Development of an Alpha/Beta T-Cell Depleted Allogeneic Stem Cell Transplantation Protocol Form Matched Related and Unrelated Donor Grafts in Patients with Poor Risk Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3885-3885 ◽  
Author(s):  
Moniek A DeWitte ◽  
Liane te Boome ◽  
Lotte van der Wagen ◽  
Jurgen H Kuball
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Conflicts Of Interest ◽  
Γδ T Cells ◽  
Great Promise ◽  
Tumor Control ◽  
Unrelated Donor ◽  
Post Transplantation ◽  
Poor Risk ◽  
Unrelated Donors

Abstract Introduction: The outcome of allo-SCT in patients with poor risk leukemia is still hampered by GVHD and relapse. The innate immune system has been reported to contribute to tumor control, with lower incidence of GVHD. Specific depletion of αβ T- cells – key players in the development of GVHD – will render NK cells and γδ T cells within the allograft. Recently reported results have shown the great promise of this approach in haploindentical transplantations. Within this study, we aim to extend αβT- cell depleted allo-SCT to patients with a MRD or MUD. Methods: Patients with either ‘poor-risk’ or ‘very poor-risk’ leukemia were included in this phase I study. Either HLA matched siblings (MRD) or fully matched HLA matched (10/10) unrelated donors (MUD) were eligible. abT-cell reduction was performed by negative selection with anti-abTCR antibodies in combination with magnetic microbeads, using the automated CliniMACS device (Miltenyi Biotec, Bergisch Gladbach, Germany). The maximal contamination with αβT-cells for all dose levels was 5x105/kg. Three conditioning regimens have been investigated (I): fludarabine 120 mg/m2 + cyclophosfamide 4800 mg/m2, (II): fludarabine 120 mg/m2 + busilvex AUC=90 and (III): ATG (Genzyme®) 4 mg/m2 + fludarabine 120 mg/m2 + busilvex AUC=90 followed by αβT- cell depleted grafts from matched related or unrelated donors. Within cohort II and III, no additional immune suppression was given after allo-SCT. Results: Products for 14 patients have been successfully processed and used for αβT-cell depleted allo-SCT between 2011 and 2013. A ~4 log depletion of αβT-cells has been observed in the product with a recovery of ~75% of CD34+ cells. In cohort I and cohort II, 60% and 25% primary graft failures were observed, whereas in cohort III primary engraftment (chimerism > 95%) was observed in all patients. The combination of ATG/fludarabine/busilvex was well tolerated with a hematological recovery of within 3 weeks. In all 14 patients immune reconstitution primarily consisted of innate cells (NK cells and γδ T cells) the first 6 months post transplantation. In addition, no increase in CMV or EBV reactivations has been observed so far under the profound “innate control”. Conclusion: ATG Busulfan Fludarabine is a low toxicity platform for abTCR-depleted transplantations, resulting in a swift reconstitution of innate cells (NK cells and γδ T cells) the first 6 months post transplantation. This transplantation strategy can serve as a tool for future immunological interventions such as a low dose DLI or genetically modified T cells. Disclosures No relevant conflicts of interest to declare.

Improved Immune Recovery after Transplantation of TCRαβ/CD19 Depleted Allografts from Haploidentical Donors in Pediatric Patients

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 852-852
Author(s):  
Peter Lang ◽  
Tobias Feuchtinger ◽  
Heiko-Manuel Teltschik ◽  
Wolfgang Schwinger ◽  
Patrick Schlegel ◽  
...  
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
T Lymphocytes ◽  
Nk Cells ◽  
Pediatric Patients ◽  
Conflicts Of Interest ◽  
Γδ T Cells ◽  
Control Group ◽  
Unrelated Donor ◽  
Immune Recovery

