scholarly journals CD38 Down-Regulation on Ex Vivo Activated and Expanded NK Cells for Cell Therapy Persists after Infusion

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4796-4796
Author(s):  
Hareth Nahi ◽  
Michael Chrobook ◽  
Stephan Meinke ◽  
Charlotte Gran ◽  
Nicole Marquardt ◽  
...  
Keyword(s):  
Nk Cells ◽  
Board Of Directors ◽  
Peripheral Blood ◽  
Nk Cell ◽  
Ex Vivo ◽  
Multiparameter Flow Cytometry ◽  
Advisory Committees ◽  
Natural Form ◽  
Cellular Therapies ◽  
Privately Held

Abstract Introduction: Immunotherapies are gaining more and more importance in the treatment of multiple myeloma (MM). Antibodies directed against MM antigens like CD38, SLAMF7 or BCMA are used either in their natural form, conjugated to drugs, or in the form of bispecific T-cell engagers. Cellular therapies make use of cytotoxic lymphocytes, i.e. T cells or NK cells that can also be modified to express chimeric antigen receptors to target MM cells. Combinations of antibody and cellular therapies could further improve the outcome as, for example, NK cells can mediate antibody dependent cellular cytotoxicity (ADCC). However, NK cells also express CD38 and SLAMF7 and would be targeted by the therapeutic antibodies against these antigens. We have recently reported our clinical study infusing multiple doses of ex vivo activated and expanded autologous NK cells in six patients with MM post autologous stem-cell transplantation (EudraCT 2010-022330-83). Here, we report results of a phenotypic analysis of the ex vivo expanded NK cells and peripheral blood NK cells before and after infusion with implications for possible combination therapies. Methods: Ex vivo activated and expanded NK cells and NK cells in peripheral blood of the patients were analyzed by multiparameter flow cytometry. Peripheral blood cells were taken from the non-NK cell infusion arm before and at three different timepoints after infusion. NK-cell sub-populations within these samples were analyzed using t-SNE clustering. Results: Upon ex vivo activation and expansion, we observed that the NK cells gained a unique activated phenotype including populations of CD56 brightCD16 +Ki67 +HLA-DR + NK cells. Interestingly, these NK cells showed a reduced expression of CD38 compared to peripheral blood NK cells. Clustering analyses of data from peripheral blood samples revealed the gradual appearance of a new NK cell population with a similar phenotype in a dose-dependent fashion over four hours following infusion of the NK cell product. Infused NK cells could be detected in circulation up to four weeks after the last infusion. Like the NK cell infusion product, these cells expressed little to none CD38, high levels of NKG2D, 2B4, TIM-3, and TIGIT and similar levels of SLAMF7 compared to peripheral blood NK cells. Conclusions: The persistent high expression of CD16 and the low expression of CD38 in infused NK cells offers the choice to combine ex vivo activated and expanded NK cells with anti-CD38 antibody therapy without concern for antibody-mediated NK-cell death. Based on these findings, we have started a clinical trial testing this combined therapy (NCT04558931). Disclosures Nahi: XNK Therapeutics AB: Consultancy. Chrobook: XNK Therapeutics AB: Consultancy. Meinke: XNK Therapeutics AB: Consultancy, Current holder of stock options in a privately-held company. Gilljam: XNK Therapeutics AB: Current holder of individual stocks in a privately-held company. Stellan: XNK Therapeutics AB: Current holder of individual stocks in a privately-held company. Walther-Jallow: XNK Therapeutics: Other: Shareholder in the company. Liwing: XNK Therapeutics AB: Current Employment. Gahrton: XNK Therapeutics AB: Current holder of individual stocks in a privately-held company; Fujimoto Pharmaceutical Corporation Japan: Membership on an entity's Board of Directors or advisory committees. Ljungman: Takeda: Consultancy, Other: Endpoint committee, speaker; OctaPharma: Other: DSMB; Enanta: Other: DSMB; Merck: Other: Investigator, speaker; AiCuris: Consultancy; Janssen: Other: Investigator. Ljunggren: XNK Therapeutics AB: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees. Alici: XNK Therapeutics AB: Current holder of individual stocks in a privately-held company.

scholarly journals CD38low Natural Killer Cells Transiently Expressing CD16F158V m-RNA Potentiates the Therapeutic Activity of Daratumumab Against Multiple Myeloma with Minimal Effector NK Cell Fratricide

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3199-3199 ◽  
Author(s):  
Subhashis Sarkar ◽  
Sachin Chauhan ◽  
Arwen Stikvoort ◽  
Alessandro Natoni ◽  
John Daly ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cell Line ◽  
Board Of Directors ◽  
Cell Lines ◽  
Research Funding ◽  
Nk Cell ◽  
Ex Vivo ◽  
Advisory Committees ◽  
Cd38 Expression ◽  
Rpmi 8226

