scholarly journals T cell–derived interferon-γ programs stem cell death in immune-mediated intestinal damage

2019 ◽  
Vol 4 (42) ◽  
pp. eaay8556 ◽  
Author(s):  
S. Takashima ◽  
M. L. Martin ◽  
S. A. Jansen ◽  
Y. Fu ◽  
J. Bos ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Paneth Cell ◽  
Interferon Γ ◽  
Cell Compartment ◽  
Stem Cell Compartment ◽  
Immune Mediated ◽  
Donor T Cells ◽  
Epithelial Cultures

Despite the importance of intestinal stem cells (ISCs) for epithelial maintenance, there is limited understanding of how immune-mediated damage affects ISCs and their niche. We found that stem cell compartment injury is a shared feature of both alloreactive and autoreactive intestinal immunopathology, reducing ISCs and impairing their recovery in T cell–mediated injury models. Although imaging revealed few T cells near the stem cell compartment in healthy mice, donor T cells infiltrating the intestinal mucosa after allogeneic bone marrow transplantation (BMT) primarily localized to the crypt region lamina propria. Further modeling with ex vivo epithelial cultures indicated ISC depletion and impaired human as well as murine organoid survival upon coculture with activated T cells, and screening of effector pathways identified interferon-γ (IFNγ) as a principal mediator of ISC compartment damage. IFNγ induced JAK1- and STAT1-dependent toxicity, initiating a proapoptotic gene expression program and stem cell death. BMT with IFNγ–deficient donor T cells, with recipients lacking the IFNγ receptor (IFNγR) specifically in the intestinal epithelium, and with pharmacologic inhibition of JAK signaling all resulted in protection of the stem cell compartment. In addition, epithelial cultures with Paneth cell–deficient organoids, IFNγR-deficient Paneth cells, IFNγR–deficient ISCs, and purified stem cell colonies all indicated direct targeting of the ISCs that was not dependent on injury to the Paneth cell niche. Dysregulated T cell activation and IFNγ production are thus potent mediators of ISC injury, and blockade of JAK/STAT signaling within target tissue stem cells can prevent this T cell–mediated pathology.

scholarly journals T Cell Recruitment to the Intestinal Stem Cell Compartment Drives Immune-Mediated Intestinal Damage after Allogeneic Transplantation

Immunity ◽  
2019 ◽  
Vol 51 (1) ◽  
pp. 90-103.e3 ◽  
Author(s):  
Ya-Yuan Fu ◽  
Anastasiya Egorova ◽  
Catherine Sobieski ◽  
Jason Kuttiyara ◽  
Marco Calafiore ◽  
...  
Keyword(s):  
Stem Cell ◽  
T Cell ◽  
Allogeneic Transplantation ◽  
Intestinal Stem Cell ◽  
Intestinal Damage ◽  
Cell Compartment ◽  
Cell Recruitment ◽  
Stem Cell Compartment ◽  
Immune Mediated

scholarly journals Retarded recovery of functional T cell frequencies in T cell-depleted bone marrow transplant recipients

Blood ◽  
1987 ◽  
Vol 70 (4) ◽  
pp. 960-964 ◽  
Author(s):  
JP Daley ◽  
MK Rozans ◽  
BR Smith ◽  
SJ Burakoff ◽  
JM Rappeport ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
T Lymphocyte ◽  
Marrow Transplant ◽  
Transplant Recipients ◽  
Cell Compartment ◽  
Donor T Cells ◽  
Limiting Dilution

Abstract We have studied the effect of removing donor T cells by treatment with the monoclonal antibody Leu-1 and complement before marrow transplantation on the regeneration of functionally competent T lymphocytes in the blood at selected times after transplant. Using sensitive limiting-dilution methods that allow us to enumerate helper, cytotoxic, and proliferating T lymphocyte precursors, we report that regeneration of a functional T cell compartment is more severely impaired for the first 180 days after transplantation in those patients given T cell-depleted bone marrow than in recipients of untreated marrow. After this first 6 months, however, patients given T cell- depleted bone marrow had blood T cell frequencies comparable to those observed in patients given untreated marrow. Diminished frequencies of reactive T cells in recipients of depleted marrow could leave them more susceptible to infection or to the recurrence of neoplastic cells.