Abstract Transplantation of haploidentical stem cells has become an accepted option for pediatric patients and adults with high risk malignancies who lack a matched related or unrelated donor. In recent years, the majority of pediatric transplant centers chose the CD34 positive selection of peripheral stem cells, which allowed minimizing GvHD by effective reduction of T cells in the graft. However, infectious complications caused by delayed immune recovery were a major reason for transplant related mortality (TRM). In order to improve the immune recovery, we have established a new T-cell depletion method which removes αβ+ T-lymphocytes via a biotinylated anti-TcRαβ antibody followed by an anti-biotin antibody conjugated to magnetic microbeads while retaining γδ+ T-lymphocytes, natural killer (NK) cells and other cells in the graft. In addition, CD19+ B-lymphocytes were concomitantly depleted for the prevention of post-transplant EBV-associated lymphoproliferative disease. Immune recovery was retrospectively analyzed in a cohort of 41 patients with acute leukemia, MDS and non-malignant diseases, who received αβ T and B cell depleted allografts from haploidentical family donors. Conditioning regimens consisted of fludarabine or clofarabine, thiotepa, melphalan and serotherapy with OKT3 or ATG-Fresenius®. Graft manipulation was carried out with anti TCRαβ and anti CD19 antibodies and immunomagnetic microbeads. γδ T cells and NK cells remained in the grafts. Primary engraftment occurred in 88%, acute graft versus host disease (aGvHD) grade II and III-IV occurred in 10% and 15%. Immune recovery data were available in 26 patients and comparable after OKT3 (n=7) or ATG-F® (n=19). Median time to reach > 100 CD3+/µl, > 200 CD19+ cells/µl and > 200 CD56+ cells/µl for the whole group was 13, 127 and 12.5 days. Compared to a historical control group of patients with CD34 positive selected grafts, significantly higher cell numbers were found for CD3+ at days +30 and +90 (267 vs. 27 and 397 vs. 163 cells/µl), for CD3+4+ at day +30 (58 vs. 11 cells/µl) and for CD56+ at day +14 (622 vs. 27 cells/µl). The clinical impact of this accelerated immune recovery will be evaluated in an ongoing prospective multi-center trial. Disclosures No relevant conflicts of interest to declare.

scholarly journals Comparison of and Immune Reconstitution and Graft Versus Host Disease in 30mg/Kg Anti-T-Lymphocyte Globuline with 60mg/Kg ATLG As Graft Versus Host Disease Prophylaxis in Matched Unrelated Donor Myeloablative Peripheral Blood Stem Cell Transplantation

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3897-3897
Author(s):  
Radwan Massoud ◽  
Evgeny Klyuchnikov ◽  
Nico Gagelmann ◽  
Tatjana Zabelina ◽  
Wolschke Christine ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Graft Versus Host Disease ◽  
Immune Reconstitution ◽  
Γδ T Cells ◽  
Unrelated Donor ◽  
Γδt Cells ◽  
Host Disease ◽  
Graft Versus Host ◽  
The Impact

Abstract Introduction: Data on the influence of different ATLG doses on immune reconstitution (IR) and GvHD in MUD allo-SCT is limited. In this study, we compared the impact of ATLG doses (30mg/kg vs 60 mg/kg) on IR and transplant outcomes. Methods: In this retrospective study we included 289 patients who received MUD allografts (HLA 10/10) between 2005-2019 in the University Cance Center University of Hamburg. All patients received PBSC-allo-SCT with MAC for various hematological malignancies. Seventy-three patients received 30mg/kg ATLG, and 216 patients received 60mg/kg (on days -3.-2 and -1) prior to allo-SCT. Periphereal blood samples were collected on days +30, +100 and +180 and analyzed by flow cytometry for following lymphocyte populations: T-cells (total and activated), T-helper cells (total, naïve and memory), cytotoxic T-cells (total, naïve and memory), B-Lymphocytes (total, naïve and memory), NK-cells, NKT-cells, γδT-cells and regulatory T-cells. Results: Neutrophil and platelet engraftments were significantly delayed after the 60mg/kg compared to 30mg/kg group with medians of 11 days (range, 8-23) vs 12 days (8-27) (p=0.009) for neutrophil and 14 days (range, 9-53) vs 16 days (range, 8-237) for platelets, respectively (p=0.002). We observed a higher incidence of EBV reactivation within the first 100 days in the 60mg/kg group (41% vs 21% in the 30mg/kg group, p=0.049). Higher cumulative incidence of Infections Day +100 was observed in the 60 mg/Kg group with an incidence of 75% vs that of 67% in the 30mg/Kg group respectively (p=0.002). At day +30 we observed a faster reconstitution of naïve-B cells (p<0.0001) and γδ T cells (p=0.045) in the 30mg/kg group. No significant differences in IR were observed at day +100. At day +180 the use of 30mg/Kg was associated with a faster naïve helper T-cell (p=0.046), NK-cells (p=0.035), and naïve B-cell reconstitution (p=0.009). The incidence of aGVHD grade II-IV was comparable between the groups: 63% and 59% in the 30mg/Kg and 60mg/Kg groups, respectively. We observed a higher incidence of grade IV aGvHD in the 30mg/kg group (8%) comparing with the rate of 0.5% in the 60mg/kg group (p=0.0002), this was confirmed in multivariate analysis: RR 0.65 (95%CI 0.005-0.363) p= 0.004. After a median follow up of 21 months (range, 1-161) there were no significant differences in OS, PFS, NRM, RI and cGVHD between the groups. Conclusion: The choice of ATLG dose has significant impact on IR after MUD-allo-SCT. Higher doses are associated with reduced severe aGVHD, however at the cost of delaying engraftment and increasing infections. Disclosures Ayuk: Celgene/BMS: Honoraria; Gilead: Honoraria; Janssen: Honoraria; Mallinckrodt/Therakos: Honoraria, Research Funding; Miltenyi Biomedicine: Honoraria; Novartis: Honoraria; Takeda: Honoraria.

