Optimizing the Procedure to Manufacture Clinical-Grade NK Cells for Adoptive Immunotherapy

Natural killer (NK) cells represent promising tools for cancer immunotherapy. We report the optimization of an NK cell activation–expansion process and its validation on clinical-scale. Methods: RPMI-1640, stem cell growth medium (SCGM), NK MACS and TexMACS were used as culture mediums. Activated and expanded NK cells (NKAE) were obtained by coculturing total peripheral blood mononuclear cells (PBMC) or CD45RA+ cells with irradiated K562mbIL15-41BBL or K562mbIL21-41BBL. Fold increase, NK cell purity, activation status, cytotoxicity and transcriptome profile were analyzed. Clinical-grade NKAE cells were manufactured in CliniMACS Prodigy. Results: NK MACS and TexMACs achieved the highest NK cell purity and lowest T cell contamination. Obtaining NKAE cells from CD45RA+ cells was feasible although PBMC yielded higher total cell numbers and NK cell purity than CD45RA+ cells. The highest fold expansion and NK purity were achieved by using PBMC and K562mbIL21-41BBL cells. However, no differences in activation and cytotoxicity were found when using either NK cell source or activating cell line. Transcriptome profile showed to be different between basal NK cells and NKAE cells expanded with K562mbIL21-41BBL or K562mbIL15-41BBL. Clinical-grade manufactured NKAE cells complied with the specifications from the Spanish Regulatory Agency. Conclusions: GMP-grade NK cells for clinical use can be obtained by using different starting cells and aAPC.

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Aberrant anti-viral response of natural killer cells in severe asthma

European Respiratory Journal ◽

10.1183/13993003.02422-2018 ◽

2020 ◽

Vol 55 (5) ◽

pp. 1802422

Author(s):

Justine Devulder ◽

Cécile Chenivesse ◽

Valérie Ledroit ◽

Stéphanie Fry ◽

Pierre-Emmanuel Lobert ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Severe Asthma ◽

Cell Activation ◽

Mononuclear Cells ◽

Nk Cell ◽

Peripheral Blood Mononuclear ◽

Healthy Donors ◽

Asthma Patients ◽

Ifn Γ

Rhinovirus infections are the main cause of asthma exacerbations. As natural killer (NK) cells are important actors of the antiviral innate response, we aimed at evaluating the functions of NK cells from severe asthma patients in response to rhinovirus-like molecules or rhinoviruses.Peripheral blood mononuclear cells from patients with severe asthma and healthy donors were stimulated with pathogen-like molecules or with the rhinoviruses (RV)-A9 and RV-2. NK cell activation, degranulation and interferon (IFN)-γ expression were analysed.NK cells from severe asthma patients were less cytotoxic than those from healthy donors in response to toll-like receptor (TLR)3, TLR7/8 or RV-A9 but not in response to RV-2 stimulation. Furthermore, when cultured with interleukin (IL)-12+IL-15, cytokines which are produced during viral infections, NK cells from patients with severe asthma were less cytotoxic and expressed less IFN-γ than NK cells from healthy donors. NK cells from severe asthmatics exhibited an exhausted phenotype, with an increased expression of the checkpoint molecule Tim-3.Together, our findings indicate that the activation of NK cells from patients with severe asthma may be insufficient during some but not all respiratory infections. The exhausted phenotype may participate in NK cell impairment and aggravation of viral-induced asthma exacerbation in these patients.

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Neutrophils Induced Licensing of Natural Killer Cells

Mediators of Inflammation ◽

10.1155/2015/747680 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 10

Author(s):

Keishiro Amano ◽

Masahiro Hirayama ◽

Eiichi Azuma ◽

Shotaro Iwamoto ◽

Yoshitaka Keida ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Cell Activation ◽

