.…”

CXCR1/2 Inhibition Blocks and Reverses Type 1 Diabetes in Mice

“…Of note is the observation of increased B cells in ladarixin-treated NOD mice. The role of B cells in the modulation of islet immune cell responses has been recently recognized in models of autoimmune diabetes (46,47) and immunomodulatory effects of Gr-1 + CD11b + cells were reported in NOD mice receiving anti-CD20 treatment (48). In addition, IL-9, IL-6, and IL-12p70 were modified by CXCR1/2 inhibitor treatment in relation to the different disease phases.…”

Discovery of Phosphorylated Peripherin as a Major Humoral Autoantigen in Type 1 Diabetes Mellitus

“…Though the binding epitope was not investigated, the use of denaturing conditions during Western blot analyses in this study argues strongly against a conformational epitope. Indeed, later studies aimed at more thoroughly mapping the peripherin epitope that is recognized by islet-infiltrating NOD mouse B cells revealed a single linear epitope located within the C-terminal domain (Garabatos et al, 2014; Puertas et al, 2007). This is obviously different than the antigen described here in human T1D patients.…”