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Deletion of mucosa-associated lymphoid tissue lymphoma translocation protein 1 in mouse T cells protects against development of autoimmune arthritis but leads to spontaneous osteoporosis

Tijdschriftbijdrage - Tijdschriftartikel

Objective: Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT-1) plays a crucial role in innate and adaptive immune signaling by modulating the threshold for activation of immune cells, including Treg cells. Therefore, MALT-1 is regarded to be an interesting therapeutic target in several immune-mediated diseases. The goal of this study was to examine the role of MALT-1 in experimental animal models of rheumatoid arthritis (RA). Methods: MALT-1 activation was assessed by measuring cleavage of the deubiquitinase CYLD in lymphocytes from mice with collagen-induced arthritis (CIA). Furthermore, the impact of MALT-1 deficiency on arthritis was evaluated in Malt1(KO) mice with CIA or with collagen antibody-induced arthritis (CAIA). T cell-specific MALT-1 deficiency was measured in mice with deletion of T cell-specific MALT-1 (Malt1(TcellKO) ), and the time-dependent effects of MALT-1 deficiency were assessed in mice with deletion of tamoxifen-inducible T cell-specific MALT-1 (Malt1(iTcellKO)). Bone density was determined in MALT-1-deficient mice using micro-computed tomography and femur-bending tests. Reconstitution of Treg cells was performed using adoptive transfer experiments. Results: MALT-1 activation was observed in the lymphocytes of mice with CIA. T cell-specific MALT-1 deletion in the induction phase of arthritis (incidence of arthritis, 25% in control mice versus 0% in Malt1(iTcellKO) mice; P < 0.05), but not in the effector phase of arthritis, completely protected mice against the development of CIA. Consistent with this finding, MALT-1 deficiency had no impact on CAIA, an effector phase model of RA. Finally, mice with MALT-1 deficiency showed a spontaneous decrease in bone density (mean SEM trabecular thickness, 46.3 +/- 0.7 mu m in control mice versus 40 +/- 1.1 mu m in Malt1(KO) mice; P < 0.001), which was linked to the loss of Treg cells in these mice. Conclusion: Overall, these data in murine models of RA highlight MALT-1 as a master regulator of T cell activation, which is relevant to the pathogenesis of autoimmune arthritis. Furthermore, these findings show that MALT-1 deficiency can lead to spontaneous osteoporosis, which is associated with impaired Treg cell numbers.
ISSN: 2326-5205
Issue: 12
Volume: 71
Pagina's: 2005 - 2015
Jaar van publicatie:2019