NKT-like Cells Research Articles

CD1d-dependent NKT cells establish Th1-polarity to promote resolution of dengue virus infection

Abstract NKT cells are innate-like T cells that can rapidly produce cytokines or acquire cytotoxicity upon activation, which can shape subsequent adaptive immunity towards invading pathogens. During infection by the arboviral pathogen dengue virus (DENV), NKT cells are recruited to the skin, yet their contributions to cutaneous virus clearance are unclear. Moreover, the individual contributions of various NKT subsets to DENV immunity are poorly defined. Here, we show CD1d-dependent (CD1d-dep) NKT cells promote DENV infection resolution in skin and draining lymph nodes (dLNs) through recruitment of cytotoxic lymphocytes (CTLs), including CD8+ T cells and NKT-like cells to the skin and CD4+ and γδT cells to the dLN. CD1ddep NKT cells and NKT-like T cells are major producers of chemotactic factors for CTLs and Th1 cytokines. Impaired Th1 immunity in CD1d-KO mice was also apparent as CD4+ and CD8+ T cells produced less IFN-γ and more IL-4 and Th2-associated IgG1 levels were higher than Th1-associated IgG2a levels and promoted antibody dependent enhanced disease. These results demonstrate that CD1ddep NKT cells establish Th1 polarity during the early response to DENV, which significantly affects infection resolution and memory formation.

Aberrant distribution of CD3+CD56+ NKT-like cells in patients with primary Sjögren's syndrome.

To elucidate the potential role of CD3+CD56+ NKT-like cells in the pathogenesis of primary Sjögren's syndrome (pSS). We enrolled pSS patients and healthy controls and examined the peripheral population, the surface chemokine receptors and the proinflammatory cytokine production of NKT-like cells by flow cytometry. The infiltration of NKT-like cells in the labial salivary gland (LSG) was examined by immunofluorescence. Serum and tissue levels of CX3CL1 were detected by Cytometric Bead Array and immunohistochemistry, respectively. The chemotaxis of NKT-like cells was examined by transwell migration assay. Peripheral NKT-like cells from pSS patients were significantly lower than those from HC (3.09±2.35% vs. 5.37±4.06%, p=0.0002), which was negatively correlated with European League Against Rheumatism Sjögren's Syndrome Disease Activity index. NKT-like cells infiltrated into the LSG of pSS patients. Serum and LSG epithelial CX3CL1 levels were higher in pSS patients than those in HC, which promoted the chemotaxis of the NKT-like cells. NKT-like cells from pSS patients expressed a higher level of CD69, and secreted high level of TNF-α and IFN-γ, which was promoted by CX3CL1 in vitro. NKT-like cells decreased in peripheral and infiltrated into the LSG of the pSS patients, which could be driven by CX3CL1-CX3CR1 axis. NKT-like cells might be implicated in the pathogenesis of pSS.

Clinical Impact of Percentage of Natural Killer Cells and Natural Killer-Like T Cell Population in Acute Myeloid Leukemia.

BackgroundNatural killer (NK) function defects have been seen in many hematological malignancies, including acute myeloid leukemia (AML). AML is associated with deficient human leukocyte antigen (HLA) expression on leukemia blasts which become targets for killing by NK and natural killer-like T (NKT) cells. However, NK and NKT cells are not effective in killing autologous leukemia blasts, maybe due to number or functional abnormalities. The aim of the work was to detect the number and percentage of NK and NKT cells in patients with AML and the impact of their percentage on the prognosis, response to treatment and survival.MethodsBone marrow and peripheral blood samples were collected from 50 adult patients diagnosed as de novo AML who presented to the Hematology Unit in the Oncology Center Mansoura University (OCMU) at time of diagnosis. NK and NKT cells were detected by using immunophenotyping by expression of cell surface and cytoplasmic markers (anti-CD3 fluorescein isothiocyanate (FITC), anti-CD16/56 phycoerythrin (PE)).ResultsWe observed significant reduction in the median values of NK and NKT cells in AML patients in comparison to normal values. There was an insignificant correlation to response to induction treatment. While a significant correlation to overall survival (OS) (P = 0.03) was observed. The correlation to risk stratification was significant with NK cells (P < 0.001), but not with NKT cells (P = 0.23).ConclusionWe concluded that the number and percentage of NK and NKT cells decreased significantly in AML patients and the frequency of NK and NKT cells is inversely proportionate with prognosis and OS in studied AML patients. We recommend correlating both number and function of NK and NKT cells in future studies to help provide a wide field of interest for possibility of demonstrating novel therapies using NK cells for curing AML.

