Changes In Natural Killer Research Articles

Immune cell profiles associated with human exposure to perfluorinated compounds (PFAS) suggest changes in natural killer, T helper, and T cytotoxic cell subpopulations

Per- and polyfluoroalkyl substances (PFAS) constitutes a group of highly persistent man-made substances. Recent evidence indicates that PFAS negatively impact the immune system. However, it remains unclear how different PFAS are associated with alterations in circulating leukocyte subpopulations. More detailed knowledge of such potential associations can provide better understanding into mechanisms of PFAS immunotoxicity in humans. In this exploratory study, associations of serum levels of common PFAS (perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS)) and immune cell profiles of peripheral blood mononuclear cells, both with and without immunostimulation, were investigated. High-dimensional single cell analysis by mass cytometry was done on blood leukocytes from fifty participants in the Norwegian human biomonitoring EuroMix study.Different PFAS were associated with changes in various subpopulations of natural killer (NK), T helper (Th), and cytotoxic T (Tc) cells. Broadly, PFAS concentrations were related to increased frequencies of NK cells and activated subpopulations of NK cells. Additionally, increased levels of activated T helper memory cell subpopulations point to Th2/Th17 and Treg-like skewed profiles. Finally, PFAS concentrations were associated with decreased frequencies of T cytotoxic cell subpopulations with CXCR3+ effector memory (EM) phenotypes. Several of these observations point to biologically plausible mechanisms that may contribute to explaining the epidemiological reports of immunosuppression by PFAS. Our results suggest that PFAS exposures even at relatively low levels are associated with changes in immune cell subpopulations, a finding which should be explored more thoroughly in a larger cohort. Additionally, causal relationships should be confirmed in experimental studies. Overall, this study demonstrates the strength of profiling by mass cytometry in revealing detailed changes in immune cells at a single cell level.

The ratio of circulating CD56dim NK cells to follicular T helper cells as a promising predictor for disease activity of relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system primarily mediated by CD4+ T helper cells. This study investigated the dynamic changes of natural killer (NK) cells and follicular T helper (Tfh) cells and their associations in relapsing-remitting MS patients. The findings revealed inverse relationships between NK cells and CD4+ T cells or Tfh cells. Specifically, CD56dim NK cells, not CD56bright NK cells, were negatively correlated with CD4+ T cells and Tfh cells. However, no significant correlations were found between NK cells and sNfL levels or EDSS scores. The ratio of CD56dim NK cells to circulating Tfh (cTfh) cells demonstrated superior discriminatory ability in distinguishing relapsing MS patients from healthy controls (HCs) and remitting patients, as determined by receiver operating characteristic (ROC) analysis. Following treatment with immunosuppressants or disease-modifying therapies (DMTs), a significant increase in the CD56dim NK/cTfh ratio was observed. These findings suggest that the CD56dim NK/cTfh ratio holds promise as a prognostic indicator for clinical relapse and treatment response in MS.

HIV/HBV coinfection remodels the immune landscape and natural killer cell ADCC functional responses.

HBV and HIV coinfection is a common occurrence globally, with significant morbidity and mortality. Both viruses lead to immune dysregulation including changes in natural killer (NK) cells, a key component of antiviral defense and a promising target for HBV cure strategies. Here we used high-throughput single-cell analysis to explore the immune cell landscape in people with HBV mono-infection and HIV/HBV coinfection, on antiviral therapy, with emphasis on identifying the distinctive characteristics of NK cell subsets that can be therapeutically harnessed. Our data show striking differences in the transcriptional programs of NK cells. HIV/HBV coinfection was characterized by an over-representation of adaptive, KLRC2 -expressing NK cells, including a higher abundance of a chemokine-enriched ( CCL3/CCL4 ) adaptive cluster. The NK cell remodeling in HIV/HBV coinfection was reflected in enriched activation pathways, including CD3ζ phosphorylation and ZAP-70 translocation that can mediate stronger antibody-dependent cellular cytotoxicity responses and a bias toward chemokine/cytokine signaling. By contrast, HBV mono-infection imposed a stronger cytotoxic profile on NK cells and a more prominent signature of "exhaustion" with higher circulating levels of HBsAg. Phenotypic alterations in the NK cell pool in coinfection were consistent with increased "adaptiveness" and better capacity for antibody-dependent cellular cytotoxicity compared to HBV mono-infection. Overall, an adaptive NK cell signature correlated inversely with circulating levels of HBsAg and HBV-RNA in our cohort. This study provides new insights into the differential signature and functional profile of NK cells in HBV and HIV/HBV coinfection, highlighting pathways that can be manipulated to tailor NK cell-focused approaches to advance HBV cure strategies in different patient groups.

