scholarly journals Adoptive transfer of cytomegalovirus-specific CTL to stem cell transplant patients after selection by HLA–peptide tetramers

2005 ◽  
Vol 202 (3) ◽  
pp. 379-386 ◽  
Author(s):  
Mark Cobbold ◽  
Naeem Khan ◽  
Batoul Pourgheysari ◽  
Sudhir Tauro ◽  
Dorothy McDonald ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Cd8 T Cells ◽  
Adoptive Transfer ◽  
Magnetic Beads ◽  
Stem Cell Transplant ◽  
Viral Reactivation ◽  
Cell Transplant ◽  
T Cell Therapy

Stem cell transplantation is used widely in the management of a range of diseases of the hemopoietic system. Patients are immunosuppressed profoundly in the early posttransplant period, and reactivation of cytomegalovirus (CMV) remains a significant cause of morbidity and mortality. Adoptive transfer of donor-derived CMV-specific CD8+ T cell clones has been shown to reduce the rate of viral reactivation; however, the complexity of this approach severely limits its clinical application. We have purified CMV-specific CD8+ T cells from the blood of stem cell transplant donors using staining with HLA–peptide tetramers followed by selection with magnetic beads. CMV-specific CD8+ cells were infused directly into nine patients within 4 h of selection. Median cell dosage was 8.6 × 103/kg with a purity of 98% of all T cells. CMV-specific CD8+ T cells became detectable in all patients within 10 d of infusion, and TCR clonotype analysis showed persistence of infused cells in two patients studied. CMV viremia was reduced in every case and eight patients cleared the infection, including one patient who had a prolonged history of CMV infection that was refractory to antiviral therapy. This novel approach to adoptive transfer has considerable potential for antigen-specific T cell therapy.

Early Adoptive Transfer of Ex Vivo Generated Multi-Virus Specific T Cells Is a Safe Strategy to Prevent Viral Reactivation in Recipients of Allogeneic T Cell Depleted Stem Cell Transplant

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 979-979
Author(s):  
Pawel Muranski ◽  
Greg Whitehill ◽  
Debbie Draper ◽  
Eleftheria Koklanaris ◽  
Jeanine Superata ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplant ◽  
Ex Vivo ◽  
Viral Reactivation ◽  
Cell Transplant ◽  
Viral Immunity ◽  
Related Disease ◽  
Cmv Reactivation

