scholarly journals Pharmacological Modulation of the Wnt/β-Catenin Pathway Inhibits Proliferation and Promotes Differentiation of Long-Lived Memory CD4+ T Cells in Antiretroviral Therapy-Suppressed Simian Immunodeficiency Virus-Infected Macaques

2019 ◽  
Vol 94 (1) ◽  
Author(s):  
M. Mavigner ◽  
M. Zanoni ◽  
G. K. Tharp ◽  
J. Habib ◽  
C. R. Mattingly ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Viral Reservoir ◽  
Self Renewal ◽  
Hiv Persistence ◽  
Latently Infected ◽  
Infected Cells

ABSTRACT The major obstacle to human immunodeficiency type 1 virus (HIV-1) eradication is a reservoir of latently infected cells that persists despite long-term antiretroviral therapy (ART) and is maintained through cellular proliferation. Long-lived memory CD4+ T cells with high self-renewal capacity, such as central memory (CM) T cells and stem cell memory (SCM) T cells, are major contributors to the viral reservoir in HIV-infected individuals on ART. The Wnt/β-catenin signaling pathway regulates the balance between self-renewal and differentiation of SCM and CM T cells, and pharmacological manipulation of this pathway offers an opportunity to interfere with the proliferation of latently infected cells. Here, we evaluated in vivo a novel approach to inhibit self-renewal of SCM and CM CD4+ T cells in the rhesus macaque (RM) model of simian immunodeficiency (SIV) infection. We used an inhibitor of the Wnt/β-catenin pathway, PRI-724, that blocks the interaction between the coactivator CREB-binding protein (CBP) and β-catenin, resulting in the cell fate decision to differentiate rather than proliferate. Our study shows that PRI-724 treatment of ART-suppressed SIVmac251-infected RMs resulted in decreased proliferation of SCM and CM T cells and modified the SCM and CM CD4+ T cell transcriptome toward a profile of more differentiated memory T cells. However, short-term treatment with PRI-724 alone did not significantly reduce the size of the viral reservoir. This work demonstrates for the first time that stemness pathways of long-lived memory CD4+ T cells can be pharmacologically modulated in vivo, thus establishing a novel strategy to target HIV persistence. IMPORTANCE Long-lasting CD4+ T cell subsets, such as central memory and stem cell memory CD4+ T cells, represent critical reservoirs for human immunodeficiency virus (HIV) persistence despite suppressive antiretroviral therapy. These cells possess stem cell-like properties of enhanced self-renewal/proliferation, and proliferation of latently infected memory CD4+ T cells plays a key role in maintaining the reservoir over time. Here, we evaluated an innovative strategy targeting the proliferation of long-lived memory CD4+ T cells to reduce viral reservoir stability. Using the rhesus macaque model, we tested a pharmacological inhibitor of the Wnt/β-catenin signaling pathway that regulates T cell proliferation. Our study shows that administration of the inhibitor PRI-724 decreased the proliferation of SCM and CM CD4+ T cells and promoted a transcriptome enriched in differentiation genes. Although the viral reservoir size was not significantly reduced by PRI-724 treatment alone, we demonstrate the potential to pharmacologically modulate the proliferation of memory CD4+ T cells as a strategy to limit HIV persistence.

scholarly journals Reactivation Kinetics of HIV-1 and Susceptibility of Reactivated Latently Infected CD4+T Cells to HIV-1-Specific CD8+T Cells

2015 ◽  
Vol 89 (18) ◽  
pp. 9631-9638 ◽  
Author(s):  
Victoria E. K. Walker-Sperling ◽  
Valerie J. Cohen ◽  
Patrick M. Tarwater ◽  
Joel N. Blankson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Time Frame ◽  
Virus Release ◽  
Latently Infected ◽  
Shock And Kill ◽  
Infected Cells ◽  
Kinetics Of ◽  
Hiv 1

