scholarly journals 34 Selective infiltration of Antibody-Dependent Cellular Cytoxicity (ADCC) mediating immune cells in response to treatment in a human tumor histo-culture platform

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A40-A40
Author(s):  
Satish Sankaran ◽  
Nandini Pal Basak ◽  
Sindhu Govindan ◽  
BV Prakash ◽  
BV Manjula ◽  
...  

BackgroundA 3D histo-culture platform provides a near native Tumor immune Micro-Environment (TiME), making it best suited for evaluating response to immunotherapy drugs. Farcast™ TiME is a human 3D tumor histo-culture platform that preserves TiME and maintains functional fidelity of intra-tumoral immune cells (IIC). In this study we investigated the utility of this platform in demonstrating treatment induced Antibody-Dependent Cellular Cytotoxicity (ADCC) mechanism driven by IICs alone versus co-culture with autologous peripheral blood immune cells.MethodsHead and neck squamous cell carcinoma tissue samples (n=5) along with matched blood from consented patients were used in this study. All Peripheral Blood Nucleated Cells (PBNCs) including lymphocytes, monocytes, NK cells and neutrophils were isolated and stained with a tracking dye to distinguish them from IICs. Tumor tissues were processed to generate explants, treated with 184 µg/ml Cetuximab (anti-EGFR) or vehicle control, and cultured with or without PBNCs for 72 hrs. Response was evaluated using flow cytometry and cytokine release assay.ResultsAmount of infiltrated autologous PBNCs showed a strong negative correlation (R2=0.98) with the amount of IICs in the absence of drug treatment. The proportions of infiltrated immune cell sub-populations were similar to the composition of PBNCs added in culture. Cetuximab treatment, however, led to enhanced infiltration of the effector cells for ADCC driven tumor killing, namely NK cells, macrophages, neutrophils, and cytotoxic T cells (CTLs). Notably the unique infiltration pattern of effector cell populations observed in each sample was reflected in the secretion of specific cytokine/chemokines associated with that cell population. NK cell increase (fold change: 1.6 ± 0.8) was observed in all samples with a concomitant increase in MCP-1 secretion (fold change: 1.7 ± 0.9). Granzyme-B expressing NK cells increased (>1.7 fold) in a subset of samples. Samples showing increase in neutrophil infiltration exhibited increased MMP9 secretion, involved in neutrophil infiltration via stromal remodeling. Sample with highest increase in infiltration of CD16+ Monocyte/Macrophages (>2.4 fold) showed maximum increase in Granzyme-B secretion with respect to the untreated arm. Increase in fold secretion (>1.4) of CXCL9/CXCL10 was associated with the sample that showed highest fold increase of Granzyme-B expressing CTL in comparison to untreated arm. IICs alone were not sufficient in eliciting optimal ADCC response.ConclusionsThe study demonstrated ADCC response in the explant/PBNC co-culture platform leading to specific infiltration of effector sub-populations. FarcastTM TiME thus provides a unique platform to explore for heterologous adoptive cell and CAR-T therapies that involve immune cell infiltration.Ethics ApprovalAll samples included in the study were approved by institutional review boards of the centers providing the samples.

2022 ◽  
Author(s):  
Ben Nicholas ◽  
Jane Guo ◽  
Hyun-Hee Lee ◽  
Alistair Bailey ◽  
Rene de Waal Malefyt ◽  
...  

Asthma is a disease of complex origin and multiple pathologies. There are currently very few biomarkers of proven utility in its diagnosis, management or response to treatment. Recent studies have identified multiple asthma phenotypes following biofluid analysis; however, such findings may be driven by the well-characterised alterations in immune cell populations in asthma. We present a study designed to identify cell type-specific gene signatures of severe allergic asthma in peripheral blood samples. Using transcriptomic profiling of four magnetically purified peripheral blood cell types, we identify significant gene expression changes in monocytes and NK cells but not T lymphocytes in severe asthmatics. Pathway analysis indicates dysfunction of immune cell regulation and bacterial suppression in the NK cells. These gene expression changes may be useful on their own as prognostic peripheral blood cell markers of severe asthma, but also may indicate novel cell pathways for therapeutic intervention.