Abstract Background: Allogeneic stem cell transplant (SCT) recipients suffer from a defective T cell mediated immunity causing potentially fatal reactivation of latent viruses. After T cell depleted SCT we have observed over 80% CMV reactivation and significant additional costs ($58-74k/patient). Despite aggressive monitoring and pre-emptive therapy, reactivation and/or positive CMV serology brings a significantly higher risk for non-relapse mortality (NRM). Adoptive transfer of ex vivo generated virus specific donor T cells is effective as a treatment of infection post-SCT but it has not been tested as a prophylaxis of early reactivation. Here in a Phase I study we transferred multi-virus specific T cells (MVSTs) immediately post SCT, targeting CMV, Ebstein-Barr virus (EBV), BK and adenovirus (Ad) as a novel strategy to prevent viral reactivation in the recipients of T cell depleted sibling HLA-matched SCT. Methods: Subjects were eligible if enrolled in HLA-matched T cell depleted transplant protocol (13-H-0144) and deemed at risk for CMV reactivation. MVST cells were manufactured from SCT sibling donors. Elutriated lymphocytes were stimulated with autologous dendritic cells (DCs) pulsed with seven overlapping peptide libraries (pepmixes) spanning the length of immunodominant proteins from CMV (pp65 and IE1), EBV (BZLF1 and EBNA1), BK (LT and VP1) and Ad5. Cultures were maintained in G-Rex flasks for 14 days in presence of IL-7, IL-15 and IL-2 (after 72hrs), tested for sterility, phenotype, potency and cryopreserved. MVST cells were thawed and administered intravenously as early as possible (day 0 to +60) post SCT. A Phase I 3+3 dose escalation design was used at the following dose levels: Cohort 1 - 1x10e5 total nucleated cells (TNC)/kg, Cohort 2 - 5x10e5 TNC/kg, Cohort 3 - 1x10e6 TNC/kg. The primary safety endpoint at day 42 post infusion was the occurrence of dose limiting toxicity (DLT), (Grade IV GVHD or any other severe adverse even (SAE) deemed to be at least "probably" or "definitely" related to the MVST infusion. Patients were followed to day +100 post SCT for secondary outcomes, including efficacy (Figure) and immune reactivity (for donor/recipient pairs). Results: MVST cells recognized the majority of pepmixes, were polyfunctional and robustly proliferated in response the cognate antigens, but minimally against allogeneic targets- suggesting a limited ability to induce GVHD. CDR3 sequencing of T cell repertoire showed a significant reduction in diversity and a striking dominance of a limited number of clonotypes in the final MVSTs. Nine subjects were enrolled and treated with MVST cells. MVSTs were successfully generated for all subjects, meeting the release criteria. Median time from SCT to MVST administration was 16 days (range D +6 to +52 post-SCT). Two subjects received MVST after day +30 due to cardiac instability and scheduling. There were no immediate infusion-related adverse events or DLT by day 42. One subject in cohort II developed a self-limiting grade I cytokine release syndrome in the setting of low-level EBV reactivation. One patient (cohort 1) developed de novo grade III aGVHD post-MVST infusion. CMV reactivation post-MVST occurred in 4 out of 8 evaluable subjects (50%) who completed D+100 post-SCT vs. 45 out of 52 patients (50% vs 87%; p value=0.031) in a historical cohort of recipients of T cell depleted SCT. In all cases CMV reactivation occurred during treatment with high dose steroids. In two cases MVST were generated from CMV seronegative donors and showed minimal activity against pp65 and IE1. In eight evaluable subjects who reached D+100 post-SCT there was no EBV-related disease, but we saw self-limiting low level EBV replication in 6 out of 8 cases. There were no cases of BK or Ad-related disease or viremia. ELISPOT analysis at D+100 revealed robust reconstitution of anti-viral immunity in analyzed recipients (vs. donors, Figure, B) Conclusions: This is the first report demonstrating that it is safe and feasible to use adoptively transferred allo-MVST immediately post-SCT to rapidly reconstitute anti-viral immunity and ameliorate the detrimental impact of the early viral reactivation in SCT recipient. No DLTs were seen. MVSTs had a markedly reduced allo-reactivity and carried a minimal risk of GVHD. Our results also suggest efficacy of this strategy in reducing viral reactivation. A Phase II portion of this study is currently enrolling patients. Figure. Figure. Disclosures Sabatino: Kite: Employment, Equity Ownership.

scholarly journals Adoptive T-Cell Therapy to Prevent and Treat Parainfluenza Virus 3 (PIV-3) Infections Post Hematopoietic Stem Cell Transplant (HSCT)

2016 ◽  
Vol 22 (3) ◽  
pp. S138-S139
Author(s):  
Paibel I. Aguayo-Hiraldo ◽  
Ifigeneia Tzannou ◽  
Reuben Arasaratnam ◽  
Nikita Koottiyaniyil ◽  
Manik Kuvalekar ◽  
...  
Keyword(s):  
Stem Cell ◽  
T Cell ◽  
Cell Therapy ◽  
Hematopoietic Stem Cell Transplant ◽  
Stem Cell Transplant ◽  
Adoptive T Cell Therapy ◽  
Parainfluenza Virus ◽  
Cell Transplant ◽  
T Cell Therapy ◽  
Hematopoietic Stem

scholarly journals Discovery of TSC-101: A First-in-Class Natural HA-2-Specific TCR to Treat Leukemia Following Hematopoietic Stem Cell Transplant Therapy

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1704-1704
Author(s):  
Ribhu Nayar ◽  
Mollie M Jurewicz ◽  
Sonal Jangalwe ◽  
Hannah Bader ◽  
Kimberly M Cirelli ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Hematopoietic Stem Cell Transplant ◽  
Stem Cell Transplant ◽  
Surface Expression ◽  
Cell Transplant ◽  
Hematopoietic Stem ◽  
Genome Wide ◽  
Clinical Candidate

