scholarly journals A Novel Toll-Like Receptor 9 Agonist, MGN1703, Enhances HIV-1 Transcription and NK Cell-Mediated Inhibition of HIV-1-Infected Autologous CD4+T Cells

2016 ◽  
Vol 90 (9) ◽  
pp. 4441-4453 ◽  
Author(s):  
Rasmus Offersen ◽  
Sara Konstantin Nissen ◽  
Thomas A. Rasmussen ◽  
Lars Østergaard ◽  
Paul W. Denton ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Mononuclear Cells ◽  
Nk Cell ◽  
Killer Cell ◽  
Clinical Testing ◽  
Toll Like Receptor ◽  
Peripheral Blood Mononuclear ◽  
Tlr Agonists ◽  
Hiv 1

ABSTRACTToll-like receptor (TLR) agonists are potent enhancers of innate antiviral immunity and may also reverse HIV-1 latency. Therefore, TLR agonists have a potential role in the context of a “shock-and-kill” approach to eradicate HIV-1. Our extensive preclinical evaluation suggests that a novel TLR9 agonist, MGN1703, may indeed perform both functions in an HIV-1 eradication trial. Peripheral blood mononuclear cells (PBMCs) from aviremic HIV-1-infected donors on antiretroviral therapy (ART) that were incubated with MGN1703ex vivoexhibited increased secretion of interferon alpha (IFN-α) (P= 0.005) and CXCL10 (P= 0.0005) in culture supernatants. Within the incubated PBMC pool, there were higher proportions of CD69-positive CD56dimCD16+NK cells (P= 0.001) as well as higher proportions of CD107a-positive (P= 0.002) and IFN-γ-producing (P= 0.038) NK cells. Incubation with MGN1703 also increased the proportions of CD69-expressing CD4+and CD8+T cells. Furthermore, CD4+T cells within the pool of MGN1703-incubated PBMCs showed enhanced levels of unspliced HIV-1 RNA (P= 0.036). Importantly, MGN1703 increased the capacity of NK cells to inhibit virus spread within a culture of autologous CD4+T cells assessed by using an HIV-1 p24 enzyme-linked immunosorbent assay (ELISA) (P= 0.03). In conclusion, we show that MGN1703 induced strong antiviral innate immune responses, enhanced HIV-1 transcription, and boosted NK cell-mediated suppression of HIV-1 infection in autologous CD4+T cells. These findings support clinical testing of MGN1703 in HIV-1 eradication trials.IMPORTANCEWe demonstrate that MGN1703 (a TLR9 agonist currently undergoing phase 3 clinical testing for the treatment of metastatic colorectal cancer) induces potent antiviral responses in immune effector cells from HIV-1-infected individuals on suppressive antiretroviral therapy. The significantly improved safety and tolerability profiles of MGN1703 versus TLR9 agonists of the CpG-oligodeoxynucleotide (CpG-ODN) family are due to its novel “dumbbell-shape” structure made of covalently closed, natural DNA. In our study, we found that incubation of peripheral blood mononuclear cells with MGN1703 results in natural killer cell activation and increased natural killer cell function, which significantly inhibited the spread of HIV in a culture of autologous CD4+T cells. Furthermore, we discovered that MGN1703-mediated activation can enhance HIV-1 transcription in CD4+T cells, suggesting that this molecule may serve a dual purpose in HIV-1 eradication therapy: enhanced immune function and latency reversal. These findings provide a strong preclinical basis for the inclusion of MGN1703 in an HIV eradication clinical trial.

scholarly journals Identification of NKG2A and NKp80 as specific natural killer cell markers in rhesus and pigtailed monkeys

Blood ◽  
2005 ◽  
Vol 106 (5) ◽  
pp. 1718-1725 ◽  
Author(s):  
Domenico Mavilio ◽  
Janet Benjamin ◽  
Diana Kim ◽  
Gabriella Lombardo ◽  
Marybeth Daucher ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Mononuclear Cells ◽  
Nk Cell ◽  
Rhesus Macaques ◽  
Killer Cell ◽  
Functional Characterization ◽  
Cross Reactivity ◽  
Target Cells ◽  
Peripheral Blood Mononuclear