Mononuclear Cells ◽

Nk Cell ◽

Peripheral Blood Mononuclear ◽

Ligand Interaction ◽

Receptor Ligand ◽

Hematopoietic Stem ◽

Nk Receptor

Natural killer (NK) cells acquire effector function through a licensing process and exert anti-leukemia/tumor effect. However, there is no means to promote a licensing effect of allogeneic NK cells other than cytomegalovirus reactivation-induced licensing in allogeneic hematopoietic stem cell transplantation in human. In mice, a licensing process is mediated by Ly49 receptors which recognize self-major histocompatibility complex class I. The distribution of four Ly49 receptors showed similar pattern in congenic mice, B10, B10.BR, and B10.D2, which have B10 background. Forty Gy-irradiated2×106B10.D2 cells including splenocytes, peripheral blood mononuclear cells in untreated mice, or granulocyte colony-stimulating factor treated mice were injected intraperitoneally into B10 mice. We found that murine NK cells were effectively licensed by intraperitoneal injection of donor neutrophils with its corresponding NK receptor ligand in B10 mice as a recipient and B10.D2 as a donor. Mechanistic studies revealed that NK cells showed the upregulation of intracellular interferon-γand CD107a expression as markers of NK cell activation. Moreover, enriched neutrophils enhanced licensing effect of NK cells; meanwhile, licensing effect was diminished by depletion of neutrophils. Collectively, injection of neutrophils induced NK cell licensing (activation) via NK receptor ligand interaction.

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Evaluation of NK Cell Function by Flowcytometric Measurement and Impedance Based Assay Using Real-Time Cell Electronic Sensing System

BioMed Research International ◽

10.1155/2013/210726 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 11

Author(s):

Ki-Hyun Park ◽

Hyesun Park ◽

Myungshin Kim ◽

Yonggoo Kim ◽

Kyungja Han ◽

...

Keyword(s):

Nk Cells ◽

Real Time ◽

Cell Activation ◽

Mononuclear Cells ◽

Cell Function ◽

Nk Cell ◽

Target Cells ◽

Peripheral Blood Mononuclear ◽

Electronic Sensing ◽

Nk Cytotoxicity

Although real-time cell electronic sensing (RT-CES) system-based natural killer (NK) cytotoxicity has been introduced, it has not been evaluated using human blood samples. In present study, we measured flowcytometry based assay (FCA) and RT-CES based NK cytotoxicity and analyzed degranulation activity (CD107a) and cytokine production. In 98 healthy individuals, FCA with peripheral blood mononuclear cells (PBMCs) at effector to target (E/T) ratio of 32 revealed 46.5 ± 2.6% cytolysis of K562 cells, and 23.5 ± 1.1% of NK cells showed increased degranulation. In RT-CES system, adherent NIH3T3 target cells were resistant to basal killing by PBMC or NK cells. NK cell activation by adding IL-2 demonstrated real-time dynamic killing activity, and lymphokine-activated PBMC (E/T ratio of 32) from 15 individuals showed 59.1 ± 6.2% cytotoxicity results after 4 hours incubation in RT-CES system. However, there was no significant correlation between FCA and RT-CES cytotoxicity. After K562 target cell stimulation, PBMC produced profound proinflammatory and immunoregulatory cytokines/chemokines including IL-2, IL-8, IL-10, MIP-1αβ, IFN-γ, and TNF-α, and cytokine/chemokine secretion was related to flowcytometry-based NK cytotoxicity. These data suggest that RT-CES and FCA differ in sensitivity, applicability and providing information, and further investigations are necessary in variable clinical conditions.

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Generation of human natural killer cells from immature progenitors does not require marrow stromal cells

Blood ◽

10.1182/blood.v84.3.841.841 ◽

1994 ◽

Vol 84 (3) ◽

pp. 841-846 ◽

Cited By ~ 37

Author(s):