ABSTRACTThe “shock and kill” model of human immunodeficiency virus type 1 (HIV-1) eradication involves the induction of transcription of HIV-1 genes in latently infected CD4+T cells, followed by the elimination of these infected CD4+T cells by CD8+T cells or other effector cells. CD8+T cells may also be needed to control the spread of new infection if residual infected cells are present at the time combination antiretroviral therapy (cART) is discontinued. In order to determine the time frame needed for CD8+T cells to effectively prevent the spread of HIV-1 infection, we examined the kinetics of HIV transcription and virus release in latently infected cells reactivatedex vivo. Isolated resting, primary CD4+T cells from HIV-positive (HIV+) subjects on suppressive regimens were found to upregulate cell-associated HIV-1 mRNA within 1 h of stimulation and produce extracellular virus as early as 6 h poststimulation. In spite of the rapid kinetics of virus production, we show that CD8+T cells from 2 out of 4 viremic controllers were capable of effectively eliminating reactivated autologous CD4+cells that upregulate cell-associated HIV-1 mRNA. The results have implications for devising strategies to prevent rebound viremia due to reactivation of rare latently infected cells that persist after potentially curative therapy.IMPORTANCEA prominent HIV-1 cure strategy termed “shock and kill” involves the induction of HIV-1 transcription in latently infected CD4+T cells with the goal of elimination of these cells by either the cytotoxic T lymphocyte response or other immune cell subsets. However, the cytotoxic T cell response may also be required after curative treatment if residual latently infected cells remain. The kinetics of HIV-1 reactivation indicate rapid upregulation of cell-associated HIV-1 mRNA and a 5-h window between transcription and virus release. Thus, HIV-specific CD8+T cell responses likely have a very short time frame to eliminate residual latently infected CD4+T cells that become reactivated after discontinuation of antiretroviral therapy following potentially curative treatment strategies.

scholarly journals The Pathway To Establishing HIV Latency Is Critical to How Latency Is Maintained and Reversed

2018 ◽  
Vol 92 (13) ◽  
pp. e02225-17 ◽  
Author(s):  
Simin D. Rezaei ◽  
Hao K. Lu ◽  
J. Judy Chang ◽  
Ajantha Rhodes ◽  
Sharon R. Lewin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Egfp Expression ◽  
Hiv Latency ◽  
Latently Infected ◽  
Infected Cells ◽  
Virus Expression

ABSTRACTHIV infection requires lifelong antiretroviral therapy because of the persistence of latently infected CD4+T cells. The induction of virus expression from latently infected cells occurs following T cell receptor (TCR) activation, but not all latently infected cells respond to TCR stimulation. We compared two models of latently infected cells using an enhanced green fluorescent protein (EGFP) reporter virus to infect CCL19-treated resting CD4+(rCD4+) T cells (preactivation latency) or activated CD4+T cells that returned to a resting state (postactivation latency). We isolated latently infected cells by sorting for EGFP-negative (EGFP−) cells after infection. These cells were cultured with antivirals and stimulated with anti-CD3/anti-CD28, mitogens, and latency-reversing agents (LRAs) and cocultured with monocytes and anti-CD3. Spontaneous EGFP expression was more frequent in postactivation than in preactivation latency. Stimulation of latently infected cells with monocytes/anti-CD3 resulted in an increase in EGFP expression compared to that for unstimulated controls using the preactivation latency model but led to a reduction in EGFP expression in the postactivation latency model. The reduced EGFP expression was not associated with reductions in the levels of viral DNA or T cell proliferation but depended on direct contact between monocytes and T cells. Monocytes added to the postactivation latency model during the establishment of latency reduced spontaneous virus expression, suggesting that monocyte-T cell interactions at an early time point postinfection can maintain HIV latency. This direct comparison of pre- and postactivation latency suggests that effective strategies needed to reverse latency will depend on how latency is established.IMPORTANCEOne strategy being evaluated to eliminate latently infected cells that persist in HIV-infected individuals on antiretroviral therapy (ART) is to activate HIV expression or production with the goal of inducing virus-mediated cytolysis or immune-mediated clearance of infected cells. The gold standard for the activation of latent virus is T cell receptor stimulation with anti-CD3/anti-CD28. However, this stimulus activates only a small proportion of latently infected cells. We show clear differences in the responses of latently infected cells to activating stimuli based on how latent infection is established, an observation that may potentially explain the persistence of noninduced intact proviruses in HIV-infected individuals on ART.

scholarly journals Significant Depletion of CD4+T Cells Occurs in the Oral Mucosa during Simian Immunodeficiency Virus Infection with the Infected CD4+T Cell Reservoir Continuing to Persist in the Oral Mucosa during Antiretroviral Therapy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jeffy George ◽  
Wendeline Wagner ◽  
Mark G. Lewis ◽  
Joseph J. Mattapallil
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Simian Immunodeficiency Virus ◽  
Oral Mucosa ◽  
Mucosal Immunity ◽  
Viral Reservoir ◽  
Long Term Outcome ◽  
Immunodeficiency Virus ◽  
A Minor

