HLA-B27/hβ2m Drosophila a new model to study HLA-B27 implication in spondyloarthritis
Abstract
Aim. Mechanisms underlying the striking association of spondyloarthritis (SpA) with the MHC class I molecule HLA-B27 remain poorly understood. Using genetic models such as Drosophila might be helpful for deciphering the whole cellular cascade, including both specific interactors and downstream elements and allows easier gene function study. For these reasons, we hypothesized that Drosophila could be a relevant model to study HLA-B27 at the cellular and molecular mechanism. To understand HLA-B/hβ2m intracellular trafficking, localization and consequence of its expression, we developed HLA-B2705, HLA-B0702 (control) and human Beta-2-microglobulin (hβ2m) transgenic Drosophila.
Methods. Gateway Technology was used for developing transgenic HLA-B/human B2m Drosophila. hβ2m was inserted in long arm of chromosome 3 and HLA-B2705 and HLAB0702 were inserted in the short arm of same chromosome position. At first, vestigial (Vg) driver was used to produce lines allowing tissue-specific GAL4 expression and the responder lines carry the coding sequence for the gene HLAB0702 and hB2m or HLA-B2705 and hB2m under the control of UAS sites.
Results. Transgenic HLA-B2705/hβ2m Drosophila was expressed in Vg domain. We observed positive staining with HC10 (class I heavy chain) and ME1 (anti-HLA B/C) antibodies, suggesting a proper conformation of HLA-B27 with hβ2m in Vg-domain. In contrast, transgenic HLA-B0702/hβ2m had positive staining only for HC10 antibodies. On the other hand, in transgenic HLA-B/hβ2m, we observed positive staining with W6/32 antibody which recognizes suitable HLA-A, HLA-B and HLA-C conformation. However, we showed that HLA-B2705/hB2m only seems to reach plasma membrane and be expressed at cell surface. Furthermore, we observed specific and different physiological consequences of HLA-B7 and B27 expression in Drosophila.
Conclusion. Taken together, our data suggest that transgenic HLA-B/hβ2m were expressed in Vg-domain and on plasma membrane for HLA-B2705/hB2m but not for HLA-B0702/hβ2m. This is the first time that difference in localization between HLA-B2705 subtype associated with SpA and not associated HLA-B0702 is reported. These results suggest that transgenic Drosophila might be a pertinent model to decipher molecular mechanisms involved in HLA-B27 trafficking and to better understand potential different comportment of HLA-B subtypes.
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Life Sciences [q-bio]Origin | Files produced by the author(s) |
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