MR Silva ◽

R Hoffman ◽

EF Srour ◽

JL Ascensao

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Mononuclear Cells ◽

Viral Infections ◽

Nk Cell ◽

Interleukin 2 ◽

Peripheral Blood Mononuclear ◽

Specific Lysis ◽

Human Natural Killer Cells

Abstract Human natural killer (NK) cells comprise 10% to 15% of peripheral blood mononuclear cells and have an important role in immune responses against tumors, viral infections, and graft rejection. NK cells originate in bone marrow (BM), but their progenitors and lineage development have not been completely characterized. We studied the generation of NK cells from purified CD34+HLADR- and CD34+HLADR+ BM progenitors and the influence of various cytokines on their production. We show that CD3-CD56+ cytotoxic NK cells can develop from both progenitors populations when interleukin-2 (IL-2) is present in an in vitro suspension culture system containing IL-1 alpha and stem cell factor. Up to 83.8% and 98.6% CD3-CD56+ cells were detected in CD34+HLADR- and CD34+DR+ cultures, respectively, after 5 weeks of culture; significant numbers of NK cells were first detected after 2 weeks. Cytotoxic activity paralleled NK cell numbers; up to 70% specific lysis at an effector:target ratio of 10:1 was observed at 5 weeks. IL-7 also triggered development of CD3-CD56+ cells from these immature progenitors (up to 24% and 55% appeared in CD34+HLADR- and CD34+HLADR+ cultures, respectively). Our data suggest that BM stromas are not necessary for NK cell development and that IL-2 remains essential for this lineage development and differentiation.

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NK-Cell Reconstitution after HLA-Identical Blood and Marrow Transplantations for CML: The Recovery of NKG2D Is Inversely Correlated with NKG2A and It Promotes the GVL Effect.

Blood ◽

10.1182/blood.v110.11.4879.4879 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4879-4879

Author(s):

Juan Tong ◽

Huilan Liu ◽

Liangquan Geng ◽

Zimin Sun ◽

Baolin Tang ◽

...

Keyword(s):

Nk Cells ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Nk Cell ◽

Linear Regression Analysis ◽

Cell Activity ◽

Target Cells ◽

Peripheral Blood Stem Cells ◽

Peripheral Blood Mononuclear ◽

Blood Stem Cells

Abstract Natural killer (NK) cell alloreactivity is reported to mediate strong graft versus leukemia (GVL) effect in patients after allogeneic stem-cell transplantation. NKG2D receptors recognize human MHC class Ichain related A and B (MICA/B) and UL16-binding protein 1∼4(ULBP 1∼4) on target cells, thereby regulating NK cell activity. To examine the recovery of NKG2D, NKG2A and other receptors expression by NK cells, we used flow cytometry to evaluate samples from 11 chronic myeloid leukemia patients and their donors in the year following unmanipulated HLA completely matched peripheral blood stem cells plus bone marrow transplantation. Peripheral blood mononuclear cells from patients and their donors were tested in standard 51Cr release assays against cultured K562 targets to determine the cytotoxicity of the NK cells in the same intervals. There is no mismatched immunoglobulin-like receptor (KIR) ligand in both GVH and HVG direction. The reconstitution of KIR2DL1 (CD158a) after this transplantation protocol was very slow and these receptors didn’t reach normal value in the year and KIR2DL2 (CD158b) was much better. The NKG2D increased and the NKG2A decreased quickly at the same time after engraftment, and used linear regression analysis we demonstrated that NKG2A recovery was inversely correlated with NKG2D recovery in the year following transplantation. The ratio of NKG2D/NKG2A was directly associated with the capacity of NK-cell cytotoxicity. Thus, the reconstitution of NKG2D makes contribution to the recovery of the NK cytotoxicity. These results reveals that the NK cells generated after HLA matched blood plus bone morrow transplantation of CML patients are promoted at an immature state characterized by specific phenotypic features and enhanced functioning, having potential impact for immune responsiveness and transplantation outcome.

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Activation of Human NK Cells by Staphylococci and Lactobacilli Requires Cell Contact-Dependent Costimulation by Autologous Monocytes

Clinical and Vaccine Immunology ◽

10.1128/cdli.9.3.649-657.2002 ◽

2002 ◽

Vol 9 (3) ◽

pp. 649-657 ◽

Cited By ~ 17

Author(s):

D. Haller ◽

P. Serrant ◽

D. Granato ◽

E. J. Schiffrin ◽

S. Blum

Keyword(s):