2021 ◽  
Vol 11 ◽  
Author(s):  
Vinicius Araujo B. de Lima ◽  
Morten Hansen ◽  
Iben Spanggaard ◽  
Kristoffer Rohrberg ◽  
Sine Reker Hadrup ◽  
...  

Despite encouraging results with immune checkpoint inhibition (ICI), a large fraction of cancer patients still does not achieve clinical benefit. Finding predictive markers in the complexity of the tumor microenvironment is a challenging task and often requires invasive procedures. In our study, we looked for putative variables related to treatment benefit among immune cells in peripheral blood across different tumor types treated with ICIs. For that, we included 33 patients with different solid tumors referred to our clinical unit for ICI. Peripheral blood mononuclear cells were isolated at baseline, 6 and 20 weeks after treatment start. Characterization of immune cells was carried out by multi-color flow cytometry. Response to treatment was assessed radiologically by RECIST 1.1. Clinical outcome correlated with a shift towards an effector-like T cell phenotype, PD-1 expression by CD8+T cells, low levels of myeloid-derived suppressor cells and classical monocytes. Dendritic cells seemed also to play a role in terms of survival. From these findings, we hypothesized that patients responding to ICI had already at baseline an immune profile, here called ‘favorable immune periphery’, providing a higher chance of benefitting from ICI. We elaborated an index comprising cell types mentioned above. This signature correlated positively with the likelihood of benefiting from the treatment and ultimately with longer survival. Our study illustrates that patients responding to ICI seem to have a pre-existing immune profile in peripheral blood that favors good outcome. Exploring this signature can help to identify patients likely to achieve benefit from ICI.


2020 ◽  
Vol 69 (10) ◽  
pp. 2009-2020
Author(s):  
Daniëlle Krijgsman ◽  
Natasja L. De Vries ◽  
Morten N. Andersen ◽  
Anni Skovbo ◽  
Rob A. E. M. Tollenaar ◽  
...  

Abstract Objective The subset distribution and immunophenotype of circulating immune cells (“peripheral blood immune cell profile”) may reflect tumor development and response to cancer treatment. In order to use the peripheral blood immune cell profile as biomarker to monitor patients over time, it is crucial to know how immune cell subsets respond to therapeutic interventions. In this study, we investigated the effects of tumor resection and adjuvant therapy on the peripheral blood immune cell profile in patients with colon carcinoma (CC). Methods The subset distribution and immunophenotype of T cells (CD3+CD56−), CD56dim NK cells (CD3−CD56dim), CD56bright NK cells (CD3−CD56bright) and NKT-like cells (CD3+CD56+) were studied in preoperative and postoperative peripheral blood mononuclear cell (PBMC) samples of 24 patients with CC by multiparameter flow cytometry. Changes in immunophenotype of circulating immune cells after tumor resection were studied in patients treated with and without (capecitabine-based) adjuvant therapy. Results The NKT-like cell (% of total PBMCs) and CD8+ T cell (% of total T cells) populations expanded in the peripheral blood of non-adjuvant-treated CC patients after surgery. NK- and NKT-like cells showed upregulation of activating receptors and downregulation of inhibitory receptors in non-adjuvant-treated CC patients after surgery. These changes were not observed in the peripheral blood of adjuvant-treated CC patients. Conclusions Our results suggest tumor-induced suppression of NK- and NKT-like cells in CC patients, an effect that could not be detected after tumor resection. In contrast, adjuvant therapy maintained tumor-induced immunosuppression of NK- and NKT-like cells in CC patients.


mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Fok-Moon Lum ◽  
David Lee ◽  
Tze-Kwang Chua ◽  
Jeslin J. L. Tan ◽  
Cheryl Y. P. Lee ◽  
...  