Abstract Background Approximately 50% of AML patients relapse following allogeneic hematopoietic stem cell transplant therapy, leaving them with very few treatment options (Rautenberg et al. (2019) Int. J. Mol. Sci. 20:228). Rare patients who naturally develop a minor antigen-specific graft-versus-leukemia T cell response show substantially lower relapse rates (Marijt et al. (2003) Proc. Natl. Acad. Sci. U.S.A. 100:2742-2747; Spierings et al. (2013) Biol. Blood Marrow Transplant. 19:1244-1253). HA-2 (YIGEVLVSV, genotype RS_61739531 C/C or T/C) is an HLA-A*02:01- and haematopoietically-restricted minor histocompatibility antigen derived from the class I myosin protein, MYO1G (Pierce et al. (2001) J. Immunol. 167:3223-3230). Patients receiving donor lymphocyte infusion from HA-2-mismatched donors who develop HA-2-specific T cells show a graft vs leukemia response and often experience long-term remission (Marijt et al. (2003) Proc. Natl. Acad. Sci. U.S.A. 100:2742-2747), making HA-2 an ideal candidate for TCR-engineered T cell immunotherapy of liquid tumors. Methods Using TScan's proprietary ReceptorScan platform, we discovered 1,302 HA-2-specific TCRs by screening 237 million naïve CD8 + T cells from 5 healthy HA-2-negative donors. We evaluated these TCRs using our proprietary DexScan platform to select the 15 TCRs with the highest surface expression and greatest affinity for the HA-2 peptide when transferred into primary human T cells. We further tested each TCR individually in our clinical vector backbone for surface expression, selective cytotoxicity, cytokine production, and proliferation using a panel of cell lines that express varying levels of HLA-A*02:01 and MYO1G. Finally, the top 5 TCRs were evaluated for alloreactivity using an array-based screen assessing 108 MHC-I molecules individually, and for off-target cross-reactivity using our proprietary genome-wide TargetScan platform. A lead TCR with limited alloreactivity and a narrow off-target profile was selected as our lead TSC-101 TCR. The avidity of TSC-101 for its putative off-targets was further measured in peptide-pulsed experiments to better appreciate the toxicity risks associated with our lead clinical candidate. Results and Conclusion Of the 1,302 HA-2-specific TCRs identified by our ReceptorScan platform, we identified TSC-101 as the most active TCR. TSC-101 displayed no alloreactivity to 107/108 HLAs tested and limited off-target risks in a genome-wide screens. Potential off-target peptides identified for TSC-101 displayed extremely weak avidities, predicting an absence of toxicity risks for our clinical candidate. Based on these results, TSC-101 has been advanced to IND-enabling activities to prepare for first-in-human testing in 2022. To our knowledge, this is the first clinical grade HA-2-specifc TCR being developed for immunotherapy for liquid tumors. Disclosures Macbeath: TScan Therapeutics: Current Employment, Current equity holder in publicly-traded company.

Adoptive Transfer and Consequential Selective Reconstitution of Streptamer-Selected Cytomegalovirus-Specific CD8+ T Cells Leads to Enduring Virus Clearance in Patients after Allogeneic Stem Cell Transplantation

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1181-1181 ◽  
Author(s):  
Anita Schmitt ◽  
Torsten Tonn ◽  
Dirk Busch ◽  
Götz Grigoleit ◽  
Hermann Einsele ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Cd8 T Cells ◽  
Adoptive Transfer ◽  
Cd8 T Cell ◽  
Adoptive T Cell Transfer ◽  
T Cell Transfer ◽  
Cmv Reactivation ◽  
Cmv Antigenemia