Daily cannabidiol and L-theanine beverage consumption does not alter anxiety, fatigue, cognitive function, or natural killer cell function: A randomized, controlled trial in healthy, young adults

Cannabidiol (CBD), a non-psychotropic Cannabis sativa derivative, and L-theanine, a green tea derivative, are gaining attention as potential promotors of psychological and cognitive health. The purpose of this double-blind, randomized, placebo-controlled study was to determine whether eight-week, daily consumption of beverages containing CBD, along with L-theanine, would improve psychological health, cognitive function, serum brain-derived neurotrophic factor (BDNF) as well as innate immune cell quantity and function in young, healthy adults. A total of 102 healthy participants were randomly assigned to, and successfully completed, 8 weeks of one of four treatment arms: 1) 60 mg CBD plus L-theanine (CB60; n = 25); 2) 30 mg CBD plus L-theanine (CB30; n = 28); 3) vehicle containing only L-theanine (LTV; n = 24); and 4) a calorie-matched placebo (PLAC; n = 25). After 8 weeks, plasma cannabinoid metabolite concentrations were significantly increased (p < 0.001) in CB60 and CB30 groups. There were no significant changes in anxiety, fatigue, and cognition, or serum BDNF concentrations as a result of the intervention and no treatment-related changes in natural killer (NK) and NKT cell populations or function. ClinicalTrials.gov (NCT05189275).

Changes in natural killer and T lymphocyte phenotypes in response to cardiovascular risk management

The pro-inflammatory and regulatory roles of T lymphocytes in atherosclerosis are well established but less is known about natural killer (NK) cells and natural killer T (NKT)-like cells. The effects of cardiovascular risk management on the phenotypes of these cells are unknown. To assess changes in NK cell and lymphocyte phenotypes and circulating inflammatory proteins in response to cardiovascular risk management in patients with carotid atherosclerosis. Fifty patients were included in a prospective clinical study. Measurements were at baseline and after 12 months of cardiovascular risk management. Circulating NK, NKT-like and T lymphocyte subpopulations were phenotyped by multi-colour flow cytometry. Proximity extension assay was performed for 176 plasma proteins associated with inflammation and cardiovascular disease. At 12 months there were significant reductions in LDL (P = 0.001) and blood pressure (P = 0.028). NK cells responded with a reduction in pro-inflammatory (NKG2C+) cells (P = 0.0003), an increase in anti-inflammatory (NKG2A+) cells (P = 0.032), and a reduction in terminally differentiated (CD57+) NK cells. NKT-like cells showed a similar decrease in terminally differentiated subpopulations (P = 0.000002). Subpopulations of T helper cells exhibited a significant reduction in central memory (P = 1.09 × 10−8) and a significant increase in CD4+ naïve- (P = 0.0008) and effector memory T cells (P = 0.006). The protein analysis indicated that cardiovascular risk management affects proteins involved in the inflammatory NF-κB pathway. The consistent decrease in senescent phenotypes of NK, NKT-like and CD4+ cells with a concomitant increase in more naïve, phenotypes suggests a change towards a less pro-inflammatory lymphocyte profile in response to cardiovascular risk management.Trial registry name: CARotid MRI of Atherosclerosis (CARMA). ClinicalTrials.gov identifier NCT04835571 (08/04/2021). https://www.clinicaltrials.gov/study/NCT04835571.