ABSTRACTZika virus (ZIKV) has reemerged in the population and caused unprecedented global outbreaks. Here, the transcriptomic consequences of ZIKV infection were studied systematically first in human peripheral blood CD14+monocytes and monocyte-derived macrophages with high-density RNA sequencing. Analyses of the ZIKV genome revealed that the virus underwent genetic diversification, and differential mRNA abundance was found in host cells during infection. Notably, there was a significant change in the cellular response, with cross talk between monocytes and natural killer (NK) cells as one of the highly identified pathways. Immunophenotyping of peripheral blood from ZIKV-infected patients further confirmed the activation of NK cells during acute infection. ZIKV infection in peripheral blood cells isolated from healthy donors led to the induction of gamma interferon (IFN-γ) and CD107a—two key markers of NK cell function. Depletion of CD14+monocytes from peripheral blood resulted in a reduction of these markers and reduced priming of NK cells during infection. This was complemented by the immunoproteomic changes observed. Mechanistically, ZIKV infection preferentially counterbalances monocyte and/or NK cell activity, with implications for targeted cytokine immunotherapies.IMPORTANCEZIKV reemerged in recent years, causing outbreaks in many parts of the world. Alarmingly, ZIKV infection has been associated with neurological complications such as Guillain-Barré syndrome (GBS) in adults and congenital fetal growth-associated anomalies in newborns. Host peripheral immune cells are one of the first to interact with the virus upon successful transmission from an infected femaleAedesmosquito. However, little is known about the role of these immune cells during infection. In this work, the immune responses of monocytes, known target cells of ZIKV infection, were investigated by high-density transcriptomics. The analysis saw a robust immune response being elicited. Importantly, it also divulged that monocytes prime NK cell activities during virus infection. Removal of monocytes during the infection changed the immune milieu, which in turn reduced NK cell stimulation. This study provides valuable insights into the pathobiology of the virus and allows for the possibility of designing novel targeted therapeutics.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1535-1535 ◽  
Author(s):  
Sandra Lockmer ◽  
Björn E Wahlin ◽  
Bjorn Ostenstad ◽  
Åsa Jeppson-Ahlberg ◽  
Birgitta Sander ◽  
...  

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


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qing Ye ◽  
Chao Zhou ◽  
Sisi Li ◽  
Jingjing Wang ◽  
Fei Liu ◽  
...  

AbstractExisting research suggests that the human immune system and immune cells are involved in the pathogenesis of nephrotic syndrome, but there is still a lack of direct evidence. This study tried to analyze the profiling of immune cells in the peripheral blood of steroid-sensitive nephrotic syndrome (SSNS) patients and steroid-resistant nephrotic syndrome (SRNS) patients before and after standard steroid treatment to clarify the immunological mechanism of nephrotic syndrome patients. The number and proportion of CD4 + T cells in patients with nephrotic syndrome remained unchanged. However, there is an imbalance of Th1 and Th2 and an excessive increase of Th17 cells. The number of CD8 + T cells and the number of effector CD8 + T cells in them increased significantly, but only in SSNS, the number of activated CD8 + T cells increased, and the number of activated Treg cells decreased significantly. Nephrotic syndrome patients also have B cell disorder, and it is more prominent in SSNS patients. Compared with the normal control, only the number of B cells and plasmablast in SSNS patients increased significantly (Z = − 2.20, P = 0.028). This study also observed that transitional B cells decreased in both SSNS and SRNS patients, but SSNS patients' decrease was lower than in SRNS patients. Compared with normal controls, monocytes in patients with nephrotic syndrome decreased significantly. The main reason was that Non-classical Monocyte decreased, while Classical Monocyte increased slightly. The total number of NK cells did not change, but the internal cell subgroups' composition occurred. Changes, realized as CD56hi NK cells increased, CD56low NK cells decreased; and the above trend is more evident in SSNS patients. Patients with nephrotic syndrome have immune disorders, including T cells, B cells, Monocytes, and NK cells. It can be confirmed that immune factors are involved in the pathogenesis of the nephrotic syndrome.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3905-3905
Author(s):  
Rebecca Lopez ◽  
Andreas Lundqvist ◽  
Stephanie Sellers ◽  
Maria Berg ◽  
Muthalagu Ramanathan ◽  
...  