Lymphocyte senescence in COPD is associated with decreased sirtuin 1 expression in steroid resistant pro-inflammatory lymphocytes

Background:The class III NAD-dependent histone deacetylase (HDAC) sirtuin 1 (SIRT1) is an important regulator of senescence, aging, and inflammation. SIRT1de-acetylates chromatin histones, thereby silencing inflammatory gene transcription. We have reported increased steroid-resistant senescent pro-inflammatory CD28nullCD8+ T cells in patients with chronic obstructive pulmonary disease (COPD). We hypothesized that SIRT1 is reduced in these cells in COPD, and that treatment with SIRT1 activators (resveratrol, curcumin) and agents preventing NAD depletion (theophylline) would upregulate SIRT1 and reduce pro-inflammatory cytokine expression in these steroid-resistant cells.Methods:Blood was collected from n = 10 COPD and n = 10 aged-matched controls. Expression of CD28, SIRT1, and pro-inflammatory cytokines was determined in CD8+ and CD8– T and natural killer T (NKT)-like cells cultured in the presence of ±1 µM prednisolone, ±5 mg/L theophylline, ±1 µM curcumin, ±25 µM resveratrol, using flow cytometry and immunofluorescence.Results:There was an increase in the percentage of CD28nullCD8+ T and NKT-like cells in COPD patients compared with controls. Decreased SIRT1 expression was identified in CD28nullCD8+T and NKT-like cells compared with CD28+ counterparts from both patients and controls (e.g. CD28null 11 ± 3% versus CD28+ 57 ± 9%). Loss of SIRT1 was associated with increased production of IFNγ and TNFα, steroid resistance, and disease severity. SIRT1 expression was upregulated in the presence of all drugs and was associated with a decrease in steroid resistance and IFNγ and TNFα production by CD28nullCD8+T and NKT-like cells. The presence of the SIRT1 inhibitor, EX-527 negated [by 92 ± 12% (median ± SEM)] the effect of the SIRT1 activator SRT720 on the percentage of CD8+ T cells producing IFNγ and TNFα.Conclusions:Steroid resistance in pro-inflammatory CD28nullCD8+ T and NKT-like cells is associated with decreased SIRT1 expression. Treatment with prednisolone, in combination with theophylline, curcumin or resveratrol increases SIRT1 expression, restores steroid sensitivity, and inhibits pro-inflammatory cytokine production from these cells and may reduce systemic inflammation in COPD. The reviews of this paper are available via the supplemental material section.

Anti-PDL1/IL-15 fusion protein increases rare effector cells in cynomolgus monkeys and mice

Abstract Background Kadmon has generated an anti-PDL1/IL-15 fusion protein (KD033) by combining a proprietary, fully human, high affinity anti-human/mouse PD-L1 antibody with human IL-15. Initial assessment of KD033 showed enhanced tolerability relative to a non-targeted IL-15 fusion protein, in addition to its potent anti-tumor activity and immune memory generation. KD033 increased CD8+ T and NK cells in peripheral blood of humans, cynomolgus monkeys and mice as expected from on target engagement of IL-15. In this study, we evaluated additional immune cell population changes in mice and cynomolgus monkeys treated with KD033. Methods Tumor size, measured at day 7 in syngeneic subcutaneous CT26 colorectal cancer mouse model after a single KD033 surrogate treatment, was used to define mice as either KD033 responders (decreasing tumor volumes) or non-responders (no change or increasing tumor volumes). Peripheral blood from KD033 responders and non-responders as well as from cynomolgus monkeys treated with KD033 at predose, 24 and 168 hours after dosing was analyzed by flow cytometry for various immune cell populations. Results Granzyme B+ CD8+ T and gamma delta T cells in peripheral blood were specifically increased in KD033 surrogate responder mice. These increases were not observed in non-responder mice. Greater increases in NKT-like cells were also observed in KD033 surrogate best responders. This is in contrast to other immune populations, such as CD8+ T and B cells, which were similarly impacted, in both KD033 surrogate responder and non-responder mice. In cynomolgus monkeys, CD3+CD4-CD8- cells, which includes gamma delta T cells, were one of the immune populations with the highest increases at 168 hours post dose. Conclusion KD033 administration increases CD8+ T and NK cells, consistent with IL-15 pharmacodynamics. In addition, analysis of peripheral blood from KD033 surrogate best and non-responder mice demonstrated increases in different immune populations, which can facilitate their use as in-treatment biomarkers of KD033 activity in tumors. Importantly, KD033 administration resulted in increases in rare cytotoxic cells such as NKT and gamma delta T cells in peripheral blood which may contribute to its anti-tumor activity and immunity. Legal entity responsible for the study Kadmon Corporation LLC. Funding Kadmon Corporation LLC. Disclosure S. Martomo: Full / Part-time employment: Kadmon Corporation. D. Lu: Full / Part-time employment: Kadmon Corporation. Z. Polonskaya: Full / Part-time employment: Kadmon Corporation. X. Luna: Full / Part-time employment: Kadmon Corporation. F. Miyara: Full / Part-time employment: Kadmon Corporation. J. Patel: Full / Part-time employment: Kadmon Corporation.