Myeloid Chimerism Reflects Engraftment of Donor Hematopoiesis, Whereas T Cell Chimerism Reflects Survival and Expansion of Donor and Recipient Residual Mature T Cells Early After T Cell Depleted Allogeneic Stem Cell Transplantation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4475-4475
Author(s):  
Jessica C. Harskamp ◽  
Esther H.M. van Egmond ◽  
Hans L. Vos ◽  
Stijn J.M. Halkes ◽  
Roel Willemze ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplantation ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Median Frequency ◽  
Cell Compartment ◽  
Hematopoietic Lineage ◽  
Chimerism Analysis

Abstract Abstract 4475 Allogeneic stem cell transplantation (alloSCT) is frequently complicated by life-threatening graft versus host disease (GVHD). Previous studies demonstrated that T cell depletion (TCD) of the graft significantly decreases the incidence and severity of GVHD, and is associated with a higher percentage of patients with mixed chimerism (MC). In most studies chimerism analysis is performed on the total bone marrow (BM) leukocyte fraction, and changes in chimerism are related to engraftment. In this study we investigated whether MC in the total BM leukocyte fraction truly reflects engraftment or if it is influenced by survival and expansion of donor and recipient residual mature T cells, and whether hematopoietic lineage specific chimerism analysis is therefore a better method to determine engraftment. It is likely that chimerism analysis of the stem cell compartment is best reflected in peripheral blood (PB) in those cells that are continuously produced and short lived, such as monocytes and granulocytes, and therefore PB myeloid chimerism primarily reflects engraftment. In contrast, previous studies have shown by T cell receptor excision circle analysis that T cell neogenesis is virtually absent in the first 6 months after alloSCT, and that predominantly memory T cells are present in PB and BM. Therefore, we hypothesize that MC of these long lived T cells merely reflects survival and expansion of recipient and donor residual T cells. Since the life span of B and NK cells is longer than myeloid cells, but shorter than T cells, we anticipate that in the first 6 months after alloSCT, B and NK cell chimerism reflects a combination of survival and neogenesis. To analyze these hypotheses we performed hematopoietic lineage specific chimerism analysis on PB cells of 22 patients (median age 52 years, range 23-73, 11 males) receiving a TCD alloSCT between June and November 2008 after a myeloablative (n=11) or non myeloablative conditioning regimen (n=11) for AML, ALL, high risk MDS, multiple myeloma, CML, CLL or NHL. At intervals of 6 weeks PB was collected, and monocytes, granulocytes, B and NK cells, CD4+ and CD8+ T cells were sorted. The total leukocyte fraction was obtained by erythrocyte lysis of BM. DNA was isolated to perform chimerism analysis using short tandem repeats - PCR. Our results show that in the BM leukocyte fraction 47% of the patients were MC at 3 months after alloSCT, with a median frequency of patient cells of 4%. However, of the patients with MC in the total leukocyte fraction, 67% was complete chimeric in the myeloid subsets and MC in the T cell compartment. In the PB myeloid subsets (monocytes and granulocytes) less than 28% of the patients were MC during the first 6 months after alloSCT with a median frequency of patient cells less than 5%. In the B and NK cell subsets, at most time points more patients were MC (7-43%) with higher frequencies of patient cells (2-14%) compared to the myeloid subsets. The CD4 and CD8 T cell subsets showed the highest frequencies of MC in numbers of patients (31-61%) as well as the highest MC frequencies of patient cells (13-80%). Phenotypic analysis of the T cell compartment showed that 98% of the CD4 and CD8 T cells were memory cells during the first 6 months after alloSCT. Preliminary data indicate that the median percentage of donor derived T cells increased during the first 6 months after alloSCT, correlating with development of mild GVHD, suggesting that T cell chimerism is influenced by immunogenic triggers. In conclusion, these results illustrate that for engraftment and neogenesis of donor hematopoiesis, myeloid chimerism analysis provides more accurate information than total BM leukocyte chimerism analysis, since the results are greatly influenced by T cell chimerism. Since almost all T cells were memory cells within the first 6 months after alloSCT, T cell chimerism analysis reflects survival and expansion of mature donor as well as recipient T cells, and can therefore not be used to measure engraftment. Disclosures: No relevant conflicts of interest to declare.

