Rearrangement analysis of immunoglobulin genes is an exceptional opportunity to look back at the B lymphocyte differentiation during ontogeny and the subsequent immune response, and thus to study the selective pressures involved in autoimmune disorders. In a recent study to characterize the antigenic specificity of B lymphocytes during T1D progression, we generated hybridomas of islet-infiltrating B lymphocytes from NOD mice and other related strains developing insulitis, but with different degrees of susceptibility to T1D. We found that a sizable proportion of hybridomas produced monoclonal antibodies reactive to peripherin, an intermediate filament protein mainly found in the peripheral nervous system. Moreover, we found that anti-peripherin antibody-producing hybridomas originated from B lymphocytes that had undergone immunoglobulin class switch recombination, a characteristic of secondary immune response. Therefore, in the present study we performed immunoglobulin VL and VH analysis of these hybridomas to ascertain whether they were derived from B lymphocytes that had undergone antigen-driven selection. The results indicated that whereas some anti-peripherin hybridomas showed signs of oligoclonality, somatic hypermutation and/or secondary rearrangements (receptor edition and receptor revision), others seemed to directly derive from the preimmune repertoire. In view of these results, we conclude that anti-peripherin B lymphocytes are positively selected and primed in the course of T1D development in NOD mice, and reinforce the idea that peripherin is a relevant autoantigen targeted during T1D development in this animal model.
It has become increasingly appreciated that autoimmune responses against neuronal components play an important role in type 1 diabetes (T1D) pathogenesis. In fact, a large proportion of islet-infiltrating B lymphocytes in the NOD mouse model of T1D produce Abs directed against the neuronal type III intermediate filament protein peripherin. NOD- mice are a previously developed BCR-transgenic model in which virtually all B lymphocytes express the H and L chain Ig molecules from the intra-islet-derived anti-peripherin-reactive hybridoma H280.
Rearrangement analysis of immunoglobulin genes is an exceptional opportunity to look back at the B lymphocyte differentiation during ontogeny and the subsequent immune response, and thus to study the selective pressures involved in autoimmune disorders. In a recent study to characterize the antigenic specificity of B lymphocytes during T1D progression, we generated hybridomas of islet-infiltrating B lymphocytes from NOD mice and other related strains developing insulitis, but with different degrees of susceptibility to T1D. We found that a sizable proportion of hybridomas produced monoclonal antibodies reactive to peripherin, an intermediate filament protein mainly found in the peripheral nervous system.
Gross nuclear morphology is a major diagnostic feature in the identification of subtypes of non-Hodgkin's lymphoma (NHL). The authors have shown that the size, shape, and chromatin distribution of the lymphocyte nuclei vary extensively both within and between samples of a subtype, and have proposed that the variations may reflect qualitative and quantitative differences in extrachromatinic components. To test this hypothesis, the organization of individual nuclear antigens in NHL and in reactive hyperplasia biopsies was examined by immunofluorescence labeling of frozen sections with previously characterized monoclonal antibodies.