Alloimmune Effect May Improve Survival of De Novo Myelodysplastic Syndrome After allogeneic hematopoietic cell transplantaion: A Single Center Analysis of 115 Patients

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2033-2033
Author(s):  
Nobuhiro Hiramoto ◽  
Kinuko Tajima ◽  
Saiko Kurosawa ◽  
Takuya Yamashita ◽  
Kenji Okinaka ◽  
...  
Keyword(s):  
T Cells ◽  
Myelodysplastic Syndrome ◽  
Acute Gvhd ◽  
De Novo ◽  
Conflicts Of Interest ◽  
International Prognostic Scoring System ◽  
Unrelated Donor ◽  
Single Center ◽  
Poor Risk ◽  
Donor T Cells

Abstract Abstract 2033 Background: As patients with myelodysplastic syndrome (MDS) tend to be older and to have more comorbidities, reduced-intensity conditioning (RIC) has been more frequently used in allogeneic hematopietic cell transplantation (HCT) for patients with MDS. Although alloimmune effect by donor T-cells is important to control disease especially after HCT using RIC, significance of this effect has not been fully evaluated in patients with MDS. Patients and Methods: We retrospectively reviewed medical records of 115 patients with de novo MDS or acute myeloid leukemia with multilineage dysplasia (AML-MLD) who underwent first allogeneic HCT at our center between 2000 and 2009.Patients with therapy-related MDS and cord blood transplant recipients were excluded. Karyotypic risk group was stratified according to the International Prognostic Scoring System (IPSS). Results: The median age of the patients was 55 yrs (range, 19–68). The median follow-up of surviving patients was 40 months (8–130). FAB classification at diagnosis included RA/RARS (n=45), RAEB (40), CMMoL (4), RAEB-T (12), and AML-MLD (14). Karyotype at diagnosis was good-risk in 45 patients, intermediate-risk in 30, and poor-risk in 40. The IPSS risk at diagnosis was Low in 4 patients, Int-1 in 33, Int-2 in 44, and High in 20. Among the 115 patients with MDS or AML-MLD, 68 (59%) received chemotherapy before HCT. Blast count at HCT was less than 5% in 60 patients, 5–19% in 38 patients, 20% or more in 10 patients, and not evaluable in 7 patients. Fifty-five patients received grafts from a related donor (BM 3, PBSC 52), and 60 patients received BM grafts from an unrelated donor. Conditioning regimens included myeloablative (MAC, n=34) and RIC (n=81). Among the 81 RIC recipients, 23 received low-dose TBI and 26 received ATG. The patients who received RIC were significantly older (median, 57 yrs vs. 46 yrs, p<0.001) and included more patients with poor karyotypic risk (41% vs. 21%, p=0.03) than those who received MAC. The incidence of grade II-IV acute GVHD was 42% and that of grade III-IV acute GVHD was 14%. Among the 107 patients who survived more than 100 days after HCT, 10 developed limited cGVHD (9%) and 48 (45%) developed extensive cGVHD. The OS (47% vs 42% at 4 yrs from HCT, p=0.84), the cumulative incidence of NRM (29% vs 33%, p=0.89), and that of relapse (26% vs. 25%, p=0.97) were not significantly different between the MAC and RIC groups, respectively. A multivariate analysis for OS showed that older patient age (≥50 yrs, HR 2.20, 95%CI 1.11–4.33, p= 0.02), high BM blast at HCT (>20%, HR 3.74, 95%CI 1.73–8.08, p<0.01/ 5%- 20%, HR 1.859, 95%CI 1.04–3.30 0.035), and karyotype (poor-risk, HR 1.88, 95%CI 1.08–3.27, p= 0.02) were associated with a significantly worse OS. The presence of cGVHD seemed to be associated with a better OS (HR 0.54, 95%CI 0.29–1.01, p= 0.054). In a landmark analysis, the OS of the patients with cGVHD was significantly higher than that of those without cGVHD (59% vs. 33%, p=0.02). The OS of 26 patients who received ATG was significantly lower than that of