HCMV seropositivity is associated with specific proinflammatory immune phenotype in women with implantation failure

HCMV coevolved with humans for millions of years and is now one of the most widespread infections worldwide. For a long time HCMV seropositivity was considered a safe clinical condition. In recent decades both clinical observations and research results indicated that the very presence of HCMV in human organism specifically influences immune system and may affect reproduction as a process greatly dependent on immune cells function.Anti-HCMV IgG, IgG avidity, lymphocyte subsets as well as NK cytotoxicity was investigated in 470 infertile women who were eligible for IVF/ET. 419 patients were IgG anti-HCMV-positive (HCMV-seropositive) and only 51 (10.8 %) were IgG anti- HCMV-negative (HCMV-seronegative). There was not a single case of clinically significant level of low-avidity IgG.HCMV-seropositive patients had significantly increased levels of HLA-DR expression on T-lymphocytes (both on CD3CD8 and especially on CD3CD4 subsets) and HLA-DR expression on NK-lymphocytes (CD56+CD3-), increased levels of NKT-like cells (CD3+CD8+CD56+) but decreased levels of CD8 + NK lymphocytes compared to HCMV-seronegative patients. That difference was caused by significant numbers of individuals with deviated “accentuated” immune phenotypes in HCMV seropositive patients. The latter had increased (>7.5 %) levels of HLA-DR expression on T helpers in 136 cases from 419 (32.4 %) while in HCMV-seronegative group this accentuation was observed only in 3 of 51 patients (5.8 %), (OR -5.9, p < 0.0003). The number of cases with significantly increased CD56 expression on Tc lymphocytes, HLA-DR on NK and decrease of CD8-positive NK cells was more often observed in HCMV-seropositive group compared to seronegative.Thus, possibly HCMV seropositivity specifically influences immune system and results in pro-inflammatory phenotype formation in part of infected population. It was found that accentuations in immune phenotype of HCMV-seropositive women are very similar to previously described in association with reproductive failures but without HCMV serostatus taken into account.

BOS Is Associated With Decreased SIRT1 in Peripheral Blood Proinflammatory T, NK, and NKT-like Lymphocytes.

Immunosuppression therapy is ineffective at preventing chronic rejection of lung allografts (bronchiolitis obliterans syndrome [BOS]) and proinflammatory cytokines by steroid-resistant lymphocytes. The class III NAD-sirtuin 1 (SIRT1) is an important negative regulator of inflammation; however, SIRT1 activity following lung transplant has not been studied. We hypothesized that SIRT1 expression is decreased in proinflammatory lymphocytes following lung transplant and that treatment with SIRT1 activators (resveratrol, curcumin) and agents that prevent NAD depletion (theophylline) upregulate SIRT1 and reduce proinflammatory cytokine expression in these cells. Intracellular proinflammatory cytokines and SIRT1 were measured in blood T, natural killer T-like cell (NKT-like), and natural killer (NK) cells from patients with BOS (n = 10), stable lung transplant patients (n = 11), and healthy aged-matched controls (n = 10). Blood was cultured in the presence of ±25 µM resveratrol, ±1 µM curcumin, ±5 mg/L theophylline, ±1µM prednisolone and cytokines, and SIRT1 assessed using flow cytometry. There was a loss of SIRT1 in T, NK-like, and NK cells in BOS patients compared with stable patients and controls (%CD8 SIRT1 T cells: 17 ± 10; 37 ± 10; 30 ± 10) (mean ± SEM BOS, stable, control, respectively) (P < 0.05 for all). Loss of SIRT1 was associated with increased T, NKT-like, and NK cells expressing interferon (IFN)γ and tumor necrosis factor (TNF)α. SIRT1 expression by T cells significantly associated with FEV1 (R = 0.655, P = 0.006) and with time posttransplant (R = -0.552, P = 0.041). All treatments upregulated SIRT1 and inhibited IFNγ and TNFα production by T, NK, and NKT-like cells additively. BOS is associated with decreased SIRT1 in peripheral blood proinflammatory T, NK, and NKT-like lymphocytes following lung transplant. Treatment options that increase SIRT1 may improve graft survival.

