Peripheral Natural Killer Research Articles

CD56brightCD16- to CD57+CD56dimCD16+ NK cell ratio discriminates disease activity and renal involvement in patients with systemic lupus erythematosus.

We aimed to discriminate subpopulations of peripheral natural killer (NK) cells of patients with systemic lupus erythematosus (SLE) and evaluate their usability in monitoring disease activity. The total number of NK cells and their subpopulations were determined by flow cytometry in 68 patients with SLE and 35 healthy controls. Clinical data were extracted from medical records, including serum anti-double-stranded-DNA (anti-dsDNA), complement C3 and C4, and urine protein. Disease activity in patients with SLE was assessed using the SLE Disease Activity Index-2000 (SLEDAI-2K). The percentages and absolute numbers of NK cells decreased, and the proportions of three major NK cell subsets defined by cell maturation status altered in SLE patients. The frequency of CD56brightCD16- NK (immature, Im NK) cells increased, while that of the CD57+CD56dimCD16- subset (mature, more differentiated, MD NK) decreased in patients with high-activity SLE, resulting in a significant increase in the Im NK-to-MD NK ratio as compared with that in patients with low-activity SLE. The area under the receiver operating characteristic curve indicated that the ratio was 0.722 in severe SLE and 0.773 in lupus nephritis, with optimal cut-off levels of 0.075 and 0.108, respectively. The ratio correlated positively with the SLEDAI-2K score, proteinuria, and serum anti-dsDNA antibody levels but negatively with C3 and C4 levels. Our data indicate that the imbalance in Im NK and MD NK cells may play a role in lupus development and serve as a predictive biomarker to assess disease activity and renal involvement in patients with SLE.

Establishment of an efficient ex vivo expansion strategy for human natural killer cells stimulated by defined cytokine cocktail and antibodies against natural killer cell activating receptors

IntroductionCell-based immunotherapy is categorized as a regenerative therapy under the Regenerative Medicine Safety Act in Japan. Natural killer (NK) cell-based immunotherapy is considered a promising strategy for treating cancer, including glioblastoma (GBM). We previously reported an expansion method for highly purified human peripheral blood-derived NK cells using a cytokine cocktail. Here, we aimed to establish a more efficient NK cell expansion method as compared to our previously reported method.MethodsT cell-depleted human peripheral blood mononuclear cells (PBMCs) were isolated from three healthy volunteers. The depleted PBMCs were cultured in the presence of recombinant human interleukin (rhIL)-18 and high-dose rhIL-2 in anti-NKp46 and/or anti-CD16 antibody immobilization settings. After 14 days of expansion, the purity and expansion ratio of CD3-CD56+ NK cells were determined. The cytotoxicity-mediated growth inhibition of T98G cells (an NK activity-sensitive GBM cell line) was evaluated using a non-labeling, impedance-based real-time cell analyzer.ResultsAnti-NKp46 stimulation increased the NK cell purity and expansion ratio as compared to the non-antibody-stimulated population. Anti-CD16 stimulation weakly enhanced the NK cell expansion ratio of the non-antibody-stimulated population and enhanced the NK cell purity and expansion ratio of anti-NKp46-stimulated populations. All NK cell-containing populations tested distinctly inhibited T98G cell growth. These effects tended to be enhanced in an NK cell purity-dependent manner. In some cases, anti-CD16 stimulation decreased growth inhibition of T98G cell compared to other conditions despite the comparable NK cell purity.ConclusionsWe established a robust large-scale feeder-free expansion system for highly purified human NK cells using a defined cytokine cocktail and anti-NK cell activating receptor antibodies. The expansion system could be feasible for autologous or allogeneic NK cell-based immunotherapy of GBM. Moreover, it is easily controlled under Japanese law on regenerative medicine.

Plasticity of natural killer cells in pregnant patients infected with SARS-CoV-2 and their neonates during childbirth.

The COVID-19 pandemic has occurred due to infection caused by the SARS-CoV-2 coronavirus, which impacts gestation and pregnancy. In SARS-CoV-2 infection, only very rare cases of vertical transmission have been reported, suggesting that fetal immune imprinting due to a maternal infection is probably a result of changes in maternal immunity. Natural killer (NK) cells are the leading maternal immune cells that act as a natural defense system to fight infections. They also play a pivotal role in the establishment and maintenance of pregnancy. While peripheral NK cells display specific features in patients infected with SARS-CoV-2 in the general population, information remains elusive in pregnant mothers and neonates. In the present study, we analyzed the characteristics of NK cells isolated from both neonatal umbilical cord blood and maternal peripheral blood close to the time of delivery. Phenotype and functions were compared in 18 healthy pregnant women and 34 COVID-19 patients during pregnancy within an ongoing infection (PCR+; N = 15) or after recovery (IgG+PCR−; N = 19). The frequency of NK cells from infected women and their neonates was correlated with the production of inflammatory cytokines in the serum. The expression of NKG2A and NKp30, as well as degranulation of NK cells in pregnant women with ongoing infection, were both negatively correlated to estradiol level. Furthermore, NK cells from the neonates born to infected women were significantly decreased and also correlated to estradiol level. This study highlights the relationship between NK cells, inflammation, and estradiol in patients with ongoing infection, providing new insights into the impact of maternal SARS-CoV-2 infection on the neonate.