those who did not (21% vs. 51% at 4 yrs, p=0.02). In subgroup analyses according to karyotypic risks, the OS of patients with cGVHD was significantly higher than that of those without cGVHD (54% vs. 12% at 4 yrs, p<0.001) in patients with poor karyotypic risk, whereas the OS was not significantly different between the two groups (62% vs. 47% at 4 yrs, p=0.37) in patients with good/intermediate karyotypic risk (Figure). The OS of the patients with cGVHD was significantly higher than that of those without cGVHD (50% vs. 11% at 4 yrs, p=0.002) in patients with more than 5% BM blast at HCT. The OS of the patients with cGVHD was significantly higher than that of those without cGVHD (54% vs. 17% at 4 yrs, p<0.001) in patients who received RIC, whereas the OS was not significantly different between the two groups in patients who received MAC. Conclusions: Our single center analysis of patients with MDS showed that the outcomes after HCT with RIC were similar to those after HCT with MAC. Our data also showed an improvement of OS and especially in patients with more advanced MDS. In the setting of RIC, alloimmune effect by donor T-cells may be more important for prevention of relapse in patients with MDS. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Activation of human γδ T cells and NK cells by Staphylococcal enterotoxins requires both monocytes and conventional T cells

2021 ◽  
Author(s):  
Manuel Mata Forsberg ◽  
Claudia Arasa ◽  
Willemien Zwol ◽  
Sibel Uzunçayir ◽  
Anna Schönbichler ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Γδ T Cells ◽  
Staphylococcal Enterotoxins

scholarly journals Distinct contributions of CD4+ T cell subsets in hepatic ischemia/reperfusion injury

2009 ◽  
Vol 296 (5) ◽  
pp. G1054-G1059 ◽  
Author(s):  
Satoshi Kuboki ◽  
Nozomu Sakai ◽  
Johannes Tschöp ◽  
Michael J. Edwards ◽  
Alex B. Lentsch ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Ischemia Reperfusion ◽  
Γδ T Cells ◽  
Nkt Cells ◽  
T Cell Subsets ◽  
Wild Type ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Helper T cells are known to mediate hepatic ischemia/reperfusion (I/R) injury. However, the precise mechanisms and subsets of CD4+ T cells that contribute to this injury are still controversial. Therefore, we sought to determine the contributions of different CD4+ T cell subsets during hepatic I/R injury. Wild-type, OT-II, or T cell receptor (TCR)-δ-deficient mice were subjected to 90 min of partial hepatic ischemia followed by 8 h of reperfusion. Additionally, wild-type mice were pretreated with anti-CD1d, -NK1.1, or -IL-2R-α antibodies before I/R injury. OT-II mice had diminished liver injury compared with wild-type mice, implicating that antigen-dependent activation of CD4+ T cells through TCRs is involved in hepatic I/R injury. TCR-δ knockout mice had decreased hepatic neutrophil accumulation, suggesting that γδ T cells regulate neutrophil recruitment. We found that natural killer T (NKT) cells, but not NK cells, contribute to hepatic I/R injury via CD1d-dependent activation of their TCRs, as depletion of NKT cells by anti-CD1d antibody or depletion of both NKT cells and NK cells by anti-NK1.1 attenuated liver injury. Although regulatory T cells (Treg) are known to suppress T cell-dependent inflammation, depletion of Treg cells had little effect on hepatic I/R injury. The data suggest that antigen-dependent activation of CD4+ T cells contributes to hepatic I/R injury. Among the subsets of CD4+ T cells, it appears that γδ T cells contribute to neutrophil recruitment and that NKT cells directly injure the liver. In contrast, NK cells and Treg have little effects on hepatic I/R injury.