Nk Cells ◽

Cell Activation ◽

Mononuclear Cells ◽

Nk Cell ◽

Interleukin 12 ◽

Accessory Cell ◽

Cell Contact ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Ifn Γ

ABSTRACT NK cells are instrumental in innate immune responses, in particular for the early production of gamma interferon (IFN-γ) and other cytokines necessary to control certain bacterial, parasitic, and viral infections. NK cell-mediated effector functions are controlled by a fine balance between distinct receptors mediating activating and inhibitory signals; however, little is known about activating receptors on NK cells and their corresponding ligands. Several studies have shown that commensal lactobacilli isolated from the human gastrointestinal tract activate human mononuclear cells and are potent inducers of IFN-γ and monocyte-derived interleukin 12 (IL-12). NK cell activation was shown for Lactobacillus johnsonii La1. In this study the cellular mechanisms of in vitro NK cell activation by gram-positive bacteria were analyzed. Staphylococcus aureus- and L. johnsonii La1-mediated activation of CD3− CD16+ CD56+ human peripheral blood NK cells, including expression of the activation antigen CD69 and secretion of IFN-γ, required cell contact-dependent costimulation by autologous monocytes. S. aureus- and L. johnsonii-preactivated monocytes retained their capacity to induce NK cell activation. In contrast, cytokine-primed monocytes completely failed to induce NK cell activation unless bacteria were present. This suggests that phagocytosis of bacteria provided additional coactivation signals on accessory cells that may differ from those induced by tumor necrosis factor and IFN-γ. Blocking of costimulatory molecules by B7.1, B7.2, and IL-12 but not CD14 monoclonal antibodies inhibited S. aureus- and L. johnsonii-induced effector function of NK cells. Our data suggest an important role for accessory cell-derived signals in the process of NK cell activation by gram-positive bacteria.

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Manufacture of Clinical-Grade Universal Antigen Presenting Cells (UAPC) for the Ex Vivo Expansion and Activation of Natural Killer (NK) Cells

Blood ◽

10.1182/blood-2018-99-118804 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 2061-2061

Author(s):

Enli Liu ◽

Sonny Ang ◽

Yijiu Tong ◽

Li Li ◽

Rafet Basar ◽

...

Keyword(s):

Nk Cells ◽

Research Funding ◽

Cell Activation ◽

Nk Cell ◽

Ex Vivo ◽

Ex Vivo Expansion ◽

High Avidity ◽

Clinical Grade ◽

Antigen Presenting ◽

Promising Source

Abstract NK cells are potent cellular immunotherapeutic agents against a wide array of human malignancies. Ex vivo expansion of NK cells to achieve clinically relevant numbers must overcome poor in vitro growth kinetics, low starting percentages within the mononuclear cell fraction (especially from autologous donors with active disease), and limited in vivo life span. We targeted three universally critical NK signaling pathways, namely IL-21, 4-1BB, and SLAM family member 4 (SLAMF4), to increase NK cell proliferation and enhance survival. We genetically-engineered HLA-A-ve and -B-ve K562 cells to enforce expression of membrane-bound IL-21 (mbIL21), 4-1BB-L, and CD48, forming a universal antigen presenting cell (UAPC) to generate highly potent clinical-grade umbilical cord blood (CB-NK) or peripheral blood NK cells (PB-NK). While the mbIL21 and 4-1BB signaling nexuses have been utilized previously, we highlight here SLAMF-mediated immunological sculpting of NK cells for clinical applications. SLAMF triggering of co-receptors modulate NK cell activation, in particular through high-avidity interactions between SLAMF4 (2B4/CD244) and its heterophilic, robust affinity, and physiological ligand CD48, a glycosyl-phosphatidyl-inositol (GPI)-anchored cell surface protein. Upon ligand binding and receptor phosphorylation, SLAMF4 recruits PTPN11/SHP-2 and SH2D1A/SAP for downstream signaling, including significant increases in NK cell-mediated cytotoxicity, granule exocytosis, and production of IFN-γ and IL-2. Other than a subset of low surface density expressers from aging subjects consistently associated with inefficient and impaired activating signal transduction, the majority of NK cells express SLAMF4. The functional prominence of SLAMF4, presently recognized as an activating co-receptor, is also evidenced by loss-of-function mutations associated with X-linked lymphoproliferative (XLP) disease. We achieved log-scale expansion of NK cells with UAPC (>1000 fold in 2 weeks), with excellent purity (>99% CD56+ve/CD3−ve and < 1% CD3+ve cells), without indications of senescence/exhaustion, even after 4 weeks of culture. Surface molecular phenotypes of UAPC-expanded CB-NK cells exhibited a phenotype similar to CB-NK cells expanded without SLAMF4. Synergistic signals from IL-21/STAT3, 4-1BB/4-1BBL, and SLAMF4 drive tonic NK propagation, supporting their clinical application. Our novel and clinically accessible platform technology for generation of high purity CB-NKs, a promising source of fresh and cryopreserved allogeneic NK cells, is well-suited for adoptive cancer immunotherapy. Disclosures Champlin: Sanofi: Research Funding; Otsuka: Research Funding. Shpall:Affirmed GmbH: Research Funding. Rezvani:Affirmed GmbH: Research Funding.