Abstract Introduction: Multiple Myeloma (MM) is a clonal plasma cell malignancy typically associated with the high and uniform expression of CD38 transmembrane glycoprotein. Daratumumab is a humanized IgG1κ CD38 monoclonal antibody (moAb) which has demonstrated impressive single agent activity even in relapsed refractory MM patients as well as strong synergy with other anti-MM drugs. Natural Killer (NK) cells are cytotoxic immune effector cells mediating tumour immunosurveillance in vivo. NK cells also play an important role during moAb therapy by inducing antibody dependent cellular cytotoxicity (ADCC) via their Fcγ RIII (CD16) receptor. Furthermore, 15% of the population express a naturally occurring high affinity variant of CD16 harbouring a single point polymorphism (F158V), and this variant has been linked to improved ADCC. However, the contribution of NK cells to the efficacy of Daratumumab remains debatable as clinical data clearly indicate rapid depletion of CD38high peripheral blood NK cells in patients upon Daratumumab administration. Therefore, we hypothesize that transiently expressing the CD16F158V receptor using a "safe" mRNA electroporation-based approach, on CD38low NK cells could significantly enhance therapeutic efficacy of Daratumumab in MM patients. In the present study, we investigate the optimal NK cell platform for generating CD38low CD16F158V NK cells which can be administered as an "off-the-shelf"cell therapy product to target both CD38high and CD38low expressing MM patients in combination with Daratumumab. Methods: MM cell lines (n=5) (MM.1S, RPMI-8226, JJN3, H929, and U266) and NK cells (n=3) (primary expanded, NK-92, and KHYG1) were immunophenotyped for CD38 expression. CD16F158V coding m-RNA transcripts were synthesized using in-vitro transcription (IVT). CD16F158V expression was determined by flow cytometry over a period of 120 hours (n=5). 24-hours post electroporation, CD16F158V expressing KHYG1 cells were co-cultured with MM cell lines (n=4; RPMI-8226, JJN3, H929, and U266) either alone or in combination with Daratumumab in a 14-hour assay. Daratumumab induced NK cell fratricide and cytokine production (IFN-γ and TNF-α) were investigated at an E:T ratio of 1:1 in a 14-hour assay (n=3). CD38+CD138+ primary MM cells from newly diagnosed or relapsed-refractory MM patients were isolated by positive selection (n=5), and co-cultured with mock electroporated or CD16F158V m-RNA electroporated KHYG1 cells. CD16F158V KHYG1 were also co-cultured with primary MM cells from Daratumumab relapsed-refractory (RR) patients. Results: MM cell lines were classified as CD38hi (RPMI-8226, H929), and CD38lo (JJN3, U266) based on immunophenotyping (n=4). KHYG1 NK cell line had significantly lower CD38 expression as compared to primary expanded NK cells and NK-92 cell line (Figure 1a). KHYG1 electroporated with CD16F158V m-RNA expressed CD16 over a period of 120-hours post-transfection (n=5) (Figure 1b). CD16F158V KHYG1 in-combination with Daratumumab were significantly more cytotoxic towards both CD38hi and CD38lo MM cell lines as compared to CD16F158V KHYG1 alone at multiple E:T ratios (n=4) (Figure 1c, 1d). More importantly, Daratumumab had no significant effect on the viability of CD38low CD16F158V KHYG1. Moreover, CD16F158V KHYG1 in combination with Daratumumab produced significantly higher levels of IFN-γ (p=0.01) upon co-culture with CD38hi H929 cell line as compared to co-culture with mock KHYG1 and Daratumumab. The combination of CD16F158V KHYG1 with Daratumumab was also significantly more cytotoxic to primary MM cell ex vivo as compared to mock KHYG1 with Daratumumab at E:T ratio of 0.5:1 (p=0.01), 1:1 (p=0.005), 2.5:1 (p=0.003) and 5:1 (p=0.004) (Figure 1e). Preliminary data (n=2) also suggests that CD16F158V expressing KHYG1 can eliminate 15-17% of primary MM cells from Daratumumab RR patients ex vivo. Analysis of more Daratumumab RR samples are currently ongoing. Conclusions: Our study provides the proof-of-concept for combination therapy of Daratumumab with "off-the-shelf" CD38low NK cells transiently expressing CD16F158V for treatment of MM. Notably, this approach was effective against MM cell lines even with low CD38 expression (JJN3) and primary MM cells cultured ex vivo. Moreover, the enhanced cytokine production by CD16F158V KHYG1 cells has the potential to improve immunosurveillance and stimulate adaptive immune responses in vivo. Disclosures Sarkar: Onkimmune: Research Funding. Chauhan:Onkimmune: Research Funding. Stikvoort:Onkimmune: Research Funding. Mutis:Genmab: Research Funding; OnkImmune: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Research Funding; Celgene: Research Funding; Novartis: Research Funding. O'Dwyer:Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; BMS: Research Funding; Glycomimetics: Research Funding; Onkimmune: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding.

scholarly journals A Phase I Clinical Trial Testing the Safety of IL-21-Expanded, Off-the-Shelf, Third-Party Natural Killer Cells for Relapsed/Refractory Acute Myeloid Leukemia and Myelodysplastic Syndrome

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 44-44
Author(s):  
Sumithira Vasu ◽  
Bhavana Bhatnagar ◽  
James S. Blachly ◽  
Nicole Szuminski ◽  
Lynn O'Donnell ◽  
...  
Keyword(s):  
Myelodysplastic Syndrome ◽  
Nk Cells ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Nk Cell ◽  
Ex Vivo ◽  
Third Party ◽  
Advisory Committees

Background: Allogeneic transplantation (allo-HCT) is an effective treatment for many patients with Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS). With HCT the long term disease free survival (DFS) rate is approximately 60% for patients transplanted in first remission. After relapse, the rate falls to approximately 40% if the patients are in remission at the time of HCT. However, many patients present with refractory chemo-resistant disease, relapse during or shortly after induction therapy, or develop complicating comorbidities due to prolonged induction. For most such relapse-refractory (R/R) AML patients, allo-HCT is not an option. These patients have a dire prognosis with only 5-10% long term DFS. Natural Killer (NK) cells are cytotoxic lymphocytes that are able to identify tumors and exert an anti-tumor effect in an MHC-I independent manner. However, NK cells from patients with cancer can be dysfunctional and reduced in number. To overcome that, NK cells expanded ex vivo to yield high numbers of cells could provide a cellular therapeutic option for cancer patients, including patients with AML/MDS. The therapeutic potential of ex vivo membrane-bound IL-21 expanded NK cells (FC21-NK) from a haploidentical donor has been established in patients with poor prognosis AML/MDS undergoing a haploidentical HCT. Besides obtaining sufficient cell numbers, having them readily available for patients is another major obstacle for adoptive NK cell immunotherapy. Patients with aggressive disease need prompt intervention yet the manufacture of patient-specific NK cells exceeds three weeks. As NK alloreactivity plays a critical role in mediating anti-tumor effects, we identified KIR and HLA-mismatched 'ideal' donors (selected through "Be The Match Biotherapies"). Using lymphocytes from these donors, we have established a third-party NK cell bank to ensure readily-available immune cell therapies that allows scalable, affordable mass-production of large numbers of NK cells suitable for banking & immediate 'off-the-shelf' administration to a broad population of recipients. This trial is to determine the safety of FC21 expanded Off-the-shelf (OTS), Third-party donor-derived NK cells for relapsed/refractory AML patients. Methods: This phase 1 study follows a 3+3 design to investigate the safety of FC21-expanded, third-party, OTS NK cells for treatment of patients with primary refractory or relapsed AML or myelodysplastic syndrome. Active GvHD is excluding. Patients aged ≥18 or ≤80 years are enrolled into two cohorts: those <60 yrs & able to tolerate intensive chemo & sensitive to Cytarabine will receive Fludarabine 30 mg/m2/day (days -6 to -2) & Cytarabine 2 g/m2/day (days -6 to -2). Patients >60 yrs or <60 yrs & unable/unwilling to tolerate intensive chemo or disease insensitive to Cytarabine will receive Fludarabine 30 mg/m2/day (days -5 to -2) & Decitabine 20 mg/m2/day (days -6 to -2). All patients subsequently receive a total of 6 infusions of NK cells administered thrice weekly for two weeks (between day 0-21). Three NK cell dose-levels: 1x107, 3x107 & 1x108 cells/kg/dose will be explored to determine MTD (maximal tolerated dose). Between 3-18 patients/cohort/dose for MTD determination, plus an additional 10 patients/dose in an expansion phase may be enrolled (maximum 28/cohort = 56 total subjects). Patients will be followed up to day 56 from first NK cell infusion. Primary objectives are to determine the recommended phase 2 dose and overall response rate (CR, CRi & MLFS). Secondary objectives will explore PFS, OS & MRD negativity, cell counts, infectious complications, and patients proceeding to transplant. Enrollment in both cohorts is ongoing. Clinical trial information: NCT04220684. Disclosures Vasu: Kiadis Inc: Other: Kiadis has obtained exclusive licensing requirements from The OHio State University; Janssen: Membership on an entity's Board of Directors or advisory committees; Omeros: Membership on an entity's Board of Directors or advisory committees. Bhatnagar:KaryoPharm Therapuetics: Research Funding; Cell Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees. Blachly:AbbVie, AstraZeneca, KITE Pharma: Consultancy. O'Donnell:Kiadis Pharma: Other: Licensing of intellectual property. Lee:Kiadis Pharma Netherlands B.V: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

