Objective To investigate the contribution of the adhesion receptor DNAX accessory molecule-1 (DNAM-1) in the development of dermal fibrosis on gene inactivation and targeted molecular strategies.
Methods Human skin expression of DNAM-1 was determined by immunohistochemistry. Mice deficient for DNAM-1 (dnam1−/−) and wild-type controls (dnam1+/+) were injected with bleomycin or NaCl. Infiltrating leucocytes, T cells, B cells and monocytes were quantified and inflammatory cytokines were measured in lesional skin of dnam1−/− and dnam1+/+ mice. The anti-fibrotic potential of a DNAM-1 neutralising monoclonal antibody (mAb) was evaluated in the mouse model of bleomycin-induced dermal fibrosis.
Results Overexpression of DNAM-1 was detected in the skin of patients with SSc (systemic sclerosis). Dnam1−/− mice were protected from bleomycin-induced dermal fibrosis with reduction of dermal thickening (75±5%, p=0.03), hydroxyproline content (46±8%, p=0.04) and myofibroblast counts (39±5%, p=0.01). Moreover, the number of T cells was significantly decreased in lesional skin of dnam1−/− mice (69±15%, p=0.0007). Dnam1−/− mice also displayed decreased levels of TNF-α and IL-6 in lesional skin. Consistent with the gene inactivation strategy, treatment of mice with DNAM-1 neutralising mAb prevented dermal fibrosis induced by bleomycin with reduction of dermal thickness (64±6%, p=0.002), hydroxyproline content (61±8%, p=0.004) and myofibroblast counts (83±12%, p=0.002).
Conclusions An inactivation gene strategy showed that DNAM-1 exerts profibrotic effects by controlling T cell activation and cytokine release. A molecular targeted strategy confirmed that DNAM-1 neutralising mAb has potent antifibrotic properties, supporting the hypothesis that inhibition of DNAM-1 might be a promising new approach for the treatment of SSc and potentially other related fibrotic diseases.
- Systemic Sclerosis
- T Cells
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.