Abstract Background: Cytomegalovirus (CMV) disease constitutes a serious complication after allogeneic peripheral blood stem cell transplantation (allo-PBSCT). For the clearance of CMV, CD8+ T cells are pivotal. Patients after allo-PBSCT with recurrent CMV reactivation usually lack such CMV specific T cells. Conventional antiviral therapy of CMV reactivation characteristically results in myelosuppression and further suppression of CMV specific T cells. Adoptive transfer of CMV specific T cells may help to overcome this problem. A novel technology designated “streptamers” allows the selection of CMVpp65 specific CD8+ T cell up to 98% purity without altering the functional properties of the selected T cells and without requiring cumbersome and time consuming T cell cultures. Materials and Methods: Here, the novel streptamer technology was used for adoptive transfer of CMV specific T cells into two acute leukemia patients with recurrent high CMV antigenemia after allo-PBSCT. Standard peripheral blood mononuclear cell apheresis was performed on the former stem cell donors of two patients with acute leukemia. Isolation of CMV specific donor lymphocytes was performed using a Good Manufacturing Product (GMP)-grade Streptamer selection kit on a CliniMacs™ device. Briefly, MHC-Streptamers (CMVpp65/HLA-B7 for patient 1; CMVpp65/HLA-A2 for patient 2) were labeled with beads overnight to obtain MHC-streptamer-bead complexes. Subsequently CMV specific T-lymphocytes were immunomagnetically labeled by incubating mononuclear cells with MHC-Streptamer-bead complexes. Cells were run on a CliniMacs™ device. The positive fraction was then incubated with biotin to detach the steptamers from the T cells. Results: A single specific donor lymphocyte infusion (sDLI) of 0.4 or 2.2 ×105 CMVpp65 specific T cells per kg body weight was performed in an AML or ALL patient respectively, after allogeneic PBSCT developing a CMVpp65 antigenemia with a maximum of 959 or 716 CMVpp65 positive/500,000 cells and treatment with foscarnet, ganciclovir and valganciclovir. After sDLI, the CMV antigenemia was cleared and remained persistently controlled even after discontinuation of valganciclovir therapy in both patients. No acute or chronic toxic side effect, particularly no aggravation of graft-versus-host disease (GvHD) was observed. A strong and sustained increase of the absolute count of CMV-specific CD8+ T cells in concordance with the increase of CD3+CD8+ T cells up to 440/μl was detected. CMV-specific CD8+ T cells showed no significant expression of CCR7, CD62L or CD107, but stained increasingly positive for CD45RA, indicating a preferential effector T cell phenotype. Results from stimulation experiments of CD3+ T cells with HLA-B7 versus HLA-A2 restricted CMVpp65 derived peptides demonstrate late reconstitution of HLA-A2-restricted CMV-specific T cells, whereas the adoptively transferred HLA-B7-restricted CMV-specific T-cell response augmented very early und was maintained over time. The chimerism analysis of the in vivo expanded CMV-specific CD8+ T cells demonstrated a 100% donor chimerism. T cell receptor excision circle (sjTRECs) analysis revealed a frequency of sjTRECs two logs lower than expected, indicating peripheral expansion rather than thymic proliferation of CMV specific CD8+ T cells. cDNA generated from FACS-purified donor-derived CMV B7 pp65-specific CD8+ T cells was probed with the indicated 5′ Vß14-specific and 3′ CDR3-specific primers for the presence of clonotypic T cells. The respective CDR3 region sequence was identical for both donor T cells and CMVpp65 specific T cells in the patients at different time points after the adoptive T cell transfer, thus clearly indicating that the expanded CMV specific T cell were of clonogenic donor origin. Conclusion: Streptamer technology offers the advantage of selecting CMV specific CD8+ T cells at GMP level for adoptive T cell transfer. Two CMVpp65 specific T cell transfers resulted in a marked increase of CMV-specific CD8+ T cells and induced long-lasting CD8+ T cell responses, which allowed the patients to discontinue toxic antiviral drug therapy without further high level reactivation of CMV.