scholarly journals Clinical-Grade mRNA Electroporation of NK Cells: A Novel and Highly Efficient Method to Genetically Reprogram Human NK Cells for Cancer Immunotherapy

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2153-2153 ◽  
Author(s):  
Mattias Carlsten ◽  
Linhong Li ◽  
Su Su ◽  
Maria Berg ◽  
Robert Reger ◽  
...  
Keyword(s):  
Nk Cells ◽  
Board Of Directors ◽  
Nk Cell ◽  
Ex Vivo ◽  
Clinical Grade ◽  
Advisory Committees ◽  
Highly Efficient ◽  
Cytotoxic Function ◽  
Mrna Electroporation

Abstract Natural killer (NK) cells are immune cells involved in the defense against cancer. They have also been shown to induce strong anti-tumor responses in the setting of hematopoietic stem cell transplantation and in early clinical trials on adoptive NK cell transfer. Several methods to expand large numbers of clinical-grade NK cells have been developed for trials exploring adoptive NK cell immunotherapy for cancer. However, long-term culturing of NK cells often lead to undesirable phenotypic changes that may compromise their homing capacity and cytotoxic function, and can also lead to senescence compromising in vivo longevity. Introducing genes into NK cells that improve their in vivo viability, cytotoxicity, and ability to home to disease sites could improve the efficacy of NK cell-based immunotherapy. Previously, we and others have shown that genetic manipulation of NK cells through viral transduction is challenging, typically resulting in substantial reduction in NK cell viability and low transduction efficiency. mRNA transfection is an alternative strategy to genetically modify ex vivo expanded NK cells that may overcome limitations of viral transduction. Here we present data characterizing the transgene expression, viability, proliferative capacity, phenotype and cytotoxic function of clinical-grade ex vivo expanded human NK cells following mRNA electroporation using the GMP compliant MaxCyte system. Using unmodified mRNA coding for GFP and the cell surface marker CD34, we established that this technology resulted in rapid and highly efficient protein expression in NK cells without compromising their viability and cytotoxic function (Figure). NK cells electroporated with GFP mRNA rapidly became GFP positive and remained fluorescent for more than two weeks. Following transfection of CD34 mRNA, nearly 100% of NK cells expressed CD34 that remained detectable on the cell surface for up to five days, without affecting viability amongst transfected cells. With the exception of a slight reduction in proliferative capacity compared to controls, no negative impacts of mRNA electroporation using the MaxCyte platform were observed. Transfection of expanded NK cells did not alter expression of twenty cellular markers as assessed by flow cytometry, including activating and inhibitory NK cell receptors and death receptor ligands such as TRAIL. Further, electroporated NK cells maintained high cytotoxic function against K562 cells and multiple myeloma cells (Figure). In conclusion, mRNA electroporation of ex vivo expanded NK cells using the clinical-grade MaxCyte transfection system is highly efficient and opens numerous new possibilities to advancethe field of NK cell-based cancer immunotherapy. Figure 1 Figure 1. Disclosures Li: MaxCyte Inc.: Employment, Patents & Royalties. Peshwa:MaxCyte Inc.: Employment, Patents & Royalties; Indian Biomedical Association: Membership on an entity's Board of Directors or advisory committees; Epidarex Capital: Membership on an entity's Board of Directors or advisory committees; BioMetrx LLC: Membership on an entity's Board of Directors or advisory committees.

Optimal Xenogeneic Adoptive Transfer of Human NK Cells: Fresh NK Cells and IL-15 Administration Are Superior to Frozen NK Cells and IL-2

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 346-346 ◽  
Author(s):  
Jakub Tolar ◽  
Julie Curtsinger ◽  
Ron McElmurry ◽  
Valarie McCullar ◽  
Michael R. Verneris ◽  
...  
Keyword(s):  
Nk Cells ◽  
Board Of Directors ◽  
Adoptive Transfer ◽  
Nk Cell ◽  
Ex Vivo ◽  
Marked Contrast ◽  
Advisory Committees ◽  
Time Points ◽  
Cell Product