Abstract Investigations of natural killer (NK) cells in simian models of disease have been hampered by a lack of appropriate phenotypic markers and by an inadequate understanding of the regulation of NK cell activities. In the present study, a panel of monoclonal antibodies (mAbs) specific for various human NK receptors was screened for cross-reactivity with NK cells from rhesus macaques and pigtailed macaques. Flow cytometric analyses using anti-human NKG2A and anti-human NKp80 mAbs individually, and particularly in combination with anti-CD16 mAb, allowed for the identification of the entire NK cell population in both species. NK cells in monkeys were generally identified by negative selection of peripheral blood mononuclear cells (PBMCs) for the absence of T-cell, B-cell, and monocyte markers. mAb-mediated ligation of NKp80 induced NK cell cytotoxicity, while in the case of NKG2A it displayed a clear capability to inhibit the lysis of target cells by NK cells from macaques, as well as from humans. This new phenotypic and functional characterization of NKG2A and NKp80 in rhesus and pigtailed macaque NK cells provides a new approach in the analysis of their innate immune system. (Blood. 2005;106:1718-1725)

Differential indirect activation of human invariant natural killer T cells by Toll-like receptor agonists

Immunotherapy ◽  
2009 ◽  
Vol 1 (4) ◽  
pp. 557-570
Author(s):  
María Moreno ◽  
Berber M Mol ◽  
Silvia von Mensdorff-Pouilly ◽  
René HM Verheijen ◽  
Esther C de Jong ◽  
...  
Keyword(s):  
T Cells ◽  
Natural Killer ◽  
Mononuclear Cells ◽  
Toll Like Receptor ◽  
Inkt Cells ◽  
Peripheral Blood Mononuclear ◽  
Tlr Agonists ◽  
Killer T Cells ◽  
Invariant Natural Killer ◽  
Dc Maturation

Aim: Invariant natural killer (iNK) T cells are activated by bacterial glycosphingolipids presented by CD1d on dendritic cells (DCs). Here, it was investigated whether Toll-like receptor (TLR) ligands derived from various microorganisms can either directly or indirectly (through DC activation) activate iNKT cells. Materials & Methods: TLR expression by iNKT cells was examined and the ability of various TLR ligands to activate iNKT cells was evaluated. Results: Although human iNKT cells express all TLRs, apart from TLR8, they did not respond directly to TLR ligands. However, iNKT cells became strongly activated when total peripheral blood mononuclear cells were stimulated with TLR2/6, 7/8 and 9 ligands, but not or to a lesser extent with TLR3, 4 and 5 ligands. TLR-stimulated monocyte-derived DCs promoted iNKT cell phenotypic activation and, in turn, these activated iNKT cells further enhanced DC maturation. Conclusion: TLR agonists may act as strong adjuvants for immunotherapy by promoting combined and reciprocal activation of iNKT cells and DCs.

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

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 577
Author(s):  
Adrián Fernández ◽  
Alfonso Navarro-Zapata ◽  
Adela Escudero ◽  
Nerea Matamala ◽  
Beatriz Ruz-Caracuel ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Nk Cell ◽  
Fold Increase ◽  
Clinical Grade ◽  
Transcriptome Profile ◽  
Expansion Process ◽  
Peripheral Blood Mononuclear ◽  
Activation Status

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.

scholarly journals Interferon Alpha Enhances NK Cell Function and the Suppressive Capacity of HIV-Specific CD8+T Cells

2018 ◽  
Vol 93 (3) ◽  
Author(s):  
Abena K. R. Kwaa ◽  
Chloe A. G. Talana ◽  
Joel N. Blankson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Effector Cell ◽  
Cell Function ◽  
Nk Cell ◽  
Suppressive Capacity ◽  
Short Course ◽  
Shock And Kill ◽  
Hiv 1