Dominant CD4+ T cell receptors remain stable throughout antiretroviral therapy-mediated immune restoration in people with HIV

In people with HIV (PWH), the post-antiretroviral therapy (ART) window is critical for immune restoration and HIV reservoir stabilization. We employ deep immune profiling and Tcell receptor (TCR) sequencing and examine proliferation to assess how ART impacts Tcell homeostasis. In PWH on long-term ART, lymphocyte frequencies and phenotypes are mostly stable. By contrast, broad phenotypic changes in natural killer (NK) cells, γδ Tcells, B cells, and CD4+ and CD8+ Tcells are observed in the post-ART window. Whereas CD8+ Tcells mostly restore, memory CD4+ T subsets and cytolytic NK cells show incomplete restoration 1.4 years post ART. Surprisingly, the hierarchies and frequencies of dominant CD4 TCR clonotypes (0.1%-11% of all CD4+ Tcells) remain stable post ART, suggesting that clonal homeostasis can be independent of homeostatic processes regulating CD4+ Tcell absolute number, phenotypes, and function. The slow restoration of host immunity post ART also has implications for the design of ART interruption studies.

Benralizumab affects NK cell maturation and proliferation in severe asthmatic patients

IntroductionThe mechanism of action of benralizumab is determined by its afucosylated constant fragment that binds CD16a receptors on the membrane of natural killer cells. Here we analysed changes in Natural Killer and T-cells in Severe asthmatic patients, before and after benralizumab. MethodsNatural Killer and T-cell subsets were detected through multiparametric flow cytometry. The concentrations of serum cytokines levels were detected through multiplex assay. Functional proliferation assay was performed in follow-up samples in severe asthmatic patients. ResultsAt baseline, severe asthmatic patients showed higher percentages of immature Natural Killer cells when compared with healthy controls. We demonstrate the proliferative capacity of these cells and their activation after benralizumab administration. Benralizumab shifted Natural Killer cell phenotypes towards maturity. Correlation between the Natural Killer cells and functional parameters and with steroid-sparing was observed. ConclusionTogether this data contributes to our understanding of the mechanisms of action of benralizumab in the resolution of inflammation in severe asthma patients.

Profiling of Natural Killer Interactions With Cancer Cells Using Mass Cytometry

We developed a comprehensive method for functional assessment of the changes in immune populations and killing activity of peripheral blood mononuclear cells after cocultures with cancer cells using mass cytometry. In this study, a 43-marker mass cytometry panel was applied to a coculture of immune cells from healthy donors’ peripheral blood mononuclear cells with diverse cancer cell lines. DNA content combined with classical CD45 surface staining was used as gating parameters for cocultures of immune cells (CD45high/DNAlow) with hematological (CD45low/DNAhigh) and solid cancer cell lines (CD45neg/DNAhigh). This strategy allows for universal discrimination of cancer cells from immune populations without the need for a specific cancer cell marker and simultaneous assessment of phenotypical changes in both populations. The use of mass cytometry allows for simultaneous detection of changes in natural killer, natural killer T cell, and T cell phenotypes and degranulation of immune populations upon target recognition, analysis of target cells for cytotoxic protein granzyme B content, and cancer cell death. These findings have broad applicability in research and clinical settings with the aim to phenotype and assess functional changes following not only NK-cancer cell interactions but also the effect of those interactions on other immune populations.

Assessment of the risk of unexplained recurrent spontaneous abortion based on the proportion and correlation of NK cells and T cells in peripheral blood.

Unexplained recurrent spontaneous abortion (URSA) is difficult to diagnose and treat clinically due to its unknown causeOBJECTIVE: Changes in natural killer (NK) cells, T lymphocytes, and Th1(IFNγ)/Th2(IL-4) cytokines were investigated in the peripheral blood of patients with URSA to examine the pathogenesis, clinical diagnosis, and inform potential treatment strategies for this condition. For this study, we selected patients with URSA as the case group and included normal women in the control group.Flow cytometry was performed to detect lymphocytes and cytokines in the peripheral blood of all subjects. The proportion of NK cells, Th1 cells, and the Th1/Th2 ratio were significantly higher in the URSA group compared to the control group; whereas the proportion of CD3+T cells was lower. Pairwise correlation analysis revealed a positive correlation between the percentage of NK cells and CD3+T cells, as well as CD3+CD4+T cells. Canonical correlation analysis indicated a significant correlation between NK cells and T cells, including their subgroups. Patients with URSA have immune balance disorders, characterised by an increased proportion of peripheral blood NK cells, Th1, and Th1/Th2 ratio along with a decreased proportion of CD3+T cells. The proportion of NK cells and CD3+T may serve as predictive factors for URSA, while NK cells are closely related to the regulation of CD3+T cells and their subsets. By regulating the level of IFN-γ, NK cells can influence the proportion of CD3+T cells and induce a Th1 (IFNγ)/Th2 (IL-4) imbalance.