Safety and Preliminary Efficacy of "Ready to Administer" Cytomegalovirus (CMV)-Specific T Cells for the Treatment of Patients with Refractory CMV Infection

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 388-388 ◽  
Author(s):  
Ifigeneia Tzannou ◽  
Kathryn S. Leung ◽  
Caridad Martinez ◽  
Swati Naik ◽  
Stephen Gottschalk ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplant ◽  
Fixed Dose ◽  
Effector Memory ◽  
Cell Transplant ◽  
Decision Tool ◽  
Widespread Application ◽  
Hematopoietic Stem

Abstract Despite advances in antiviral drugs, Cytomegalovirus (CMV) infections remain a significant cause of morbidity and mortality in immunocompromised individuals. We have recently demonstrated in hematopoietic stem cell transplant (HSCT) recipients that adoptively-transferred virus-specific T cells, generated from healthy 3rd party donors and administered as an "ready to administer" product, can be curative, even in patients with drug-refractory CMV infections. However, broader implementation has been hindered by the postulated need for extensive panels of T cell lines representing a diverse HLA profile, as well as the complexities of large scale manufacturing for widespread clinical application. To address these potential issues, we have developed a decision tool that identified a short list of donors who provide HLA coverage for >90% of the stem cell transplant population. Furthermore, to generate banks of CMV-specific T cells from these donors, we have created a simple, robust, and linearly scalable manufacturing process. To determine whether these advances would enable the widespread application of "ready to administer" T cells, we generated CMV cell banks (Viralym-C™) from 9 healthy donors selected by our decision tool, and initiated a fixed-dose (2x107 cells/m2) Phase I clinical trial for the treatment of drug-refractory CMV infections in pediatric and adult HSCT recipients. To generate the Viralym-C™ banks, we stimulated donor peripheral blood mononuclear cells (PBMCs) with overlapping peptide libraries spanning the immunodominant CMV antigens pp65 and IE1. Cells were subsequently expanded in a G-Rex device, resulting in a mean fold expansion of 103±12. The lines were polyclonal, comprising both CD4+ (21.3±6.7%) and CD8+ (74.8±6.9%) T cells, and expressed central CD45RO+/CD62L+ (58.5±4.2%) and effector memory markers CD45RO+/CD62L- (35.3±12.2%). Furthermore, the lines generated were specific for the target antigens (IE1: 419±100; pp65 1070±31 SFC/2x105, n=9). To date, we have screened 12 patients for study participation, and from our bank of just 9 lines we have successfully identified a suitable line for all patients within 24 hours. Of these, 6 patients have been infused; 5 received a single infusion and 1 patient required 2 infusions for sustained benefit. There were no immediate infusion-related toxicities; and despite the HLA disparity between the Viralym-C lines and the patients infused, there were no cases of de novo or recurrent graft versus host disease (GvHD). One patient developed a transient fever a few hours post-infusion, which spontaneously resolved. Based on viral load, measured by quantitative PCR, or symptom resolution (in patients with disease), Viralym-C™ cells controlled active infections in all 5 evaluable patients; 4 patients had complete responses, and 1 patient had a partial response within 4 weeks of cell infusion. One patient with CMV retinitis had complete resolution of symptoms following Viralym-C™ infusion. In conclusion, our results demonstrate the feasibility, preliminary safety and efficacy of "ready to administer" Viralym-C™ cells that have been generated from a small panel of healthy, eligible CMV seropositive donors identified by our decision support tool. These data suggest that cost-effective, broadly applicable T cell anti-viral therapy may be feasible for patients following HSCT and potentially other conditions. Disclosures Tzannou: ViraCyte LLC: Consultancy. Leen:ViraCyte LLC: Equity Ownership, Patents & Royalties. Kakarla:ViraCyte LLC: Employment.

scholarly journals Severe Cytokine Release Syndrome Associated with Worse Outcomes in Recipients of a Haploidentical Stem Cell Transplant