P-394 Peripheral and uterine natural killer cell cut-off levels and their correlation in fertile controls and women with unexplained recurrent implantation failure (RIF)

Abstract Study question What is cut-off value for peripheral and uterine natural killer (pNK, uNK) cells and any correlation between them in fertile and RIF women? Summary answer Cut-off values were 7% for uNK and 11.6% for pNK in fertile controls. No significant correlation observed among fertile and infertile women with RIF. What is known already Association of uNK and pNK cells with infertility is debatable. It is not clear whether measuring NK cell levels in RIF has a role. pNk cell levels however has been used in various studies to guide the need of immunotherapy in RIF women. Definition of normal range of uNK cell numbers has also not been stated clearly because of lack of standardised protocol. Literature reveals the cut off values for pNk cells to be 12% or 18% and for uNK cells between 5-12.9%. Correlation between uNK and pNK cells in fertile or RIF women has not been studied earlier. Study design, size, duration A prospective study was conducted at ART Centre, Department of Obstetrics and Gynecology at tertiary care institute during a period from January 2019 to January 2021. Thirty women with RIF and fifty fertile controls with age <35 years having regular menstrual cycles and no hormonal treatment in last 3 months were enrolled in the study for uNK and pNK cell testing. The permission was obtained from the Institute Ethics Committee. Participants/materials, setting, methods Subjects included women with RIF with age 20-35 years, tubal and unexplained factors, normal ovarian reserve, normal karyotype and normal uterine cavity. In both subjects and controls, midluteal endometrial biopsy sample was taken for Immunohistochemistry staining of CD 56+ cells to determine uNK cells. Peripheral venous blood was also obtained at the time of biopsy for flow cytometry in peripheral blood mononuclear cells to determine pNK cells. Cut off values were derived from fertile controls. Main results and the role of chance The mean age and BMI were comparable between fertile control and study group(29.45±3.3 vs 31.17±3.3 years, 22.97±1.89 vs 23.21±2.2 kg/m2; p-value >0.05). The control group had median value of 7% for uNK cell levels and 11.6% for pNK cell levels. In RIF subjects, the median value for uNK cells was 13.5% and even though higher compared to controls it was not statistically significant(p-value >0.05) . The median pNK values were comparable among controls and RIF group (11.6% vs. 12%). All RIF subjects did not have elevated NK cell levels. 18 (60%) subjects had elevated uNK cell levels (more than 7%) whereas 40% had below the reference value. pNK cells were also elevated in only 53.3% of subject population. There was positive correlation found between uNK and pNK cell levels in RIF subjects, however it was not statistically significant (r 0.312, p-value 0.09). In fertile controls, there was insignificant negative correlation between uNK and pNK cell levels (r -0.231, p-value 0.33). Limitations, reasons for caution The small sample size is the foremost limitation of study. Wider implications of the findings uNK cell testing may be worthwhile in women with unexplained RIF so as to guide immunotherapy to improve pregnancy outcomes. As no significant correlation has been found between pNK and uNK cells in fertile and RIF women, pNK cell testing in RIF women may be done with caution. Trial registration number Not Applicable

Pbrm1 intrinsically controls the development and effector differentiation of iNKT cells.

Under static condition, the pool size of peripheral invariant natural killer T (iNKT) cells is determined by their homeostatic proliferation, survival and thymic input. However, the underlying mechanism is not fully understood. In the present study, we found that the percentage and number of iNKT cells were significantly reduced in the spleen, but not in the thymus of mice with deletion of polybromo‐1 (Pbrm1) compared to wild type (WT) mice. Pbrm1 deletion did not affect iNKT cell proliferation and survival, instead significantly impaired their development from stage 1 to stage 2. Importantly, loss of Pbrm1 led to a dysfunction of RORγt expression and iNKT17 cell differentiation, but not iNKT1 and iNKT2 proportion. Collectively, our study reveals a novel mechanism of Pbrm1 controlling the peripheral size of iNKT cells through regulating their development and differentiation.