NKT-Like (CD3+CD56+) Cells in Chronic Myeloid Leukemia Patients Treated With Tyrosine Kinase Inhibitors.

Therapy with Tyrosine Kinase Inhibitors (TKI) aiming stable deep molecular response is the gold standard to treat Chronic Myeloid Leukemia (CML). NKT-like cells (CD3+CD56+) combine characteristics of T and NK cells. The physiopathological role of these cells remains unknown although the literature refers their association with inflammation, autoimmune diseases, and cancer. Since the information regarding the role of NKT-like cells in CML is rare, we aimed at the characterization of these cells in CML patients treated with TKIs. Peripheral blood NKT-like cells from 48 CML patients and 40 healthy donors were analyzed by multiparametric flow cytometry. Functional tests consisting of co-culture with leukemic target cells (K562 cell line) were used to measure degranulation and cytokine production. Our results revealed that NKT-like cells are decreased in treated CML patients, although they present increased expression of activation markers (CD69 and HLA-DR), increased degranulation (CD107a) and impaired IFN-γ production. Significantly alterations on the expression of tumor recognition (NCRs and NKp80), and immune regulation receptors (LAG-3, TIM-3, and CD137) by NKT-like cells were observed in CML patients. Second generation TKIs increased cell activation (CD69) and decreased expression of NKp44 and NKp80 by NKT-like cells from CML patients when compared to Imatinib. CML patients that achieved deep molecular response (MR4.5) presented downregulation of NKp44 and LAG-3. Further studies are needed to clarify the role of these cells as biomarkers of therapy response and also to evaluate their value for discrimination of better candidates for sustained treatment-free remission after TKI discontinuation.

NK and NKT-like cells in granulomatous and fibrotic lung diseases.

Background The pathogenetic and regulatory roles of natural killer (NK) and natural killer T-like cells in interstitial lung diseases (ILDs), fibrotic and granulomatous of unknown etiology are unclear. Objectives Here we investigated NK and NKT-like cells in peripheral blood (PB) and Bronchoalveolar lavage (BAL) from patients with ILDs. Method 190 patients (94 male mean age 61 ± 14.3years) and 8 controls undergoing bronchoscopy for ILD diagnostic work-up were enrolled consecutively; 115 patients sarcoidosis, 24 chronic fibrotic hypersensitivity pneumonitis and 43 patients other ILDs [32 idiopathic pulmonary fibrosis (IPF) and 11 non-specific interstitial pneumonia (NSIP)]. PB and BAL were processed by flow cytometry using monoclonal antibodies to differentiate NK and NKT-like cells. Results NK% in BAL was significantly different among ILDs (p = 0.02). Lower NK% was observed in BAL from sarcoidosis than other ILDs (p < 0.05). Similar findings were observed for NKT-like, whereas no differences were found for PB NK%. Difference of NK% was observed between BAL and PB in all groups (p < 0.001). Sarcoidosis patients reported the best area under the curve for NKT-like (AUC = 0.678, p = 0.0015) and NK cells (AUC = 0.61, p = 0.001). In the IPF-NSIP subgroup, NK% cell was inversely correlated with FVC% (r = - 0.34, p = 0.03) and DLCO% (r = - 0.47, p = 0.0044). Conclusions NK and NKT-like were expressed differently in BAL from patients with different ILD and were significantly depleted in sarcoidosis respect to other ILDs. This suggests that these cells may play a protective role in the pathogenesis of sarcoidosis.