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Selinexor Enhances NK Cell Activation Against Lymphoma Cells Via Downregulation of HLA-E

Blood ◽

10.1182/blood-2021-144836 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 2411-2411

Author(s):

Jack Fisher ◽

Christopher J. Walker ◽

Peter Johnson ◽

Mark S Cragg ◽

Francesco Forconi ◽

...

Keyword(s):

Nk Cells ◽

Peripheral Blood ◽

Research Funding ◽

Cell Activation ◽

Nk Cell ◽

Cell Activity ◽

Fold Increase ◽

Target Cells ◽

Lymphoma Cells ◽

Pre Treatment

Abstract Introduction: Natural killer (NK) cells are powerful immune effectors which induce direct cytotoxicity, promote adaptive immune responses and mediate antibody dependent cellular cytotoxicity (ADCC). Enhancement of NK cell activity against cancer is currently the focus of intense research efforts and strategies include CAR-NK, stimulatory antibodies, cytokines and checkpoint inhibitors. Upregulation of exportin-1 (XPO1) is common in human cancers and high expression is negatively associated with survival in various cancers including diffuse large B cell lymphoma (DLBCL). Targeted inhibition of XPO1 by the selective inhibitor selinexor leads to cancer cell death via accumulation of tumour suppressor proteins in the nucleus, dysregulation of growth regulatory proteins and blockade of oncogene protein translation. The therapeutic efficacy of XPO1 inhibition has led to FDA approval of the oral XPO1 inhibitor selinexor for the treatment of multiple myeloma and DLBCL. The effect of selinexor on NK cell activity has not previously been investigated and was therefore addressed in this study. Methods: The B lymphoma cell lines JeKo-1, SU-DHL-4 and Ramos were incubated with selinexor (50-2000nM) for 18 hours before analysis. Flow cytometry was used to assess cell surface expression of activating and inhibitory ligands for NK cells. For NK based assays, peripheral blood derived NK cells were isolated from healthy donors and incubated with IL-15 (1ng/ml) overnight prior to co-culture with target lymphoma cells for a further 4 hours. Cytotoxicity was assessed using propidium iodide staining of target cells and degranulation of NK cells was assessed by measurement of CD107a. Whole blood samples from colorectal cancer patients (n=11) at pre-treatment and 3 weeks post selinexor monotherapy were assessed by flow cytometry for CD45+CD3-CD19-CD56+ NK cells. Results: Selinexor pre-treatment of target lymphoma cells significantly increased NK cell mediated cytotoxicity against SU-DHL-4 (2.2 Fold increase, p<0.01), JeKo-1 (2 Fold increase, p<0.01) and Ramos (1.7 Fold increase, p<0.01) cells. In accordance with this, selinexor pre-treatment of target cells also increased the activation of NK cells against SU-DHL-4, JeKo-1 and Ramos cells as measured by CD107a expression in both CD56 bright and CD56 dim NK cell sub-groups. To identify the mechanism behind this, we measured expression of activating and inhibitory ligands for NK cells on SU-DHL-4 cells after incubation with selinexor. No significant changes in expression of activating ligands (MICA/B, ULBP-2/5/6, ULBP-1, Vimentin, B7H6, CD54) were