Abstract 559: Targeting hematological malignancies and solid tumors with switchable chimeric antigen receptor-engineered iPSC-derived natural killer cells

Abstract Switchable chimeric antigen receptors (sCAR) provide an important new strategy to precisely regulate CAR-mediated anti-tumor activity. The sCAR system combines a CAR that recognizes peptide neoepitope (PNE) with an injectable “switch” molecule that consists of an anti-tumor Fab linked to PNE. Configurating PNE at different location or chain of the Fab enables us to identify best switches optimal for tumor targeting. Previous studies demonstrate that this sCAR system expressed in T cells provides tight control over anti-tumor activity. Here, we translated this approach to engineer natural killer (NK) cells with the sCAR to provide a universal, targeted cell-therapy approach in a patient-nonspecific manner. First, we engineered human induced pluripotent stem cells (iPSCs) with the sCAR combining the PNE-specific CAR scFv with our previously described NK cell optimized CAR4 signaling motifs consisting of the NKG2D transmembrane domain, 2B4 co-stimulatory domain and the CD3ζ chain. We selected clones that maintained highest level of pluripotency and most stable expression of the sCAR4 on the surface. Next, we generated mature sCAR4-expressing iPSC-derived NK cells that expressed common surface receptors similar to that of donor peripheral blood mononuclear cell-derived NK cells. We then used three panels of switches with specificity to CD19 (consisting of 9 different configurations), to CD33, CD123 and CLL1 (1 configuration each), and to FRIZZLED7 (FZD7; 6 configurations) to target CD19+ B cell lymphoma, acute myeloid leukemia (AML), and ovarian cancer, respectively. All three targets demonstrated switch-specific dose response in killing tumor cell lines. Different configurations conferred variable efficiencies in switch-mediating tumor cell killings and the optimal switch concentrations were found to be different from what was observed previously with sCAR-expressing T cells. In a comparison with the “conventional” (non-switchable) CARs (cCARs), iPSC-NK cells expressing either sCAR4 and treated with an anti-CD19 switch or iPSC-NK cells with an anti-CD19-cCAR4 demonstrated similar level of cytotoxicity against B cell leukemia cells. Finally, we have built a mouse model and are currently testing the iPSC-NK-sCAR system in vivo. Together, this iPSC-NK-sCAR strategy enables close control over CAR-mediated activity with flexibility to target multiple tumor types and a potential to become a novel off-the-shelf therapy. Citation Format: Xiao-Hua Li, Benjamin Goldenson, Jaya Lakshmi Thangaraj, Matthew Gynn, Diana Gumber, Myan Do, Karl Willert, Dan S. Kaufman. Targeting hematological malignancies and solid tumors with switchable chimeric antigen receptor-engineered iPSC-derived natural killer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 559.

Abstract 5215: MOA study of KD050, an anti-PD-1/IL-15 bi-functional antibody selectively targeted PD-1 positive tumor-infiltrating lymphocytes resulted in robust anti-tumor activity and low systemic toxicity

Abstract Anti-tumor efficacy, treated by immune checkpoint inhibitor (ICI) such as anti-PD-1/PD-L1 antibody or immunostimulatory cytokine IL-2 or IL-15, has been confirmed clinically in multiple cancer indications, but both treatments have some limitations. Only ~30% patients respond to ICI treatment, and cytokines have been associated with short half-lives and systemic toxicities. Kadmon has established a cytokine fusion antibody platform to synergize the antibody and cytokine anti-tumor activity, extend cytokine serum half-life and reduce systemic toxicity. One of novel asset in this platform is KD050, an anti-PD-1/IL-15 bi-functional antibody with strong PD-1 antagonist function, but lower lymphocyte stimulation enabled by a novel mutation on the IL-15. KD050 was designed to deliver PD-1-mediated, avidity-driven lymphocyte stimulation to PD-1+ tumor-infiltrating lymphocytes (TIL) while minimally affecting circulating peripheral natural killer (NK) cells and T cells. We have reported previously (SITC2020, Abstract ID: 573) that KD050 (also called mut-1N-IL-15/38B2) showed robust anti-tumor efficacy and low systemic toxicity to treat hPD-L1-CT26 tumor inoculated in hPD-1/hPD-L1 transgenic BALB/c mice. Here, we conducted the MOA study in the same animal model by treating the mice with vehicle, KD050, PD-1 antibody (38B2), non-target counterpart of KD050 (ntKD050) and combination of 38B2 and ntKD050. The peripheral blood, draining lymph nodes and tumors were isolated at day 7 after the treatment. Immune cell types were analyzed by FACS for all isolated samples, and Nanostring RNA sequence and IHC was performed for the isolated tumors. Compared to the other treatments, we observed significant higher effector memory CD8 T cells (EM CD8 T), expanded Granzyme B+ and CD8+ T cells, and high CD8/CD4 ratio in tumor when treated with KD050. Tumor Differential Gene Expression (DGE) analysis revealed that many lymphocyte markers were specific to KD050. Functional Enrichment by Gene Set Variation Analysis (GSVA) in tumor showed that many cell types especially CD8 T cells, cytotoxic cells and Th1 cells were statistically (p. adjust < 0.05) significant higher relative to other treatments. We further found that binding of KD050 to PD-1 mediated delivery of IL15 to PD-1+ T cells and the simultaneous binding of KD050 to PD-1 and IL-2 receptor βγ (IL-2Rβγ) resulted in enhanced potency of IL-2Rβγ activation and anti-tumor activity. In conclusion, we demonstrated that KD050 treatment activated different gene pathways which were unique from PD-1 monospecific antibody 38B2, ntKD050 alone or combined with 38B2. These findings indicated that KD050 may have potential to benefit patients that were not responsive to the PD-1/PD-L1 treatment or cytokine treatment. Citation Format: Zhanna Polonskaya, Tzu-Pei Chang, Stella Martomo, Xenia Luna, Zhikai Zhang, Stanley Ng, Alessandro Mora, Jeegar P. Patel, Dan Lu. MOA study of KD050, an anti-PD-1/IL-15 bi-functional antibody selectively targeted PD-1 positive tumor-infiltrating lymphocytes resulted in robust anti-tumor activity and low systemic toxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5215.