scholarly journals γδ T Cells and NK Cells – Distinct Pathogenic Roles as Innate-Like Immune Cells in CNS Autoimmunity

2015 ◽  
Vol 6 ◽  
Author(s):  
Sarah C. Edwards ◽  
Aoife M. McGinley ◽  
Niamh C. McGuinness ◽  
Kingston H. G. Mills
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Immune Cells ◽  
Γδ T Cells ◽  
Cns Autoimmunity

Impact Of CMV And EBV Infections On The Exercise-induced Mobilization Of Nk-cells And γδ T-cells

2011 ◽  
Vol 43 (Suppl 1) ◽  
pp. 337-338
Author(s):  
Austin B. Bigley ◽  
Guillaume Spielmann ◽  
Jerrald L. Rector ◽  
Mark R. Morrison ◽  
Richard J. Simpson
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Γδ T Cells ◽  
Exercise Induced

scholarly journals P02.02 Single-cell RNA sequencing of neuroblastoma tumors reveals immunoregulatory interactions as novel targets for immunotherapy

2021 ◽  
Vol 9 (Suppl 1) ◽  
pp. A8.1-A8
Author(s):  
J Wienke ◽  
WM Kholosy ◽  
LL Visser ◽  
KM Keller ◽  
P Lijnzaad ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Single Cell ◽  
Cell Function ◽  
Γδ T Cells ◽  
Lymphoid Cells ◽  
Gene Set Enrichment Analysis ◽  
Mycn Amplification ◽  
Solid Cancer ◽  
Novel Targets

