Natural killer cells 56bnght16- have higher counts in the umbilical cord blood than in the adult peripheral blood

ABSTRACT Introduction and hypothesis: Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells for allogeneic hematopoietic stem cell transplantation in the absence of a compatible donor. The UCB transplantation has a lower incidence of chronic graft versus host disease (GvHD), but is associated with slower engraftment and slower immune reconstitution, compared to other sources. Dendritic cells (DCs) and Natural Killer cells (NKs) play a central role in the development of GvHD and the graft versus leukemia (GvL) effect, as well as in the control of infectious complications. Method: We quantified by multiparametric flow cytometry monocytes, lymphocytes, NK cells, and DCs, including their subsets, in UCB samples from 54 healthy newborns and peripheral blood (PB) from 25 healthy adult volunteers. Results: In the UCB samples, there were higher counts of NK cells 56bright16- (median 0.024 × 109/L), compared to the PB samples (0.012 × 109/L, p < 0.0001), NK 56dim16bright (median 0.446 × 109/L vs. 0.259 × 109/L for PB samples, p = 0.001) and plasmacytoid dendritic cells (pDCs, median 0.008 × 109/L for UCB samples vs. 0.006 × 109/L for PB samples, p = 0.03). Moreover, non-classic monocyte counts were lower in UCB than in PB (median 0.024 × 109/L vs. 0.051 × 109/L, respectively, p < 0.0001). Conclusion: In conclusion, there were higher counts of NK cells and pDCs and lower counts of non-classic monocytes in UCB than in PB from healthy individuals. These findings might explain the lower incidence and severity of chronic GvHD, although maintaining the GvL effect, in UCB transplant recipients, compared to other stem cell sources.

Immunostaining of stromal CD56 cells in ovarian malignancies

SUMMARY OBJECTIVES: The aim of this study was to evaluate CD56 immunostaining in the stroma of benign and malignant ovarian epithelial neoplasms and associate the CD56 immunostaining with prognostic factors and survival in ovarian cancer. METHODS: Patients with ovarian epithelial neoplasia (n=77) were studied with a prospective cohort. The CD56 immunostaining was evaluated in the peritumoral stroma. Two groups were evaluated: benign ovarian neoplasms (n=40) and malignant ovarian neoplasms (n=37). Data were recorded for histological type and grade, International Federation of Gynecology and Obstetrics staging, molecular subtype, and lymph node metastases. Fisher's exact test and Kaplan-Meier survival curves were used, with a significance level of ≤0.05. RESULTS: We found greater CD56 stromal immunostaining in malignant neoplasms when compared to the group of benign neoplasms (p=0.00001). There was no significant difference in relation to the prognostic factors and survival. CONCLUSION: Malignant ovarian neoplasms showed higher stromal CD56 immunostaining. As the prognostic value of natural killer in ovarian cancer is controversial, knowing the specific function of each cell present both in the tumor tissue and systemically may help guide successful immunotherapies in the near future.

AKT inhibition interferes with the expression of immune checkpoint proteins and increases NK-induced killing of HL60-AML cells

ABSTRACT Objective To determine the role of the AKT pathway in the regulating of natural Killer-induced apoptosis of acute myeloid leukemia cells and to characterize the associated molecular mechanisms. Methods BALB/c nude mice were injected with HL60 cells to induce a xenogenic model of subcutaneous leukemic tumors. Mice were treated with perifosine, and their spleens were analyzed using biometry, histopathology, and immunohistochemistry. Gene expression analysis in leukemia cells was performed by real-time PCR. Protein analysis of leukemia and natural Killer cells was performed by flow cytometry. AKT inhibition in HL60 cells, followed by co-culture with natural Killer cells was performed to assess cytotoxicity. Apoptosis rate was quantified using flow cytometry. Results Perifosine treatment caused a reduction in leukemic infiltration in the spleens of BALB/c nude mice. In vitro , AKT inhibition reduced HL60 resistance to natural Killer-induced apoptosis. AKT inhibition suppressed the immune checkpoint proteins PD-L1, galectin-9, and CD122 in HL60 cells, but did not change the expression of their co-receptors PD1, Tim3, and CD96 on the natural Killer cell surface. In addition, the death receptors DR4, TNFR1, and FAS were overexpressed by AKT inhibition, thus increasing the susceptibility of HL60 cells to the extrinsic pathway of apoptosis. Conclusion The AKT pathway is involved in resistance to natural Killer-induced apoptosis in HL60 cells by regulating the expression of immune suppressor receptors. These findings highlight the importance of AKT in contributing to immune evasion mechanisms in acute myeloid leukemia and suggests the potential of AKT inhibition as an adjunct to immunotherapy.