Mouse CD8+NKT-like cells exert dual cytotoxicity against mouse tumor cells and myeloid-derived suppressor cells

Our previous work has demonstrated the high efficiency of CD8+ natural killer T (NKT)-like cells in killing antigen-bearing dendritic cells. To evaluate their role in the tumor microenvironment, we performed in vitro and in vivo antitumor experiments to investigate whether CD8+NKT-like cells could kill Yac-1 and B16 cells like NK cells and kill EL4-OVA8 cells in an antigen-specific manner like cytotoxic T lymphocytes (CTLs). Unlike NK1.1−CTLs, CD8+NKT-like cells also exhibit the capability to kill myeloid-derived suppressor cells (MDSCs) in an antigen-specific manner, indicative of their potential role in clearing tumor antigen-bearing MDSCs to improve the antitumor microenvironment. In vitro blocking experiments showed that granzyme B inhibitor efficiently suppressed the cytotoxicity of CD8+NKT-like cells against tumor cells and MDSCs, while Fas ligand (FasL) or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) inhibition failed to produce similar effects. Transcriptomic and phenotypic analyses of CD8+NKT-like cells, NK cells, and NK1.1−CTLs indicated that CD8+NKT-like cells expressed both T-cell activation markers and NK cell markers, thus bearing features of both the activated T cells and NK cells. Taken together, CD8+NKT-like cells could exert NK- and CTL-like antitumor effects through the elimination of both tumor cells and MDSCs in a granzyme B-dependent manner.

Characterization of circulating T-, NK-, and NKT cell subsets in patients with colorectal cancer: the peripheral blood immune cell profile

ObjectiveAs the development and progression of colorectal cancer (CRC) are known to be affected by the immune system, cell subsets such as T cells, natural killer (NK) cells, and natural killer T (NKT) cells are considered interesting targets for immunotherapy and clinical biomarker research. Until now, the role of systemic immune profiles in tumor progression remains unclear. In this study, we aimed to characterize the immunophenotype of circulating T cells, NK cells, and NKT-like cells in patients with CRC, and to subsequently correlate these immunophenotypes to clinical follow-up data.MethodsUsing multiparameter flow cytometry, the subset distribution and immunophenotype of T cells (CD3+CD56−), CD56dim NK cells (CD3−CD56dim), CD56bright NK cells (CD3−CD56bright), and NKT-like (CD3+CD56+) cells were investigated in peripheral blood mononuclear cell (PBMC) samples from 71 CRC patients and 19 healthy donors.ResultsCRC patients showed profound differences in immune cell subset distribution and their immunophenotype compared to healthy donors, as characterized by increased percentage of regulatory T cells, and reduced expression level of the natural cytotoxicity receptors NKp44 and NKp46 on both CD56dim NK cells and NKT-like cells. Finally, we showed in a multivariate analysis that above-median percentage of CD16+ NKT-like cells was independently associated with shorter disease-free survival in CRC patients.ConclusionThe altered phenotype of circulating immune cell subsets in CRC and its association with clinical outcome highlight the potential use of PBMC subsets as prognostic biomarkers in CRC, thereby contributing to better insight into the role of systemic immune profiles in tumor progression.

Cytotoxic Function and Cytokine Production of Natural Killer Cells and Natural Killer T-Like Cells in Systemic Lupus Erythematosis Regulation with Interleukin-15.

Natural killer cells and NKT-like cells are the first line immune defense against tumor and virus infection. Deficient NK and NKT-like cell effector function may contribute to increased susceptibility to infection in SLE patients. We sought to examine the perforin and granzyme B expression, interferon-gamma (IFN-γ), and tumor-necrosis factor-alpha (TNF-α) production and CD107a degranulation of NK and NKT-like cells from SLE patients and their regulation by IL-15. We established that (1) perforin expression on SLE NK cells was decreased but unrelated to disease activity; (2) the MFI of granzyme B was increased in NK cells from SLE patients with active disease, associated with increased percentages of granzyme B+ CD56bright NK cells; (3) NK cells from active SLE patients, both CD56dim and CD56bright NK subsets, produced higher IFN-γ compared to controls; (4) CD56dim, but not CD56bright NK cells from active SLE patients, produced lower TNF-α, compared to inactive SLE patients and controls; (5) CD107a degranulation of SLE NK cells was comparable to controls; (6) IL-15 enhanced perforin/granzyme B expression, IFN-γ/TNF-α production, and CD107a degranulation of NK cells from SLE patients; and (7) similar observations were found for CD56+CD3+ NKT-like cells. Taken together, we demonstrated the differential expression of the heightened granzyme B and decreased TNF-α in NK and NKT-like cells in SLE patients. Higher granzyme B expression of NK and NKT-like cells in active SLE patients, further enhanced by circulating IL-15, may contribute to the maintenance of inflammation in SLE.

