scholarly journals Sildenafil Citrate Downregulates PDE5A mRNA Expression in Women with Recurrent Pregnancy Loss without Altering Angiogenic Factors—A Preliminary Study

2021 ◽  
Vol 10 (21) ◽  
pp. 5086
Author(s):  
Monika Kniotek ◽  
Aleksander Roszczyk ◽  
Michał Zych ◽  
Małgorzata Wrzosek ◽  
Monika Szafarowska ◽  
...  

In our previous study, we showed that sildenafil citrate (SC), a selective PDE5A blocker, modulated NK cell activity in patients with recurrent pregnancy loss, which correlated with positive pregnancy outcomes. It was found that NK cells had a pivotal role in decidualization, angiogenesis, spiral artery remodeling, and the regulation of trophoblast invasion. Thus, in the current study, we determined the effects of SC on angiogenic factor expression and production, as well as idNK cell activity in the presence of nitric synthase blocker L-NMMA. Methods: NK cells (CD56+) were isolated from the peripheral blood of 15 patients and 15 fertile women on MACS columns and cultured in transformation media containing IL-15, TGF-β, and AZA—a methylation agent—for 7 days in hypoxia (94% N2, 1% O2, 5% CO2). Cultures were set up in four variants: (1) with SC, (2) without SC, (3) with NO, a synthase blocker, and (4) with SC and NO synthase blocker. NK cell activity was determined after 7 days of culturing as CD107a expression after an additional 4h of stimulation with K562 erythroleukemia cells. The expression of the PDE5A, VEGF-A, PIGF, IL-8, and RENBP genes was determined with quantitative real-time PCR (qRT-PCR) using TaqMan probes and ELISA was used to measure the concentrations of VEGF-A, PLGF, IL-8, Ang-I, Ang-II, IFN–γ proteins in culture supernatants after SC supplementation. Results: SC downregulated PDE5A expression and had no effect on other studied angiogenic factors. VEGF-A expression was increased in RPL patients compared with fertile women. Similarly, VEGF production was enhanced in RPL patients’ supernatants and SC increased the concentration of PIGF in culture supernatants. SC did not affect the expression or concentration of other studied factors, nor idNK cell activity, regardless of NO synthase blockade.

2015 ◽  
Vol 89 (15) ◽  
pp. 7932-7943 ◽  
Author(s):  
Tessa M. Campbell ◽  
Brian P. McSharry ◽  
Megan Steain ◽  
Barry Slobedman ◽  
Allison Abendroth

ABSTRACTNatural killer (NK) cell-deficient patients are particularly susceptible to severe infection with herpesviruses, especially varicella-zoster virus (VZV) and herpes simplex virus 1 (HSV-1). The critical role that NK cells play in controlling these infections denotes an intricate struggle for dominance between virus and NK cell antiviral immunity; however, research in this area has remained surprisingly limited. Our study addressed this absence of knowledge and found that infection with VZV was not associated with enhanced NK cell activation, suggesting that the virus uses specific mechanisms to limit NK cell activity. Analysis of viral regulation of ligands for NKG2D, a potent activating receptor ubiquitously expressed on NK cells, revealed that VZV differentially modulates expression of the NKG2D ligands MICA, ULBP2, and ULBP3 by upregulating MICA expression while reducing ULBP2 and ULBP3 expression on the surface of infected cells. Despite being closely related to VZV, infection with HSV-1 produced a remarkably different effect on NKG2D ligand expression. A significant decrease in MICA, ULBP2, and ULBP3 was observed with HSV-1 infection at a total cellular protein level, as well as on the cell surface. We also demonstrate that HSV-1 differentially regulates expression of an additional NKG2D ligand, ULBP1, by reducing cell surface expression while total protein levels are unchanged. Our findings illustrate both a striking point of difference between two closely related alphaherpesviruses, as well as suggest a powerful capacity for VZV and HSV-1 to evade antiviral NK cell activity through novel modulation of NKG2D ligand expression.IMPORTANCEPatients with deficiencies in NK cell function experience an extreme susceptibility to infection with herpesviruses, in particular, VZV and HSV-1. Despite this striking correlation, research into understanding how these two alphaherpesviruses interact with NK cells is surprisingly limited. Through examination of viral regulation of ligands to the activating NK cell receptor NKG2D, we reveal patterns of modulation by VZV, which were unexpectedly varied in response to regulation by HSV-1 infection. Our study begins to unravel the undoubtedly complex interactions that occur between NK cells and alphaherpesvirus infection by providing novel insights into how VZV and HSV-1 manipulate NKG2D ligand expression to modulate NK cell activity, while also illuminating a distinct variation between two closely related alphaherpesviruses.


Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 557
Author(s):  
Xuewen Deng ◽  
Hiroshi Terunuma ◽  
Mie Nieda

Natural killer (NK) cells are cytotoxic immune cells with an innate capacity for eliminating cancer cells and virus- infected cells. NK cells are critical effector cells in the immunosurveillance of cancer and viral infections. Patients with low NK cell activity or NK cell deficiencies are predisposed to increased risks of cancer and severe viral infections. However, functional alterations of human NK cells are associated with lifestyles and aging. Personal lifestyles, such as cigarette smoking, alcohol consumption, stress, obesity, and aging are correlated with NK cell dysfunction, whereas adequate sleep, moderate exercise, forest bathing, and listening to music are associated with functional healthy NK cells. Therefore, adherence to a healthy lifestyle is essential and will be favorable for immunosurveillance of cancer and viral infections with healthy NK cells.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Yan Feng ◽  
Yan Li ◽  
Ying Zhang ◽  
Bo-Hao Zhang ◽  
Hui Zhao ◽  
...  

Abstract Background Brain ischemia compromises natural killer (NK) cell-mediated immune defenses by acting on neurogenic and intracellular pathways. Less is known about the posttranscriptional mechanisms that regulate NK cell activation and cytotoxicity after ischemic stroke. Methods Using a NanoString nCounter® miRNA array panel, we explored the microRNA (miRNA) profile of splenic NK cells in mice subjected to middle cerebral artery occlusion. Differential gene expression and function/pathway analysis were applied to investigate the main functions of predicted miRNA target genes. miR-1224 inhibitor/mimics transfection and passive transfer of NK cells were performed to confirm the impact of miR-1224 in NK cells after brain ischemia. Results We observed striking dysregulation of several miRNAs in response to ischemia. Among those miRNAs, miR-1224 markedly increased 3 days after ischemic stroke. Transfection of miR-1224 mimics into NK cells resulted in suppression of NK cell activity, while an miR-1224 inhibitor enhanced NK cell activity and cytotoxicity, especially in the periphery. Passive transfer of NK cells treated with an miR-1224 inhibitor prevented the accumulation of a bacterial burden in the lungs after ischemic stroke, suggesting an enhanced immune defense of NK cells. The transcription factor Sp1, which controls cytokine/chemokine release by NK cells at the transcriptional level, is a predicted target of miR-1224. The inhibitory effect of miR-1224 on NK cell activity was blocked in Sp1 knockout mice. Conclusions These findings indicate that miR-1224 may serve as a negative regulator of NK cell activation in an Sp1-dependent manner; this mechanism may be a novel target to prevent poststroke infection specifically in the periphery and preserve immune defense in the brain.


1995 ◽  
Vol 79 (3) ◽  
pp. 732-737 ◽  
Author(s):  
S. J. Won ◽  
M. T. Lin

The effects of different ambient temperatures (Ta) on the splenic natural killer (NK) cell activity, effector-target cell conjugation activity, and NK cell numbers were assessed in male inbred C3H/HeNCrj mice (7–10 wk old). The splenic NK cytotoxic activities were examined in a 4-h 51Cr release assay in mouse spleen cells that were obtained 1, 2, 4, 8, or 16 days after exposure to Ta of 22, 4, or 35 degrees C. The percentage of conjugating lymphocytes was calculated by counting the number of single lymphocytes bound to single target cells per 400 effector cells. The numbers of NK cells were expressed by the percentage of 5E6-positive cells. The 5E6 identifies only a subset of NK cells. It was found that the splenic NK cell activity, the effector-target cell conjugation activity, or the NK cell number began to fall 1 day after cold (Ta 4 degrees C) or heat (Ta 35 degrees C) stress. After a 16-day period of either cold or heat exposure, the fall in the splenic NK cell activity, the effector-target cell conjugation activity, or the number of 5E6-positive subsets of NK cells was still evident. Compared with those of the control group (Ta 22 degrees C), the cold-stressed mice had higher adrenal cortisol concentration and lower colonic temperature, whereas the heat-stressed animals had higher adrenal cortisol concentration and higher colonic temperature during a 16-day period of thermal exposure. However, neither cold nor heat stress affected both the body weight gain and the spleen weight in our mice.