Abstract 2096: Natural killer cells inhibit CD4+ T cell mediated IL-9 production in head and neck Cancer

Abstract Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer in the world, yet 5 year survival remains poor for those with recurrence despite advances in treatment such as immunotherapy. Checkpoint blockade substantially improved survival in ~20% of recurrent and/or metastatic HNSCC patients. However, given the lack of efficacy in most patients, and the known immunosuppressive nature of HNSCC, exploring other potential immune cell therapeutic targets is of interest. Decreased natural killer (NK) as well as increased immunosuppressive CD4+ regulatory T cells (Tregs) in both peripheral blood and the tumor microenvironment are associated with a poor prognosis in HNSCC. We discovered that the anti-diabetes drug, metformin, which is also known to improve immune cell function, not only increases peripheral NK cells in HNSCC patients to the level of healthy controls, but also suppresses IL-9 secretion from NK cells. IL-9 has been implicated as a driving factor in allergic disease, a poor prognosis factor in hematologic malignancies, and an enhancer of T-reg immunosuppressive abilities. However, the function of IL-9 in solid tumors is poorly understood. Interestingly, upon depletion of CD56+ NK and NKT cells from peripheral blood mononuclear cells (PBMCs), there was a significant increase of IL-9 secretion. This effect was negated upon depletion of CD4+ T cells suggesting that NK cells may directly or indirectly inhibit CD4+ T cell IL-9 production. In order to understand potential consequences of IL-9 overproduction, we subjected HNSCC cell lines, which we demonstrated express IL9 receptor, to exogenous IL-9 which resulted in enhanced proliferation. We also found that IL-9 plasma levels are high in HNSCC patients compared to healthy controls corroborating a potential tumorigenic role for IL-9. In order to elucidate potential mechanism(s) by which NK/NKT cells regulate CD4+ T cell production, we performed single-cell RNAseq on PBMCs upon NK and NKT cell depletion. We also performed flow cytometry to identify specific CD4+ cell types responsible for increased IL-9 production and the consequential changes in other immune cell phenotypes upon the absence of NK/NKT cells. Understanding the role of IL-9 in HNSCC will be important for utilizing IL-9 as a potential marker for HNSCC prognosis as well as a possible target for future immunotherapy approaches. Citation Format: McKenzie Crist, Maria Lehn, Vinita Takiar, Trisha Wise-Draper. Natural killer cells inhibit CD4+ T cell mediated IL-9 production in head and neck Cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2096.

Several active components within MSCs secretome inhibit the IL-2-mediated effector functions of NK cells

Abstract Mesenchymal stem cells (MSCs) are well-known for their immunomodulatory functions in innate and adaptive immunity. Their functional diversity was verified in various disease model through paracrine mechanisms. MSCs-derived secretome consists of a variety of bioactive components such as nucleic acids, cytokines, chemokines, and small molecules. However, the effect of MSCs on natural killer (NK) cells activity is still controversial. In this study, we tried to identify active components within MSCs secretome possessing ability to affect NK cells activity and to investigate their action mechanisms. We found that MSCs secretome had no effect on survival and proliferation of NK-92 cells but specifically diminished cell activity, as evidenced by lower secretion of cytotoxic granules and effector cytokines and also reducing killing ability. This effect was reproduced in human peripheral NK cells equally. Moreover, seven candidates for modulating inflammation within MSCs secretome were identified via LC-MS/MS proteomic analysis. Interestingly, they are totally different factors from those known as MSC’s immunomodulatory factor. After treatment of neutralizing antibodies to each candidate, we observed that only three of the groups with neutralizing antibodies recovered cytokine secretion and cytotoxic ability of NK-92 cells. These findings suggest that MSCs secretome can inhibit the effector functions of NK cells via some particular molecules, which are increasing expression of inhibitory receptor CD96 on NK cells, consequently activating inhibitory signal. This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. 2021R1F1A1049630).