Abstract 2912: High-throughput screening and single-cell transcriptomics identify synergies between oncology drugs and natural killer cell immunotherapy

Abstract Background &amp; Objective: Natural killer (NK) cell-based immunotherapies are emerging therapeutic approaches that aim to target malignant cells resistant to conventional treatments and T cell-based immunotherapies. Existing oncology drugs may enhance the anti-cancer function of NK cells, although large-scale high-throughput testing of NK cell-drug combinations has not been previously attempted. Our objective was to evaluate the potential of approved and investigational oncology drugs to synergize with NK cell-based immunotherapy in acute myeloid leukemia (AML), with the aim to discover both potentiating and inhibiting compounds. Methods: A high-throughput drug sensitivity and resistance screen including 528 oncology drugs was combined with expanded NK cells to evaluate their cytotoxicity against luciferase-expressing AML cells (MOLM-14). The most prominent drugs were investigated further with single-cell RNA sequencing to reveal underlying biological mechanisms. Results: Overall, 191 drugs had an inhibitory effect on cytotoxicity, 294 had no effect, and 43 had an enhancing effect. The most notable NK cell cytotoxicity-potentiating drugs were pevonedistat (NEDD8 inhibitor), daporinad (NAMPT inhibitor), and JAK inhibitors. These drugs also induced distinct changes in NK and target cell transcriptional profiles. When combined with NK cells, pevonedistat and daporinad induced an upregulation of HLA-E and CXCL10 in target cells. In addition, MYC and FLT3 proto-oncogenes were downregulated in target cells when combining NK cells with pevonedistat. Moreover, in NK cells, daporinad induced dysregulated expression of genes related to NK cell effector functions such as TYROBP, TXNIP and KLRC1. Treatment with JAK inhibitors downregulated MHC I expression on target cells, providing a putative mechanism for increased NK cell activity. Validation of key hits is ongoing in additional AML cell lines. Conclusion: We discovered novel drugs with both potentiating and inhibiting effects on NK cell cytotoxicity against AML cells in vitro. Our results demonstrate the potential of using a high-throughput framework for studying NK cell-drug interactions against malignant cells, while aiming to improve treatment for AML and other malignancies through combination immunotherapies. Citation Format: Jonas O. Bouhlal, Petra Nygren, Essi Laajala, Aleksandr Ianevski, Jay Klievink, Hanna Lähteenmäki, Khalid Saeed, Dean Lee, Tero Aittokallio, Olli Dufva, Satu Mustjoki. High-throughput screening and single-cell transcriptomics identify synergies between oncology drugs and natural killer cell immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2912.

Evaluation of host cellular responses to Epstein-Barr virus (EBV) in adult lung transplant patients with EBV-associated diseases.

Epstein-Barr virus (EBV)reactivation is commonly observed in lung transplant recipients (LTRs).However, cellular immune responses to EBV in adult LTRs have not been well described. We aimed to study CD4/CD8ratio, EBV-specificT cells polyfunctional responses and phenotypic changes in natural killer (NK)cells in adult LTRs presenting with EBV-associateddiseases. The CD4/CD8ratio was significantly decreased in LTRs with EBV DNAemia compared withLTRs without EBV DNAemia and healthy controls (HCs).Stimulation with EBV lytic antigen BZLF1 peptide pools induced significant individual and polyfunctional responses from CD8+ CD69+ T cells. Frequencies of CD8+ CD69+ T cells expressing CD107a were significantly higher in LTRs without EBV DNAemia than in LTRs with DNAemia. Frequencies of CD8+ CD69+ T cells concurrently expressing CD107a, IFN-γ,and TNF-αwere significantly greater in LTRs with and without EBV DNAemia than in HCs. Finally, BZLF1 induced significantly higher frequencies of CD8+ CD69+ T cells expressing CD107a and IFN-γin LTRs without EBV DNAemia when compared withEBNA3B. Frequency of more differentiated CD56dim CD16pos NK cells was significantly decreased in LTRs with EBV DNAemia and PTLD compared withHCs. In conclusion, we noted the presence of significant changes in circulating cellular immune responses to EBV in adult LTRs.