Circulating NK cell subsets and NKT‑like cells in renal transplant recipients with acute T‑cell‑mediated renal allograft rejection.

Emerging evidence indicates that natural killer (NK) cells and NKT-like cells may affect allograft outcomes following solid organ transplantation. However, the roles of these cells in allograft acceptance and dysfunction are controversial. To assess the changes in NK cell and CD3+CD56+ NKT-like cell frequency and phenotype in renal allograft recipients and to explore their associations with acute T-cell-mediated renal allograft rejection (ACR), longitudinal changes in NK and NKT-like cell frequency and phenotype were characterized using flow cytometry and immunohistochemistry in the peripheral blood and kidney allograft tissues in 142 recipients undergoing kidney transplantation. The serum concentrations of NK cell-associated cytokines were also detected by cytokine multiplex immunoassay. In contrast to the healthy controls, recipients with stable graft function exhibited increased proportions of CD56brightCD16dim subsets and decreased proportions of NKT-like cells in their peripheral blood mononuclear cells (PBMCs). Patients with ACR demonstrated increased proportions of NK cells, which were associated with increased CD3−CD56bright subsets and decreased CD3−CD56dim subsets, an increase in the CD56bright/CD56dim ratio in PBMCs and increased CD56+ NK cell infiltration in the kidney allograft, compared with the stable controls. In addition, there was a decreased proportion of NKT-like cells in patients with ACR, and an increased ratio of CD56bright/NKT-like cells compared with the stable controls. These differences appeared to be consistent with the increase in the serum concentrations of C-C motif chemokine 19 and the decrease in the serum concentrations of interleukin-15. These data indicate that CD56bright NK cells may promote the development of ACR, and that NKT-like cells may have immunoregulatory function. The results also imply that the CD56bright/CD56dim ratio may affect the ACR signatures.

Therapeutic Targeting Steroid Resistant Pro-Inflammatory NK and NKT-Like Cells in Chronic Inflammatory Lung Disease.

The innate immune system drives the initiation of inflammation and progression to chronic inflammation in two important chronic inflammatory lung diseases involving the small airways, chronic obstructive pulmonary disease (COPD) and bronchiolitis obliterans syndrome (BOS), following lung transplantation. Recently natural killer T cell like (NKT-like) cells, which represent a bridge between the innate and adaptive immune response as well as the innate natural killer cell (NK) cells, have been shown to be important cells in these two chronic lung diseases. Importantly these cells have been shown to be resistant to commonly used anti-inflammatory drugs such as glucocorticoids and as such their inflammatory nature has been difficult to suppress. Mechanisms leading to steroid resistance in both diseases has recently been shown. Glucocorticoids switch off inflammatory genes by first entering the cell and binding to glucocorticoid receptors (GCRs). The steroid-GCR complex must then be chaperoned into the nucleus via several heat shock proteins, where they engage histone deacetylase 2 to switch off pro-inflammatory gene transcription. Many of these mechanisms are altered in NK and NKT-like cells in COPD and BOS requiring novel intervention using combinations of currently available drugs. Evidence will be presented to show how these drugs can overcome these mechanisms of drug resistance ex vivo advising novel therapeutic strategies for the treatment these two important chronic inflammatory lung diseases.

The importance of the PD-1/PD-L1 pathway at the maternal-fetal interface

BackgroundOur goal with this study was to investigate the contribution of PD-1/PD-L1 immune-checkpoint pathway to maternal immunotolerance mechanisms.MethodsThirteen healthy pregnant women and 10 non-pregnant controls were involved in this project. PBMCs and DICs were isolated from peripheral blood and from decidual tissues. After the characterization of different immune cell subsets, we used fluorochrome-conjugated monoclonal antibodies to measure the expression level of PD-1, PD-L1, NKG2D, and CD107a molecules by flow cytometry.ResultsWe measured significant alternations in the proportion of decidual immune cell subsets compared to the periphery. Elevated PD-1 expression by decidual CD8+ T, CD4+ T, and NKT-like cells were also detected accompanied by the increased PD-L1 expression by decidual CD4+ T, Treg, NKT-like and CD56 + NK cell subsets compared to peripheral blood. The cytotoxic potential was significantly higher in PD-1- decidual immune cells compared to the periphery, however we measured a significantly lower cytotoxicity in the decidual PD-1+ CD8+ T cells compared with the peripheral subsets. An activation receptor NKG2D expression was decreased by the PD-1+ CD8+ T subsets in the first trimester compared to non-pregnant condition but the expression level of the decidual counterparts was significantly elevated compared to the periphery. The cytotoxic potential of decidual PD1/NKG2D double positive CD8+ T cells was significantly decreased compared to the peripheral subsets.ConclusionsBased on our results we assume that PD-1/PD-L1 pathway might have a novel role in the maintaining of the local immunological environment. Accompanied by NKG2D activating receptor this checkpoint interaction could regulate decidual CD8 Tc cell subsets and may contribute maternal immunotolerance.