Abstract NK cell based immunotherapy represents a promising treatment approach for patients with cancer. Although preliminary clinical trials in humans suggest NK cell infusions can mediate anti-tumor effects, animal models are needed to provide insight into methods to enhance both the function and in vivo longevity of adoptively infused NK cells. Research conducted in our laboratory has shown that ex vivo expanded human NK cells are highly activated, up-regulating NKG2D, Granzyme B, TRAIL and Fas-ligand expression making them much more cytotoxic to tumor cells compared to freshly isolated NK cells. However, important questions remain regarding whether in vitro expansion alters the capacity of these cells to replicate, and traffic to tissues in vivo following their adoptive infusion into recipients. Differences in the genotype and phenotype of mouse NK cells compared to human NK cells limit the value of murine animal models to address these questions. In contrast to mice, Rhesus macaques have orthologues to most of the human MHC class I and II genes and possess NK cells expressing KIRs that are phenotypically and functionally similar to human NK cells, thus providing an excellent model system for evaluating questions related to adoptive NK cell therapy. We developed an in vitro method to expand macaque NK cells to characterize their in vivo longevity and tissue trafficking following adoptive infusion. Macaque NK cells were enriched from peripheral blood mononuclear cells by depleting CD3+ cells using immunomagnetic beads and were then expanded in vitro with autologous plasma and a human EBV-LCL feeder cell line using culture conditions identical to those used to expand NK cells from humans. NK cell cultures expanded 50- to 100-fold over 7 to 20 days, were greater than 99% CD3 negative, and had a similar phenotype to human NK cells including a large proportion of CD16/CD56 double positive cells, and ubiquitous expression of NKG2D, KIR2D, LFA-1, granzyme B, and CXCR3. In contrast to mice but analogous to human NK cells, macaque expanded NK cells upregulated surface expression of TRAIL and were highly cytotoxic to K562 cells and other human tumor lines (Figure). CFSE labelling of expanded NK cells did not alter their phenotype or tumor cytotoxic function. Data characterizing the longevity, proliferative capacity, and tissue trafficking patterns in the blood, bone marrow and lymph node of in vitro expanded and adoptively infused CFSE labeled NK cells (up to 1 × 108 NK Cells/kg i.v.) in macaque recipients will be presented from this analysis. Figure Figure


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4800-4800
Author(s):  
Alan M Williams ◽  
Ken Hayama ◽  
Yijia Pan ◽  
Brian Groff ◽  
Rina M Mbofung ◽  
...  

