Department of Periodontics
http://hdl.handle.net/10675.2/887
2024-03-26T00:50:45ZDendritic Cell Derived Exosomes Loaded with Immunoregulatory Cargo Reprogram local Immune Responses and Inhibit Degenerative Bone Disease In vivo
http://hdl.handle.net/10675.2/623672
Dendritic Cell Derived Exosomes Loaded with Immunoregulatory Cargo Reprogram local Immune Responses and Inhibit Degenerative Bone Disease In vivo
Elashiry, Mahmoud
Background: Histopathological study of periodontitis (PD) lesions at sites of bone
loss reveals infiltration with dendritic cells (DC) CD4+ T cell clusters and other
inflammatory cells. DCs can direct bone protective T-regulatory cell (Tregs) responses,
or bone destructive T-helper 17 (Th17). The use of exosomes (EXO), natural
nanoparticles released by DCs and other cells, are under intense scrutiny in clinical trials
for autoimmune diseases and cancer, but no studies to date have harnessed DC-derived
EXO to regulate alveolar bone loss in PD.
Aim: To determine the ability of custom DC-derived EXO to reprogram immune
cell functions of recipient DCs and T cells and mitigate inflammatory bone loss in mice.
Methods: Murine bone marrow derived donor DC subtypes, including immune
regulatory DCs (regDC), immature DCs (iDC) and immune stimulatory (stimDC) DCs
were the source of purified DC EXO. Reg DC EXO were actively loaded with TGFB1/IL10
using ultrasonication. Preliminary in vitro studies of EXO cargo, stability and resistance
of cytokine cargo to proteolysis, as well as immune functions and osteoclastogenesis was
investigated. The following DC EXO subtypes were then tested in vivo in six groups of
mice, in the ligature induced PD model: Group 1, no ligature, Groups 2, 3, 4, 5 and 6,
8
ligature plus gingival injection of, respectively, PBS, regDC EXO, iDC EXO, stimDC EXO
and free TGFB1/IL10. Biodistribution and in vivo uptake of EXO by gingival recipient DCs
and T cells were tracked. The ability of DC EXO to modulate gingival recipient DC and
CD4 T cells and cytokine expression was confirmed. TRAP staining of histological
sections measured osteoclast number, while bone loss volume was measured in 3-D by
micro-CT.
Results: Injected EXO showed a high affinity for gingival site of inflammatory bone
loss. RegDC EXO containing TGFb/IL-10 cargo, protected cargo against proteolytic
degradation and were taken up by recipient DCs and T cells in vivo, promoting Tregs,
while inhibiting Th17 recruitment and inhibiting bone loss. In contrast, EXO subtypes
lacking TGFb/IL-10 or free TGFB/IL-10 did not shift the Treg-Th17 balance and did not
inhibit bone loss. Mechanistically, a key role for TGFb1 in induction of Tregs by regDC
EXO was found using blocking antibodies to TGFb and/or IL-10. T.E.M. analysis revealed
TGFb1 localized in the EXO lumen and in the transmembrane domain, which sustained
signaling in recipient DCs. Blocking experiments revealed that sustainable prolonged
TGFb1 signaling required initial interaction between regDCs EXO and TGFBR1 complex
on acceptor cells, followed by internalization of regDC EXO with TGFB1-TGFBR1
complex for sustained SMAD2/3 phosphorylation.
Conclusion: This is the first study to demonstrate the efficacy of DCs exosomes
for inhibition of experimental bone loss and the cellular immune mechanisms involved.
This provides the basis for a future novel immunotherapeutic strategy for PD in humans.
2020-12-01T00:00:00ZInfluence of Porphyromonas gingivalis on Anti-Apoptotic/Autophagic Signaling Pathways in Human Dendritic Cells
http://hdl.handle.net/10675.2/623041
Influence of Porphyromonas gingivalis on Anti-Apoptotic/Autophagic Signaling Pathways in Human Dendritic Cells
Meghil, Mohamed; Tawfik, Omnia; Elashirty, Mahmoud; Rajendran, Mythilypriya; Arce, Roger; Schoenlein, Patricia V.; Cutler, Christopher
The purpose of this study was to investigate the molecular mechanisims of P. gingivalis-mediated disruption of homeostatic apoptosis and autophagy in DCs.
2019-01-01T00:00:00ZMurine Dendritic Cell Interactions with Minor-fimbriae P. gingivalis
http://hdl.handle.net/10675.2/623040
Murine Dendritic Cell Interactions with Minor-fimbriae P. gingivalis
Yuan, J; Auersvald, c; Elashiry, M; Meghil, M; Elashiry, M; Finger Stadler, A; Arce, R.M.
The objective was to determine DC maturity phenotype of murine bone marrow-derived DCs in response to wild/type (PgWT) and minor-fimbriated DPG3.
2019-01-01T00:00:00ZInnate Lymphoid Cells in Periodontitis: A Novel Therapeutic Modality
http://hdl.handle.net/10675.2/623037
Innate Lymphoid Cells in Periodontitis: A Novel Therapeutic Modality
Ghaly, Mira; Emami, Golnaz; Khodadadi, Hesam; Mozaffari, Mahmood; Baban, Babak
To determine the presence of ILCs in human periodontium which are emerging immune cells with the potential to be targeted, via novel therapies, in the treatment of peridontitis.
2019-01-01T00:00:00Z