Effects of Alloferon versus Valaciclovir for Treating Chronic Epstein-Barr Virus Infection

Background and objectivesThis study aimed to analyze the influence of alloferon on the Epstein-Barr virus (EBV) DNA copy number in saliva samples and the changes of natural killer (NK) cell content, cytotoxic activity of killer cells, and production of interferon alpha and gamma in patients suffering chronic EBV infection (CEBVI) at 6 weeks after therapy completion.

Changes of natural killer cells' phenotype in patients with chronic hepatitis B in intermittent interferon therapy.

To investigate the changes of natural killer (NK) cell phenotype in the interferon alpha (IFN-α) treatment of chronic hepatitis B (CHB) and its relationship with clinical indicators. The CHB patients who did not receive any antiviral treatment were set as initial treatment group and used pegylated interferon alpha (PEG-IFN α). Peripheral blood samples were collected at baseline, 4 weeks, and 12-24 weeks. For IFN-treated patients who entered the plateau were set as plateau group, and PEG-IFN α was discontinued and resumed after an interval of 12-24 weeks. Besides, we also enrolled some patients who had received oral drug for more than 6 months as oral drug group without follow up. Peripheral blood was collected during the plateau period, which was set as baseline, and after 12-24 weeks of intermittent treatment, and after 12-24 weeks of additional treatment with PEG-IFN α. The aim of the collection was to detect hepatitis B virus (HBV) virology, serology and biochemical indicators, and the NK cell related phenotype was detected by flow cytometry. In the plateau group, subgroup of CD69+CD56dim was higher with statistical significance when comparing with the initial treatment group and oral drug group [10.49 (5.27, 19.07) vs 5.03 (3.67, 8.58), Z = -3.11, P = 0.002; 10.49 (5.27, 19.07) vs 4.04 (1.90, 7.26), Z = -5.30, P < 0.001)]. CD57+CD56dim was significantly lower than that in initial treatment group and oral drug group respectively [68.42±10.37 vs 55.85±12.87, t = 5.84, P < 0.001; 76.38±9.49 vs 55.85±12.87, t = -9.65, P < 0.001]. The CD56brightCD16- subgroup in the plateau group was higher with statistical significance compared with initial treatment group and oral drug group respectively [11.64 (6.05, 19.61) vs 3.58 (1.94, 5.60), Z = -6.35, P < 0.001; 11.64 (6.05, 19.61) vs 2.37 (1.70, 4.30), Z = -7.74, P < 0.001)]. CD57+CD56dim in the plateau group had a significant higher percentage than that at baseline after IFN discontinuation for 12-24 weeks (55.85±12.87 vs 65.95±12.94, t = -2.78, P = 0.011). During the long-term treatment of IFN, the killer subgroup of NK cells is continuously depleted, leading to the differentiation of the regulatory subgroup into the killer subgroup. In the killing subgroup, although the number is continuously depleted, the activity of the subgroup is continuously increased. In the plateau phase, after stopping IFN for a period of time, the number of NK cell subsets would gradually recover, but was still lower than that in the initial treatment group.

Effect of orally administered heat-treated Lactobacillus plantarum LM1004 on the innate immune system: A randomized, placebo-controlled, double-blind study

• Supplementation with heat-treated Lactobacillus plantarum LM1004 (HT-LM1004) for eight weeks activated the innate immunity in healthy adults. • Natural killer cells were enhanced with HT-LM1004 compared to the control group. • Serum level of interleukin-12 by dietary intake of HT-LM1004 was elevated from baseline. • Treatment of HT-LM1004 was safe and well tolerated. Heat-treated Lactobacillus plantarum LM1004 (HT-LM1004) isolated from Korean kimchi and further processed has been reported to exert the stimulatory activities on the innate immune system in our previous in vitro and in vivo studies. The aim of the present study was to examine the effect of HT-LM1004 on changes in natural killer (NK) cell activity, the serum concentrations of cytokines and safety parameters in healthy adults aged 19–75 years. In the present randomized, placebo-controlled, double-blind trial, one hundred subjects consumed a capsule containing 2 × 10 10 cells of HT-LM1004 or placebo once per day over eight weeks. Significant increases in NK cell activity (%) were observed in the treatment group after eight weeks of HT-LM1004 ingestion compared to the control group ( p = 0.036). This study also demonstrated a consistent trend of enhanced serum level of interleukin (IL)-12 by dietary intake of HT-LM1004 without any side effects.

