scholarly journals Pre-Clinical and Clinical Immunomodulatory Effects of Pomalidomide or CC-92480 in Combination with Bortezomib in Multiple Myeloma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1613-1613
Author(s):  
Chad C Bjorklund ◽  
Michael Amatangelo ◽  
Hsiling Chiu ◽  
Jian Kang ◽  
Tiziana Civardi ◽  
...  

Abstract Background: Pomalidomide (POM) is an established agent in relapsed/refractory (R/R) multiple myeloma (MM) with direct cytotoxicity against MM cells and immunostimulatory activities in multiple cell types including T cells and NK cells. CC-92480 is a novel Aiolos/Ikaros degrading cereblon E3 ligase modulator (CELMoD ®) agent is currently being investigated in combination with the proteasome inhibitor (PI) bortezomib (BTZ) and corticosteroid dexamethasone (DEX), or with DEX only in R/R MM (CC-92480-MM-002 and CC-92480-MM-001). Previous results indicate that triplet combination of POM/BTZ/DEX may enhance some T, B and NK cell subpopulations, overcoming immunosuppression when compared to BTZ/DEX-only treated patients (Rao et al, 2019). Mechanisms of action (MOA) of CC-92480- and POM-mediated substrate depletion occurs via ubiquitination and proteasome degradation, where BTZ has been speculated as potentially antagonistic as a PI. Here, we report pre-clinical and clinical observations of an immune MOA of CC-92480 or POM in combination with BTZ. Results: To mimic the clinical pharmacokinetics, BTZ was utilized as a high-dose pulse method alone and in combination with POM or CC-92480, followed by flow cytometric measurements of Aiolos and Ikaros protein abundance in healthy donor (HD) T cells. The addition of BTZ modestly delayed CRBN-dependent substrate depletion compared to single agent POM or CC-92480; however, this effect was only apparent at early time points (1-6 hr) where the effect was negligible by 24 hr. To understand the functional implications of BTZ combination, we conducted CD3-stimulated PBMC-mediated cytotoxicity assay against H929 MM target cells in a co-culture model. The efficiency of POM or CC-92480 induced PBMC-mediated killing in a dose dependent manner (~65% increase compared to DMSO) were similar at a 100-fold lower dose range of CC-92480 compared to POM, with the effect not being altered by co-treatment with BTZ. These data were replicated with a POM or CC-92480 treated supernatant stimulation of purified NK cells co-culture, which induced an 80% reduction in target cell viability with the BTZ combination having no negative effects on CELMoD-mediated activity. Cytokine analysis on PBMC supernatants treated with either POM or CC-92480 in the absence or presence of BTZ-pulse showed a dose-dependent increase in IL-2 (>2.4-fold) and Granzyme B (>3.1-fold), which were not impacted by BTZ co-treatment. As a secondary readout on activation status, we measured multiple signaling molecules and activation markers on the cell surface of T and NK cell subsets in CD3 stimulated HD PBMCs treated with dose-dependent POM or CC-92480 with or without co-treatment of BTZ. Compared to DMSO controls, elevated expression levels of CD25 (IL2RA), CD278 (ICOS), Granzyme B, CD134 (OX40R) and HLA-DR were observed with both POM and CC-92480 on CD4, CD8 and NK cells demonstrating a CELMoD-mediated increase in immune activation. These effects were not impacted by the co-treatment of BTZ. Examination of peripheral blood samples from MM patients enrolled in the CC-92480-MM-001/002 (NCT03374085/NCT03989414) clinical trials revealed that CC-92480 promoted potent immunomodulation when administered in combination with DEX and with BTZ/DEX. These data included increased numbers of activated and central memory T cells, as well as increased Ki67+ proliferating T and NK cell populations compared to samples collected during the screening period before any drugs had been administered, consistent with earlier observation of POM in combination with BTZ/DEX treated patients. Conclusions: Taken together, these data demonstrate that POM and CC-92480 are potent immunomodulatory agents with enhanced induction of PBMC and NK mediated cell killing of MM tumor cells and activation of T and NK cells, at 100-fold lower concentrations of CC-92480 compared to POM. Additionally, we showed that combination with BTZ in preclinical assays and in the clinical setting did not antagonistically affect the immunostimulatory ability of POM or CC-92480. Disclosures Bjorklund: BMS: Current Employment, Current equity holder in publicly-traded company. Amatangelo: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Chiu: Bristol Myers Squibb: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Kang: BMS: Current equity holder in publicly-traded company. Civardi: Bristol Myers Squibb: Current Employment. Katz: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Maciag: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Hagner: BMS: Current Employment, Current equity holder in publicly-traded company. Pourdehnad: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: No royalty. Bahlis: Pfizer: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Genentech: Consultancy; BMS/Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; GlaxoSmithKline: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria. Richardson: Oncopeptides: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Karyopharm: Consultancy, Research Funding; Protocol Intelligence: Consultancy; Janssen: Consultancy; Sanofi: Consultancy; Secura Bio: Consultancy; GlaxoSmithKline: Consultancy; Regeneron: Consultancy; AstraZeneca: Consultancy; AbbVie: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding. Thakurta: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4357-4357
Author(s):  
Arghya Ray ◽  
Ting DU ◽  
Nina N. Nupponen ◽  
Fredrik Lehmann ◽  
Jakob Lindberg ◽  
...  