Abstract Abstract 346 Expansion of NK cells after adoptive transfer is a major determinant of their anti-tumor efficacy but the mechanisms of their expansion are not completely understood. To study in vivo NK cell expansion and the relative merits of fresh versus frozen NK cell products, we used xenotransplantation of human GMP NK cell products (provided by two PACT centers funded by the NHLBI) into immune deficient mice. NOD/IL-2Rγc/Rag (NOG) that lack T-, B-, and NK cells and that have a macrophage defect that renders recipients highly amenable to human cell engraftment, were given 250 cGy total body irradiation, and infused with fresh or frozen NK cells. Two products were tested: 1) an enriched fresh NK cell product obtained by CD3 and CD19 depletion followed by overnight activation with IL-2 or IL-15 (U. of Minnesota) or 2) ex vivo expanded NK cells using membrane bound IL-15 and 41BB-L transduced K562 cells with 10 U/ml IL-2 in G-Rex devices for 10 days (Baylor). NK cells (1–2 million NK cells for each individual experiment) were given IV and mice were treated with no cytokines, 5 or 10 mg of IL-2 (Novartis), or 5 mg IL-15 (produced by the NCI for clinical use) as 3 injections per week for 2 weeks. Peripheral blood (Table), spleen and marrow were evaluated on days 7, 14, 21 and 28 after adoptive transfer. Counts were converted to absolute cell numbers per 100 μL of blood or the number of cells recovered per spleen or after flushing of a single femur. On day 7, the number of huNK cells in blood in the absence of cytokine administration was low with both cell products and numbers continued to diminish by day 14. In marked contrast, every other day IL-2 or IL-15 significantly increased huNK cells in murine blood. On day 7 and 14, ex vivo expanded NK cell products resulted in significantly higher numbers of huNK in mice receiving 5μg IL-2 compared to mice who received fresh NK cells activated overnight with IL-2. With 5μg IL-2, huNK number decreased between day 7 and 14 irrespective of cell product. In contrast, only IL-15 lead to increased numbers of huNK cells between days 7 and 14. Previously cryopreserved NK cells showed significantly worse survival for both cell products, with a larger fold decrease seen with ex vivo expanded cells. Blood collected from cytokine treated mice at day 14 after infusion of fresh products contained huNK cells that were fully functional as assessed by potent CD107a degranulation, TNF and IFN production after exposure to K562 target cells as well as augmented IFN production induced by IL-12 and IL-18. On day 8, Ki67+ (proliferating) huNK cells were significantly higher with IL-15 compared to IL-2 (both at 5μg) in marrow for fresh (76% vs 35%, p=<0.001) and ex vivo expanded (88% vs 53%, p=0.003) NK cells. Ki67+ proliferating NK cells had decreased by day 14 under all conditions. With fresh NK cells and IL-15 on day 8, there were 1371 huNK relative counts recovered from spleen compared to 450 recovered from marrow (p=0.01). In marked contrast, ex vivo expanded NK cells (that express a lower percentage of CD62L compared to fresh NK cells) had a reverse homing pattern with 874 huNK cells in spleen versus 2146 in marrow (p=0.07). There was a significant difference between the two cells products in terms of the absolute numbers of huNK cells found in marrow at day 8 (p=0.0007). We conclude that 1) ex vivo expanded NK cells home better to BM which may be useful in treating AML localized to BM, whereas fresh NK cells may be preferable for homing to lymphoid tissue in the periphery; 2) at early time points fresh huNK cells were less abundant than expanded cells but catch up at late time points; and 2) IL-15 is more effective than IL-2 on a mcg basis. Overall, fresh and ex vivo expanded NK cells have different properties and kinetics after infusion. This xenogeneic model results in definitive readouts to optimize the best characteristics of each cell product to tailor a product to have maximal efficacy for clinical testing. Results of experiments with fresh or ex vivo expanded NK cells Exp. Activated NK source In vivo cytokine # mice Avg hu NK Day 7/100 μL muBlood Avg hu NK Day 14/100 μL muBlood 1 Fresh NK none 6 117 24 IL2-5 ug 6 238 53 Ex vivo expanded none 6 28 1 IL2-5 ug 6 760 235 2 Fresh NK none 4 212 16 IL2-5 ug 4 465 93 IL15-5 ug 4 540 1151 Ex vivo expanded none 4 63 9 IL2-5 ug 4 888 181 IL15-5 ug 4 3221 2930 3 Fresh NK none 12-16 141 55 IL2-5 ug 12-16 331 169 IL2-10 ug 12-16 197 182 IL15-5 ug 12-16 266 1177 Ex vivo expanded none 12-16 22 3 IL2-5 ug 12-16 323 106 IL2-10 ug 12-16 372 673 IL15-5 ug 12-16 735 1955 Disclosures: Miller: Celgene: Membership on an entity's Board of Directors or advisory committees; Coronado Bioscience: Membership on an entity's Board of Directors or advisory committees.

Education and Cytokine Receptor Balance Play a Critical Role in Long Term Survival of the Most Differentiated Natural Killer (NK) Cells.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2148-2148
Author(s):  
Martin Felices ◽  
Todd Lenvik ◽  
Dave Ankarlo ◽  
Julie Curtsinger ◽  
Jakub Tolar ◽  
...  
Keyword(s):  
Cell Survival ◽  
Nk Cells ◽  
Board Of Directors ◽  
Peripheral Blood ◽  
Nk Cell ◽  
Myelogenous Leukemia ◽  
Advisory Committees ◽  
Healthy Human ◽  
In Trans ◽  
The Common

Abstract Abstract 2148 NK cells can effectively treat advanced acute myelogenous leukemia if they survive and maintain functional competency after adoptive transfer. In the peripheral blood of healthy human donors the balance between Killer-cell immunoglobulin-like receptor positive (KIR+) NK cells, which are more differentiated and functional in terms of tumor killing and cytokine production, and KIR− NK cells is maintained by proliferation, differentiation, and survival. The mechanism that governs this process is largely unknown. Given that we and others have shown that KIR− NK cells proliferate better than KIR+ NK cells with IL-15 in vitro, we chose to study whether the balance between these two subsets could be maintained by enhanced survival of KIR+ NK cells. To explore this further, peripheral blood mononuclear cells (PBMCs) from healthy human donors were put in serum free conditions overnight and NK cell survival was assessed. A significantly larger proportion of the KIR− NK cells died (33±2.41%) compared to well characterized KIR+ NK cells: KIR2DL1/DS1 (8.9±1.22%), KIR2DL2/DL3 (6.7±0.51%), and KIR3DL1 (6.1±0.95%) (all P < 0.0001). A similar effect was seen when looking at Annexin V+ cells that still had membrane integrity. In order to further understand why KIR+ NK cells exhibited superior survival, we quantified expression of anti-apoptotic markers and found that KIR-expressing NK cells express more Bcl-xL, by Q-PCR and Western blotting. They also express more Bcl-2, by Q-PCR and flow median fluorescence intensity (MFI), particularly when the cells are treated with IL-15 overnight (P ≤ 0.0005). We next investigated expression of cell death family receptors Fas and Fas-Ligand (FasL). Under every condition tested Fas was expressed at significantly higher levels in the KIR− NK cells (P ≤ 0.03). FasL on the other hand was only expressed at higher levels in KIR− NK cells post 60 hrs in culture alone or with IL-2 but not IL-15. Although NK cells can signal through IL-7 or IL-2, only IL-15 mouse knockouts demonstrate a complete deficit of NK cells. Both IL-15 and IL-2 signal through 2 common shared components, IL-2Rb and the common g chain, and an individual cytokine specific component, IL-2Ra for IL-2 and IL-15Ra for IL-15. Interestingly, although all the components for IL-2 signaling are present on the NK cell, IL-15Ra bound to IL-15 is presented in trans from other cells or in complexes in order to achieve IL-15 signaling in NK cells, thereby discarding the necessity for IL-15Ra expression on the NK cell itself. Based on this information, the expression of all of these components was evaluated on KIR+ and KIR− NK cells. We found that IL-2Ra is expressed, by MFI, at statistically significant lower levels (P ≤ 0.0023) on KIR+ NK cells when compared to KIR− NK cells. In contrast, the common g chain is expressed, by MFI, at statistically higher levels (P < 0.0001) on KIR+ NK cells. No statistical differences were seen in IL-15Ra and IL-2Rb expression. We hypothesized that competition for common components, IL-2Rb and the common g chain, between IL-2Ra and IL-15Ra (in trans) plays a role in regulating survival through IL-15. In agreement with this premise, IL-2Ralo NK cells died significantly less than IL-2Rahi NK cells with transpresentation of IL-15 (3.5±1.5% vs. 30.8±2.6%, P = 0.0025). Transient overexpression of IL-2Ra ablates this enhanced survival. Finally we wanted to see if the educational status of the NK cell has a role in its survival. Of the KIR+ NK cells the educated NK cells, which have KIRs corresponding to self-ligands, represent the most differentiated and functional subset. We found that educated NK cells consistently had more Bcl-2 than uneducated NK cells (P ≤ 0.0021). This was associated with enhanced common g chain expression in the educated NK cell population (P = 0.0001). Previous studies have shown that CD57+ NK cells are long lived. We show here that educated NK cells had a statistically larger proportion and density of CD57 expression on a per cell basis (P < 0.0001). These data indicate that educated NK cells could survive better, through enhanced Bcl-2 upregulation, and persist longer, as determined by CD57 expression, than their uneducated counterparts. In summary we find that the mechanism for maintenance of more differentiated NK cells involves enhanced cell survival and differential responses to cytokines limited by the alpha chains of IL-2 and IL-15, which may be manipulated for therapeutic purposes. Disclosures: Miller: Celgene: Membership on an entity's Board of Directors or advisory committees; Coronado Bioscience: Membership on an entity's Board of Directors or advisory committees.