NKT-like cells reveal higher than T lymphocytes expression of cellular protective proteins HSP70 and SOD2 and comparably increased expression of SIRT1 in the oldest seniors.

NKT-like cells are "non-classical", "CD1d-independent" NKT cells which represent highly differentiated, conventional T lymphocytes coexpressing several NK (natural killer) associated receptors. They are effector lymphocytes of both innate and adaptive immunity and simultaneously regulatory cells of the adaptive immune system. They reveal large granular lymphocyte morphology and can mediate both MHC-restricted and MHC-unrestricted cytotoxicity, secrete many cytokines and modulate Th1 immune responses. The aim of our study was to analyze the expression of proteins involved in cellular stress response: sirtuin 1 (SIRT1), heat shock protein 70 (HSP70) and manganese superoxide dismutase (SOD2) in NKT-like cells compared to T lymphocytes during ageing. The study involved three groups of participants: the oldest seniors (n = 25; aged over 85; mean age 88 ± 0.5 ys), the old (n = 30; aged under 85; mean age 76 ± 0.9 ys) and the young (n = 32; mean age 21 ± 0.3 ys). Whole blood samples were analyzed by flow cytometry to assess the NKT-like (CD3+CD56+) and T (CD3+) cell populations. The group of the oldest seniors differed from the other age groups by much higher percentage of both NKT-like cells and T lymphocytes expressing SIRT1, HSP70 and SOD2. The expression of these proteins correlated positively with the age of the participants. Interestingly, the significantly higher expression of the studied protective proteins; i.e. HSP70 and SOD2 was found in CD3+CD56+ cells compared to CD3+ lymphocytes and this phenomenon concerned all the studied age groups. These differences were not significant regarding the expression of SIRT1; however, the same tendency was noticeable. The analysis of CD3+ and CD3+CD56+ lymphocytes showed the increase in the number of NKT-like cells and decreased number of T cells in the process of ageing. The increased expression of cellular protective proteins SIRT1, HSP70 and SOD2 in NKT-like and T-lymphocytes of the oldest seniors seems to correspond to longevity and the observed correlations may suggest the involvement of these proteins in establishing cellular homeostasis specific for healthy ageing. Furthermore, the higher expression of the protective proteins in NKT-like cells compared to T lymphocytes may indicate their particular role in the interplay between innate and adaptive immunity responses during the process of ageing.

Diminished Frequency of Menstrual and Peripheral Blood NKT-Like Cells in Patients With Unexplained Recurrent Spontaneous Abortion and Infertile Women.

Systemic monitoring of immune system may not precisely outline the local immune status in the uterus. This survey is a continuation of our previous studies on potential usefulness of menstrual blood (MB) immunophenotyping as a tool for investigation of immunological disturbances in pregnancy-related disorders. Peripheral blood (PB) and MB from healthy fertile (n = 15), unexplained recurrent spontaneous abortion (URSA; n = 15), and unexplained infertile women (n = 8) were collected simultaneously in the second day of their menstrual cycle and frequency of natural killer T (NKT)-like cell subpopulations were assessed by flow cytometry. Menstrual blood of all experimental groups contained higher percentage of TCRαβ+, CD45RO+, and CD16- NKT-like cells compared to corresponding PB. Frequency of MB NKT-like cells in unexplained infertile participants was lower than fertile and URSA groups. Compared to normal participants, patients with URSA had lower frequency of PB TCRαβ+ and higher CD16+, while in infertile woman frequencies of PB CD45RO+, CD45RO-, CD16-, IL17+, and MB CD45RO+ NKT-like cells were lower. Although, PB and MB seemingly have the same histological nature, our results showed that MB contained different composition of NKT-like subsets with different cytokine profiles and could be viewed as one potential biological sample for evaluation of patients with infertility and URSA.