Abstract Introduction Melphalan flufenamide (Melflufen; Oncopeptides AB) is a novel enzyme-activated analogue of melphalan that enables a more rapid and higher intracellular accumulation of melphalan in tumor cells than is achievable by direct exposure to equimolar doses of melphalan. Our preclinical study showed that melflufen is a more potent anti-myeloma (MM) agent than melphalan, overcomes drug-resistance, and induces synergistic anti-MM activity in combination with bortezomib, lenalidomide, or dexamethasone (Chauhan et al, Clinical Cancer Res 2013;19:3019). However, the effect of melflufen on the immunosuppressive and tumor-promoting MM-host bone marrow (BM) accessory cells such as immunologically dysfunctional plasmacytoid dendritic cells (pDCs; CD123/IL-3Rα) remains unclear. Here, we utilized our coculture models of pDCs, T-, and NK cells with autologous patient MM cells to examine whether a combination of melflufen and immune checkpoint inhibitor anti-PD-L1 Ab, or daratumumab (anti-CD38 Ab), restores anti-MM immunity. Methods MM patient BM and PB samples (N=10; obtained after informed consent), and cell lines were used for the study. Minimally cytotoxic concentration of melflufen (0.1 µM) was used to assess immune functions. CTL/NK activity assays MM CD8 + T- or NK-cells were cultured with autologous pDCs (1:10 pDC:T/NK ratio) with melflufen (0.1 μM) alone, and with anti-PD-L1 (5 μg/ml) or anti-CD38 (0.5 μg/ml) Abs for 3-5 days; cells were washed to remove the drugs, and then cultured for another 24h with pre-stained target MM cells (10:1 E/T ratio; T/NK:MM), followed by quantification of viable MM cells by flow. Results 1) Both MM tumor cells and pDCs showed higher PD-L1 and CD38 levels vs normal plasma cells; 2) Treatment of MM patient total BM mononuclear cells or purified MM cells with melflufen (0.1 µM) increased PD-L1 expression on MM cells (1.84-fold, treated vs untreated; p<0.05). Importantly, treatment of MM cells with melflufen and anti-PD-L1 Abs enhanced anti-MM cytotoxicity; 3) Combination of melflufen and anti-PD-L1 Ab triggers activation of CD3 + T cells, evidenced by an increase in CD69 expression on CD3 + T cells (1.15-fold, treated vs untreated, p<0.05); 4) Combination of melflufen and anti-PD-L1 Ab induced a more robust autologous MM-specific CD8 + cytotoxic T lymphocyte (CTL) activity than melflufen alone (% MM lysis: melflufen: 20%; melflufen plus anti-PD-L1 Ab: 60%; n=5; p=0.013); 5) Meflufen and anti-PD-L1 also triggered pDC-induced NK cell-mediated MM-specific cytolytic activity (p<0.05); and finally, 6) Low doses of melflufen and anti-CD38 Abs enhanced pDC-induced NK cell-mediated MM-specific cytolytic activity (%Viability: melflufen: 75%; melflufen + anti-CD38 Ab: 12.5%; n=4; p=0.001). Conclusions The combination of melflufen and anti-PD-L1 increases pDC-induced T- and NK cell-mediated cytolytic activities against MM. Moreover, combined melflufen and anti-CD38 Abs modestly enhance pDC-induced NK cell-mediated MM-specific cytolytic activity. Our preclinical data suggest targeting PD-L1 in combination with melflufen as well as support an ongoing clinical trial of melflufen with anti-CD38 Abs to enhance anti-MM immunity. Disclosures Nupponen: Oncopeptides AB: Consultancy. Lehmann: Oncopeptides AB: Current Employment. Lindberg: Oncopeptides: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months, Other: Travel, Accommodations, Expenses; Camurus: Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Affibody: Membership on an entity's Board of Directors or advisory committees. Gullbo: Oncopeptides AB: Consultancy. Richardson: Takeda: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Janssen: Consultancy; Sanofi: Consultancy; Protocol Intelligence: Consultancy; Karyopharm: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; Regeneron: Consultancy; AstraZeneca: Consultancy; Secura Bio: Consultancy; AbbVie: Consultancy; Oncopeptides: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding. Chauhan: C4 Therapeutics: Current equity holder in publicly-traded company; Oncopeptides: Consultancy; Stemline Therapeutics: Consultancy. Anderson: Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium-Takeda: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Scientific Founder of Oncopep and C4 Therapeutics: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Mana Therapeutics: Membership on an entity's Board of Directors or advisory committees.



Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1904-1904 ◽  
Author(s):  
Andy K Hsu ◽  
Nick Gherardin ◽  
Hang Quach ◽  
Simon J. Harrison ◽  
H Miles Prince ◽  
...  