Attenuated Acute Graft-Versus-Host Disease Following Allogeneic Stem Cell Transplantation In the Absence of RORγt.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3742-3742
Author(s):  
LeShara M Fulton ◽  
Michael J Carlson ◽  
James Coghill ◽  
Michelle L. West ◽  
Angela Panoskaltisis-Mortari ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplantation ◽  
Graft Versus Host Disease ◽  
Allogeneic Stem Cell Transplantation ◽  
Graft Versus Host ◽  
Donor T Cells

Abstract Abstract 3742 CD4+ T helper (Th) cells play a critical role in the development of Graft-versus-Host Disease (GvHD). The relative contributions of particular Th subsets to GVHD pathogenesis, however, are incompletely understood. In order to clarify the contribution of the Th17 subset to GVHD induction, we made use of mice knocked out at the RORgt locus (RORgt−/−), a transcription factor crucial for Th17 polarization. Methods: Haplotype matched and complete MHC mismatched murine HSCT models were used. For the haploidentical model C57BL/6 (H-2b, B6) mice served as donors while C57BL/6 × DBA2 F1 (H-2bxd, B6D2) mice functioned as recipients. Effector T cells (Teffs) were isolated from the spleens of wild type (WT) B6 and RORgt knockout mice backcrossed 7–8 generations onto a B6 background. B6D2 mice were lethally irradiated with 900 rads on day -1 and injected intravenously with 4 × 106 Teffs from WT or RORgt−/− mice supplemented with 3 × 106 WT T cell depleted bone marrow cells (TCD BM) on day 0. For the completely MHC mismatched model, BALB/c mice (H-2d) were lethally irradiated with 800 rads on day -1 and administered 5 × 105 WT or RORgt−/− Teffs supplemented with 5 × 106 B6 TCD BM on day 0. Results: B6D2 mice that received RORgt−/− Teffs displayed significantly attenuated GvHD, recovering from weight loss by day +31 and demonstrating 100% survival on day +60. Conversely, mice that received WT Teffs showed intense disease progression with 100% mortality by day +31 (Figure A, p<0.0001 for survival comparison between WT and RORgt−/− recipients using Fisher's exact test). Similar results were seen using the completely MHC mismatched model, with superior overall survival noted in those animals receiving RORgt −/− Teffs (put in p value here). Recipients of RORgt −/− T cells demonstrated statistically significant decreased TNF in serum compared to WT recipients (Figure B, p=0.001 comparing WT and RORgt−/− recipients using student's t test). Interestingly, despite the decreased severity of GvHD, serum concentrations of IFN-g were increased in recipients transplanted with RORgt −/− T cells. Chimerism studies post-transplant revealed complete donor reconstitution in recipients of both RORgt−/− and WT Teffs. Donor Teffs isolated from recipient livers post-transplant consistently demonstrated an activated phenotype, with low L selectin and high CD25 expression. Conclusions: T cell expression of the Th17 transcription factor, RORgt, is critical for the development of lethal GvHD following allogeneic stem cell transplantation in both the haploidentical and MHC complete mismatch models. GvHD attenuation in the absence of RORgt is not the result of an inability for donor T cells to undergo activation or to engraft in vivo. Interestingly, the absence of RORgt from donor T cells led to enhanced IFN-g in serum. Thus, in vivo, the Th17 pathway is critical for the induction of GvHD. Disclosures: No relevant conflicts of interest to declare.

Interruption of IFNγR Signaling Results in Altered T Cell Trafficking in Vivo and Abrogation of GvHD While Maintaining a Robust Gvl Response

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 455-455
Author(s):  
Jaebok Choi ◽  
Edward Dela Ziga ◽  
Julie Ritchey ◽  
Lynne Collins ◽  
Julie Prior ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Hematopoietic Stem Cell ◽  
Cell Trafficking ◽  
Hematopoietic Stem ◽  
T Cell Trafficking ◽  
Target Organs ◽  
Donor T Cells