Human and simian immunodeficiency virus (HIV and SIV) infections are characterized by manifestation of numerous opportunistic infections and inflammatory conditions in the oral mucosa. The loss of CD4+T cells that play a critical role in maintaining mucosal immunity likely contributes to this process. Here we show that CD4+T cells constitute a minor population of T cells in the oral mucosa and display a predominantly central memory phenotype mirroring other mucosal sites such as the rectal mucosa. Chronic SIV infection was associated with a near total depletion of CD4+T cells in the oral mucosa that appear to repopulate during antiretroviral therapy (ART). Repopulating CD4+T cells harbored a large fraction of Th17 cells suggesting that ART potentially reconstitutes oral mucosal immunity. However, a minor fraction of repopulating CD4+T cells harbored SIV DNA suggesting that the viral reservoir continues to persist in the oral mucosa during ART. Therapeutic approaches aimed at obtaining sustainable CD4+T cell repopulation in combination with strategies that can eradicate the latent viral reservoir in the oral mucosa are essential for better oral health and long-term outcome in HIV infected patients.

scholarly journals Early Reconstitution of Antibody Secreting Cells after Allogeneic Stem Cell Transplantation

2022 ◽  
Vol 11 (1) ◽  
pp. 270
Author(s):  
Martina Hinterleitner ◽  
Clemens Hinterleitner ◽  
Elke Malenke ◽  
Birgit Federmann ◽  
Ursula Holzer ◽  
...  
Keyword(s):  
Innate Immunity ◽  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
B Cells ◽  
Stem Cell Transplantation ◽  
B Cell ◽  
Cell Transplantation ◽  
Antibody Secreting Cells

Immune cell reconstitution after stem cell transplantation is allocated over several stages. Whereas cells mediating innate immunity recover rapidly, adaptive immune cells, including T and B cells, recover slowly over several months. In this study we investigated kinetics and reconstitution of de novo B cell formation in patients receiving CD3 and CD19 depleted haploidentical stem cell transplantation with additional in vivo T cell depletion with monoclonal anti-CD3 antibody. This model enables a detailed in vivo evaluation of hierarchy and attribution of defined lymphocyte populations without skewing by mTOR- or NFAT-inhibitors. As expected CD3+ T cells and their subsets had delayed reconstitution (<100 cells/μL at day +90). Well defined CD19+ B lymphocytes of naïve and memory phenotype were detected at day +60. Remarkably, we observed a very early reconstitution of antibody-secreting cells (ASC) at day +14. These ASC carried the HLA-haplotype of the donor and secreted the isotypes IgM and IgA more prevalent than IgG. They correlated with a population of CD19− CD27− CD38low/+ CD138− cells. Of note, reconstitution of this ASC occurred without detectable circulating T cells and before increase of BAFF or other B cell stimulating factors. In summary, we describe a rapid reconstitution of peripheral blood ASC after CD3 and CD19 depleted haploidentical stem cell transplantation, far preceding detection of naïve and memory type B cells. Incidence before T cell reconstitution and spontaneous secretion of immunoglobulins allocate these early ASC to innate immunity, eventually maintaining natural antibody levels.

scholarly journals Infectious Virus Persists in CD4+T Cells and Macrophages in Antiretroviral Therapy-Suppressed Simian Immunodeficiency Virus-Infected Macaques

2019 ◽  
Vol 93 (15) ◽  
Author(s):  
Celina M. Abreu ◽  
Rebecca T. Veenhuis ◽  
Claudia R. Avalos ◽  
Shelby Graham ◽  
Suzanne E. Queen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Infectious Virus ◽  
Treatment Interruption ◽  
Viral Rebound ◽  
Hiv Cure ◽  
Macaque Model ◽  
Immunodeficiency Virus ◽  
Latently Infected