Abstract Introduction CD57+ NK cells are a subset of CD56lo/CD16+ NK cells which have been alternatively described as terminally differentiated or memory NK cells; however their physiological role remains unclear. In this study, we explored this unique NK subset and define their role in the context of MM. Results CD57+ NK cell frequency was initially assessed by FACS. Thus, newly diagnosed untreated (NEW) Multiple Myeloma (MM) patients had a significantly increased frequency of CD57+ NK cells in the PB (p=0.0029) and BM (p=0.0095) compared with age matched normal donor controls. Refractory relapsed (RR) MM patients also had significantly increased CD57+ cells in the BM (p=0.008) (Figure 1). There was no change in CD57+ NK cell numbers (in either patient cohort) following three cycles of lenalidomide+dexamethasone (len+dex) therapy. Normal donor CD57+ NK cells had significantly less natural cytotoxicity function (compared with CD57- NK cells) against K562 (p=0.04) or U266 (p=0.0265) (Figure 2A). The same trend was observed in MM patient CD57+ NK cells; however this did not reach statistical significance (Figure 2B). In contrast, the ADCC activity for CD57+ and CD57- NK cells was the same whether the effector cells were from normal donors (Figure 2A) or MM patients (Figure 2B). To explain the reason for this difference in natural cytotoxicity function between the two NK cell subsets, the balance of NK activating (KAR) and inhibitory receptors (KIR) was examined (Figure 3). CD57+NK cells expressed significantly lower levels of the NK activating receptor Nkp46 than CD57-NK cells, in the PB of normal donors (p=0.001), NEW MM patients at presentation (p=0.008) or NEW MM patients after three cycles of len-dex therapy (p=0.0237) (Figure 3). In contrast, both CD57+ and CD57- NK cell subsets in RR MM patients had the same levels of Nkp46, this did not change with len-dex therapy. To further explore reasons for the CD57+ NK cell functional state, expression of NK effector molecules (perforin and granzyme) and NK effector transcription factors (TF) T-bet and Eomesdermin (Eomes) was assessed. Surprisingly, PB CD57+ NK cells had significantly higher perforin expression than CD57- NK cells in the PB of normal donors (p=0.0089) and NEW (p=0.0815) MM patients, and the BM of NEW MM patients (p=0.0487). Similarly, granzyme B was significantly elevated in CD57+ compared to CD57- NK cells in normal donors (p=0.013), NEW MM patients in the PB (p=0.0024) and BM (p=0.0007). There was no statistical difference in the expression of Eomes or T-bet in either NK subset, whether the cells were from normal donors or MM patients. Nonetheless, a trend in higher Eomes expression was observed in CD57+ NK cells from MM patients compared to age matched controls. Lastly, CD57+ (compared to CD57-) NK cells have a significantly lower proliferation rate in a NK homeostatic proliferation assay. Discussion and Conclusions Studies to date indicate CD57+ NK cells are terminally differentiated NK cells; however to date their role remains undefined. We observed an increased frequency of CD57+ NK in the PB and BM of newly diagnosed untreated MM patients. These CD57+ NK cells have the same functional and phenotypic features in normal donors and MM patients, whether at diagnosis or in RR patients. The strikingly reduced natural cytotoxicity in CD57+ NK cells, coupled with reduced Nkp46 expression, indicates these cells are not important for surveillance of viral infected or tumour cells. Rather CD57+ NK express elevated effector proteins and the effector TF Eomes and are ‘primed’ for killing of target cells via ADCC. Unlike CD57- NK cells, CD57+ NK cells do not undergo homeostatic proliferation; whilst this is consistent with terminally differentiated cells, it is not clear how these cells persist in the periphery of MM patients. Nonetheless, CD57+ NK cells are elevated in MM patients at presentation, whilst this likely contributes to the overall decreased natural cytotoxicity observed in MM patients, it also provides an opportunity to activate NK cells via CD16 (FcγRIII) to induce ADCC against MM. Disclosures: Harrison: Celgene Corp: Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Janssen Cilag: Honoraria, Research Funding; Virolytics: Consultancy.



Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 4-5
Author(s):  
Jode P Goodridge ◽  
Ryan Bjordahl ◽  
Sajid Mahmood ◽  
John Reiser ◽  
Svetlana Gaidarova ◽  
...  

