Efficient and Selective Prevention of Graft-Versus-Host Disease by Ag-Specific Induced Regulatory T Cells In Mice.

Abstract Abstract 3745 Naturally occurring regulatory T cells (nTregs) suppress the development of graft-versus-host disease (GVHD). The non-selective suppression against tumor associated antigens in some models severely dampened our enthusiasm for the application of nTregs in the control of GVHD after allogeneic hematopoietic cell transplantation (HCT). In this study, we used an alternative strategy to generate antigen-specific, induced Tregs (iTregs), and tested their potential in the prevention of GVHD in murine model of myeloablative BMT. CD4+CD25+Foxp3+ iTregs generated from OT-II TCR transgenic mice specific for OVA target antigen efficiently prevented GVHD induced by polyclonal T effector cells (Teffs) in allogeneic recipients that express OVA protein but not in those that do not express OVA. The efficacy of these antigen-specific iTregs was significantly higher than polyclonal iTregs in preventing GVHD. As controls, OT-II CD4+Foxp3− cells had no effect on GVHD development in OVA− recipients and exacerbated GVHD in OVA+ recipients when transplanted together with polyclonal Teffs. Mechanistically, OT-II iTregs expanded extensively, and significantly suppressed expansion and infiltration of Teffs in OVA+ recipients. In sharp contrast, OT-II iTregs failed to expand and had no effect on Teffs in OVA− recipients. These results reveal the therapeutic potential of TGFβ-induced, antigen-specific iTregs to prevent GVHD efficiently and selectively. Disclosures: No relevant conflicts of interest to declare.

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Prevention of Graft-Versus-Host Disease by HY-Specific Induced Tregs Through Activation-Dependent Manner,

Blood ◽

10.1182/blood.v118.21.4023.4023 ◽

2011 ◽

Vol 118 (21) ◽

pp. 4023-4023

Author(s):

Jun Li ◽

Kenrick Semple ◽

Kane Koasaard ◽

Kelley M.K. Haarberg ◽

Fang-ping Chen ◽

...

Keyword(s):

Graft Versus Host Disease ◽

Hematopoietic Cell Transplantation ◽

Conflicts Of Interest ◽

Target Antigen ◽

Dependent Manner ◽

Host Disease ◽

T Effector Cells ◽

Graft Versus Host

Abstract Abstract 4023 Naturally occurring regulatory T cells (nTregs) may prevent graft-versus-host disease (GVHD) while preserving graft-versus-leukemia (GVL) activity. However, clinical application of nTregs has been severely hampered by their scarce availability and non-selective suppression. To overcome these limitations, we took the alternative approach to induce antigen-specific Tregs (iTregs) and tested their efficacy and selectivity in the prevention of GVHD in a pre-clinical model of bone marrow transplantation (BMT). We selected HY as target antigen, because it is a naturally processed and ubiquitously expressed minor histocompatibility antigen (miHAg) with a proven role in GVHD and GVL effect. To generate HY-specific iTregs, naïve CD4+CD25− cells were isolated from MHC II-restricted, HY-specific transgenic and Foxp3/GFP knock-in mice, and were stimulated with HY peptide and APC, in the presence of TGFb and retinoic acid. Marrow plus polyclonal CD4 T effector cells (Teffs) from B6 donor splenocytes induced GVHD when transplanted into lethally irradiated (B6 x bm12)F1 recipients, and adoptive transfer of HY-specific iTregs (CD4+CD25+GFP+) significantly decreased GVHD mortality in male (HY+) but not female (HY−) recipients. On a per cell basis, HY-specific iTregs were significantly more potent than polyclonal Tregs in the prevention of GVHD. These data indicate that HY-specific iTregs were effective in controlling GVHD in an activation-dependent manner. Because polyclonal Teffs cells recognize bm12 alloantigen whereas iTregs recognize HY miHAg, these data suggest that Tregs may control GVHD through a linked-suppression on Teffs in vivo. Mechanistically, by measuring iTregs and Teffs in spleen and liver of the recipients, we found that HY-specific iTregs expanded extensively and significantly suppressed expansion and infiltration of Teffs in male but not female recipients. We finally generated alloreactive iTregs from polyclonal CD4 precursors, and found that these iTregs highly suppressed the Teffs alloresponse in vitro and in vivo. These results show that Ag-specific iTregs are promising cell therapy for effective GVHD prevention in human allogeneic hematopoietic cell transplantation. Disclosures: No relevant conflicts of interest to declare.

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Preparation of Human Alloantigen-Specific Natural Regulatory T-Cells for the Control of Graft Versus Host Disease.

Blood ◽

10.1182/blood.v114.22.47.47 ◽

2009 ◽

Vol 114 (22) ◽

pp. 47-47

Author(s):

Yamina Hamel ◽

Claude Baillou ◽

Maude Guillot-Delost ◽

Soumia Touil ◽

Mustapha Cherai ◽

...