Bone marrow mesenchymal stem cells regulate the dysfunction of NK cells via the T cell immunoglobulin and ITIM domain in patients with myelodysplastic syndromes

BackgroundMyelodysplastic syndrome (MDS) is a clonal disease of hematopoietic cells, characterized by hematopoietic cell hematopoiesis and a high risk of transformation into acute myeloid leukemia (AML). Although the underlying mechanism is unclear, MDS is often associated with immune system disorders, especially cellular immune abnormalities. We analyzed the number of lymphocyte subsets by flow cytometry assay and explored the alteration of lymphocyte subsets in MDS.MethodsHealthy controls, inpatients with primary MDS and patients with AML diagnosed from January 2017 to July 2021 were included. Flow cytometry assays were used to study lymphocyte subsets obtained from the bone marrow of the participants as well as changes in natural killer (NK) cell function. One-way analysis of variance and Student’s t-test were used to analyze the data.ResultsWe found a reduction in the number and function of NK cells in patients with MDS. By further measuring the activating and inhibitory receptors on the surface of NK cells, we found that the T cell immunoglobulin and ITIM domain (TIGIT) was the highest expressed marker on NK cells. Additionally, the expression of CD155, which is the ligand of TIGIT, was significantly higher than expressions of CD112 and CD113 on bone marrow mesenchymal stem cells (BMSCs).ConclusionsThe co-culture results of BMSCs and NK cells demonstrated that BMSCs regulate NK cells through the TIGIT/CD155 interaction, indicating that NK cells play a vital role in MDS progression. BMSCs regulate the function of NK cells via TIGIT/CD155.EvM_ycHj6U8mjawjepZzLzVideo

Inflammatory-mediated taste dysfunction – Is NO the key?

Diabetes mellitus (DM), also called diabetes, is a chronic metabolic disorder, with complications that include failure of immune responses, such as immune cell proliferation and activation. The current study investigated changes in natural killer (NK) cell activity under diabetic conditions. To demonstrate the influence of hyperglycemia on NK cell activity, type 1 and 2 diabetes models were constructed using C57/BL6 mice. NK cells isolated from mice with either type 1 or 2 diabetes showed lower cytotoxic activity against cancer cells than NK cells isolated from healthy control mice, and the longer the duration since induction of diabetes, the lower was the cytotoxic activity. Moreover, in the diabetic mouse models, fewer NK cells expressed activation markers, such as NKG2D and NKp46, compared to NK cells from control mice. Production of the apoptosis inducer, granzyme B, was also lower in NK cells from diabetic mice than control mice. These results demonstrate that high glucose conditions influence NK cell activity.

Type 1 and 2 diabetes are associated with reduced natural killer cell cytotoxicity

Diabetes mellitus (DM), also called diabetes, is a chronic metabolic disorder, with complications that include failure of immune responses, such as immune cell proliferation and activation. The current study investigated changes in natural killer (NK) cell activity under diabetic conditions. To demonstrate the influence of hyperglycemia on NK cell activity, type 1 and 2 diabetes models were constructed using C57/BL6 mice. NK cells isolated from mice with either type 1 or 2 diabetes showed lower cytotoxic activity against cancer cells than NK cells isolated from healthy control mice, and the longer the duration since induction of diabetes, the lower was the cytotoxic activity. Moreover, in the diabetic mouse models, fewer NK cells expressed activation markers, such as NKG2D and NKp46, compared to NK cells from control mice. Production of the apoptosis inducer, granzyme B, was also lower in NK cells from diabetic mice than control mice. These results demonstrate that high glucose conditions influence NK cell activity.

Primary infection by E. multilocularis induces distinct patterns of hepatic crosstalk between natural killer T and regulatory T cells in mice