Abstract Abstract 455 Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative treatment for patients with relapsed/refractory leukemia, and marrow failure states such as myelodysplasia and aplastic anemia. However, allo-HSCT is complicated by allogeneic donor T cell-mediated graft-versus-host disease (GvHD) which can be life-threatening especially in recipients of unrelated or HLA-mismatched hematopoietic stem cell products. These same alloreactive donor T cells also mediate a beneficial graft-versus-leukemia (GvL) effect. Thus, the clinical goal in allo-HSCT is to minimize GvHD while maintaining GvL. Recent studies have suggested that this might be achieved by infusing regulatory T cells (Tregs) which in some preclinical models suppress GvHD-causing alloreactive donor T cells but have only limited effects on GvL-promoting alloreactive donor T cells. Unfortunately, Tregs exist in low frequency in the peripheral blood, are costly to purify and expand, and after expansion are difficult to isolate due to the lack of cell surface markers, all of which prevent their routine use in the clinic. Thus, alternative therapeutic approaches that do not require Tregs are needed. We have found that interferon gamma receptor deficient (IFNγR−/−) allogeneic donor T cells induce significantly less GvHD in both a MHC fully-mismatched (B6 (H-2b) → Balb/c (H-2d)) and a minor-mismatched (B6 (H-2b) → B6×129(H-2b)) allo-HSCT models compared to WT T cells. In addition, IFNγR−/− donor T cells maintain a beneficial GvL effect, which has been examined in both systemic leukemia and solid tumor models using luciferase-expressing A20 cells derived from Balb/c. We find that IFNγR−/− T cells migrate primarily to the spleen while WT T cells to GI tract and peripheral lymph nodes (LNs) using bioluminescence imaging (BLI), suggesting that altered T cell trafficking of IFNγR−/− T cells to GvHD target organs might be the major reason for the reduced GvHD. We further demonstrate that the IFNγR-mediated signaling in alloreactive donor T cells is required for expression of CXCR3 which has been implicated in trafficking of T cells to areas of inflammation and target organs, commonly known to be the sites of GvHD. Indeed, CXCR3−/− T cells recapitulate the reduced GvHD potential of IFNγR−/− T cells. In addition, forced overexpression of CXCR3 in IFNγR−/− T cells via retroviral transduction partially rescues the GvHD defect observed in IFNγR−/− T cells. We next examine if inhibition of IFNγR signaling using a small molecule inhibitor can recapitulate the anti-GVHD effects seen in IFNγR−/− T cells. We find that INCB018424, an inhibitor of JAK1/JAK2 which are the mediators of IFNγR signaling, blocks CXCR3 expression in vitro. Most importantly, in vivo administration of INCB018424 after allo-HSCT alters T cell trafficking and significantly reduces GvHD. Thus, the IFNγR signaling pathway represents a promising therapeutic target for future efforts to mitigate GvHD while maintaining GvL after allo-HSCT. Moreover, this pathway can be exploited in other diseases besides GvHD such as those from organ transplantation, chronic inflammatory diseases and autoimmune diseases. Disclosures: DiPersio: genzyme: Honoraria.

Upregulation of Immune Checkpoint Blockade Molecules Post Allogeneic Stem Cell Transplantation Is Necessary but Insufficient to Prevent GvHD

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1101-1101
Author(s):  
Mohammad Sohrab Hossain ◽  
Ghada M Kunter ◽  
Vicky Fayez Najjar ◽  
David L. Jaye ◽  
Edmund K. Waller
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Stem Cell ◽  
T Cell ◽  
Cd8 T Cells ◽  
Acute Gvhd ◽  
Time Points ◽  
Post Transplant ◽  
Donor T Cells ◽  
Over Time