Multiple redundancy within the spectrum of an immune response is required to prevent antigen escape or adaptation of the targeted population to host defenses. As adoptive cell therapies continue to evolve, multi-modal engineering of effector cells offers the prospect of tackling increasingly complex disease settings such as multiple myeloma (MM), where targeting of a single tumor associated antigen is frequently confounded by antigen shedding and escape variation resulting in the inability to develop a curative therapy. There are multiple advantages in expanding treatment options beyond autologous primary T and NK cells, including the use of induced pluripotent stem cells (iPSC) to derive effector cells that can be uniformly manufactured at scale from renewable starting cellular material and where precision genetic engineering can be achieved at the clonal level which can be applied sequentially in order to build multiple specificities and functional modalities. To create a platform targeted toward MM, a multiplexed edited base iPSC-derived NK (iNK) cell configuration consisting of a CD38 KO iPSC modified to overexpress a recombinant IL-15 signaling complex (IL15RF) for autonomous persistence and a functionally enhanced high-affinity, non-cleavable CD16 (hnCD16) was developed. Introduction of IL15RF enabled expansion of iNK cells without additional exogenous cytokine support during the manufacturing process and greatly improved functional persistence of iNK cells both in vitro and in various xenograft mouse models (Figure 1). To target MM in a broad and comprehensive manner, we tested our novel BCMA-CAR in combination with different myeloma targeted antibodies. In combination with hnCD16, co-expression of BCMA-CAR and IL15RF culminates in an iNK cell therapeutic, termed FT576, capable of multiantigen-specificity through combinatorial use of CAR and hnCD16 with monoclonal antibodies to tackle antigen escape. Chimerization of an anti-BCMA scFv shown to elicit higher affinity onto the CAR platform produced specific in vitro recognition of BCMA+ myeloma cells in short-term and long-term NK cell cytotoxicity assays. Specificity of the BCMA-CAR was demonstrated using NALM6 overexpressing BCMA using a short range 4H caspase assay (NALM6_BCMA EC50 14.4, NALM6wt EC50 39.1, p*<0.0001). Utilizing a long range clearance assay, serial restimulation by repeated rounds of exposure to fresh MM1S MM target cells was tested, showing remarkable persistence and antigen-mediated expansion of CAR function in isolation or combined with antibody through 3 rounds of stimulation in the absence of exogenous cytokine support (Figure 2). Continuous long-range clearance assays demonstrated levels of BCMA targeting activity of FT576 alone was equivalent to primary BCMA-targeted CAR-T cells against a panel of BCMA+ target cells. Utilizing hnCD16, BCMA-CAR was tested in combination with anti-CD38 (daratumumab), anti-SLAMF7 (elotuzumab), or anti-CD19, showing synergistic increase in tumor targeting through various tumor associated antigens (TAAs). Polyfunctionality of FT576 stimulated either through CAR or ADCC was similarly measured by both Isoplexis and single cell RNA sequencing. Specificity for plasma cells was confirmed using primary bone marrow samples from either healthy donors or patients. In animal models, as a monotherapy, FT576 achieved sustained tumor control against disseminated MM1s with persistence profile suggestive of antigen mediated expansion (Figure 3). In combination with daratumumab, FT576 was able to achieve complete clearance of MM1S. Combination with other monoclonal antibodies displayed a similar response demonstrating the unique ability of FT576 to be directed to target multiple TAAs. Together, these studies demonstrate the versatility of FT576 as a highly effective multi-antigen targeting and cost-effective off-the-shelf BCMA-CAR iNK cell product and supports the rational for a first-of-kind Phase I Study as a monotherapy or in combination with therapeutic mAbs targeted to MM-associated surface antigens, driving a path towards a curative therapeutic in MM. Disclosures Goodridge: Fate Therapeutics, Inc: Current Employment. Bjordahl:Fate Therapeutics: Current Employment. Mahmood:Fate Therapeutics, Inc: Current Employment. Reiser:FATE THERAPEUTICS: Current Employment. Gaidarova:Fate Therapeutics, Inc: Current Employment. Blum:Fate Therapeutics: Current Employment. Cichocki:Fate Therapeutics, Inc: Consultancy, Patents & Royalties, Research Funding. Chu:Fate Therapeutics, Inc: Current Employment. Bonello:Fate Therapeutics, Inc: Current Employment. Lee:Fate Therapeutics, Inc.: Current Employment. Groff:Fate Therapeutics, Inc: Current Employment. Meza:Fate Therapeutics, Inc: Current Employment. Chu:Roche Holding AG: Current equity holder in publicly-traded company; Fate Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company. Walcheck:Fate Therapeutics: Consultancy, Research Funding. Malmberg:Vycellix: Membership on an entity's Board of Directors or advisory committees; Fate Therapeutics: Consultancy, Patents & Royalties. Miller:Vycellix: Consultancy; Onkimmune: Honoraria, Membership on an entity's Board of Directors or advisory committees; Nektar: Honoraria, Membership on an entity's Board of Directors or advisory committees; Fate Therapeutics, Inc: Consultancy, Patents & Royalties, Research Funding; GT Biopharma: Consultancy, Patents & Royalties, Research Funding. Valamehr:Fate Therapeutics, Inc: Current Employment, Current equity holder in publicly-traded company.



2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A159-A159
Author(s):  
Michael Whang ◽  
Ming-Hong Xie ◽  
Kate Jamboretz ◽  
Hadia Lemar ◽  
Chao Guo ◽  
...  