BackgroundImmunotherapy with CAR-T cells, as well as immune checkpoint blockade, show limited clinical efficacy in the pediatric solid cancer neuroblastoma, despite the success in various adult cancers. The lacking efficacy may be due to various immune evasion strategies employed by neuroblastoma tumors, leading to altered functionality of tumor-infiltrating immune cells. We aimed to provide a comprehensive overview of the composition and function of the neuroblastoma immune environment, as well as relevant immunoregulatory interactions (=), to identify novel targets for immunotherapy.Materials and Methods25 tumor samples from 20 patients (17 with high-risk disease, 6 with MYCN amplification), were collected during diagnostic biopsy pre-treatment (n=10) or during resection surgery after induction chemotherapy (n=15). Samples were enzymatically digested, single-cell FACS sorted and sequenced by Cel-Seq2 protocol.ResultsLymphoid cells in the TME consisted of αβ-, γδ-T cells, NK cells and B cells. Among αβ-T cells we identified CD8+ T cells, two functionally distinct clusters of CD4+ T cells, naive-like T cells and FOXP3+ regulatory T cells (Tregs). CD8+ T cells had reduced cytotoxic capacity compared to blood-derived T cells from a reference group. Tregs expressed high levels of PRDM1, LAYN and ICOS, suggesting an effector Treg profile, which is associated with increased inhibitory capacity. Although NK cells expressed the cytotoxic genes NKG7, KLRF1, GNLY, GZMB and PRF1, their expression was significantly lower than in blood-derived reference NK cells. Gene set enrichment analysis (GSEA) confirmed a reduced cytotoxic capacity of tumoral NK cells, which correlated with a decreased expression of activating receptors (r=0.41, p<0.001) and increased TGFβ signaling (r=-0.45, p<0.001). In addition, NK cells highly expressed the heterodimeric receptor KLRC1:KLRD1, which can inhibit NK cell function through HLA-E binding. High HLA-E expression by endothelial, immune and mesenchymal cells confirmed its inhibitory activity in the TME. Within the myeloid compartment we identified various immunosuppressive populations, comprising a cluster of IL10 and VEGFA expressing macrophages, three clusters of M2 differentiated macrophages expressing MMP9 and LGALS3, and dendritic cells with intact antigen presenting capacity, but high expression of numerous genes encoding immunosuppressive molecules such as IDO1, LGALS1, LGALS2, CCL22 and NECTIN2. In MYCN amplified tumors, specifically, we observed even lower cytotoxic capacity of CD8+ T and NK cells. We identified increased TGFB1 expression and defective antigen presentation by myeloid and tumor cells as potential causes for reduced cytotoxicity in MYCN amplified tumors. To identify relevant targets for immunotherapy we constructed an unbiased interaction network, which revealed NECTIN1=CD96 and MIF=CD74 as active immunoregulatory interactions between tumor and T/NK cells, and CD80/CD86=CTLA4, CLEC2D=KLRB1, HLA-E=KLRC1/KLRC2, CD99=PILRA, LGALS9=HAVCR2, and NECTIN2=TIGIT between myeloid and T/NK cells.ConclusionsCytotoxic lymphocytes in the neuroblastoma TME show reduced cytotoxic capacity, likely due to highly immunosuppressive myeloid cells, Tregs and numerous immunoregulatory interactions, which may serve as novel targets for immunotherapy in neuroblastoma.Disclosure InformationJ. Wienke: None. W.M. Kholosy: None. L.L. Visser: None. K.M. Keller: None. P. Lijnzaad: None. T. Margaritis: None. K.P.S. Langenberg: None. R.R. De Krijger: None. F.C.P. Holstege: None. J.J. Molenaar: None.

scholarly journals P01.08 Beyond PD-1: characterization of new checkpoints restricting function of cytotoxic lymphocytes infiltrating human carcinoma

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A11.2-A12
Author(s):  
AS Herbstritt ◽  
PU Prinz ◽  
M Maxwell ◽  
M Kadiyala ◽  
D Yan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cell ◽  
Nk Cells ◽  
Solid Tumors ◽  
Principal Investigator ◽  
Tumor Control ◽  
Research Support ◽  
Part Time ◽  
Research Grant