GPP (composition of Ganoderma lucidum polysaccharides and Polyporus umbellatus polysaccharides) protects against DSS-induced murine colitis by enhancing immune function and regulating intestinal flora

Previous study have demonstrated that a compound composed of water-soluable Ganoderma lucidum polysaccharides (GLP) and Polyporus umbellatus polysaccharides (PUP) in a ratio of 3:1 named GPP enhances innate immune function in mice through enhancing the function of macrophage cells and activity of natural killer (NK) cells. Here in our research, we further investigated the effect of GPP on the diversity and composition of intestinal flora, and explored its effect on colitis model mice. The immunoregulatory verification experiments of GPP were conducted in both normal and DSS-induced mice model. Our research showed that GPP increased the diversity of intestinal microorganisms in mice with the extension of administration time. Daily GPP intake attenuated DSS-induced colon injury, protected the splenic lymphocyte proliferation ability, enhanced the serum hemolysin synthesis, and increased peripheral phagocytes and NK cell activity in model mice. Comparisons of the predominant gene pathways of the bacterial microbiota showed that DNA repair and recombination, base mismatch repair pathways was stronger in GPP-treatment group than in control group, indicating the possible molecular mechanisms of immune function regulation. Our study showed that GPP regulated immune function in both health and colitis model, and had a positive effect on maintaining intestinal flora homeostasis.

Increased expression of TIGIT and KLRG1 correlates with impaired CD56bright NK cell immunity in HPV16-related cervical intraepithelial neoplasia

BackgroundThe onset and progression of cervical intraepithelial neoplasia (CIN) are closely associated with the persistent infection of high-risk HPV (especially type16), which is mainly caused by immune escape. Natural killer (NK) cells play an important role against virally infected cells and tumor cells through a fine balance of signals from multiple surface receptors. Overexpression of non-MHC-I specific inhibitory receptors TIGIT, KLRG1, Siglec-7, LAIR-1, and CD300a on NK cells correlates with cellular exhaustion and immune evasion, but these receptors have not been investigated in CIN. The aim of the present study was to examine the potential role of NK cell non-MHC-I specific inhibitory receptors expression in immune escape from HPV16(+)CIN patients.MethodsThe subset distribution, IFN-γ and TNF-α expression levels and immunophenotype of TIGIT, KLRG1, Siglec-7, LAIR-1, and CD300a of NK cells were investigated in peripheral blood mononuclear cell samples by flow cytometry from 82 women who were HPV16(+) with CIN grades 0, I, II–III or HPV(−) CIN 0. Immunohistochemistry was applied to detect the expression of ligands for NK receptors in the cervical tissues. HPV types were identified by PCR assays.ResultsThe HPV16(+) subjects with high-grade lesions had an increased number of circulating peripheral blood CD56bright NK cells with reduced functionality and IFN-γ secretion. The expression levels of the inhibitory molecules TIGIT and KLRG1 on CD56bright NK cells increased in parallel with increasing CIN grade. In addition, TIGIT and KLRG1 related ligands, Poliovirus receptor (PVR), N-Cadherin and E-Cadherin expression level was also elevated with increasing CIN grade.ConclusionsOur results suggest that up-regulation of the inhibitory TIGIT, KLRG1 and their ligands may negatively regulate cervical CD56bright NK-mediated immunity to HPV16 and contribute to the progression of CIN. These results may facilitate the development of early-warning immune predictors and therapeutic strategies for HPV16(+) CIN based on the TIGIT and KLRG1 inhibitory pathways of NK cells.

Allogeneic Expanded Human Peripheral NK Cells Control Prostate Cancer Growth in a Preclinical Mouse Model of Castration-Resistant Prostate Cancer.

Adoptive allogeneic natural killer (NK) cell therapy has shown promise in treating castration-resistant prostate cancer (CRPC), which is the terminal stage of prostate cancer (PCa) and incurable. Thus, we employed an efficient manufacturing method for the large-scale ex vivo expansion of high-quality NK cells from peripheral blood of healthy donors. In the present study, we evaluated the in vitro cytotoxicity of NK cells against human PCa cell lines and in vivo antitumor activity in a preclinical mouse model of CRPC. CCK-8 results demonstrated that the NK cells exerted potent cytotoxicity against all PCa cell lines in vitro. The NK cells were activated when cocultured with PCa C4-2 cells, evidenced by upregulation of the degranulation marker CD107a and secretion of cytokines (TNF-α and IFN-γ). In a xenograft mouse model of CRPC, the caliper, CT, and ultrasonography examination results showed that the size of tumors treated with NK cells was significantly smaller than that in the control group. Moreover, ultrasonography examination also indicated that the NK cell treatment evidently reduced the blood supply of the tumors and HE staining results demonstrated that the NK treatment increased the proportion of necrosis in the tumor specimen compared to PBS treatment. Meanwhile, the NK cell treatment did not cause significant serum IL-6 elevation. Therefore, our study suggested that the expanded NK cells exhibited significant cytotoxicity against PCa cell lines in vitro and excellent therapeutic efficacy against CRPC in a xenograft mouse model, which was of great value for the clinical treatment of CRPC.

