IADR Abstract Archives
The Role of B-Cells in Orthodontic Tooth Movement
Objectives: Orthodontic tooth movement (OTM) relies on a coordinated process of bone resorption and apposition, triggered by an aseptic inflammatory response. Previous studies demonstrated immediate activation of innate and adaptive immunity in response to force application, including upregulation of pathways related to B-cells, however, their role is still obscure. Here, we aim to study the involvement of B cells and their molecular mechanism of action in OTM.
Methods: Ni-Ti springs were set between the upper first molar (M1 mesial shift) and upper incisor of C57BL/6 male mice. Two groups were compared: CD19cre homozygote and WT (control). OTM distance and bone volume fraction (BV/TV) were measured using µCT scanner. Osteoclasts-like cells and B cells were evaluated using Tartrate-Resistant Acid Phosphatase (TRAP) and immunofluorescence staining, respectively. Additionally, RNA sequencing analysis was employed in order to determine the impact of B-cells ablation on the gene expression profile in the force-subjected periodontal tissues.
Results: 14 days following force application CD19cre mice presented a significant reduction of 28% in OTM rate (p<0.0001), 24% in bone volume fraction (p<0.01) and 37% in TRAP+ cells around the compressed alveolar bone (p<0.001). Moreover, numerous CD19+ B-cells were found in the alveolar bone of the WT mice following 3 days of OTM. The RNA sequencing analysis exhibited a distinct down-regulation of genes associated with bone physiology (Amelx), B-cells homing and action in aseptic inflammation (Ccr6, Cxcl13) and pro-inflammatory chemokines (Cxcl2/3/5).
Conclusions: Collectively, the current findings suggest that B-cells and their CD19 receptor play a role in the immune processes underlying the bone remodeling of OTM. This data is supported by the genetic analysis which indicate that B-cells contribute for both inflammatory and bone response pathways associated with force application. These results add “new pieces for the puzzle” in the role of adaptive immunity and B-cells in OTM.
Methods: Ni-Ti springs were set between the upper first molar (M1 mesial shift) and upper incisor of C57BL/6 male mice. Two groups were compared: CD19cre homozygote and WT (control). OTM distance and bone volume fraction (BV/TV) were measured using µCT scanner. Osteoclasts-like cells and B cells were evaluated using Tartrate-Resistant Acid Phosphatase (TRAP) and immunofluorescence staining, respectively. Additionally, RNA sequencing analysis was employed in order to determine the impact of B-cells ablation on the gene expression profile in the force-subjected periodontal tissues.
Results: 14 days following force application CD19cre mice presented a significant reduction of 28% in OTM rate (p<0.0001), 24% in bone volume fraction (p<0.01) and 37% in TRAP+ cells around the compressed alveolar bone (p<0.001). Moreover, numerous CD19+ B-cells were found in the alveolar bone of the WT mice following 3 days of OTM. The RNA sequencing analysis exhibited a distinct down-regulation of genes associated with bone physiology (Amelx), B-cells homing and action in aseptic inflammation (Ccr6, Cxcl13) and pro-inflammatory chemokines (Cxcl2/3/5).
Conclusions: Collectively, the current findings suggest that B-cells and their CD19 receptor play a role in the immune processes underlying the bone remodeling of OTM. This data is supported by the genetic analysis which indicate that B-cells contribute for both inflammatory and bone response pathways associated with force application. These results add “new pieces for the puzzle” in the role of adaptive immunity and B-cells in OTM.