Regulatory T cells manifest IFN-α mediated protection during antigen induced arthritis
(English)Manuscript (preprint) (Other academic)
Type I interferon induces tolerance against arthritogenic antigen and protects against antigen induced arthritis (AIA). Regulatory T cells (Treg cells) resolve aberrant immune reaction, maintain self-tolerance and prevent the development of autoimmune diseases. We here investigated the impact of Interferon alpha (IFN-α) on Treg cells development and function during antigen induced arthritis.
For AIA, mice were immunized with methylated bovine serum albumin (mBSA) at day 1 and 7 in presence or absence of IFN-α. At day 21, arthritis was induced by intra-articular injection of mBSA and arthritis was evaluated at day 28. At various days of AIA, CD4, CD25, Foxp3 and CTLA-4 expression was quantified by FACS in blood cells, splenocytes, lymph nodes cells and in ex vivo re-stimulated leucocytes (pooled splenocytes and lymph nodes cells) isolated at same days. To investigate the importance of Treg cells in IFN-α protection in AIA, Foxp3DTReGFP+mice were used, where Treg cells can be depleted transiently by administration of diptherin toxin. CFSE based suppression assay was used to assess the suppression by Treg cells isolated day 4, 10, 20 of AIA against proliferation of mBSA or anti-CD3 stimulated responder T cells (Tresp cells) isolated at same days. For adoptive transfer experiments, 250,000 Treg cells from IFN-α treated or untreated mice day 20 of AIA were intravenously injected to recipient pre-immunized mice without IFN-α treatment during the induction of arthritis. The importance of IFN-α signalling on T cells for the IFN-α protection was evaluated by using CD4-Cre+/- IFNAR flox/flox mice.
Protective effects of IFN-α in AIA were associated with significant TGF-β dependent increase in Foxp3+ T cells in blood at day 4 and minor increase of Foxp3+T cells in spleen and lymph node cells. However IFN-α signalling in T cells is not required for IFN-α-protection. Upon ex vivo re-stimulation in presence of IFN-α with mBSA but not anti-CD3, the Treg cells numbers were increased in leucocytes isolated from day 4 and day 10 of AIA. Transient depletion of Treg cells during induction of arthritis (day 21) abolished IFN-α-protection however the protection was not affected when Treg cells are depleted during immunization phase (day 1 and day 7). Against mBSA-stimulated proliferation of Tresp cells, suppression by Treg cells isolated from day 10 and day 20 from IFN-α treated mice are significantly higher than Treg cells from untreated mice. Treg cells isolated from IFN-α or untreated mice at day 20 of AIA when transferred to pre-immunized untreated mice prevent the development of arthritis.
Treg cells are critically associated with IFN-α protective effects in AIA. IFN-α enhances TGF-β dependent early development of Treg cells and later IFN-α enhances their suppressive capacity against T cells proliferation in antigen specific manner during AIA.
Interferon alpha, regulatory T cells, antigen induced arthritis, TGF-beta
Pharmacology and Toxicology Rheumatology and Autoimmunity Clinical Medicine
IdentifiersURN: urn:nbn:se:liu:diva-122462OAI: oai:DiVA.org:liu-122462DiVA: diva2:866560
FunderSwedish Research CouncilSwedish Rheumatism AssociationLinköpings universitet