Sequential Immune Cell Modulation in Nordic Follicular Lymphoma Patients in the SAKK 35/10 Randomized Trial with Rituximab and Lenalidomide

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1535-1535 ◽  
Author(s):  
Sandra Lockmer ◽  
Björn E Wahlin ◽  
Bjorn Ostenstad ◽  
Åsa Jeppson-Ahlberg ◽  
Birgitta Sander ◽  
...  
Keyword(s):  
Follicular Lymphoma ◽  
Nk Cells ◽  
Board Of Directors ◽  
Peripheral Blood ◽  
Research Funding ◽  
Immune Cell ◽  
Nk Cell ◽  
Disease Stage ◽  
Advisory Committees ◽  
Immune Cell Subsets

Abstract Background Follicular lymphoma (FL) is the second most common lymphoma in adults. Although responsive to therapies it is still considered incurable. The introduction of the CD20 antibody rituximab is well known to have improved outcome. Rituximab acts through complement-mediated cytotoxicity, antibody-dependent cellular cytotoxicity (ADCC) and direct induction of apoptosis. To enhance the efficacy of rituximab, different combination regimens have been used, mostly with chemotherapy but also with cytokines. Lenalidomide, an immunomodulatory agent commonly used in the treatment of multiple myeloma, has been shown to induce durable responses with manageable toxicity in indolent lymphomas and mantle cell lymphoma, especially in combination with rituximab. It acts on both the malignant cells and their microenvironment. The drug modulates signaling pathways, enhances the capacity of T cells and increases ADCC by natural killer (NK) cells, as well as suppresses angiogenesis. When combined with rituximab, the clinical effects seem to be synergistic (Fowler 2014). We aimed to investigate the dynamics of immune cell subsets in peripheral blood in patients given rituximab with or without lenalidomide. Patients and Methods FL patients included in a multicenter randomized phase II trial performed by the Swiss Group for Clinical Cancer Research (SAKK) in collaboration with the Nordic Lymphoma Group (NLG) were randomized 1:1 to treatment either with rituximab alone or rituximab and lenalidomide. Inclusion criteria were histologically confirmed CD20+ FL grade 1, 2 or 3A in disease stage Ann Arbor III-IV (or II not suitable for radiotherapy). Patients had to be in need of systemic therapy because of clinical symptoms, cytopenia, bulky disease or significant disease progression. In both treatment arms rituximab was administered as 4 single infusions of 375 mg/m2 weeks 1, 2, 3 and 4; in patients who showed at least a minor response 4 additional infusions were administered at weeks 12, 13, 14 and 15. In the combination arm, lenalidomide, 15 mg p.o. daily, was started 14 days before the first infusion and given continuously until 14 days after the last. Peripheral blood cells were sequentially sampled: at baseline, after 2 weeks' use of lenalidomide, 24 hours after first rituximab infusion and at follow-up at weeks 10 and 23. Analyses of CD3+, CD4+, CD8+ and CD56+CD3- (NK) cells were performed with flow cytometry. Results Immune cell activity was assessed on blood samples of 28 Norwegian and Swedish patients until July 2015. In all patients, irrespective of treatment arm, NK cell numbers markedly decreased at 24 hours after the first rituximab infusion compared to baseline counts (P=0.046), but returned to baseline levels by week 10 in most. However, patients in the combination arm exhibited a heterogeneous response with a diverse NK cell depletion/proliferation pattern, some showing a transient rise already after 14 days of lenalidomide use (Figure 1). CD3 levels were not affected at 24 hours after rituximab but increased over time in 15 of 18 patients (without differences between treatment arms). The increase at week 23 was statistically significant (P=0.004) with a median of 1.4 x 109 /L CD3+ cells compared to a baseline median of 0.88 x 109/L. In all patients, independent of treatment arm, the CD4/CD8 ratio increased compared to baseline already 24 hours after rituximab (P=0.011) and persisted throughout the study (week 10, P=0,005; week 23, P=0.019). The increased ratio was due to a large rise in CD4 counts (week 10, P=0.014; week 23, P=0.003), and a less pronounced rise in CD8 counts (week 10, P=0.094; week 23, P=0.007; Figure 2). Conclusion We found changes in the composition of immune cell subsets in peripheral blood in rituximab treated FL patients, with a larger interindividual variation when combined with lenalidomide. Ongoing analyses will reveal whether these patterns of immune cell response correlate with clinical outcome and long-term treatment effects. Figure 1. NK cell absolute counts (x 109/L) in (a) patients treated with rituximab and in (b) patients treated with rituximab plus lenalidomide. 1=baseline, 2=after 14 days of lenalidomide (b only), 3=24h after rituximab, 4=week 10, 5=week 23. Figure 1. NK cell absolute counts (x 109/L) in (a) patients treated with rituximab and in (b) patients treated with rituximab plus lenalidomide. 1=baseline, 2=after 14 days of lenalidomide (b only), 3=24h after rituximab, 4=week 10, 5=week 23. Figure 2. CD4/CD8 ratios in all 28 patients. The y scale is logarithmic. 1=baseline, 2=after 14 days of lenalidomide (14 patients only), 3=24h after rituximab, 4=week 10, 5=week 23. Figure 2. CD4/CD8 ratios in all 28 patients. The y scale is logarithmic. 1=baseline, 2=after 14 days of lenalidomide (14 patients only), 3=24h after rituximab, 4=week 10, 5=week 23. Figure 3. Figure 3. Disclosures Off Label Use: Lenalidomide was used together with rituximab in a randomized clinical trial.. Kimby:Gilead: Membership on an entity's Board of Directors or advisory committees; Jansen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding.