BackgroundPeripheral blood natural killer (NK) cells are mature cytotoxic innate lymphocytes possessing an inherent capacity for tumor cell killing, thus making them attractive candidates for adoptive cell therapy. These NK cells are also amenable to CRISPR and chimeric antigen receptor (CAR) genomic engineering for enhanced functions. Moreover, NK cells possess an inherent capacity for off-the-shelf therapy since they are not known to cause graft-versus-host disease, unlike T cells. Presently, approved CAR cell therapy is custom-made from each patient‘s own T cells, a process that can limit patient pool, narrow therapeutic window, and contribute to product variability. In this study, we investigate whether peripheral blood NK cells from a selected donor can be edited, engineered, and expanded sufficiently for off-the-shelf use in a wide patient population.MethodsUsing the CRISPR/Cas9 system, we knocked out CISH expression in isolated peripheral blood NK cells from 3 healthy donors. Subsequently, we expanded edited NK cells by using IL-2 and sequential stimulations using NKSTIM, a modified K562 stimulatory cell line expressing membrane-bound form of IL-15 (mbIL-15) and 4-1BBL. IL-12 and IL-18 were added twice during expansion to drive memory-like NK cell differentiation. We transduced the expanded NK cells to express engineered CD19-targeted CAR and mbIL-15 during an interval between the first and second NKSTIM pulses. We assessed NK cell cytotoxicity against Nalm6 target cells by IncuCyte.ResultsIsolated peripheral blood NK cells from 3 healthy donors were successfully edited using CRISPR/Cas9, engineered to express high levels of CAR, extensively expanded using a series of NKSTIM pulses in the presence of IL-2, and differentiated into memory-like NK cells using IL-12 and IL-18. Interestingly, NK cells from the 3 donors exhibited distinct outcomes. NK cells from one donor reached a peak expansion limit of approximately 7-million-fold before undergoing contraction whereas NK cells from two donors continued to expand over the length of the study surpassing 100-million-fold expansion, without appearing to have reached a terminal expansion limit. At the end of the study, NK cells from one donor exceeded 1-billion-fold expansion and maintained 88% cytolytic activity compared to Nkarta’s standard process control in a 72-hour IncuCyte assay.ConclusionsIn this study, we demonstrate that healthy donor-derived peripheral blood NK cells are capable of expanding over billion-fold while maintaining potency. These results provide a rationale for the development of off-the-shelf CAR NK cell therapies using NK cells from donors selected to provide optimal product characteristics.Ethics ApprovalHuman samples were collected with written informed consent by an approved vendor.



1993 ◽  
Vol 178 (3) ◽  
pp. 961-969 ◽  
Author(s):  
M S Malnati ◽  
P Lusso ◽  
E Ciccone ◽  
A Moretta ◽  
L Moretta ◽  
...  

Natural killer (NK) cells provide a first line of defense against viral infections. The mechanisms by which NK cells recognize and eliminate infected cells are still largely unknown. To test whether target cell elements contribute to NK cell recognition of virus-infected cells, human NK cells were cloned from two unrelated donors and assayed for their ability to kill normal autologous or allogeneic cells before and after infection by human herpesvirus 6 (HHV-6), a T-lymphotropic herpesvirus. Of 132 NK clones isolated from donor 1, all displayed strong cytolytic activity against the NK-sensitive cell line K562, none killed uninfected autologous T cells, and 65 (49%) killed autologous T cells infected with HHV-6. A panel of representative NK clones from donors 1 and 2 was tested on targets obtained from four donors. A wide heterogeneity was observed in the specificity of lysis of infected target cells among the NK clones. Some clones killed none, some killed only one, and others killed more than one of the different HHV-6-infected target cells. Killing of infected targets was not due to complete absence of class I molecules because class I surface levels were only partially affected by HHV-6 infection. Thus, target cell recognition is not controlled by the effector NK cell alone, but also by polymorphic elements on the target cell that restrict NK cell recognition. Furthermore, NK clones from different donors display a variable range of specificities in their recognition of infected target cells.



2014 ◽  
Vol 89 (1) ◽  
pp. 97-109 ◽  
Author(s):  
Shayarana L. Gooneratne ◽  
Jonathan Richard ◽  
Wen Shi Lee ◽  
Andrés Finzi ◽  
Stephen J. Kent ◽  
...  

ABSTRACTMany attempts to design prophylactic human immunodeficiency virus type 1 (HIV-1) vaccines have focused on the induction of neutralizing antibodies (Abs) that block infection by free virions. Despite the focus on viral particles, virus-infected cells, which can be found within mucosal secretions, are more infectious than free virus bothin vitroandin vivo. Furthermore, assessment of human transmission couples suggests infected seminal lymphocytes might be responsible for a proportion of HIV-1 transmissions. Although vaccines that induce neutralizing Abs are sought, only some broadly neutralizing Abs efficiently block cell-to-cell transmission of HIV-1. As HIV-1 vaccines need to elicit immune responses capable of controlling both free and cell-associated virus, we evaluated the potential of natural killer (NK) cells to respond in an Ab-dependent manner to allogeneic T cells bearing HIV-1 antigens. This study presents data measuring Ab-dependent anti-HIV-1 NK cell responses to primary and transformed allogeneic T-cell targets. We found that NK cells are robustly activated in an anti-HIV-1 Ab-dependent manner against allogeneic targets and that tested target cells are subject to Ab-dependent cytolysis. Furthermore, the educated KIR3DL1+NK cell subset from HLA-Bw4+individuals exhibits an activation advantage over the KIR3DL1−subset that contains both NK cells educated through other receptor/ligand combinations and uneducated NK cells. These results are intriguing and important for understanding the regulation of Ab-dependent NK cell responses and are potentially valuable for designing Ab-dependent therapies and/or vaccines.IMPORTANCENK cell-mediated anti-HIV-1 antibody-dependent functions have been associated with protection from infection and disease progression; however, their role in protecting from infection with allogeneic cells infected with HIV-1 is unknown. We found that HIV-1-specific ADCC antibodies bound to allogeneic cells infected with HIV-1 or coated with HIV-1 gp120 were capable of activating NK cells and/or trigging cytolysis of the allogeneic target cells. This suggests ADCC may be able to assist in preventing infection with cell-associated HIV-1. In order to fully utilize NK cell-mediated Ab-dependent effector functions, it might also be important that educated NK cells, which hold the highest activation potential, can become activated against targets bearing HIV-1 antigens and expressing the ligands for self-inhibitory receptors. Here, we show that with Ab-dependent stimulation, NK cells expressing inhibitory receptors can mediate robust activation against targets expressing the ligands for those receptors.



Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 33-33
Author(s):  
Christopher M Borges ◽  
Kevin Wasko ◽  
Jared M Nasser ◽  
Kelly Donahue ◽  
Amanda Pfautz ◽  
...  

Natural killer (NK) cells distinguish tumor from healthy tissue via multiple mechanisms, including recognition of stress ligands and loss of MHC class I expression. For example, KIR mismatching enables allogenic NK cells to respond to MHC positive tumors in a similar manner to MHC negative tumors, making allogeneic NK cell therapy a promising approach for broad oncology indications. Accordingly, allogenic human HD-NK cells, including gene-modified cells, have demonstrated an impressive safety and efficacy profile when administered to patients with advanced hematologic malignancies. However, effector function of allogeneic NK cells can be diminished by the lack of functional persistence, as well as tumor-intrinsic immunosuppressive mechanisms, such as production of TGF-β. To this end, we developed a next-generation allogeneic NK cell therapy using CRISPR-Cas12a gene editing to enhance NK cell function through knockout of the genes CISH and TGFBR2. Both single and simultaneous targeting (DKO) of TGFBR2 and CISH in NK cells using CRISPR-Cas12a produced in/dels at both targets in greater than 80% of NK cells, with greater than 90% of edited NK cells viable at 72 hours post-editing. Importantly, we find that DKO NK cells do not phosphorylate the SMAD2/3 protein downstream of the TGF-b receptor complex and demonstrate increased phosphorylation of pSTAT3 and pSTAT5 upon IL-15 stimulation, consistent with protein level knockout of TGFBR2 and CISH. To determine whether DKO NK cells exhibited superior function relative to control NK cells, we first measured the ability of DKO NK cells to kill Nalm6 cells (adult B cell ALL) relative to unedited control NK cells. We find that in the presence of exogenous TGF-b, DKO NK cells demonstrate improved cytotoxicity against Nalm6 tumor targets by delaying tumor re-growth in comparison to control NK cells. To better characterize the ability of DKO NK cells to kill tumor cells, we developed an in vitro serial killing assay. In this long-duration assay, up to 30 days, control and DKO NK cells (grown in the presence of IL-15) were challenged every 48 hours with a new bolus of Nalm6 tumor targets. Both DKO and unedited NK cells control Nalm6 target cell growth for greater than 18 days (9 additions of new Nalm6 target cells), demonstrating a surprising ability for the same NK cells to serially kill new Nalm6 target cells for a prolonged period of time in vitro. We find that DKO NK cells produce higher levels of IFN-γ and TNF-α relative to control NK cells over the duration of the entire serial killing assay, suggesting that DKO NK cells can continue to produce these inflammatory cytokines even after serial killing. As many tumors, including hematologic malignancies, have high concentrations of TGF-β in their microenvironments, we next tested the ability of DKO NK cells to control the growth of Nalm6 cells in our serial killing assay in the presence of TGF-b. 10ng/mL TGF-β was added at the start of the assay as well as at each addition of new Nalm6 target cells. We observed that control NK cells fail to restrict Nalm6 target cell growth beyond 4 days (after 1 addition of new Nalm6 target cells) whereas DKO NK cells control Nalm6 target cell growth for greater than 18 days (after 9 additions of new Nalm6 target cells). Similar to the serial killing assay without TGF-b, we find that DKO NK cells produce higher concentrations of IFN-γ and TNF-α relative to control NK cells over the duration of the entire serial killing assay. Broadening our repertoire of target cells beyond B cell malignancies is now in progress, including the AML-like cell lines HL-60 and THP-1, the multiple myeloma cell line RPMI 8226, and various solid tumor targets. In summary, using CRISPR-Cas12a we demonstrated highly efficient gene editing of primary human NK cells at two unique targets designed to augment NK cell anti-tumor activity across a variety of malignancies. Most significantly, we demonstrate sustained anti-tumor serial-killing activity in the presence of the potent immunosuppressive cytokine TGF-β. Together, the increased overall effector function of CISH/TGFBR2 DKO primary human NK cells and their ability to serial kill, support their development as a potent allogeneic cell-based medicine for cancer. This potential medicine, termed EDIT-201, is being advanced to clinical study. Disclosures Borges: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Wasko:Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Nasser:Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Donahue:Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Pfautz:Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Antony:Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Leary:Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Sexton:Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Morgan:Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Wong:Editas Medicine: Current Employment, Current equity holder in publicly-traded company.



Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3244-3244
Author(s):  
Gabriele Multhoff ◽  
Catharina Gross ◽  
Anne Dickinson ◽  
Ernst Holler

Abstract Purpose: Hsp70 was frequently found on the plasma membrane of bone marrow-derived leukemic blasts, but not on normal bone marrow cells. Hsp70 membrane expression could be correlated with protection against therapy-induced apoptosis (Nylandsted et al 2004). In contrast, these tumor cells have been found to be highly sensitive to the cytolytic attack mediated by NK cells. In vitro, Hsp70-activated NK cells efficiently lysed autologous Hsp70 membrane-positive leukemic blasts (Gehrmann et al 2003). Granzyme B release served as a surrogate marker for estimating the cytolytic response of NK cells against Hsp70 membrane-positive tumor target cells (Gross et al 2003). Here, we studied the development of NK and T cells in AML patients (n=6) after allogeneic SCT at different time points (days 14–20, 45, 90, 180, 1 year) after allogeneic stem cell transplantation (SCT). Methods: HLA class I, HLA-E and Hsp70 surface expression was determined on all patient-derived leukemic blasts of the bone marrow by flow cytometry. The amount of NK and T cells was investigated by multicolor flow cytometry using CD3/ CD16 and CD56 and CD94/ CD56 antibody-combinations detecting NK cell specific markers. Effector cell function was tested in a granzyme B ELISPOT assay against patient-derived leukemic blasts and K562 cells. Results: All tested leukemic blasts were positive for HLA class I, HLA-E, and Hsp70. After induction therapy the amount of CD3-negative, CD56/CD94-positive NK cells was 28±16%, that of CD3-positive T cells was 58±3%. On days 14–21 after allogeneic SCT, 58±9% of the donor-derived peripheral blood lymphocytes (PBL) were CD3-negative, CD56/CD94-positive NK cells; the amount of CD3-positive T cells was 26±7.5%. On day 45, the amount of NK cells further increased up to 68±7.9%; that of T cells further decreased down to 16±5.6%. On day 90 and day 180 the amount of NK cells was still 41±10%; that of T cells was 29±12%. Interestingly, high NK cell counts correlated with an increased cytolytic response against leukemic blast and K562 cells. One year after allogeneic SCT, NK (20±1%) and T cell (52±18%) ratios were comparable to that of healthy human individuals. Conclusions: Between days 14 and 180 after allogeneic SCT, the amount of NK cells was significantly elevated if compared to that of T cells. Concomitantly, cytolytic function against leukemic blasts was significantly elevated. Normal levels, in the composition of NK and T cells were reached 1 year after SCT. Project funded by EU-TRANS-EUROPE grant QLK3-CT-2002-01936.



Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3870-3870 ◽  
Author(s):  
Don Benson ◽  
Courtney E Bakan ◽  
Shuhong Zhang ◽  
Lana Alghothani ◽  
Jing Liang ◽  
...  