ABSTRACTUnderstanding the cellular and anatomical sites of latent virus that contribute to human immunodeficiency virus (HIV) rebound is essential for eradication. In HIV-positive patients, CD4+T lymphocytes comprise a well-defined functional latent reservoir, defined as cells containing transcriptionally silent genomes able to produce infectious virus once reactivated. However, the persistence of infectious latent virus in CD4+T cells in compartments other than blood and lymph nodes is unclear. Macrophages (Mϕ) are infected by HIV/simian immunodeficiency virus (SIV) and are likely to carry latent viral genomes during antiretroviral therapy (ART), contributing to the reservoir. Currently, the gold standard assay used to measure reservoirs containing replication-competent virus is the quantitative viral outgrowth assay (QVOA). Using an SIV-macaque model, the CD4+T cell and Mϕ functional latent reservoirs were measured in various tissues using cell-specific QVOAs. Our results showed that blood, spleen, and lung in the majority of suppressed animals contain latently infected Mϕs. Surprisingly, the numbers of CD4+T cells, monocytes, and Mϕs carrying infectious genomes in blood and spleen were at comparable frequencies (∼1 infected cell per million). We also demonstrate thatex vivoviruses produced in the Mϕ QVOA are capable of infecting activated CD4+T cells. These results strongly suggest that latently infected tissue Mϕs can reestablish productive infection upon treatment interruption. This study provides the first comparison of CD4+T cell and Mϕ functional reservoirs in a macaque model. It is the first confirmation of the persistence of latent genomes in monocytes in blood and Mϕs in the spleen and lung of SIV-infected ART-suppressed macaques. Our results demonstrate that transcriptionally silent genomes in Mϕs can contribute to viral rebound after ART interruption and should be considered in future HIV cure strategies.IMPORTANCEThis study suggests that CD4+T cells found throughout tissues in the body can contain replication-competent SIV and contribute to rebound of the virus after treatment interruption. In addition, this study demonstrates that macrophages in tissues are another cellular reservoir for SIV and may contribute to viral rebound after treatment interruption. This new insight into the size and location of the SIV reservoir could have great implications for HIV-infected individuals and should be taken into consideration for the development of future HIV cure strategies.

scholarly journals Interleukin-7 promotes HIV persistence during antiretroviral therapy

Blood ◽  
2013 ◽  
Vol 121 (21) ◽  
pp. 4321-4329 ◽  
Author(s):  
Claire Vandergeeten ◽  
Rémi Fromentin ◽  
Sandrina DaFonseca ◽  
Mariam B. Lawani ◽  
Irini Sereti ◽  
...  
Keyword(s):  
T Cells ◽  
Antiretroviral Therapy ◽  
Cd4 T Cells ◽  
Viral Latency ◽  
Absolute Number ◽  
Hiv Persistence ◽  
Hiv Dna ◽  
Interleukin 7 ◽  
Key Points ◽  
Latently Infected

Key Points IL-7 does not disrupt viral latency in highly pure resting latently infected CD4+ T cells from HIV-infected subjects receiving ART. IL-7 therapy leads to a 70% increase in the absolute number of circulating CD4+ T cells harboring integrated HIV DNA 4 weeks posttherapy.

Retroviral Gene Transfer of T Cell Receptors (TCR) Specific for Minor Histocompatibility Antigens to Virus-Specific T Cells as Cellular Immunotherapy of Patients with Relapsed Hematological Malignancies after Allogeneic Stem Cell Transplantation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5529-5529
Author(s):  
Marieke Griffioen ◽  
H.M. Esther van Egmond ◽  
Menno A.W.G. van der Hoorn ◽  
Renate S. Hagedoorn ◽  
Michel Kester ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Hematological Malignancies ◽  
Surface Expression ◽  
Retroviral Vector ◽  
Cellular Immunotherapy ◽  
Minor Histocompatibility Antigens ◽  
Vector Coding