Abstract Donor T-lymphocytes are effective adoptive immunotherapy in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT), but life threatening complications related to GVHD limits its clinical application. Recent advancement in the field of immunotherapy has directed our interest to enhancing the anti-tumor response of donor T cells by modulating expression of checkpoint blockade molecules including programmed death-1 (PD-1), cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) and foxp3, the transcription factor associated with regulatory T cells. The two ligands of PD-1, PD-L1 or PD-L2 are highly expressed in the presence of inflammatory signal induced by infection or cancer and PD-1/PD-L1 interaction negatively regulates T-cell antigen receptor (TCR) signaling and dampen T cell cytotoxic activity. Herein, we studied the role of PD-1, CTLA-4 and transcription factor foxp3 expressing donor CD4+ and CD8+ T cells in the development of GVHD. Methods: We have used two established allo-HSCT murine GvHD models. Lethally irradiated wild type (WT) B6, PD-L1 knock out (KO) B6 and PD-L2 KO B6 mice were transplanted with 2 x 106 splenic T cells and 2 x 106 T cell depleted bone marrow (TCD BM) cells from H-2Kdonors. Lethally irradiated CB6F1 recipients were similarly transplanted with splenocytes and TCD BM cells from B6 donors. Acute GvHD scores were determined by combining scores obtained from histological tissue sections and weight-loss, posture, activity, fur texture and skin integrity following standard published procedures. The activation status of donor T-cells and BM and host-derived non-T cells in GvHD target organs was analyzed by flow cytometry. Data from allo-HSCT recipients were compared with the respective data obtained from B6 à B6 syngenic HSCT (syn-HSCT) recipients. Serum cytokines were determined by Luminex assay. Results: PD-L1 KO B6 allo-HSCT recipients had significantly increased acute GvHD scores compared with WT B6 allo-HSCT recipients (p<0.0005) and B6 PD-L2 KO allo-HSCT recipients (p<0.0005) measured on day 8 after transplant. All PD-L1 KO allo-HSCT recipients died within 10 days post transplant while WT B6 and PD-L2 KO allo-HSCT recipients had 20% mortality until 36 days post transplant. Increased acute GvHD was associated with increased amount of serum inflammatory cytokines and increased numbers of activated PD-1+CD69+CD4+ donor T cells. Interestingly, PD-1 expression on donor CD4+ T cells significantly increased in the spleen of transplant recipients but not in BM, while PD-1 expression was significantly increased on donor CD8+ T cells in both spleen and BM compartments of allo-HSCT recipients compared with the syn-HSCT recipients. CTLA-4 expression on CD4+ and CD8+ donor T cells were significantly increased in spleen in the first two weeks post transplant but decreased at later time points compared with syn-HSCT. Again, CTLA-4 expression on CD4+ donor T cells in the BM remained significantly higher measured on 100+ days post transplant in allo-HSCT recipients compared with the syn-HSCT but similar levels of CTLA-4 expression on CD8+ T cells were measured in BM between these two HSCT recipients. Foxp3 expression on donor T cells and the numbers of CD4+CD25+foxp3+ regulatory T (Tregs) were markedly suppressed in donor T cells on day 4 post HSCT of allo-HSCT recipients compared with the syn-HSCT recipients. Although total numbers of donor T cells in the spleen of allo-HSCT recipients remained low over time, the percentage of PD-L1-expressing donor T cells in spleen were significantly higher (p<0.005) at early time points (day 4) in allo-HSCT recipients compared with the syn-HSCT. While total numbers of host-derived cells in spleen decreased over time in mice that developed GvHD, host-derived PD-L1 expressing CD3+ T cells persisted at higher levels through day 36 post transplant. Additionally, PD-L1 expression was also increased in donor BM-derived T cells and non-T cells populations over time. Collectively, these data indicate that severe GvHD occurs in allo-HSCT recipients in spite of increased numbers of PD-1, CTLA-4 and PD-L1 expressing donor and host cells. The occurrence of severe GvHD in these allo-HSCT models systems was associated with markedly reduced levels of CTLA-4 and foxp3 transcription factor expressing Tregs indicating that these pathways may be more relevant to controlling GvHD than PD-1:PD-L1 expression. Disclosures No relevant conflicts of interest to declare.

Rapamycin Generated Murine Th2/Tc2 Cells Potently Abrogate Fully MHC-Mismatched Hematopoietic Stem Cell (HSC) Graft Rejection.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 192-192
Author(s):  
Jacopo Mariotti ◽  
Jason Foley ◽  
Todd Borenstein ◽  
Soo Han ◽  
Daniel H. Fowler
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Graft Rejection ◽  
Fas Ligand ◽  
Absolute Number ◽  
Th2 Cells ◽  
Ifn Gamma ◽  
Donor T Cells