ABSTRACTCurrent shock-and-kill strategies for the eradication of the HIV-1 reservoir have resulted in blips of viremia but not in a decrease in the size of the latent reservoir in patients on suppressive antiretroviral therapy (ART). This discrepancy could potentially be explained by an inability of the immune system to kill HIV-1-infected cells following the reversal of latency. Furthermore, some studies have suggested that certain latency-reversing agents (LRAs) may inhibit CD8+T cell and natural killer (NK) cell responses. In this study, we tested the hypothesis that alpha interferon (IFN-α) could improve the function of NK cells from chronic progressors (CP) on ART. We show here that IFN-α treatment enhanced cytokine secretion, polyfunctionality, degranulation, and the cytotoxic potential of NK cells from healthy donors (HD) and CP. We also show that this cytokine enhanced the viral suppressive capacity of NK cells from HD and elite controllers or suppressors. Furthermore, IFN-α enhanced global CP CD8+T cell cytokine responses and the suppressive capacity of ES CD8+T cells. Our data suggest that IFN-α treatment may potentially be used as an immunomodulatory agent in HIV-1 cure strategies.IMPORTANCEData suggest that HIV+individuals unable to control infection fail to do so due to impaired cytokine production and/cytotoxic effector cell function. Consequently, the success of cure agendas such as the shock-and-kill strategy will probably depend on enhancing patient effector cell function. In this regard, NK cells are of particular interest since they complement the function of CD8+T cells. Here, we demonstrate the ability of short-course alpha interferon (IFN-α) treatments to effectively enhance such effector functions in chronic progressor NK cells without inhibiting their general CD8+T cell function. These results point to the possibility of exploring such short-course IFN-α treatments for the enhancement of effector cell function in HIV+patients in future cure strategies.

scholarly journals Prognostic significance of natural killer cell-associated markers in gastric cancer: quantitative analysis using multiplex immunohistochemistry

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hee Young Na ◽  
Yujun Park ◽  
Soo Kyung Nam ◽  
Jiwon Koh ◽  
Yoonjin Kwak ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
T Cells ◽  
B Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Immune Cells ◽  
Nk Cell ◽  
Critical Role ◽  
Killer Cell ◽  
Prognostic Significance

Abstract Background Natural killer (NK) cells mediate the anti-tumoral immune response as an important component of innate immunity. The aim of this study was to investigate the prognostic significance and functional implication of NK cell-associated surface receptors in gastric cancer (GC) by using multiplex immunohistochemistry (mIHC). Methods We performed an mIHC on tissue microarray slides, including 55 GC tissue samples. A total of 11 antibodies including CD57, NKG2A, CD16, HLA-E, CD3, CD20, CD45, CD68, CK, SMA, and ki-67 were used. CD45 + CD3-CD57 + cells were considered as CD57 + NK cells. Results Among CD45 + immune cells, the proportion of CD57 + NK cell was the lowest (3.8%), whereas that of CD57 + and CD57- T cells (65.5%) was the highest, followed by macrophages (25.4%), and B cells (5.3%). CD57 + NK cells constituted 20% of CD45 + CD57 + immune cells while the remaining 80% were CD57 + T cells. The expression of HLA-E in tumor cells correlated with that in tumoral T cells, B cells, and macrophages, but not CD57 + NK cells. The higher density of tumoral CD57 + NK cells and tumoral CD57 + NKG2A + NK cells was associated with inferior survival. Conclusions Although the number of CD57 + NK cells was lower than that of other immune cells, CD57 + NK cells and CD57 + NKG2A + NK cells were significantly associated with poor outcomes, suggesting that NK cell subsets play a critical role in GC progression. NK cells and their inhibitory receptor, NKG2A, may be potential targets in GC.

scholarly journals Selection following isolation of human immunodeficiency virus type 1 in peripheral blood mononuclear cells and herpesvirus saimiri-transformed T cells is comparable

2002 ◽  
Vol 83 (6) ◽  
pp. 1343-1352 ◽  
Author(s):  
Natalie N. Zheng ◽  
Cherelyn Vella ◽  
Philippa J. Easterbrook ◽  
Rod S. Daniels
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Peripheral Blood Mononuclear Cells ◽  
Mononuclear Cells ◽  
Cell Types ◽  
Herpesvirus Saimiri ◽  
Peripheral Blood Mononuclear ◽  
Immunodeficiency Virus ◽  
Blood Mononuclear Cells ◽  
Hiv 1