Abstract Patients with hematological malignancies can be successfully treated by T cell-depleted allogeneic stem cell transplantation (alloSCT) followed by donor lymphocyte infusion (DLI). Failure of some relapsed hematological malignancies to respond to DLI is probably due to immune tolerance induced by regulatory and/or anergic T cells. We previously showed that functional T cells with redirected anti-leukemic reactivity can be generated by transfer of TCRs specific for minor histocompatibility antigens (mHags) to total peripheral blood mononuclear cells (PBMC) as well as CMV-specific T cells. By introducing TCRs into CMV or EBV specific T cells, T cells with proper memory/effector phenotypes are targeted, and due to virus persistence these T cells may show prolonged survival in vivo. The purpose of this study is to develop an efficient method for the isolation, retroviral transduction and expansion of TCR-transduced CMV- and EBV-specific T cells for cellular immunotherapy of patients with relapsed hematological malignancies after alloSCT. For clinical application, construction of single retroviral vectors coding for the α as well as β chains of mHag-specific TCRs is required. We used the MP71 retroviral vector for TCR gene transfer, since this vector contains Myeloproliferative Sarcoma Virus LTR sequences and a Mouse Embryonic Stem Cell Virus leader, which has been optimized for use in the clinic. The MP71 vector also contained a Woodchuck Hepatitis Response Element (WPRE). The WPRE, which is used as an element enhancing transgene expression at the post-transcriptional level, has recently been described to encode 60 amino acids of a protein with potential oncogenic activity. Therefore, we reconstructed the MP71 vector by introduction of a multiple cloning site (MCS) and, for safety issues, deleted the WPRE. The TCR α and β genes specific for the hematopoietic-restricted mHag HA-2 were linked by a 50-bp sequence encoding a “self-cleaving” 2A-like peptide and introduced into the MCS of the MP71 vector. Linkage of the TCR α and β genes by the 2A-like sequence allowed additional linkage of the low affinity nerve growth factor receptor (LNGFR) or human CD20 selection marker genes by an IRES sequence. The advantage of the human CD20 gene is that it can also function as suicide gene, allowing elimination of transduced cells in vivo if undesired side effects occur. Introduction of the single MP71 retroviral vector coding for the HA-2 TCR α and β chains as well as LNGFR into a TCR α- and β-deficient Jurkat T cell line led to high levels of TCR surface expression correlating with LNGFR marker gene expression. These data indicate proper cleavage and assembly of the transduced TCR α and β chains. Moreover, removal of the WPRE did not affect the surface expression level of the transduced TCR. Furthermore, CMV- and EBV-specific T cells were isolated from human individuals by the IFN-γ capture assay and subsequently transduced with a single retroviral vector coding for the HA-2-TCR α and β chains as well as LNGFR. CMV- and EBV-specific T cells from different human individuals could be successfully isolated to 60–90% purity and the TCR-transduced CMV- and EBV-specific T cells were shown to be fully functional, recognizing the viral peptides as well as the endogenously-processed HA-2 mHag.

Adoptive Transfer of Adenovirus Specific T-Cells in Children with Systemic Adenovirus Infection after Allogeneic Stem Cell Transplantation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 80-80
Author(s):  
Tobias F. Feuchtinger ◽  
Susanne Matthes-Martin ◽  
Celine Richard ◽  
Thomas Lion ◽  
Klaus Hamprecht ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplantation ◽  
Adoptive Transfer ◽  
Cell Transfer ◽  
New Treatment ◽  
T Cell Transfer

Abstract Allogeneic stem cell transplantation (SCT) has become an increasing treatment option for a variety of malignant and non-malignant disease. During immune reconstitution the host is at significant risk for viral infections. Human adenovirus (HAdV) infection is especially in children an important and serious complication. Virus-specific T-cells are essential for the clearance of HAdV, since antiviral chemotherapy has been insufficient to date. We present a new treatment option using virus-specific donor T-cells for adoptive transfer of immunity to patients with systemic HAdV-infection. We isolated in 6 patients with systemic HAdV-infection after SCT virus-specific T-cells of the donor, according to INF-γ secretion after short in vitro stimulation with viral antigen, resulting in a combination of CD4+ and CD8+ T-cells. Between 5-50x103/kg T-cells were infused for adoptive transfer. For follow-up, the infection and the in-vivo expansion of infused T-cells were evaluated. Isolated cells showed high specificity and markedly reduced but residual alloreactivity in-vitro. In three of four evaluable patients the infused T-cells underwent an in-vivo expansion and in these three patients the viral load decreased in peripheral blood after adoptive T-cell transfer. In-vivo expansion of specific T-cells was dose-independent. T-cell infusion was well tolerated. One patient experienced GvHD°II of the skin after T-cell transfer. In conclusion specific T-cell immunotherapy as a new treatment approach for children was performed in 6 cases of systemic HAdV-infection after allogeneic SCT. Induction of a specific T-cell response through adoptive transfer has been shown feasible and effective to protect from HAdV-related complications.

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.