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Graft Versus Host Disease ◽

Conflicts Of Interest ◽

Therapeutic Potential ◽

Third Party ◽

Host Disease ◽

Cell Ratio ◽

Graft Versus Host ◽

Teff Cell

Abstract Abstract 47 Adoptive transfer of natural regulatory T-cells (Tregs) may have a great therapeutic potential for the induction of tolerance in transplantation patients. This concept was demonstrated in murine models of graft versus host disease (GVHD) where alloantigen-specific Tregs (sTregs) were always more efficient to control GVHD than polyclonal Tregs (pTregs). Recently, we reported a procedure for expanding human pTregs in the presence of anti-CD3/anti-CD28 coated beads, cells being cultured in RPMI medium containing 10% human serum, interleukin (IL)-2 and rapamycin (namely TCM for Tregs Culture Medium) during 3 weeks. Whether or not alloantigen sTregs could be generated for the control of GVHD was investigated. In a first set of experiments, we compared the activation of Tregs when stimulated by allogeneic monocyte-derived dendritic cells (DCs) under different conditions. To follow cell divisions, Tregs (CD4+CD25high T-cells) were purified by FACS, stained with CFSE and co-cultured in TCM ± IL-15 in the presence of either immature (i) or mature (m) allogeneic DCs. Data showed that: i) mDCs yielded higher Treg divisions than iDCs; ii) combination of IL-2 + IL-15 triggered better cell division than IL-2 or IL-15 alone; iii) Tregs divided from day-3 to day-10 when stimulated by mDCs and cultured in TCM + IL-15. Next, the alloantigen specificity of divided Tregs was evaluated: Tregs stimulated by allogeneic mDCs (mDC1) were FACS-sorted at day-4 on the basis of CFSE-staining. CFSElow, CFSEintermediate (int) and CFSEhigh cell fractions were separated and expanded in TCM medium IL-15 in the presence anti-CD3/anti-CD28 coated beads. At day-21, they were assayed for their ability to inhibit within 4 days the proliferation of autologous effector T-cells (Teff) stimulated by either mDC1 or a third party of allogeneic mDCs (mDC2), used as control of specificity. In these mixed leukocyte cultures, different Tregs/Teff cell ratio were tested. Results showed that the CFSElow fraction (highly dividing Tregs) was greatly enriched in sTregs, by contrast to the CFSEhigh and CFSEint fractions. From these data, further experiments that are more suitable for clinical application were performed. Tregs selected by FACS or by immunomagnetic selection (MACs), based on CD25 expression, were cultured in TCM + IL-15 and stimulated twice (day-0 and day-10) by allogeneic mDCs (mDC1). At day-21, the alloantigen-specific suppression of sTregs was studied and compared to the suppression activity of pTregs. Results showed that sTregs better suppressed the proliferation of mDC1-stimulated Teff than pTregs. In addition, sTregs better maintained their suppressive activity than pTregs at low Tregs/Teff cell ratio. Under these culture conditions, sTregs can be expanded ∼12 fold within 3-weeks. Our data showed that human sTregs can be generated under clinical grade conditions. Further experiments using a xenogeneic GVHD model are now envisaged to compare the respective capacity for sTregs and pTregs to control GVHD. Disclosures: No relevant conflicts of interest to declare.

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Therapeutic Potential of Induced and Natural FoxP3+ Regulatory T Cells for the Treatment of Graft-Versus-Host Disease

Archivum Immunologiae et Therapiae Experimentalis ◽

10.1007/s00005-012-0172-3 ◽

2012 ◽

Vol 60 (3) ◽

pp. 183-190 ◽

Cited By ~ 10

Author(s):

Immo Prinz ◽

Christian Koenecke

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Graft Versus Host Disease ◽

Therapeutic Potential ◽

Host Disease ◽

Graft Versus Host

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Regulatory T Cells Preserve Anti-Viral Immunity While Preventing Lethal Graft-Versus-Host Disease

Blood ◽

10.1182/blood.v122.21.5432.5432 ◽

2013 ◽

Vol 122 (21) ◽

pp. 5432-5432

Author(s):

Thomas H. Winkler ◽

Martina Seefried ◽

Irena Kroeger ◽

Petra Hoffmann ◽

Matthias Edinger ◽

...

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Graft Versus Host Disease ◽

Conflicts Of Interest ◽

Viral Immunity ◽

Post Transplantation ◽

Hematopoietic Stem ◽

Host Disease ◽

Graft Versus Host ◽

Cmv Reactivation

Abstract Graft-versus-host disease (GvHD) is a frequent and life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT) and is therefore one of the main factors that limits the broad application of HSCT. Over the last decades, several studies have reported a clinical association between GvHD and reactivation of cytomegalovirus (CMV). Using a lethal murine GvHD model with major MHC mismatch (C57BL/6 -> Balb/c), we were able to demonstrate that recipients latently infected with murine CMV (MCMV) before transplantation showed recurrence of CMV infection concomitant with the manifestation of GvHD. Moreover, these preinfected recipients showed an accelerated mortality compared to recipients that were not preinfected. The therapeutic co-infusion of CD4+CD25+ regulatory T cells (Tregs) with conventional T cells (Tcons) prevented lethal GvHD in preinfected mice and, markedly reduced the recurrence of MCMV infection. Remarkably, these mice showed clearance of MCMV 5 weeks post transplantation in contrast to mice receiving only Tcons in which massive virus infection persisted. Enhanced reconstitution of T lymphocytes and establishment of an anti-MCMV antibody titer from donor B cells in these animals suggest that CD4+CD25+ Tregs do not interfere with an anti-viral response while suppressing Tcon-mediated GvHD. Therefore, our study revealed that the suppressive function of CD4+CD25+ Tregs is not affected by CMV reactivation and more importantly, that Tregs do not adversely affect the anti-viral immunity in the recipient. In sum, these results provide important information on the correlation of GvHD and CMV reactivation and underline the possible clinical benefit of Treg application in GvHD patients. Disclosures: No relevant conflicts of interest to declare.

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