Abstract Chimeric antigen receptor (CAR) T-cell therapies have revolutionized the treatment of hematologic malignancies, however, logistical complexities associated with patient-specific CAR T-cell therapies often limit broad accessibility to patients. Many of these challenges can be overcome with an allogeneic cellular product that is available off-the-shelf, and overcoming immune cell-mediated rejection of allogeneic cell therapy is an area of significant research. Conditioning chemotherapies, which are commonly administered with CAR T-cell therapy, suppress a patient's immune system and may create a suitable window of activity for allogeneic cell therapies to elicit clinical response. However, protracted lympho-conditioning has been associated with poor immune reconstitution and increased susceptibility to opportunistic infections. Deletion of human leukocyte antigen (HLA) surface expression is known to abrogate T-cell alloreactivity, but deletion of class I HLA must be combined with other immune-modulating strategies to avoid NK cell-mediated recognition. To this end, allogeneic models combining class I HLA deletion with NK cell inhibitory molecules, such as HLA-E and CD47, have been shown to abrogate NK cell reactivity in mouse models. However, since HLA-E is the canonical activator of NKG2C, a dominant activating receptor found on human NK cells, and since the ligand for CD47, SIRPα, is known to be expressed on macrophages and dendritic cells and not on human NK cells, the observed effects of these immune-modulating strategies may not translate into the patient-treatment setting. In assessment of their protective effects in a defined human system, we found that HLA-E or CD47 overexpression on class I HLA null human cells offer only partial protection in evading various human NK cell compartments. We found that class I HLA-null K562 cells engineered to over-express CD47 were ineffective in inhibiting NK cells (0 to 7% inhibition). Separately, K562 cells engineered to over-express HLA-E, while effective in inhibiting NKG2A+ NK cells (90.2% +/- 3.7% inhibition), were unable to completely inhibit CD56 dim NK cells (33.2% +/- 29.6% inhibition) and not only failed, but instead activated, NKG2C+ NK cells (167% +/- 69% activation). Our data highlight the limitations of engineered CD47 and HLA-E modalities in suppressing broad populations of NK cells in clinically relevant settings. We therefore evaluated expression of the alloimmune defense receptor (ADR) that uniquely targets alloreactive immune cells (Mo et al. Nat Biotechnol 2021). We have shown that the expression of ADR has the potential to evade host immune cells without the need for further genetic editing such as class I HLA deletion. To determine its applicability for off-the-shelf cell therapy, ADR expression was engineered into induced pluripotent stem cells (iPSCs) and iPSC-derived CAR-NK (CAR-iNK) cells were generated. CAR-iNK cells carrying the ADR modality (ADR+ CAR-iNK cells) showed normal patterns of differentiation (>99% CD56+ with co-expression of NK cell receptors such as NKG2D, NKp30 and NKp46), suggesting that ADR expression did not disrupt hematopoiesis or the expansion of iNK cells. Additionally, ADR+ and ADR-negative CAR-iNK cells produced similar cytotoxicity against tumor cells. We next tested the ability of ADR to provide resistance to alloimmune rejection by coculturing ADR+ CAR-iNK cells with allogeneic pBMCs in a mixed lymphocyte reaction (MLR) assay. Notably, ADR+ CAR-iNK cells maintained durable persistence throughout the entire duration of the MLR assay and suppressed the expansion of alloreactive T- and NK-cells in comparison to the control arm (Figure 1). Collectively, initial preclinical studies suggest that ADR-modified CAR-iNK cells resist host immune cell rejection, while eliciting a durable anti-tumor response. Our preliminary data show evidence toward a promising off-the-shelf solution for elimination of broad pools of alloreactive T- and NK- effector cells in the clinical setting without the need for lympho-depleting conditioning or genetic editing strategies. Figure 1 Figure 1. Disclosures Williams: Fate Therapeutics: Current Employment. Abujarour: Fate Therapeutics, Inc.: Current Employment. Lee: Fate Therapeutics, Inc.: Current Employment. Malmberg: Merck: Research Funding; Vycellix: Consultancy; Fate Therapeutics: Consultancy, Research Funding. Mamonkin: Beam Therapeutics: Other: Licensing payments; Fate Therapeutics: Other: Licensing payments; Allogene Therapeutics: Consultancy, Other: Licensing payments; Xenetic Biosciences: Consultancy, Membership on an entity's Board of Directors or advisory committees. Bjordahl: Fate Therapeutics: Current Employment. Valamehr: Fate Therapeutics, Inc.: Current Employment.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3004-3004
Author(s):  
Mieszko Lachota ◽  
Marta Siernicka ◽  
Zofia Pilch ◽  
Agnieszka Graczyk-Jarzynka ◽  
Magdalena Winiarska