Effect of a Novel Nucleoside Analogue, Triciribine Phosphate (TCN-P) on Murine Acute Graft-Vrs-Host Disease (aGvHD)

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2977-2977
Author(s):  
Edward Dela Ziga ◽  
Jaebok Choi ◽  
Mark Needles ◽  
Julie Ritchey ◽  
John F. DiPersio
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Nucleoside Analogue ◽  
Foxp3 Expression ◽  
Negative Control ◽  
Jurkat Cells ◽  
Acute Graft

Abstract Abstract 2977 BACKGROUND: The successful establishment of donor registries and development of improved conditioning regimens among others, has led to the increased use of hematopoietic stem cell transplant (HSCT) as a key component in the treatment of some malignant and benign hematopoietic/lymphoid disorders as well as some metabolic disorders. Although a potential curative therapy for many hematologic diseases, allogeneic stem cell transplantation is associated with considerable morbidity and mortality primarily from acute graft-versus-host disease (aGvHD). Furthermore, graft-versus-leukemia (GVL) mediated by donor T cells can be abrogated with T cell depletion or suppression in vivo resulting in disease relapse with treatment of aGvHD. Moreso, modern therapies for aGvHD are limited and often toxic, thus there is a need for novel treatments and approaches that control aGvHD without compromising GVL. Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor has been shown to decrease the severity of aGvHD (Reddy et al, PNAS 2004) through its effect on pro-inflammatory cytokines while maintaining GVL in a murine GvHD model. Also, previous work from our lab demonstrated that treatment of mice with the hypomethylating agent azacitidine (AzaC) after allogeneic HSCT mitigates aGvHD while preserving GVL by inducing FOXP3 expression in activated non-T regulatory cells (Choi et al, Blood 2010). However, the myelosuppression mediated by AzaC is a potential limitation that results in delayed donor engraftment. This led us to explore alternate options for single or combination drug therapy in the treatment of aGvHD. We screened a library of 2000 chemical agents obtained from the National Institutes of Health. Screening resulted in a single hit identified as Triciribine phosphate (TCN-P), an Akt inhibitor with structural similarity to the nucleoside analogue AzaC. In this experiment, a Foxp3 promoter-luciferase construct was designed and transfected into Jurkat cells. Cells were incubated for 2 days and then treated with three concentrations (0.1uM, 1umM and 10uM) of each chemical agent in the library. Bioluminescence imaging (BLI) was done on day 4 with AzaC as positive control (Choi et al, Blood 2010) and PBS as negative control. Only wells treated with TCN-P 10uM showed a signal, suggesting luciferase activity secondary to the Foxp3-promoter activation. We therefore hypothesized that TCN-P as a single agent or in combination with SAHA and or AzaC would mitigate GvHD by inducing FOXP3 without interfering with engraftment or immune reconstitution. METHODS: Using a C57BL/6(H2b) into Balb/c (H2d) murine MHC mismatch bone marrow transplant (BMT) model, we transplanted 5 × 106 T cell-depleted (TCD) bone marrow cells obtained from C57BL/6 (H2b, CD45.1+) mice into Balb/c (H2d, CD45.2+) mice after 900cGy of TBI. Delayed donor infusions of 2 × 106 pan-T cells/mouse obtained from FOXP3/GFP KI: B6 CD45.2+ H2b mice were infused on Day +11 in order to induce GvHD. Azacitidine 2mg/kg, SAHA 35mg/kg and TCN-P 10mg/kg were injected intraperitoneally every other day from Day +15 to Day +21(total of 4 doses). Acute GvHD was assessed by a standardized scoring developed by Cooke and Ferrara. (Blood, 1996) RESULTS : 1. Using our Foxp3-reporter system, both AzaC and TCN-P induced significant luciferase expression in Jurkat cells. SAHA had no effect. 2. Only AzaC but neither SAHA nor TCN-P induced significant Foxp3 expression in WT bead activated T cells. 3. In vivo, both AzaC 2mg/kg and TCN-P 10mg/kg but not SAHA 35mg/kg significantly improved survival of mice with less weight loss and clinical signs of aGvHD in a MHC mismatched aGvHD model. CONCLUSION: A novel nucleoside analogue TCN-P that was previously FDA approved for treatment of multiple myeloma and structurally related to AzaC, induces Foxp3 using a luciferase reporter construct in Jurkat cells and improves survival in mice after MHC mismatched allogeneic transplant. Though the 100 day survival between TCN-P and PBS (as negative control) in our murine aGvHD model was not quite statistically significant, the findings suggest a therapeutic potential for TCN-P and possibly other Akt inhibitors in the mitigation of aGvHD. Disclosures: No relevant conflicts of interest to declare.

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