2020 ◽  
Vol 9 (1) ◽  
pp. 143 ◽  
Author(s):  
Cinzia Fionda ◽  
Helena Stabile ◽  
Cristina Cerboni ◽  
Alessandra Soriani ◽  
Angela Gismondi ◽  
...  

Transforming growth factor (TGF)-β is a central immunosuppressive cytokine within tumor microenvironment inhibiting the expansion and function of major cellular components of adaptive and innate immune system. Among them, compelling evidence has demonstrated that TGF-β is a key regulator of natural killer (NK) cells, innate lymphoid cells (ILCs) with a critical role in immunosurveillance against different kinds of cancer cells. A TGF-β rich tumor microenvironment blocks NK cell activity at multiple levels. This immunosuppressive factor exerts direct regulatory effects on NK cells including inhibition of cytokine production, alteration of activating/inhibitory receptor expression, and promotion of the conversion into non cytotoxic group I ILC (ILC1). Concomitantly, TGF-β can render tumor cells less susceptible to NK cell-mediated recognition and lysis. Indeed, accumulating evidence suggest that changes in levels of NKG2D ligands, mainly MICA, as well as an increase of immune checkpoint inhibitors (e.g., PD-L1) and other inhibitory ligands on cancer cells significantly contribute to TGF-β-mediated suppression of NK cell activity. Here, we will take into consideration two major mechanisms underlying the negative regulation of ILC function by TGF-β in cancer. First, we will address how TGF-β impacts the balance of signals governing NK cell activity. Second, we will review recent advances on the role of this cytokine in driving ILC plasticity in cancer. Finally, we will discuss how the development of therapeutic approaches blocking TGF-β may reverse the suppression of host immune surveillance and improve anti-tumor NK cell response in the clinic.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3870-3870 ◽  
Author(s):  
Don Benson ◽  
Courtney E Bakan ◽  
Shuhong Zhang ◽  
Lana Alghothani ◽  
Jing Liang ◽  
...  

Abstract Abstract 3870 Poster Board III-806 Background NK cell activity against tumor cells is regulated by a balance of inhibitory and activating signals mediated by receptors on NK cells that recognize inhibitory and activating ligands expressed by cancer cells. IPH2101 (1-7F9) is a novel monoclonal anti-inhibitor KIR blocking antibody that has been shown to augment NK cell function against MM targets. Moreover, lenalidomide has been shown to expand and activate NK cells in vivo and in vitro. We have previously reported that the combination of IPH2101 and lenalidomide enhances NK cell mediated cytotoxicity against MM cells compared to each agent alone (Zhang et al., AACR 2009). We expand our studies to investigate potential mechanisms for the enhancement of NK cell activity by the combination of IPH2101 and lenalidomide. Methods The effects of IPH2101 and lenalidomide alone and in combination were studied using primary human NK cells from healthy donors as well as from MM patients. The MM cell lines U266 and RPMI 8226 as well as primary tumor cells from marrow aspirates of MM patients served as target cells. The effect of lenalidomide on MM activating and inhibitory ligand expression was studied by flow cytometry. NK cell trafficking was investigated with standard transwell plate migration assay. Immune complex formation between NK cell effectors and MM tumor targets was characterized by flow cytometry in control conditions and with NK cells pre-treated with IPH2101 and lenalidomide. The effects of IPH2101 and lenalidomide were studied regarding interferon-gamma and granzyme B production by ELISPOT and target-specific cytotoxicity studies were conducted to complement effector-based assays. Results IPH2101 (30 ug/ml) significantly enhanced cytotoxicity against U266 cells and primary MM tumor cells by both purified NK cells at effector:target (E:T) ratios of 10:1 or less, and also of freshly isolated peripheral blood mononuclear cells (PBMC) at E:T ratios of 60:1 or less, from more than 10 random donors. In addition, treatment of PBMC with 5-10 μmol/L lenalidomide for 72h without interleukin (IL)-2 increased NK cell lysis of U266. Treatment of PBMC from normal donors did not enhance the expression of the NK receptors KIR, NKG2D, NCR, TRAIL, and DNAM-1. Incubation of U266 cells with lenalidomide (5 uM) for 3-5 days resulted in significant enhancement of cytotoxicity by normal donor NK cells. This was associated with upregulation of the activating ligands, MICA, ULBP-2, DR4, and CD112. Using blocking antibodies to NKG2D, TRAIL, and DNAM-1, lenalidomide enhancement of MM cell killing was abrogated indicating the importance of the modulation of the ligands to the latter receptors by lenalidomide. Although IPH2101 and lenalidomide did not significantly increase NK cell migration into normal media, migration was enhanced 2.98-fold (+/− 0.36, p < 0.05) towards U266 cell targets (n= 3, p < 0.05) and MM patient serum 3.2-fold (+/− 0.4, n=3, p < 0.05). IPH2101 and lenalidomide also led to a 2.3-fold (+/− 0.43, p < 0.05) increase in immune complex formation between NK cells and MM tumor cells. IPH2101 and lenalidomide also augmented NK cell interferon gamma production against MM (control mean 303 spots/well +/− 13 versus 525 +/− 83, n=3, p < 0.05) and granzyme B production (control mean 115 +/− 98 versus 449 +/−72, n=3, p < 0.05). Importantly, in all experiments described herein, the effects of IPH2101 and lenalidomide together were greater than either agent alone. Conclusions Taken together, our data suggest that IPH2101 and lenalidomide may exert complementary mechanisms on both effector and target cells to enhance NK cell mediated killing of MM cells. Moreover, these agents have no predicted clinical cross-toxicities. A single-agent phase 1 clinical trial of IPH2101 has shown the mAb to be safe and well tolerated in MM patients. These findings support a phase 1/2 clinical trial of IPH2101 with lenalidomide as a first dual-innate immunotherapy for patients with MM. Disclosures: Andre: Innate Pharma: Employment. Squiban:Innate pharma: Employment. Romagne:Innate Pharma: Employment.