Abstract We previously showed that costimulated Th2/Tc2 cells abrogate graft rejection. In recent experiments, we found that ex vivo rapamycin generates Th2 cells (Th2R cells) that more potently prevent GVHD relative to control Th2 cells. We thus hypothesized that rapamycin may improve the ability of Th2/Tc2 cells to abrogate graft rejection. To test this hypothesis, we utilized a recently defined model of rejection involving lethal host irradiation and subsequent quantitative host T cell addback [B6(H-2b) into BALB/c(H-2d), TBI:10.5 Gy; 0.1x10^6 host T cell addback]. To generate stem-cell enriched allografts, donor mice were treated with G-CSF (5 microgram/d for 5 d) and resultant spleen cells were expanded for 6 d in rhTPO, rmSCF and rhFLT3L: relative to input cells, the final product was T cell depleted (%CD3 reduced from 9.7±0.6% to 0.4±0.03%) and stem-cell enriched by KLS analysis (%c-kit+Lin-Sca-1+ increased from 5.7±1.8% to 49.08±2.8%) and by functional analysis (%side population increased from 0.24±0.04% to 1.7±0.2). In an initial experiment that did not involve host T cell addback, we determined that 10x10^6 of the HSC product was radioprotective in 100% of recipients (10/10 subjects, 90 d follow-up) and yielded 100% donor chimerism without clinical GVHD. To generate donor Th2/Tc2 and Th2/Tc2R cells, donor T cells were costimulated with anti-CD3/CD28 coated beads and expanded in media supplemented with rmIL-4, rhIL-2, rhIL-7 either without or with high dose rapamycin (10 micromolar). Host-vs-graft (HVG) responses were quantified at d 5 post transplant by the following method: (a) spleen cell harvest and enumeration; (b) 24 h host (syngeneic) or donor (allogeneic) dendritic cell stimulation; (c) cell-surface flow cytometry with anti-CD4, anti-CD8 and anti-host (H-2d) antibodies; (d) Miltenyi IFN-gamma cytokine capture flow cytometry; and (e) calculation of absolute number of host anti-donor alloreactive CD4+ and CD8+ T cells per spleen. HSC transfer without Th2/Tc2 cells induced robust CD4- and CD8-mediated HVG responses (Fig.1, cohort 2>cohort 1; p<0.001). HSC transfer augmented with donor Th2/Tc2R cells fully abrogated HVG responses; in marked contrast, HSC transfer augmented with control Th2/Tc2 cells only partially reduced HVG responses. Rapamycin generated Th2/Tc2 cells were more potent than control Th2/Tc2 cells with respect to abrogation of both CD4- and CD8-mediated HVG responses (p<0.05). The mechanism of Th2/Tc2R cells abrogation of HVG responses involved both CD4+Th2R and CD8+Tc2R cell components, and did not require IL-4, perforin, or fas ligand. At day 90 post transplant, Th2/Tc2R cell recipients had nominal GVHD (<5% weight loss) and consistent alloengraftment (>99% chimerism, 9 of 10 recipients; rejection, 1 of 10 recipients); in marked contrast, control Th2/Tc2 cell recipients had either graft rejection (9 of 10 recipients) or mixed chimerism (1 of 10 recipients). In conclusion, ex vivo rapamycin generates donor Th2/Tc2 cells that potently abrogate HVG responses and HSC graft rejection through a mechanism that involves CD4+Th2 and CD8+Tc2 cells and non-classical molecular effectors. Figure 1: Donor Th2/Tc2R Cell Modulation of HVG Responses. B6-into-BALB/c transplantation was performed (10 x 106 donor HSC; 10 x 106 donor T cells; 1 x 106 host T cells; 1050 cGy XRT; n=10 mice per cohort). Mice were killed at d 5 post-SCT, and absolute number of host anti-donor alloreactive CD4 and CD8 Cells was determined by IFN-gamma cytokine capture flow cytometry. * indicates p<0.05 and ** indicates p<0.001 (student’s t-test); each cohort compared with cohort #2. Abbreviations: KO, Knockout, PFN, perfocin, FASL, fas ligand. Figure 1:. Donor Th2/Tc2R Cell Modulation of HVG Responses. B6-into-BALB/c transplantation was performed (10 x 106 donor HSC; 10 x 106 donor T cells; 1 x 106 host T cells; 1050 cGy XRT; n=10 mice per cohort). Mice were killed at d 5 post-SCT, and absolute number of host anti-donor alloreactive CD4 and CD8 Cells was determined by IFN-gamma cytokine capture flow cytometry. * indicates p<0.05 and ** indicates p<0.001 (student’s t-test); each cohort compared with cohort #2. Abbreviations: KO, Knockout, PFN, perfocin, FASL, fas ligand.