Effect of Postoperative ω-3 Fatty Acid Immunonutritional Therapy on NK Cell Gene Methylation in Elderly Patients with Gastric Cancer.

This study aims to investigate the effect of ω-3 fatty acid immunonutritional therapy on natural killer (NK) cell gene methylation and function in elderly patients with gastric cancer. A total of 70 cases of elderly patients with gastric cancer were randomized into the ω-3 fatty acid group and placebo group, according to the type of nutritional support administered. The methylation status of the tumor necrosis factor (TNF)-α gene promoter in peripheral NK cells was detected by methylation specific polymerase chain reaction, and the TNF-α level in peripheral NK cells was detected by enzyme-linked immunosorbent assay. After 14 days of immunonutritional therapy with ω-3 fatty acid or placebo, patients in the ω-3 group had significantly higher average NK cell activity (0.27 vs. 0.24, P=0.013) and lower percentages of TNF-α gene promoter methylation (25.7% vs. 60%, P<0.05) than the placebo group. However, there were no significant differences in the concentration of albumin, prealbumin and TNF-α in serum, and the NK cell count between the ω-3 group and placebo group. The postoperative application of ω-3 fatty acid may improve the activity of NK cells, which is correlated to the methylation status of the TNF-α gene promoter.

CD158a+ /CD158b+ NK cell imbalance correlates with hypertension in patients with pre-eclampsia.

Preeclampsia, a pregnancy complication with hypertension and proteinuria, seriously threats the health and lives of the mother and the baby. The pathogenesis of pre-eclampsia remains incompletely understood. The role of peripheral natural killer cells (NK cells) in the pre-eclampsia is unclear. Flow cytometry was performed to detect the expression of CD158a (KIR2DL1) and CD158b (KIR2DL2/3) in peripheral NK cells of healthy pregnant women (HP) and patients with pre-eclampsia (PE). Differentially expressed genes (DEGs) in CD158a+ and CD158b+ NK cells were identified by RNA-sequencing and real-time PCR. Protein array analysis was used to identify altered protein levels in the serum of study participants. CD158a+ NK cell numbers were increased in the peripheral blood of patients while the number of CD158b+ NK cells was reduced. In addition, the percentage of CD158a+ NK cells within the peripheral NK subset was positively correlated with systolic blood pressure while the percentage of CD158b+ NK cells was negatively correlated with systolic blood pressure. RNA-seq and real-time PCR showed that the expression of ERAP2 and GCH1, the genes that regulate blood pressure and angiogenesis, was decreased in CD158a+ compared to CD158b+ NK cells. Consistently, the level of proteins involved in angiogenesis was altered in the serum of pre-eclampsia patients compared to healthy individuals. CD158a+ NK cells increased while CD158b+ NK cells decreased in the peripheral blood of patients with pre-eclampsia compared to healthy individuals. The change in the frequency of CD158a+ /CD158b+ NK cells is related to the increase in blood pressure.

A validated nomogram integrating baseline peripheral T-lymphocyte subsets and NK cells for predicting survival in stage I-IIIA non-small cell lung cancer after resection.

BackgroundAccurately predicting the risk of recurrence in stage I–IIIA non-small cell lung cancer (NSCLC) after resection is critical in the treatment process. This study aimed to establish a novel nomogram to identify patients with a risk of disease progression in stage I–IIIA lung cancer based on clinical characteristics, peripheral T-lymphocyte subsets, and CD16+56 natural killer (NK) cells.MethodsA total of 306 NSCLC patients from Shanghai Municipal Hospital of Traditional Chinese Medicine between 2010 and 2020 who met the inclusion and exclusion criteria between January 2011 and December 2020 were retrospectively reviewed. Patients were randomly assigned to the training cohort (206 patients) and the validation cohort (100 patients). A nomogram model was developed based on the results of multivariate Cox regression in the training cohort. The optimal cut-off values were determined by X-tile software. The bootstrap method was used to validate the nomogram. Receiver operating characteristics curves (ROC) and the area under the ROC curve (AUC) were used to compare prognostic factors. The concordance index (C-index) was calculated to determine the accuracy of the nomogram in predicting disease-free survival (DFS).ResultsGender, drinking history, TNM stage, and CD4+T/CD8+T were independent factors for DFS and were integrated into the model, while CD16+56 NK cells were not proven to be significant independent factors for DFS. The calibration curves for probability of 3- and 5-year DFS showed excellent agreement between predicted and actual survival. The C-index for the nomogram to predict DFS was 0.839 in the training cohort. The nomogram showed an excellent predictive performance in the training cohort (3-/5-year AUC: 0.860/0.847) and in the validation cohort (3-/5-year AUC: 0.726/0.748).ConclusionsWe developed a prognostic model which provided individual prediction of DFS for stage I–IIIA NSCLC patients after resection. This practical prognostic tool may help oncologists in clinical treatment planning.