Abstract Introduction Dasatinib is a potent small molecule kinase inhibitor targeting BCR-ABL kinase - oncogenic driver in Philadelphia chromosome-positive (Ph+) cases of chronic myelogenous leukemia (CML). In addition to BCR-ABL kinase, it also targets a broad array of other kinases, affecting not only leukemia cells but also immune cells. Just one hour after dasatinib oral administration a rapid increase of NK, NKT, T and B cells is observed in peripheral blood. Dasatinib has been also shown to influence NK cell cytotoxicity, however, the results are discordant. Some groups observe potentiation of NK cell cytotoxic activity while others strong inhibitory effects. These inconsistencies may be explained by differences in in vitro protocols used to study this phenomenon. Aim Our study aims to investigate dasatinib influence on immune cells in whole blood assays resembling physiological conditions observed in patients. In particular, we want to investigate dasatinib effect on NK cell mobilization, degranulation, and anti-tumor immunity. In light of clinical and pre-clinical studies involving dasatinib and the importance of NK cells in cancer, it is crucial to establish the mechanisms and kinetics of dasatinib immunomodulatory activity. Methods Before and one hour after first dasatinib administration peripheral blood was collected from CML patients. Collected whole blood was directly added to the target K562 cell line. After co-incubation, erythrocytes were lysed, cells were stained with a panel of monoclonal antibodies and analyzed with flow cytometry. A relative increase in lymphocyte count was determined by Trucount Tubes (BD). Dasatinib effect on NK cells in vitro was studied with degranulation and cytotoxicity assays using NK cells isolated from healthy volunteers PBMCs. Dasatinib at clinically relevant concentrations (20-200mM) was used to assess its effect on NK cell degranulation, cytotoxicity, cytokine, and chemokine production with flow cytometry upon staining with anti-CD107a, TNF-α, IFN-γ and CCL-4 monoclonal antibodies. For in vivo experiments C57BL/6 mice were inoculated with EL4 tumor cell line stably expressing luciferase and human CD20. 3 days after tumor inoculation mice were treated with dasatinib or vehicle intraperitoneally (i.p.) in a dose of 30 mg/kg. To monitor tumor growth, mice were injected with luciferin and imaged using the IVIS system. Results In agreement with previous reports, we confirm NK, NKT, T and B cell count increase in peripheral blood after dasatinib administration. To evaluate how dasatinib influences NK cell cytokine and chemokine production we stimulated NK cells with K562 cell line. Production of major proinflammatory cytokines secreted by NK cells, TNF-α and IFN-γ, was inhibited by dasatinib treatment. Production of MIP-1β (CCL4), a chemokine secreted by NK cells attracting a broad spectrum of immune cells to inflammation sites, was also profoundly decreased. According to our findings, dasatinib presence during the cytotoxicity assay, in a dose-dependent manner, inhibits NK cell cytotoxicity. However, 24-hour dasatinib pretreatment increases their cytotoxic potential. To better mimic the physiological conditions we used whole blood degranulation assay which closely resembles patient settings, including dasatinib concentration. One hour after dasatinib intake we observed a potent inhibitory effect of dasatinib on NK cell degranulation. Additionally, we observed a shift in NK cell subpopulations - dasatinib present during degranulation assay decreases CD16⁻ NK cell number. Finally, we evaluated the influence of high-dose dasatinib treatment on tumor rejection in mice. Mice treated with dasatinib exhibit significantly increased tumor growth compared with vehicle-treated mice. Conclusions Using whole blood degranulation assay and in vitro degranulation and cytotoxicity assays we report that dasatinib effect on NK cell cytotoxicity is dose- and time-dependent. Our results indicate that dasatinib has a dual effect on NK cell degranulation and affects other NK cell functions including cytokine production and migration. Further studies are needed to evaluate the significance of these findings. Disclosures No relevant conflicts of interest to declare.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 263
Author(s):  
Philip Rosenstock ◽  
Thomas Kaufmann

Sialic acids are sugars with a nine-carbon backbone, present on the surface of all cells in humans, including immune cells and their target cells, with various functions. Natural Killer (NK) cells are cells of the innate immune system, capable of killing virus-infected and tumor cells. Sialic acids can influence the interaction of NK cells with potential targets in several ways. Different NK cell receptors can bind sialic acids, leading to NK cell inhibition or activation. Moreover, NK cells have sialic acids on their surface, which can regulate receptor abundance and activity. This review is focused on how sialic acids on NK cells and their target cells are involved in NK cell function.


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