scholarly journals Haploidentical Mbil-21 Ex Vivo Expanded NK Cells (FC21-NK) for Patients with Multiple Relapsed and Refractory Acute Myeloid Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 11-12
Author(s):  
Stefan O. Ciurea ◽  
Jolie Schafer ◽  
Piyanuch Kongtim ◽  
Julianne Chen ◽  
Doris Soebbing ◽  
...  
Keyword(s):  
Cell Therapy ◽  
Nk Cells ◽  
Board Of Directors ◽  
Research Funding ◽  
Nk Cell ◽  
Ex Vivo ◽  
Median Number ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Nk Cell Therapy

Background: Allogeneic stem-cell transplantation (alloSCT) remains the only curative treatment for patients with advanced AML. However, only a minority of these patients achieve disease control prior to transplantation. Natural Killer (NK) cells have potent anti-leukemic activity but are functionally deficient in AML. Adoptive NK-cell therapy using high-doses of functionally active NK-cells could overcome these limitations. We previously developed an ex vivo NK-cell expansion method based on K562 feeder cells modified to express membrane bound IL-21 (mbIL-21) and 4-1BB ligand, (FC21), which resulted in high numbers of hyperfunctional FC21-NK cells with enhanced cytotoxicity and cytokine production. Here we report outcomes of a phase I clinical trial designed to assess the safety, feasibility and maximum tolerated dose (MTD) of haploidentical FC21-NK cells for patients with relapse/refractory (R/R) AML at MD Anderson Cancer Center. Methods: Eligible patients were ≥18 years, KPS ≥70 with good organ function. Patients with relapsed AML after alloSCT were eligible if they had no active GVHD and did not require immunosuppression. Haploidentical donors were selected based on KIR characteristics, when multiple donors were available. Donor NK cells were expanded over 3 weeks and cryopreserved. Three dose levels between 106-108 cells/kg were planned. Patients received cytoreductive chemotherapy with fludarabine 30 mg/m2/day and cytarabine 2 g/m2/day for 5 days (4 days for age &gt;60) and G-CSF (subsequently eliminated). 3-7 days after chemotherapy, patients received FC21-NK cell infusions 3 times per week, up to 6 infusions. Results: As of 4/14/2020, 15 patients were screened, 12 of whom were eligible and received the FC21-NK cells. Median age was 60 years (range 25-70); 6 (50%) had adverse cytogenetics, 8 (66.7%) had adverse ELN genetic risk, 6 (50%) had primary induction failure, 2 (16.7%) had CNS disease and 4 (33.3%) had secondary AML. Median number of prior treatment regimens was 5 (range 2-8), median blast count at enrollment was 47% (range 7-88). Median time from diagnosis to enrollment and to first NK-cell infusion was 16.6 (range 2.5-98.1) and 17.2 (range 3.1-98.6) months, respectively. Donor-recipient NK-cell alloreactivity was seen in 5 patients (41.7%). Median number of NK-cell infusion was 6 (range 3-6); 8 (66.7%) and 4 (33.3%) patients received NK-cell dose of 1 X106 and 1 X107 cells/kg, respectively. MTD was not reached. Seven patients had ANC recovery post-NK cell infusion with cumulative incidence (CI) of ANC recovery to 500/mm3 at 60 days of 58.3%. Eight patients (66.7%) achieved complete remission (CR) (N=4, 33.3%) or CR with incomplete hematologic recovery (CRi) (N=4, 33.3%) at 30 days post-NK cell infusion. One patient with CR had negative minimal residual disease (MRD). Five patients (41.7%) proceeded to haploidentical alloSCT from the same donor and were transplanted in CR/CRi, all but one with persistent MRD. With a median follow-up of 13 months (range 4.1-42.7), median OS and DFS were 17.6 and 3.3 months, and 28 and 20 months for patients receiving alloSCT, respectively. Other outcomes including 2-year OS, DFS, relapse and TRM are shown in Figure 1 and Table 1. No infusion related toxicity or cytokine release syndrome was observed. Two patients were evaluable for FC21-NK cell persistence with haplotype-specific anti-HLA antibodies. FC21-NK cells were detected 5 and 6 weeks after the last FC21-NK cell infusion, respectively. A progressive decrease of the blast population with progressive expansion of the FC21-NK cell population after repeated NK-cell infusions was noted in samples collected from one pt (Figure 2). Persistence is also being evaluated by STR chimerism. Conclusions: Multiple infusions of FC21-NK cells yielded unprecedented outcomes with 66.7% of patients responding and approximately half proceeding to alloSCT in a heavily pre-treated, ultra-refractory, high-risk patient population. Responses were observed irrespective of dose. FC21-NK cell therapy was very well tolerated with no attributable AEs and were shown to persist for at least 5 weeks after infusion. These encouraging results warrant further clinical evaluation of FC21-NK cells in R/R AML patients. Disclosures Ciurea: Kiadis Pharma: Current equity holder in publicly-traded company, Research Funding. Schafer:Kiadis Pharma: Current Employment. Shpall:Zelluna: Membership on an entity's Board of Directors or advisory committees; Adaptimmune: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Magenta: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda: Other: Licensing Agreement. Konopleva:Calithera: Research Funding; Eli Lilly: Research Funding; Kisoji: Consultancy; Reata Pharmaceutical Inc.;: Patents & Royalties: patents and royalties with patent US 7,795,305 B2 on CDDO-compounds and combination therapies, licensed to Reata Pharmaceutical; Forty-Seven: Consultancy, Research Funding; Sanofi: Research Funding; AstraZeneca: Research Funding; Agios: Research Funding; Ablynx: Research Funding; AbbVie: Consultancy, Research Funding; Ascentage: Research Funding; Rafael Pharmaceutical: Research Funding; Cellectis: Research Funding; F. Hoffmann La-Roche: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Amgen: Consultancy; Stemline Therapeutics: Consultancy, Research Funding. Lee:Kiadis Pharma Netherlands B.V: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Champlin:Actinium: Consultancy; Johnson and Johnson: Consultancy; Omeros: Consultancy; DKMS America: Membership on an entity's Board of Directors or advisory committees; Cytonus: Consultancy; Genzyme: Speakers Bureau; Takeda: Patents & Royalties.