Increased oxidative stress contributes to impaired peripheral CD56dimCD57+ NK cells from patients with systemic lupus erythematosus

BackgroundSystemic lupus erythematosus (SLE) is characterized by loss of immune tolerance and imbalance of immune cell subsets. Natural killer (NK) cells contribute to regulate both the innate and adaptive immune response. In this study, we aimed to detect alterations of peripheral NK cells and explore intrinsic mechanisms involving in NK cell abnormality in SLE.MethodsBlood samples from healthy controls (HCs) and patients with SLE and rheumatoid arthritis (RA) were collected. The NK count, NK subsets (CD56bright, CD56dimCD57−, and CD56dimCD57+), phenotypes, and apoptosis were evaluated with flow cytometer. Mitochondrial reactive oxygen species (mtROS) and total ROS levels were detected with MitoSOX Red and DCFH-DA staining respectively. Published data (GSE63829 and GSE23695) from Gene Expression Omnibus (GEO) was analyzed by Gene Set Enrichment Analysis (GSEA).ResultsTotal peripheral NK count was down-regulated in untreated SLE patients in comparison to that in untreated RA patients and HCs. SLE patients exhibited a selective reduction in peripheral CD56dimCD57+ NK cell proportion, which was negatively associated with disease activity and positively correlated with levels of complement(C)3 and C4. Compared with HCs, peripheral CD56dimCD57+ NK cells from SLE patients exhibited altered phenotypes, increased endogenous apoptosis and higher levels of mtROS and ROS. In addition, when treated with hydrogen peroxide (H2O2), peripheral CD56dimCD57+ NK cell subset was more prone to undergo apoptosis than CD56dimCD57− NK cells. Furthermore, this NK cell subset from SLE patients exhibited impaired cytotoxicity in response to activated CD4+ T cells in vitro.ConclusionOur study demonstrated a selective loss of mature CD56dimCD57+ NK cell subset in SLE patients, which may caused by preferential apoptosis of this subset under increased oxidative stress in SLE. The attenuated in vitro cytotoxicity of CD56dimCD57+ NK cells may contribute to the impaired ability of eliminating pathogenic CD4+ T cells in SLE.

Tofacitinib Suppresses Natural Killer Cells In Vitro and In Vivo: Implications for Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal and incurable neurodegenerative disease with few therapeutic options. However, the immune system, including natural killer (NK) cells, is linked to ALS progression and may constitute a viable therapeutic ALS target. Tofacitinib is an FDA-approved immunomodulating small molecule which suppresses immune cell function by blocking proinflammatory cytokine signaling. This includes the cytokine IL-15 which is the primary cytokine associated with NK cell function and proliferation. However, the impact of tofacitinib on NK activation and cytotoxicity has not been thoroughly investigated, particularly in ALS. We therefore tested the ability of tofacitinib to suppress cytotoxicity and cytokine production in an NK cell line and in primary NK cells derived from control and ALS participants. We also investigated whether tofacitinib protected ALS neurons from NK cell cytotoxicity. Finally, we conducted a comprehensive pharmacokinetic study of tofacitinib in mice and tested the feasibility of administration formulated in chow. Success was assessed through the impact of tofacitinib on peripheral NK cell levels in mice. We found tofacitinib suppressed IL-15-induced activation as measured by STAT1 phosphorylation, cytotoxicity, pro-inflammatory gene expression, and pro-inflammatory cytokine secretion in both an NK cell line and primary NK cells. Furthermore, tofacitinib protected ALS neurons from NK cell-mediated cytotoxicity. In mice, we found tofacitinib bioavailability was 37% in both male and female mice; using these data we formulated mouse containing low and high doses of tofacitinib and found that the drug suppressed peripheral NK cell levels in a dose-dependent manner. These results demonstrate that tofacitinib can suppress NK cell function and may be a viable therapeutic strategy for ALS.