BackgroundT and NK cells from human renal cell carcinoma (RCC) are functionally non-responsive. Analysis of the TCR signaling cascade required for effector function identified that proximal signaling molecules were activated whereas activation of downstream ERK was blocked. Further investigation showed increased diacylglycerol kinase alpha (DGK-α) levels in T and NK cells from the RCC tumor microenvironment (TME). These cells were refractory to stimulation showing no degranulation or IFN-γ production. Using a small molecule DGK–α inhibitor (R59022), the function of tumor-infiltrating lymphocytes was restored ex vivo. A correlation of high DGK-α and loss of function was also observed in an experimental mouse model of adoptive therapy where CAR T cells that had lost their activity after infiltrating into solid tumors were found to have increased DGK-α.1 Blockade of the Programmed cell death protein 1 (PD-1) with monoclonal antibodies is used in the clinic enabling some patients to achieve tumor control. However, not all patients respond. DGK-α activity is positioned downstream of PD-1 and should, if overactive, curb T cell function even if PD-1 inhibition is released. Thus, we hypothesize that dual inhibition of PD-1 and DGK–α might be required to fully unleash the T cell’s potential in the TME. Current DGK-α inhibitors are not suitable for clinical application. Therefore, we investigated alternative means using an RNA interference (RNAi) approach to target DGK-α alone as well as in combination with PD-1 in T and NK cells.Material and MethodsKnockdown is performed by RNAi using INTASYLTM compounds developed by Phio Pharmaceuticals. INTASYLTM compounds incorporate drug-like properties into the siRNA, resulting in enhanced uptake in the presence of serum with no need for further transfection reagents. Knockdown is analyzed by RT-qPCR and flow cytometry. Functional assays include cytotoxicity, degranulation and cytokine production in tumor mimicking environments.ResultsA tumor mimicking in vitro system was developed which allows for the demonstration of functional restoration or prevention of functional loss of cell activity. Using T cell/tumor cell co–cultures at high tumor cell density, functional suppression could be induced in T and NK cells comparable to those observed in the TME. Testing of DGK-α targeting INTASYLTM compounds, silencing of DGK-α was observed in human U2OS osteosarcoma cells. Using a fluorescently labeled compound, highly efficient transfection of human primary immune cells was seen. Combinations of PD-1 and DGK-α targeting compounds are being tested and evaluated for synergism in experimental models.ConclusionsStrong activity of specific T and NK cells is necessary for tumor control. Dual targeting of PD-1 and DGK-α may be required to fully enable T and NK cell reactivity in the TME. Current DGK-α inhibitors do not exhibit the desirable pharmacokinetic/pharmacodynamic (PK/PD) properties for clinical development. The tested self-delivering RNAi technology represents a promising approach to targeting intracellular immune checkpoints such as DGK-α.ReferenceMoon EK, Wang L-C, Dolfi DV, Wilson CB, Ranganathan R, Sun J, et al. Multifactorial T-cell hypofunction that is reversible can limit the efficacy of chimeric antigen receptor-transduced human T cells in solid tumors. Clin Cancer Res 2014; 20(16):4262–73Disclosure InformationA.S. Herbstritt: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Significant; Phio Pharmaceuticals. C. Other Research Support (supplies, equipment, receipt of drugs or other in-kind support); Significant; Phio Pharmaceuticals. P.U. Prinz: None. M. Maxwell: A. Employment (full or part-time); Significant; Phio Pharmaceuticals. M. Kadiyala: A. Employment (full or part-time); Significant; Phio Pharmaceuticals. D. Yan: A. Employment (full or part-time); Significant; Phio Pharmaceuticals. E. Noessner: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Significant; Phio Pharmaceuticals. C. Other Research Support (supplies, equipment, receipt of drugs or other in-kind support); Significant; Phio Pharmaceuticals.

scholarly journals KIR reconstitution is altered by T cells in the graft and correlates with clinical outcomes after unrelated donor transplantation

Blood ◽  
2005 ◽  
Vol 106 (13) ◽  
pp. 4370-4376 ◽  
Author(s):  
Sarah Cooley ◽  
Valarie McCullar ◽  
Rosanna Wangen ◽  
Tracy L. Bergemann ◽  
Stephen Spellman ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Clinical Outcomes ◽  
Hematopoietic Cell Transplantation ◽  
Cell Function ◽  
Nk Cell ◽  
Interferon Γ ◽  
Unrelated Donor ◽  
Ifn Γ

Although unrelated hematopoietic cell transplantation (HCT) is curative for many hematologic malignancies, complications and relapse remain challenging obstacles. Natural killer (NK) cells, which recover quickly after transplantation, produce cytokines and express killer immunoglobulin-like receptors (KIRs) that regulate their cytotoxicity. Some clinical trials based on a KIR ligand mismatch strategy are associated with less relapse and increased survival, but results are mixed. We hypothesized that T cells in the graft may affect NK cell function and KIR expression after unrelated transplantation and that these differences correlate with clinical outcomes. NK cell function was evaluated using 77 paired samples from the National Marrow Donor Program Research Repository. Recipient NK cells at 100 days after both unmanipulated bone marrow (UBM) and T-cell depleted (TCD) transplants were compared with NK cells from their healthy donors. NK cells expressed fewer KIRs and produced more interferon γ (IFN-γ) after UBM compared to TCD transplants. Multivariate models showed that increased NK cell IFN-γ production correlated with more acute graft-versus-host disease (GVHD), and decreased KIR expression correlated with inferior survival. These results support the notion that T cells in the graft affect NK cell reconstitution in vivo. Understanding these mechanisms may result in strategies to improve clinical outcomes from unrelated HCT.

Sign in / Sign up

Export Citation Format

Share Document