scholarly journals Results of a Phase 1 Trial of Gda-201, Nicotinamide-Expanded Allogeneic Natural Killer Cells (NAM-NK) in Patients with Refractory Non-Hodgkin Lymphoma (NHL) and Multiple Myeloma (MM)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 777-777
Author(s):  
Veronika Bachanova ◽  
David H. McKenna ◽  
Xianghua Luo ◽  
Todd E. DeFor ◽  
Fiona He ◽  
...  
Keyword(s):  
Nk Cells ◽  
Board Of Directors ◽  
Research Funding ◽  
Nk Cell ◽  
Ex Vivo ◽  
Phase 1 ◽  
Large Cell ◽  
Clinical Activity ◽  
Advisory Committees

Background: NK cells have the capacity to kill tumor targets, representing a novel immunotherapeutic approach to cancer. We have shown promising clinical activity in AML with a previous NK cell preparation. Limitations of NK therapies have included specificity, persistence after infusion, and potential for maximal activity of NK cells in vivo. GDA-201 is a cellular product composed of natural killer (NK) cells from healthy donors expanded ex vivo with nicotinamide (NAM) and IL-15; this is a unique ex vivo activation strategy to induce persistence of potent anti-tumor activity. Prior in vitro studies and pre-clinical models demonstrated that NAM-exposed NK cells exhibited augmented resistance against exhaustion and improved killing function, proliferation, and organ retention. We now report safety and efficacy from a phase 1 clinical trial of GDA-201 in patients (pts) with relapsed or refractory (R/R) NHL or MM. Methods: Following donor apheresis, CD3-depleted mononuclear cells were cultured for 14-16 days with NAM (5mM) and IL-15 (20ng/ml), resulting in a 40-fold increase in NK cells and increased expression of CD62L from 2.9% to 21%. GDA-201 contained ~98% NK cells, and CD3 content was maintained at &lt;0.5% (&lt;5x105/kg/dose). Pts with R/R CD 20-positive NHL or refractory MM received cyclophosphamide (400mg/m2 IV x 3d) and fludarabine (30 mg/m2 /d IV x 3d), followed by two doses of GDA-201 (Days 0 and 2) and low-dose IL-2 (6 million units sc). Pts with NHL or MM received rituximab (375 mg/m2 x 4 weekly or elotuzumab (10 mg/kg x 3 weekly), respectively, to enhance NK cell targeting through antibody-dependent cellular cytotoxicity (ADCC). Results: 20 pts were enrolled: 7 with NHL (4 follicular, 2 transformed, 1 diffuse large cell lymphoma) and 13 with MM, in 3 cohorts of escalating GDA-201 dose; 11 pts received the maximum target dose (median 1.7 x 108 cells/kg, range 1.6-2.0 x 108 cells/kg). There were no dose limiting toxicities. The most common grade 3/4 adverse events were neutropenia and thrombocytopenia, febrile neutropenia (n=2), increased creatinine, hyponatremia, pulmonary edema; all events were transient. One pt had grade 2 cytokine release syndrome at day 18, presenting with fever, hypoxemia and hypotension, responding to tocilizumab; pt later died of E Coli sepsis. There were no neurotoxic events, GVHD or marrow aplasia. Among 7 NHL pts, there were 3 CR and 2 PR with overall response rate of 71%. Median duration of response was 12 months (CR patients) and 5 months (PR patients). Figure 1A illustrates a 57-year-old man with history of CLL and Richter's transformation (large cell lymphoma), pre- GDA-201 and 6 months post therapy; the pt had continued response with 80% tumor shrinkage at 6 months. In MM patients, 1 patient with extramedullary disease had CR and 4 had SD with median duration 2.5 months. In our previous study using overnight-activated NK cells, persistence 7 days after adoptive transfer was limited. Using GDA-201, flow cytometry confirmed persistence of donor NAM-NK in peripheral blood up to day 7-10 (day 7 range 2-55% donor NK cells; Figure 1B), as well as enhanced in vivo proliferation (median Ki67 99%). Conclusions: Cellular therapy using GDA-201 with monoclonal antibodies was safe, and demonstrated early evidence of clinical activity in heavily pre-treated pts with advanced NHL and MM. The recommended dose of GDA-201 for phase 2 is 2.0 x 108 cells/kg. The clinical responses showed that NK cell targeting through ADCC can be efficacious and increase response. Laboratory studies showed that GDA-201 had better persistence than observed in our previous studies using overnight activated cytokine alone stimulated NK cells. This study demonstrated that GDA-201 has an efficacy signal, and larger phase II studies are warranted. Disclosures Bachanova: Incyte: Research Funding; Gamida Cell: Research Funding; Novartis: Research Funding; GT Biopharma: Research Funding; Celgene: Research Funding; Kite: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. McKenna:Fate Therapeutics: Research Funding; Magenta Therapeutics: Research Funding; CIBMTR BMT CTN (NIH): Other: Medical Monitor; Icahn School of Medicine, New York, New York: Consultancy; National Eye Institute (NIH): Other: DSMB (2); Gamida: Research Funding; NMDP: Other: Donor and Patient Safety Monitoring Advisory Group; Intima: Patents & Royalties: Royalities, Research Funding. Brachya:Gamida Cell: Employment, Equity Ownership. Peled:Gamida Cell: Employment, Equity Ownership. Miller:GT BioPharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; CytoSen: Membership on an entity's Board of Directors or advisory committees; Dr. Reddys Laboratory: Membership on an entity's Board of Directors or advisory committees; Moderna: Membership on an entity's Board of Directors or advisory committees; Fate Therapeutics, Inc: Consultancy, Research Funding; OnKImmune: Membership on an entity's Board of Directors or advisory committees.

scholarly journals PD-1 Is Expressed at Low Levels on All Peripheral Blood Natural Killer Cells but Is a Significant Suppressor of NK Function Against PD-1 Ligand Expressing Tumor Targets

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 621-621
Author(s):  
Zachary Davis ◽  
Martin Felices ◽  
Todd R Lenvik ◽  
Sujan Badal ◽  
Peter Hinderlie ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Board Of Directors ◽  
Peripheral Blood ◽  
Research Funding ◽  
Cytokine Production ◽  
Nk Cell ◽  
Fold Increase ◽  
Advisory Committees ◽  
Fund Research