A Safety Evaluation of Intravenous Administration of ex vivo Expanded Human Peripheral Blood-Derived NK Cells: A Preclinical Study

The use of natural killer (NK) cells in the treatment of various cancers is emerging as a promising approach in adoptive immunotherapy. However, the safety of ex vivo activated and expanded cells in in vivo conditions remain unknown. In this study, the toxicity of NK cells was evaluated at different doses, with 5 × 106, 20 × 106 and 50 × 106 cells injected intravenously into pre-irradiated (30Gy) immunodeficient mice twice a week for three weeks and the mice were followed-up on for 90 days. Throughout the study, no mortality, abnormal clinical signs, or behavioural changes related to the testing material were observed in either the treated or control groups of mice. There were no significant variations in food and water consumption between both genders in the NK cell treated and control groups. However, certain significant changes were observed between the groups in the clinical biochemistry and urine analysis reports. As autopsy showed no significant variations in absolute and relative organ weights between the groups, except for the livers of the treated mice. The histopathological analysis also demonstrated that there were no significant abnormalities in most of the organs of both genders, except for the liver. Some necrotic lesions were observed in the livers of both the treated and control mice, and these lesions may be due to the effects of irradiation or could be common in NOD.SCID mice. The findings of this study indicate that intravenous administration of NK cells is safe and does not cause any adverse effects up to the dose of 50 × 106 cells/mouse.

Differences in tolerogenic status of NK cells between luminal A type, luminal B type, and triple-negative breast cancer.

Globally, breast cancer is the main cause of death among female cancer patients. The tumor-infiltrating lymphocytes (TILs) in breast cancer are associated with a more favorable outcome of a disease. Natural killer (NK) cells are important cytotoxic cells involved in tumor immunosurveillance, causing the direct killing of tumor cells. In solid tumors, peripheral NK cells and tumor-infiltrating NK cells display an altered phenotype characterized by reduced cytotoxicity or anergy. The goal of this study was to investigate the NK cells' phenotype and activation status in order to get into the pathological process of breast cancer subtypes. In our study, the normal tissues and tumoral breast tissue were fixed in formalin, embedded in paraffin, and the phenotypic marker CD56 and proinflammatory cytokine IL-15 were identified by immunohistology. The distribution and expression of receptors repertoire (NKG2A, NKG2C, NKp46, CD94, CD69, and CD107a) were investigated in peripheral NK cells of mononuclear cells by flow cytometry. mRNA of cytolytic mediators was determined by real-time PCR. The frequency of CD56+ and IL-15+ cells were significantly higher in triple-negative breast cancer tissue. The frequency of NK cell activating receptors was decreased in investigated breast cancer subtypes while the inhibitory NKG2A receptor was increased. Decreased percentage of CD69+/CD107a+ in NK cells could indicate lower cellular activation and cytotoxicity. In luminal B breast cancer, the mRNA of cytolytic mediators was upregulated. In conclusion, modulation of activation status in tumor-infiltration NK cells could be involved in the pathogenesis of molecular breast cancer subtypes. This highlights the importance of NK cells as an appropriate target for potent anti-tumor response in the immunosuppressive tumor microenvironment of breast cancer.

Progesterone induced blocking factor in health and disease

The foetus expressing paternal antigens ought to be “rejected” by the maternal immune system. However, the immunological relationship of the mother and the foetus does not follow the rules of transplantation immunology. Maternal immune functions are re-adjusted during pregnancy, to create a tolerant environment for the developing foetus. Progesterone and its downstream mediator; the progesterone induced blocking factor (PIBF) are important in this process. The mRNA transcribed from the PIBF1 gene contains 18 exons, and codes for a 90 kDa protein. The 90 kDa form is associated with the centrosome and plays a role in cell cycle regulation, while smaller isoforms produced by alternative spicing are secreted, and bind to the glycosylphosphatidylinositol (GPI) anchored PIBF receptor. Upon ligation, the former forms a heterodimer with the alpha chain of the interleukin-4 (IL-4) receptor and activates the Janus kinase/signal transducers and activators of transcription (Jak/STAT) pathway, via which, PIBF induces increased production of T helper2 (Th2) cytokines. PIBF regulates natural killer (NK) cytotoxicity, by inhibiting perforin release from the cytoplasmic granules of NK cells. During normal human pregnancy, the serum concentrations of PIBF increase with gestational age, and lower than normal serum levels predict spontaneous pregnancy termination. Depletion of PIBF during the peri-implantation period in mice, results in lower implantation and increased resorption rates, together with increased decidual and peripheral NK activity, downregulation of the genes implicated in T cell activation in CD4+ cells, and Th1 differentiation of the T cells. PIBF is expressed in rapidly proliferating immature cells as well as several tumours, and regulates invasion. The PIBF gene has been identified in the chromosomal region 13q21-q22—which is a common site for somatic deletions in a variety of malignant tumours. These data suggest that PIBF might be involved in tumorigenesis.