Interruption of the IFN γR/CXCR3 Axis Results in Altered T Cell Trafficking In Vivo and Abrogation of GvHD While Maintaining a Robust Gvl Response

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2971-2971
Author(s):  
Jaebok Choi ◽  
Edward Dela Ziga ◽  
Julie Ritchey ◽  
Julie Prior ◽  
Lynne Collins ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Hematopoietic Stem Cell ◽  
Neutralizing Antibodies ◽  
Conflicts Of Interest ◽  
Hematopoietic Stem ◽  
Target Organs ◽  
Donor T Cells

Abstract Abstract 2971 Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative treatment for patients with relapsed/refractory leukemia, and marrow failure states such as myelodysplasia and aplastic anemia. However, allo-HSCT is complicated by allogeneic donor T cell-mediated graft-versus-host disease (GvHD) which can be life-threatening especially in recipients of unrelated or HLA-mismatched hematopoietic stem cell products. These same alloreactive donor T cells also mediate a beneficial graft-versus-leukemia (GvL) effect. Thus, the clinical goal in allo-HSCT is to minimize GvHD while maintaining GvL. Recent studies have suggested that this might be achieved by infusing regulatory T cells (Tregs) which in some preclinical models suppress GvHD-causing alloreactive donor T cells but have only limited effects on GvL-promoting alloreactive donor T cells. Unfortunately, Tregs exist in low frequency in the peripheral blood, are costly to purify and expand, and after expansion are difficult to isolate due to the lack of cell surface markers, all of which prevent their routine use in the clinic. Thus, alternative therapeutic approaches that do not require Tregs are needed. Using a MHC-mismatched GvHD model, B6 (H-2b) → Balb/c (H-2d), we demonstrated that infusion of IFN γR deficient allogeneic donor T cells induce significantly less GvHD, compared to WT T cells, determined by survival (74% vs. 0 % in overall survival; p =0.0004), weight and percentages of B220+ B cells (12.4% vs. 3.8%; p =0.0205), CD3+ T cells (14.3% vs. 4.3%; p =0.0025) in blood. Of note was that the IFN γR deficient donor T cells maintained a beneficial GvL effect, which was examined in both a systemic leukemia and a solid tumor model using luciferase-expressing A20 cells derived from Balb/c. We found that IFN γR deficient donor T cells responded normally to allogeneic antigens as measured by in vitro mixed lymphocyte reaction analyses, and express similar levels of granzyme B, compared to WT T cells. However, IFN γR deficient T cells trafficked predominantly to the spleen while WT T cells trafficked to gastrointestinal tract and peripheral lymph nodes, which are major GvHD target organs, based on in vivo bioluminescence imaging. All of these findings suggest that the reduced GvHD was not due to reduced function, altered subsets or relative deficiency of allogeneic donor T cells but from modification of in vivo trafficking of IFN γR deficient donor T cells compared to WT T cells. We further demonstrated that the IFN γR-mediated signaling in alloreactive donor T cells was required for expression of CXCR3 which has been implicated in trafficking of T cells to areas of inflammation and target organs, commonly known to be the sites of GvHD. CXCR3−/− T cells demonstrated a reduction in GvHD while maintenance of the same robust GvL effect using the same MHC mismatched transplant model. Thus, the IFN γR-CXCR3 axis represents a promising therapeutic target for future efforts to mitigate GvHD while maintaining GvL after allo-HSCT. Current studies are focused on 1) whether forced expression of CXCR3 rescues the GvHD-inducing potential of IFN γR deficient donor T cells and 2) if inhibition of IFN γR signaling (IFN γR, JAK1 and/or JAK2, CXCR3 and STAT1) using both neutralizing antibodies and small molecule inhibitors can recapitulate the anti-GvHD and pro-GvL effects seen in IFN γR−/− and CXCR3−/− T cells. Disclosures: No relevant conflicts of interest to declare.

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