evident. In contrast, selinexor significantly (p<0.001) reduced the surface expression of HLA-E on SU-DHL-4 cells by 50%. Selinexor mediated downregulation of HLA-E was also evident in Ramos (60% reduction, p<0.001) and JeKo-1 cells (20% reduction, p<0.01). HLA-E binds the ITIM containing receptor NKG2A, a key inhibitory receptor for NK cells and subsets of T cells. In accordance with this, selinexor pre-treatment of SU-DHL-4 cells selectively increased NKG2A+ NK cell activation (p<0.01) following co-culture. To examine the effect of selinexor on NK cells in patients, we assessed the proportion of NK cells in the peripheral blood of 11 colorectal cancer patients at pre-treatment and three weeks post selinexor monotherapy. % NK cells of CD45+ peripheral blood lymphocytes following treatment with selinexor was increased 2-fold (Median 5% pre-treatment vs 10% post selinexor). In addition, increased abundance of the less mature and less cytotoxic CD56 bright subset of NK cells was associated with poor response to therapy (Median 4% responders (n=3) vs 20% non-responders (n=8)). Larger patient datasets are required to confirm these effects and this analysis is currently ongoing. The effect of selinexor on NK cells in patients with lymphoma is also currently under investigation. Conclusions: The NKG2A:HLA-E axis is a novel immune checkpoint target and our data identifies that selinexor sensitises lymphoma cells to NK cell mediated killing via disruption of this interaction. In addition, we provide initial evidence that NK cells may be associated with clinical response to selinexor. This data indicates that NK cells may contribute to the therapeutic efficacy of selinexor and that selinexor may synergise with NK cell targeted therapies for the treatment of lymphoma. Disclosures Walker: Karyopharm Therapeutics: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Johnson: Morphosys: Honoraria; Kymera: Honoraria; Kite Pharma: Honoraria; Incyte: Honoraria; Genmab: Honoraria; Celgene: Honoraria; Bristol-Myers: Honoraria; Epizyme: Consultancy, Research Funding; Boehringer Ingelheim: Consultancy; Novartis: Honoraria; Takeda: Honoraria; Oncimmune: Consultancy; Janssen: Consultancy. Cragg: BioInvent International: Consultancy, Research Funding; GSK: Research Funding; UCB: Research Funding; iTeos: Research Funding; Roche: Research Funding. Forconi: Novartis: Honoraria; Roche: Honoraria; Janssen: Consultancy, Honoraria, Speakers Bureau; AbbVie: Consultancy, Honoraria, Speakers Bureau; Gilead: Research Funding. Landesman: Karyopharm Therapeutics: Current Employment, Current equity holder in publicly-traded company. Blunt: Karyopharm Therapeutics: Research Funding.

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Anti-CD20 Monoclonal Antibody (mAb) with Enhanced Affinity for CD16 Activates NK Cells at Lower Concentrations and More Effectively Than Rituximab ®.

Blood ◽

10.1182/blood.v106.11.348.348 ◽

2005 ◽

Vol 106 (11) ◽

pp. 348-348 ◽

Cited By ~ 4

Author(s):

George J. Weiner ◽

Julie A. Bowles ◽

Brian K. Link ◽

Mary A. Campbell ◽

James E. Wooldridge ◽

...

Keyword(s):