In attempts to improve isolation rates and virus yields for human immunodeficiency virus (HIV), the use of herpesvirus saimiri-immortalized T cells (HVS T cells) has been investigated as an alternative to/improvement over peripheral blood mononuclear cells (PBMCs). Here we characterize isolates rescued, in the two cell types, from two asymptomatic, long-term non-progressing HIV-1-infected individuals. All rescued viruses replicated in PBMCs and HVS T cells only, displaying a non-syncytium inducing (NSI) phenotype, and using CCR5 as co-receptor. Furthemore, PBMC/HVS T cell virus pairs displayed similar neutralization profiles. Full-length, expression-competent env genes were rescued from all virus isolates and directly from the patient samples using proviral DNA and viral RNA as templates. Compared with the sequences retrieved directly from the patient samples, both cell types showed similar selection characteristics. Whilst the selections were distinct for individual patient samples, they shared a common characteristic in selecting for viruses with increased negative charge across the V2 domain of the viral glycoproteins. The latter was observed at the env gene sequencing level for three other patients whose HIV strains were isolated in PBMCs only. This further supports a common selection for viral sequences that display a macrophage-tropic/NSI phenotype and shows that HVS T cells are a viable alternative to PBMCs for HIV-1 isolation.

Dynamic behavior of NK cells during activation in lymph nodes

Blood ◽  
2009 ◽  
Vol 114 (15) ◽  
pp. 3227-3234 ◽  
Author(s):  
Hélène Beuneu ◽  
Jacques Deguine ◽  
Béatrice Breart ◽  
Ofer Mandelboim ◽  
James P. Di Santo ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Cell Activation ◽  
Nk Cell ◽  
Fluorescent Proteins ◽  
Migratory Behavior ◽  
Lymphoid Tissues ◽  
Toll Like Receptor ◽  
Secondary Lymphoid Organs ◽  
Short Contacts

Abstract During infection, Toll-like receptor agonists induce natural killer (NK)–cell activation by stimulating dendritic cells (DCs) to produce cytokines and transpresent IL-15 to NK cells. Yet the cellular dynamics underlying NK-cell activation by DCs in secondary lymphoid organs are largely unknown. Here, we have visualized NK-cell activation using mice in which NK cells and DCs express different fluorescent proteins. In response to polyI:C or lipopolysaccharide, NK cells maintained a vigorous migratory behavior, establishing multiple short contacts with maturing DCs. Furthermore, mature antigen-loaded DCs that made long-lived interactions with T cells formed short-lived contacts with NK cells. The different behaviors of T cells and NK cells during activation was correlated with distinct calcium responses upon interaction with DCs. That NK cells become activated while remaining motile may constitute an efficient strategy for sampling local concentrations of cytokines around DCs in secondary lymphoid tissues.

scholarly journals Enhanced adaptive immune responses in lung adenocarcinoma through natural killer cell stimulation

2019 ◽  
Vol 116 (35) ◽  
pp. 17460-17469 ◽  
Author(s):  
Leah Schmidt ◽  
Banu Eskiocak ◽  
Ryan Kohn ◽  
Celeste Dang ◽  
Nikhil S. Joshi ◽  
...  
Keyword(s):  
T Cells ◽  
Lung Adenocarcinoma ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Killer Cell ◽  
Production Capacity ◽  
Dependent Manner ◽  
Cell Stimulation ◽  
Established Disease

Natural killer (NK) cells inhibit tumor development in mouse models and their presence in tumors correlates with patient survival. However, tumor-associated NK cells become dysfunctional; thus, stimulation of NK cells in cancer is emerging as an attractive immunotherapeutic strategy. In a mouse model of lung adenocarcinoma, NK cells localized to tumor stroma with immature phenotypes and low functional capacity. To test their responsiveness within established disease, we engineered a system for inducible expression of activating ligands in tumors. After stimulation, NK cells localized inside tumors, with increased cytokine production capacity. Strikingly, T cells were also recruited to tumors in an NK cell-dependent manner, and exhibited higher functionality. In neoantigen-expressing tumors, NK cell stimulation enhanced the number and function of tumor-specific T cells and, in long-term settings, reduced tumor growth. Thus, even in established disease NK cells can be activated to contribute to antitumor immunity, supporting their potential as an important target in cancer immunotherapy.