Checkpoint blockade has become a promising immunotherapy for the treatment of a variety of malignancies. In particular, the receptor programmed death-1 (PD-1) has become a focus of intense study due to its expression on and negative regulation of T-cell function. The ligand for PD-1, PD-L1, is upregulated on many tumors and, as a result, can suppress antigen-specific T-cells thereby limiting their anti-tumor response. Pharmacological PD-1/PD-L1 axis disruption can occur with either Pembrolizumab and Nivolumab (PD-1 antagonists) and Avelumab and Atezolizumab (PD-L1 antagonists). These antibodies (mAbs) are being used to treat melanoma, non-small cell lung cancer, kidney, bladder and head and neck cancer with varying degrees of success. Like T-cells, natural killer cells (NK) also have potent antitumor cytolytic properties. The expression and functional effects of PD-1 on NK cells remain unclear due to difficulties in receptor detection and efficacy of receptor blockade by available commercial reagents. While some studies have been unable to detect PD-1 on resting NK cells, others have identified PD-1 expression only on specific NK populations under certain conditions (e.g. Cytokine stimulation or virus infection). Here, we identify PD-1 expression on peripheral blood NK cells. Using commercial reagents (Figure 1A) and a FITC-labeled clinical mAb (Pembrolizumab, Pembro), we detect low yet consistent PD-1 expression on all circulating, resting NK cells. Since FITC-Pembro mean fluorescent intensity was low and a high proportion of FITC labeled NK cells overlapped with the isotype control (Figure 1B), we designed a short-chain variable fragment (scFv) of the mAb to determine whether the smaller scFv molecule has better binding and functional activity than the intact mAb. The Pembro scFv bound to resting NK cells with a distinct fluorescent peak compared to the native Prembro from which the scFv was derived (Figure 1B). Compared to intact Prembro, use of the Pembro scFv as a PD-1 antagonist resulted in a 2-fold increase of NK cell cytolytic activity and a 3-4 fold increase in cytokine production against the PD-L1 expressing CML target, K562 (Figure 1C-D) and the AML target, THP-1 (Figure 1E-F). While PD-1 blockade enhanced NK cell degranulation and target cell killing, a greater functional enhancement was seen for interferon-γ production. PD-1 signaling inhibits PI3K induced pAkt and NK function. PD-1/PD-1 ligand blockade by the Pembro scFv resulted in increased NK cell pAKT in the presence of PD-L1 and NK activating NKG2D-ligand-expressing THP-1 cells. In addition to natural cytotoxicity, NK-mediated ADCC was also enhanced with PD-1 blockade. CD33 mAb immunoconjugates have been used to treat AML. Combined anti-CD33 mAb and PD-1 blockade against THP-1 cells resulted in a small but significant increase in NK cell degranulation and a 4-fold increase in cytokine production compared to anti-CD33 mAb without PD-1 blockade (Figure 1G-H). Since stimulation with IL-15, a cytokine that effectively lowers the NK activation threshold, abrogated the benefits of Pembro scFv in diminishing PD-1 inhibitory effects on NK cells, PD-1 control of NK function appears limited to be mostly relevant to resting NK cells. To understand the physiologic expression of PD-1 in vivo, we studied samples taken from AML patients receiving matched sibling donor transplantation at the University of Minnesota. Increased PD-1 on reconstituting NK cells in BMT recipients up to day 100 post-transplant was shown by both flow-cytometric (Figure 2A) and mass-cytometric (CyTOF) analyses (Figure 2B). Blockade of PD-1 on these cells significantly enhanced both NK degranulation (Figure 2C) and cytokine production (Figure 2D) against K562 targets. A similar increase in NK function was observed with PD-1 blockade in AML patients receiving umbilical cord transplants (not shown). These data indicate that PD-1 is present on human NK cells and PD-1 ligation negatively regulates NK function against PD-L1 expressing tumor targets. The observation that functional PD-1 is expressed on NK cells under resting conditions strongly suggests that the use of a PD-1 antagonist, in combination with NK cell therapy, should be clinically effective for treatment of cancer. Disclosures Felices: GT Biopharma.: Other: consulting funds, Research Funding. Blazar:Kamon Pharmaceuticals, Inc: Membership on an entity's Board of Directors or advisory committees; Tmunity: Other: Co-Founder; BlueRock Therapeutics: Membership on an entity's Board of Directors or advisory committees; Regeneron Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Five Prime Therapeutics Inc: Co-Founder, Membership on an entity's Board of Directors or advisory committees; KidsFirst Fund: Research Funding; Childrens' Cancer Research Fund: Research Funding; Leukemia and Lymphoma Society: Research Funding; Abbvie Inc: Research Funding; Alpine Immune Sciences, Inc.: Research Funding; RXi Pharmaceuticals: Research Funding; Fate Therapeutics, Inc.: Research Funding; Magenta Therapeutics and BlueRock Therapeuetics: Membership on an entity's Board of Directors or advisory committees. Vallera:GT Biopharma, Inc.: Consultancy, Research Funding. Miller:Fate Therapeutics, Inc: Consultancy, Research Funding; GT BioPharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; CytoSen: Membership on an entity's Board of Directors or advisory committees; OnKImmune: Membership on an entity's Board of Directors or advisory committees; Dr. Reddys Laboratory: Membership on an entity's Board of Directors or advisory committees; Moderna: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Keytruda. PD-1 blockade on NK cells for tumor immunotherapy

scholarly journals Directed Differentiation of Mobilized Hematopoietic Stem and Progenitor Cells into Functional NK Cells with Enhanced Antitumor Activity

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 811
Author(s):  
Pranav Oberoi ◽  
Kathrina Kamenjarin ◽  
Jose Francisco Villena Ossa ◽  
Barbara Uherek ◽  
Halvard Bönig ◽  
...  
Keyword(s):  
Nk Cells ◽  
Progenitor Cells ◽  
Peripheral Blood ◽  
Cell Expansion ◽  
Nk Cell ◽  
Ex Vivo ◽  
Feeder Cells ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Stem And Progenitor Cells

Obtaining sufficient numbers of functional natural killer (NK) cells is crucial for the success of NK-cell-based adoptive immunotherapies. While expansion from peripheral blood (PB) is the current method of choice, ex vivo generation of NK cells from hematopoietic stem and progenitor cells (HSCs) may constitute an attractive alternative. Thereby, HSCs mobilized into peripheral blood (PB-CD34+) represent a valuable starting material, but the rather poor and donor-dependent differentiation of isolated PB-CD34+ cells into NK cells observed in earlier studies still represents a major hurdle. Here, we report a refined approach based on ex vivo culture of PB-CD34+ cells with optimized cytokine cocktails that reliably generates functionally mature NK cells, as assessed by analyzing NK-cell-associated surface markers and cytotoxicity. To further enhance NK cell expansion, we generated K562 feeder cells co-expressing 4-1BB ligand and membrane-anchored IL-15 and IL-21. Co-culture of PB-derived NK cells and NK cells that were ex-vivo-differentiated from HSCs with these feeder cells dramatically improved NK cell expansion, and fully compensated for donor-to-donor variability observed during only cytokine-based propagation. Our findings suggest mobilized PB-CD34+ cells expanded and differentiated according to this two-step protocol as a promising source for the generation of allogeneic NK cells for adoptive cancer immunotherapy.

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