Nk Cells ◽

Mononuclear Cells ◽

Nk Cell ◽

Normal Subjects ◽

Cell Phenotype ◽

P Value ◽

Peripheral Blood Mononuclear ◽

Anti Cd20 ◽

Anti Tumor Activity ◽

Ifng Production

Abstract Growing evidence indicates the affinity of mAb for CD16 (FcgRIII) plays a central role in the ability of the mAb to mediate anti-tumor activity. Both polymorphisms in CD16 and structure of mAb Fc can impact on the affinity between CD16 and mAb. Little is known about how affinity between mAb and CD16 impacts on the ability of mAb to activate NK cells. We evaluated how CD16 polymorphisms, and mAb with modified affinity for CD16, impact on NK cell phenotype and cytokine production. MAb consisted of R, anti-CD20 with enhanced affinity for CD20 (AME-133), and AME-133 with Fc engineered to have enhanced affinity for both CD20 and CD16 (Fc-eng-133). Peripheral blood mononuclear cells were obtained from normal subjects that were homozygous for high affinity CD16 (VV at position 158), homozygous low affinity (FF at 158), and heterozygotes and were mixed with mAb and Raji lymphoma cells at an effector:target ratio of 1:1. Higher concentrations of mAb were needed to induce CD16 modulation, CD54 upregulation, and IFNg production on NK cells from subjects with the lower affinity CD16 polymorphism. The dose of mAb needed to induce NK activation was lower with Fc-eng-133 irrespective of CD16 polymorphism. Measure of activation - % of NK cells CD54 bright: EC50 ng/ml (mean moAb concentration +/− SEM): N=4 per polymorphism R AME-133 Fc-eng-133 p<0.01 - R vs AME-133; R vs Fc-eng-133; AME-133 vs Fc-eng-133 for each polymorphism VV 6.2 +/− 1.0 3.9 +/− 0.5 1.0 +/− 0.3 VF 11.6 +/− 1.7 5.7 +/− 0.6 1.4 +/− 0.4 FF 29.9 +/− 10.6 11.5 +/− 2.5 2.8 +/− 0.3 p value VV vs FF <0.05 <0.05 <0.05 At saturating mAb concentrations, peak NK activation was greater for Fc engineered AME-133 when compared to R mAb for all samples studied Ratio of Fc-eng-133 to R % NK cells CD54 bright 1.35 +/− 0.07 IFNg production 2.64 +/− 0.43 These data indicate tumor cells coated with mAb with enhanced affinity for CD16 are more effective at activating NK cells at both low and saturating mAb concentrations irrespective of CD16 polymorphism, and provide further evidence for the clinical development of such mAb with the goal of improving clinical response to mAb.

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Rhesus rotavirus VP4 sequence-specific activation of mononuclear cells is associated with cholangiopathy in murine biliary atresia

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00079.2015 ◽

2015 ◽

Vol 309 (6) ◽

pp. G466-G474 ◽

Cited By ~ 8

Author(s):

Ashley Walther ◽

Sujit K. Mohanty ◽

Bryan Donnelly ◽

Abigail Coots ◽

Celine S. Lages ◽

...

Keyword(s):

Flow Cytometry ◽

Biliary Atresia ◽

Nk Cells ◽

Bile Ducts ◽

Cell Activation ◽

Mononuclear Cells ◽

Nk Cell ◽

The United States ◽

Newborn Mice

Biliary atresia (BA), a neonatal obstructive cholangiopathy, remains the most common indication for pediatric liver transplantation in the United States. In the murine model of BA, Rhesus rotavirus (RRV) VP4 surface protein determines biliary duct tropism. In this study, we investigated how VP4 governs induction of murine BA. Newborn mice were injected with 16 strains of rotavirus and observed for clinical symptoms of BA and mortality. Cholangiograms were performed to confirm bile duct obstruction. Livers and bile ducts were harvested 7 days postinfection for virus titers and histology. Flow cytometry assessed mononuclear cell activation in harvested cell populations from the liver. Cytotoxic NK cell activity was determined by the ability of NK cells to kill noninfected cholangiocytes. Of the 16 strains investigated, the 6 with the highest homology to the RRV VP4 (>87%) were capable of infecting bile ducts in vivo. Although the strain Ro1845 replicated to a titer similar to RRV in vivo, it caused no symptoms or mortality. A Ro1845 reassortant containing the RRV VP4 induced all BA symptoms, with a mortality rate of 89%. Flow cytometry revealed that NK cell activation was significantly increased in the disease-inducing strains and these NK cells demonstrated a significantly higher percentage of cytotoxicity against noninfected cholangiocytes. Rotavirus strains with >87% homology to RRV's VP4 were capable of infecting murine bile ducts in vivo. Development of murine BA was mediated by RRV VP4-specific activation of mononuclear cells, independent of viral titers.

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