Abstract Abstract 3870 Poster Board III-806 Background NK cell activity against tumor cells is regulated by a balance of inhibitory and activating signals mediated by receptors on NK cells that recognize inhibitory and activating ligands expressed by cancer cells. IPH2101 (1-7F9) is a novel monoclonal anti-inhibitor KIR blocking antibody that has been shown to augment NK cell function against MM targets. Moreover, lenalidomide has been shown to expand and activate NK cells in vivo and in vitro. We have previously reported that the combination of IPH2101 and lenalidomide enhances NK cell mediated cytotoxicity against MM cells compared to each agent alone (Zhang et al., AACR 2009). We expand our studies to investigate potential mechanisms for the enhancement of NK cell activity by the combination of IPH2101 and lenalidomide. Methods The effects of IPH2101 and lenalidomide alone and in combination were studied using primary human NK cells from healthy donors as well as from MM patients. The MM cell lines U266 and RPMI 8226 as well as primary tumor cells from marrow aspirates of MM patients served as target cells. The effect of lenalidomide on MM activating and inhibitory ligand expression was studied by flow cytometry. NK cell trafficking was investigated with standard transwell plate migration assay. Immune complex formation between NK cell effectors and MM tumor targets was characterized by flow cytometry in control conditions and with NK cells pre-treated with IPH2101 and lenalidomide. The effects of IPH2101 and lenalidomide were studied regarding interferon-gamma and granzyme B production by ELISPOT and target-specific cytotoxicity studies were conducted to complement effector-based assays. Results IPH2101 (30 ug/ml) significantly enhanced cytotoxicity against U266 cells and primary MM tumor cells by both purified NK cells at effector:target (E:T) ratios of 10:1 or less, and also of freshly isolated peripheral blood mononuclear cells (PBMC) at E:T ratios of 60:1 or less, from more than 10 random donors. In addition, treatment of PBMC with 5-10 μmol/L lenalidomide for 72h without interleukin (IL)-2 increased NK cell lysis of U266. Treatment of PBMC from normal donors did not enhance the expression of the NK receptors KIR, NKG2D, NCR, TRAIL, and DNAM-1. Incubation of U266 cells with lenalidomide (5 uM) for 3-5 days resulted in significant enhancement of cytotoxicity by normal donor NK cells. This was associated with upregulation of the activating ligands, MICA, ULBP-2, DR4, and CD112. Using blocking antibodies to NKG2D, TRAIL, and DNAM-1, lenalidomide enhancement of MM cell killing was abrogated indicating the importance of the modulation of the ligands to the latter receptors by lenalidomide. Although IPH2101 and lenalidomide did not significantly increase NK cell migration into normal media, migration was enhanced 2.98-fold (+/− 0.36, p < 0.05) towards U266 cell targets (n= 3, p < 0.05) and MM patient serum 3.2-fold (+/− 0.4, n=3, p < 0.05). IPH2101 and lenalidomide also led to a 2.3-fold (+/− 0.43, p < 0.05) increase in immune complex formation between NK cells and MM tumor cells. IPH2101 and lenalidomide also augmented NK cell interferon gamma production against MM (control mean 303 spots/well +/− 13 versus 525 +/− 83, n=3, p < 0.05) and granzyme B production (control mean 115 +/− 98 versus 449 +/−72, n=3, p < 0.05). Importantly, in all experiments described herein, the effects of IPH2101 and lenalidomide together were greater than either agent alone. Conclusions Taken together, our data suggest that IPH2101 and lenalidomide may exert complementary mechanisms on both effector and target cells to enhance NK cell mediated killing of MM cells. Moreover, these agents have no predicted clinical cross-toxicities. A single-agent phase 1 clinical trial of IPH2101 has shown the mAb to be safe and well tolerated in MM patients. These findings support a phase 1/2 clinical trial of IPH2101 with lenalidomide as a first dual-innate immunotherapy for patients with MM. Disclosures: Andre: Innate Pharma: Employment. Squiban:Innate pharma: Employment. Romagne:Innate Pharma: Employment.



Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1865-1865
Author(s):  
Inger S. Nijhof ◽  
Michel de Weers ◽  
Pascale Andre ◽  
Berris van Kessel ◽  
Henk M. Lokhorst ◽  
...  

Abstract Abstract 1865 Despite significant improvements in the treatment of multiple myeloma (MM), this progressive malignancy of antibody-producing clonal plasma cells is still considered incurable. New innovative treatments need to be developed to improve long term outcomes. Recent successes of CD20 antibodies in the clinical lymphoma management indicate that targeted immunotherapy can represent a powerful therapeutical strategy for hematological malignancies. Towards developing a similar strategy for MM, we have recently generated a novel human monoclonal antibody, daratumumab (DARA), which targets the CD38 molecule expressed at high levels on MM cells. We have demonstrated that DARA mediates the lysis of CD38+ MM cells via direct apoptosis, complement mediated lysis and antibody-dependent cell mediated cytotoxicity (ADCC). Natural killer (NK) cells appeared important effector cells mediating the ADCC effect. Since NK cell activity against tumor cells is regulated by the balance of signals generated by inhibitory or activating receptors of NK cells (KIRs), we now explored whether blocking the inhibitory KIRs would improve the NK cell mediated DARA dependent lysis of MM cells. Thus, we evaluated the potential benefits of combining DARA with a novel human anti KIR monoclonal antibody, IPH2102, which blocks the inhibitory KIR2DL1/2/3 receptors (HLA-C specific KIRs), and has been shown to augment NK cell function against MM cells. We recently developed FACS-based ex vivo MM cell lysis assays, in which DARA-dependent NK cell-mediated lysis of MM cells can be directly measured in bone marrow MNCs, thus without separating the malignant cells from autologous NK cells and other accessory cells. Using these, we investigated whether the addition of IPH2102 would augment the DARA dependent lysis of MM cells. As expected, DARA induced lysis of MM cells in bone marrow MNCs isolated from MM patients (n=10). Mean lysis at 10 μg/ml DARA was 27.6% (range 11.3–48.1%). IPH2102 showed little or no lysis of MM cells (at 0.3, 1, 3 and 10 μg/ml) in this setting. The combination of 10 μg/ml IPH2102 with 3 and 10 μg/ml DARA significantly enhanced cytotoxicity against primary MM tumor cells compared to DARA alone (p=0.013 and p=0.028 respectively). Mean lysis of MM tumor cells at 10 μg/ml DARA and 10 μg/ml IPH2102 was 38%. These data confirm our previous findings that NK-cell mediated killing is an important mechanism of action of DARA. We demonstrate a clear synergy between DARA and IPH2102 to achieve effective lysis of MM cells directly in the bone marrow MNC of MM patients, indicating that complementary effects may be achieved by combining IPH2102 and DARA in clinical MM management. Disclosures: Weers: Genmab: Employment. Andre:Innate Pharma: Employment. Lokhorst:Genmab: Research Funding. Parren:Genmab: Employment. Morel:Innate Pharma: Employment. Mutis:Genmab: Research Funding.



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