2017 ◽  
Vol 91 (22) ◽  
Author(s):  
Elisabeth Littwitz-Salomon ◽  
Simone Schimmer ◽  
Ulf Dittmer

ABSTRACT Natural killer (NK) cells are part of the innate immune system and recognize virus-infected cells as well as tumor cells. Conflicting data about the beneficial or even detrimental role of NK cells in different infectious diseases have been described previously. While the type of pathogen strongly influences NK cell functionality, less is known about how the infection dose influences the quality of a NK cell response against retroviruses. In this study, we used the well-established Friend retrovirus (FV) mouse model to investigate the impact of virus dose on the induction of antiviral NK cell functions. High-dose virus inoculation increased initial virus replication compared to that with medium- or low-dose viral challenge and significantly improved NK cell activation. Antiviral NK cell activity, including in vivo cytotoxicity toward infected target cells, was also enhanced by high-dose virus infection. NK cell activation following high-dose viral challenge was likely mediated by activated dendritic cells (DCs) and macrophages and the NK cell-stimulating cytokines interleukin 15 (IL-15) and IL-18. Neutralization of these cytokines decreased NK cell functions and increased viral loads, whereas IL-15 and IL-18 therapy improved NK cell activity. Here we demonstrate that virus dose positively correlates with antiviral NK cell activity and function, which are at least partly driven by IL-15 and IL-18. Our results suggest that NK cell activity may be therapeutically enhanced by administering IL-15 and IL-18 in virus infections that inadequately activate NK cells. IMPORTANCE In infections with retroviruses, like HIV and FV infection of mice, NK cells clearly mediate antiviral activities, but they are usually not sufficient to prevent severe pathology. Here we show that the initial infection dose impacts the induction of an antiviral NK cell response during an acute retroviral infection, which had not investigated before. High-dose infection resulted in a strong NK cell functionality, whereas no antiviral activities were detected after low- or medium-dose infection. Interestingly, DCs and macrophages were highly activated after high-dose FV challenge, which corresponded with increased levels of NK cell-stimulating cytokines IL-15 and IL-18. IL-15 and IL-18 neutralization decreased NK cell functions, whereas IL-15 and IL-18 therapy improved NK cell activity. Here we show the importance of cytokines for NK cell activation in retroviral infections; our findings suggest that immunotherapy combining the well-tolerated cytokines IL-15 and IL-18 might be an interesting approach for antiretroviral treatment.


2020 ◽  
Vol 8 ◽  
Author(s):  
Marvin Huynhle ◽  
Kawaljit Kaur

Obesity has been known for years to be a major health problem. Rates of obesity have been steadily increasing all over the world. Many factors, including healthy eating habits and exercise, play important roles in controlling obesity. In our study, we compared the function of cells of the immune system called natural killer (NK) cells between healthy and obese groups of mice. We found that obese mice have lower numbers of NK cells and that NK cells from obese mice are less functional. Lower NK cell activity is related to a higher risk of infections and cancer in the obese group. This research could show a relationship between what we eat and our ability to defend ourselves against diseases like cancer.


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