Cytotoxic lymphocytes in COPD airways: increased NK cells associated with disease, iNKT and NKT-like cells with current smoking

BackgroundCytotoxic lymphocytes are increased in the airways of COPD patients. Whether this increase is driven primarily by the disease or by smoking is not clear, nor whether it correlates with the rate of decline in lung function.MethodsBronchoscopy with BAL was performed in 52 subjects recruited from the longitudinal OLIN COPD study according to pre-determined criteria; 12 with COPD and a rapid decline in lung function (loss of FEV1 ≥ 60 ml/year), 10 with COPD and a non-rapid decline in lung function (loss of FEV1 ≤ 30 ml/year), 15 current and ex-smokers and 15 non-smokers with normal lung function. BAL lymphocyte subsets were determined using flow cytometry.ResultsIn BAL fluid, the proportions of NK, iNKT and NKT-like cells all increased with pack-years. Within the COPD group, NK cells – but not iNKT or NKT-like cells – were significantly elevated also in subjects that had quit smoking. In contrast, current smoking was associated with a marked increase in iNKT and NKT-like cells but not in NK cells. Rate of lung function decline did not significantly affect any of the results.ConclusionsIn summary, increased proportions of NK cells in BAL fluid were associated with COPD; iNKT and NKT-like cells with current smoking but not with COPD. Interestingly, NK cell percentages did not normalize in COPD subjects that had quit smoking, indicating that these cells might play a role in the continued disease progression seen in COPD even after smoking cessation.Trial registrationClinicaltrials.gov identifier NCT02729220.

Unusual expansion of CD3+CD56+ natural killer T-like cells in peripheral blood after anticytokine treatment for graft-versus-host disease

Rationale:Basiliximab and etanercept have achieved promising responses in steroid-refractory graft versus host disease (SR-GVHD). However, the in vivo immune changes following the treatment have not been elucidated.Patient concerns:A 14-year-old boy presented with skin rash and diarrhea 20 days after haploidentical hemotopoietic stem cell transplantation.Diagnoses:We made the diagnose of grade 3 acute GVHD with skin and gastrointestinal involvement.Interventions:After the failure of the first-line treatment with methylprednisolone, combined anti-cytokine therapies with basiliximab and etanercept were prescibed.Outcomes:He achieved complete remission by basiliximab and etanercept. Furthermore, we detected that donor CD3+CD56+ Natural killer T(NKT)-like cells expanded gradually after the period of lymphocytopenia caused by GVHD and anti-cytokine therapy. The expansion of NKT-like cells was in association with high serum IFN-γ. NKT-like cells showed preferred proliferation in response to IFN-γ and potent cytotoxicity against leukemia cells. The expansion persisted > 2 years and the patient had a leukemia-free survival of 66 months.Lessons:Our case indicated that combined anti-cytokine treatment may reset the immune system and cause NKT-like cells to exhibit a predilection for expansion.

Deviations in Peripheral Blood Cell Populations are Associated with the Stage of Primary Biliary Cholangitis and Presence of Itching

To evaluate the role of Th17, Treg cells, activated T CD3+ and B CD19+ lymphocytes in primary biliary cholangitis (PBC) patients. 40 female patients with PBC and 20 healthy donors were enrolled in this study. The percentages and absolute counts of Th17, Treg, activated T CD3+, B CD19+, NK, NKT-like lymphocytes were measured by flow cytometry. Our research revealed significantly lower frequencies and absolute counts of CD4+CD25+FOXP3+ Treg cells (p < 0.0001), higher percentages and absolute counts of Th17 cells (IL-17A+CD3+CD4+; p < 0.0001 and p = 0.009, respectively), CD3−/CD16+CD56+ NK cells (p < 0.0001 and p = 0.039, respectively), CD3+/CD16+CD56+ NKT-like cells (p < 0.0001 and p = 0.048, respectively). There were also higher percentages and numbers of B CD19+ lymphocytes (p = 0.002 and p = 0.001, respectively) and higher percentages and absolute counts of activated B CD19+CD25+ cells (p = 0.007 and p = 0.002, respectively). Moreover, we observed a statistically significant correlation between the presence of itching and particular peripheral blood subpopulations in PBC patients. Absolute counts of both CD4+CD3+ cells (p = 0.0119) and CD3+CD25+ cells (p = 0.0329) were lower in patients with pruritus. A similar dependency was noted in reference to percentages of NKT-like cells (CD3+/CD16+CD56+; p = 0.0359) and (CD3+) T lymphocytes (p = 0.0302). Th17 and Treg cells are involved in the course of PBC. There is also the association between the pruritus and peripheral blood subpopulations.