scholarly journals Potential of the NKG2D/NKG2DL Axis in NK Cell-Mediated Clearance of the HIV-1 Reservoir

2019 ◽  
Vol 20 (18) ◽  
pp. 4490 ◽  
Author(s):  
Maria G. Desimio ◽  
Daniela A. Covino ◽  
Margherita Doria
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
Virus Reactivation ◽  
Major Drawback ◽  
Virus Eradication ◽  
Latent Hiv ◽  
Hiv 1

Viral persistency in latently infected CD4+ T cells despite antiretroviral therapy (ART) represents a major drawback in the fight against HIV-1. Efforts to purge latent HIV-1 have been attempted using latency reversing agents (LRAs) that activate expression of the quiescent virus. However, initial trials have shown that immune responses of ART-treated patients are ineffective at clearing LRA-reactivated HIV-1 reservoirs, suggesting that an adjuvant immunotherapy is needed. Here we overview multiple lines of evidence indicating that natural killer (NK) cells have the potential to induce anti-HIV-1 responses relevant for virus eradication. In particular, we focus on the role of the NKG2D activating receptor that crucially enables NK cell-mediated killing of HIV-1-infected cells. We describe recent data indicating that LRAs can synergize with HIV-1 at upregulating ligands for NKG2D (NKG2DLs), hence sensitizing T cells that exit from viral latency for recognition and lysis by NK cells; in addition, we report in vivo and ex vivo data showing the potential benefits and drawbacks that LRAs may have on NKG2D expression and, more in general, on the cytotoxicity of NK cells. Finally, we discuss how the NKG2D/NKG2DLs axis can be exploited for the development of effective HIV-1 eradication strategies combining LRA-induced virus reactivation with recently optimized NK cell-based immunotherapies.

scholarly journals Defective HIV-1 proviruses produce viral proteins

2020 ◽  
Vol 117 (7) ◽  
pp. 3704-3710 ◽  
Author(s):  
Hiromi Imamichi ◽  
Mindy Smith ◽  
Joseph W. Adelsberger ◽  
Taisuke Izumi ◽  
Francesca Scrimieri ◽  
...  
Keyword(s):  
T Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Viral Proteins ◽  
Open Reading Frames ◽  
Peripheral Blood Mononuclear ◽  
Hiv Rna ◽  
Rna Transcripts ◽  
Extracellular Virus ◽  
Hiv 1

HIV-1 proviruses persist in the CD4+ T cells of HIV-infected individuals despite years of combination antiretroviral therapy (cART) with suppression of HIV-1 RNA levels <40 copies/mL. Greater than 95% of these proviruses detected in circulating peripheral blood mononuclear cells (PBMCs) are referred to as “defective” by virtue of having large internal deletions and lethal genetic mutations. As these defective proviruses are unable to encode intact and replication-competent viruses, they have long been thought of as biologically irrelevant “graveyard” of viruses with little significance to HIV-1 pathogenesis. Contrary to this notion, we have recently demonstrated that these defective proviruses are not silent, are capable of transcribing novel unspliced forms of HIV-RNA transcripts with competent open reading frames (ORFs), and can be found in the peripheral blood CD4+ T cells of patients at all stages of HIV-1 infection. In the present study, by an approach of combining serial dilutions of CD4+ T cells and T cell–cloning technologies, we are able to demonstrate that defective proviruses that persist in HIV-infected individuals during suppressive cART are translationally competent and produce the HIV-1 Gag and Nef proteins. The HIV-RNA transcripts expressed from these defective proviruses may trigger an element of innate immunity. Likewise, the viral proteins coded in the defective proviruses may form extracellular virus-like particles and may trigger immune responses. The persistent production of HIV-1 proteins in the absence of viral replication helps explain persistent immune activation despite HIV-1 levels below detection, and also presents new challenges to HIV-1 eradication.

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