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2869-2869
Author(s):  
Hayley J Hawkins ◽  
Ted A Gooley ◽  
Michael Tees
Keyword(s):  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplant ◽  
Chronic Gvhd ◽  
Conditioning Regimen ◽  
Cell Transplant ◽  
T Cell Therapy ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract Introduction: The utilization of haploidentical (haplo) donors for allogeneic hematopoietic stem cell transplant (HCT) recipients has allowed more donor options to treat a multitude of hematopoietic malignancies and disorders. However, there are substantial complications and morbidities associated with haplo HCT. Cytokine release syndrome (CRS), a manifestation of alloreactive T cell expansion, has posed an obstacle early after stem cell infusion. CRS is well described among chimeric antigen receptor (CAR) T cell therapy recipients, where anti-interleukin (IL) 6 therapy and glucocorticoids to abrogate cytokine activity depends on objective physiologic markers and neurologic changes. In 2019, the American Society of Transplantation and Cellular Therapy (ASTCT) developed a consensus CRS grading scale for CAR T cell therapy that has since been widely adopted for these recipients (Lee et al, Biol Blood Marrow Transpl 2019). While the etiology of CRS differs between haplo HCT and CAR T cell recipients, severe CRS (grade 3 or 4) is seen in both patient populations, defined by ASTCT CRS grading as non-fluid responsive hypotension and/or capillary leak necessitating increased ventilatory support. We investigated whether the newly adopted ASTCT CRS grading could apply to a haplo HCT population in predicting overall survival (OS) and progression-free survival (PFS) at 1 year as well as the 2-year probability of graft-versus-host disease (GVHD). Methods: This IRB-approved retrospective analysis assessed 64 patients who underwent haplo HCT at Colorado Blood Cancer Institute from July 2015 to December 2018. All but one patient received peripheral blood-derived stem cells, and all patients received post-transplant cyclophosphamide, tacrolimus, and mycophenolate mofetil for GVHD prophylaxis. Variables of birth sex, primary disease, disease risk index (DRI), blood type, degree of HLA-mismatching, presence of donor-specific antibodies, Hematopoietic Cell Transplant Comorbidity Index (HCT-CI), conditioning regimen, and cell dose were assessed. In all patients, fever, blood pressure, and oxygen supplementation were used to identify the maximum CRS grade between 0-5 days after HCT using ASTCT CRS grading. Patients with other etiologies (i.e. infection, cardiomyopathy) were excluded from the analysis. CRS grading was then dichotomized to mild (CRS grades 0-2) or severe (grades 3-4), reflecting the physiologic changes that align with minimal compared to intensive cardiopulmonary support. As all patients had complete follow-up to 2 years, logistic regression was used to estimate association between severe CRS and outcome. Results: When adjusted for age, DRI and HCT-CI, development of severe CRS was associated with an inferior PFS at 1 year (odds ratio (OR) 0.22, (95% Confidence Interval (CI) 0.07, 0.69), p = 0.01). Inferior OS was also seen in those who developed severe CRS but the magnitude of the effect was smaller and not considered definitive (OR 0.38, (95%CI 0.13, 1.13), p=0.082). Increased non-relapse mortality (NRM) was also seen with severe CRS. Due to the low number of events, adjustment for only one factor at a time was necessary. When adjusted for age (OR 2.94, (95%CI 0.82, 11.1), p=0.101), DRI (OR 3.23, (95%CI 0.91, 11.1), p=0.069), HCT-CI (OR 2.94, (95%CI 0.85, 10), p=0.089), and conditioning regimen (OR 3.23, (95%CI 0.91, 11.1), p=0.071), consistent results were demonstrated, although not definitive. This was also observed with the risk of relapse, adjusted for conditioning regimen (OR 2.56, (95%CI 0.76, 9.09), p=0.126) and DRI (OR 2.56, (95%CI 0.75, 8.33), p=0.132). There was no demonstrable association between CRS and the probability of acute GVHD. However, severe CRS was associated with a reduction in the development of any chronic GVHD at 2 years (OR 0.24, (95%CI 0.08, 0.72), p=0.011). Conclusion: This analysis suggests that an adapted ASTCT CRS grading, dichotomizing into those with mild (grades 0-2) or severe (grades 3-4) CRS may identify haplo HCT recipients at risk for inferior outcomes. Haplo HCT recipients with severe CRS demonstrated an inferior PFS. The data also showed numerical decreases in overall survival, higher relapse, and higher NRM. On the other hand, severe CRS was associated with a decreased probability of chronic GVHD. As the analysis was limited to a single site, validation of adapted ASTCT grading in a larger haplo HCT population is necessary. Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document