Abstract Objective The larval stage of the helminthic cestode Echinococcus multilocularis can inflict tumor-like hepatic lesions that cause the parasitic disease alveolar echinococcosis (AE) in humans. Recently, opportunistic properties of the disease have been proposed based on the increased incidence in immunocompromised patients as well as on mouse models, indicating that an appropriate adaptive immune response is required for the control of the disease. However, little is known about how the local hepatic immune responses modulate the infection with E. multilocularis. Methods In a mouse model of oral infection that mimics the normal infection route in human patients, the adaptive immune response in the liver was assessed using single cell RNA sequencing of isolated hepatic CD3+ T cells at different infection stages. Results Single-cell RNA sequencing revealed specific temporal changes of natural killer T (NKT) cells and regulatory T (Treg) cells, indicating that these two cell types expand in the early phase and are subsequently inhibited in the late phase of infection. Receptor-ligand complex analysis via CellPhoneDB, consistently revealed high number of interactions between Tregs and NKT mainly at day 10 post infection. Relevant interactions between NKT and Treg cells at early phases include regulation of cell adhesion molecules such as integrins and selectins and TNF-dependent signalling. Immune suppressing interactions that include the checkpoint inhibitors (PD-1 and PD-L1), purinergic (ENTPD1, ADORA2A) and TGF-beta signalling are down regulated at early time points. String analysis supported these findings. Conclusion The data indicate that early interactions between NKT and Tregs potentially promote the formation of hepatic lesions and later also contribute to immunological suppression of the resolution of parasite-induced pathology. The obtained data provide a fresh insight on the adaptive immune responses and local regulatory pathways at different infection stages of E. multilocularis in mice.

HO-1/BMMSC perfusion using a normothermic machine perfusion system reduces the acute rejection of DCD liver transplantation by regulating NKT cell co-inhibitory receptors in rats

BackgroundLiver transplantation (LT) is required in many end-stage liver diseases. Donation after cardiac death (DCD) livers are often used, and treatment of acute rejection (ACR) requires the use of immunosuppressive drugs that are associated with complications. Bone marrow mesenchymal stem cells (BMMSCs) are used in treatment following LT; however, they have limitations, including low colonization in the liver. An optimized BMMSC application method is required to suppress ACR.MethodsBMMSCs were isolated and modified with the heme oxygenase 1 (HO-1) gene. HO-1/BMMSCs were perfused into donor liver in vitro using a normothermic machine perfusion (NMP) system, followed by LT into rats. The severity of ACR was evaluated based on liver histopathology. Gene chip technology was used to detect differential gene expression, and flow cytometry to analyze changes in natural killer (NK) T cells.ResultsNMP induced BMMSCs to colonize the donor liver during in vitro preservation. The survival of HO-1/BMMSCs in liver grafts was significantly longer than that of unmodified BMMSCs. When the donor liver contained HO-1/BMMSCs, the local immunosuppressive effect was improved and prolonged, ACR was controlled, and survival time was significantly prolonged. The application of HO-1/BMMSCs reduced the number of NKT cells in liver grafts, increased the expression of NKT cell co-inhibitory receptors, and reduced NKT cell expression of interferon-γ.ConclusionsNK cell and CD8+ T cell activation was inhibited by application of HO-1/BMMSCs, which reduced ACR of transplanted liver. This approach could be developed to enhance the success rate of LT.

Supplementation with a Natural Source of Amino Acids, Sil-Q1 (Silk Peptide), Enhances Natural Killer Cell Activity: A Redesigned Clinical Trial with a Reduced Supplementation Dose and Minimized Seasonal Effects in a Larger Population.

The aim of this study was to re-validate the changes in natural killer (NK) cell cytotoxicity and cytokines related to T cells after Sil-Q1 (SQ; silk peptide) supplementation in a larger pool of Korean adults with minimized daily dose of SQ and controlling seasonal influence compared to the previous study. A total of 130 subjects were randomly assigned (1:1) to consume either 7.5 g of SQ or placebo for 8 weeks. NK cell cytotoxicity and cytokines were measured at T0 (baseline) and T8 (follow-up). Comparing the NK cell cytotoxicity values at T0 and T8 within each group, the cytotoxicity at all effector cell (E) to target cell (T) ratios of 10:1, 5:1, 2.5:1, and 1.25:1 was significantly increased in the SQ group at T8. Additionally, significant differences in the changed value (Δ, subtract baseline values from follow-up values) comparison between the groups at E:T = 10:1, 5:1, and 2.5:1 were found. As a secondary endpoint, the interleukin (IL)-12 level in the SQ group was significantly increased for 8 weeks, and Δ IL-12 in the SQ group was greater than in the placebo group. In conclusion, the present study showed considerable practical implications of SQ supplementation. Thus, SQ is an effective and safe functional food supplement for enhancing immune function.