Progress in Chimeric Antigen Receptor-Modified Natural Killer Cells for Multiple Myeloma / 中国医学科学院学报

Although the development of novel drugs has significantly improved the survival of patients with multiple myeloma (MM) over the past decades,the lack of effective therapeutic options for relapsed and refractory MM results in poor prognosis.The chimeric antigen receptor (CAR) T-cell therapy has achieved considerable progress in relapsed and refractory MM.Nevertheless,this therapy still has limitations such as cytokine release syndrome,neurotoxicity,and off-target effects.Natural killer (NK) cells,as a critical component of the innate immune system,play an essential role in tumor immunosurveillance.Therefore,CAR-modified NK (CAR-NK) cells are put forward as a therapeutic option for MM.The available studies have suggested that multiple targets can be used as specific therapeutic targets for CAR-NK cell therapy and confirmed their antitumor effects in MM cell lines and animal models.This review summarizes the anti-tumor mechanisms,biological characteristics,and dysfunction of NK cells in the MM tumor microenvironment,as well as the basic and clinical research progress of CAR-NK cells in treating MM.

Research advances in natural killer cell-based immunotherapy in liver cancer / 临床肝胆病杂志

Natural killer (NK) cells are important immune cells in the human body and are also the main lymphocytes in the liver. They are considered the first defense mechanism against tumor and have a significant impact on the development and progression of liver cancer. The characteristics of NK cells help them become a new choice for immunotherapy, and NK cell-based immunotherapy may succeed in the treatment of liver cancer. This article reviews the biological characteristics of NK cells, their role in the development and progression of liver cancer, and the research advances in related treatment.

Acid-switchable nanoparticles induce self-adaptive aggregation for enhancing antitumor immunity of natural killer cells

Deficiency of natural killer (NK) cells shows a significant impact on tumor progression and failure of immunotherapy. It is highly desirable to boost NK cell immunity by upregulating active receptors and relieving the immunosuppressive tumor microenvironment. Unfortunately, mobilization of NK cells is hampered by poor accumulation and short retention of drugs in tumors, thus declining antitumor efficiency. Herein, we develop an acid-switchable nanoparticle with self-adaptive aggregation property for co-delivering galunisertib and interleukin 15 (IL-15). The nanoparticles induce morphology switch by a decomposition-metal coordination cascade reaction, which provides a new methodology to trigger aggregation. It shows self-adaptive size-enlargement upon acidity, thus improving drug retention in tumor to over 120 h. The diameter of agglomerates is increased and drug release is effectively promoted following reduced pH values. The nanoparticles activate both NK cell and CD8+ T cell immunity in vivo. It significantly suppresses CT26 tumor in immune-deficient BALB/c mice, and the efficiency is further improved in immunocompetent mice, indicating that the nanoparticles can not only boost innate NK cell immunity but also adaptive T cell immunity. The approach reported here provides an innovative strategy to improve drug retention in tumors, which will enhance cancer immunotherapy by boosting NK cells.

Value of cytotoxic T lymphocyte and natural killer cell levels in prognosis evaluation of patients with ST-elevation myocardial infarction / 中国基层医药

Objective:To analyze the value of cytotoxic T lymphocyte and natural killer cell levels in prognosis evaluation of patients with ST-elevation myocardial infarction (STEMI).Methods:A total of 158 patients with STEMI who underwent percutaneous coronary intervention in The Second People's Hospital of Liaocheng from September 2020 to August 2021 were included in this study. The ratio of cytotoxic T lymphocytes to natural killer cells was measured immediately after admission and 48 hours after surgery. These patients were followed up for 1 month after treatment. They were divided into the adverse cardiovascular event group (occurrence group) and no adverse cardiovascular event group (non-occurrence group) according to the occurrence of cardiovascular adverse events. The influential factors of the prognosis of STEMI and the correlation between the influential factors and STEMI were analyzed.Results:Among 158 patients with STEMI, 27 patients had adverse cardiovascular events, accounting for 17.09%. There were significant differences in systolic blood pressure, left ventricular ejection fraction, and low-density lipoprotein levels between the occurrence and non-occurrence groups ( t = 2.82, 4.27, 2.32, all P < 0.05). At 48 hours after surgery, the levels of cytotoxic T lymphocytes [(22.75 ± 8.39)%, (29.23 ± 4.61)%] and natural killer cells [(13.73 ± 4.64)%, (20.64 ± 4.52)%] in the peripheral blood in the occurrence and non-occurrence groups were significantly decreased compared with before surgery [ t = -5.05, -83.68, -142.71, -7 084.80, all P < 0.001]. Before and 48 hours after surgery, the levels of cytotoxic T lymphocytes [(27.47 ± 3.35)%, (22.75 ± 8.39)%] and natural killer cells [(21.42 ± 4.36)%, (13.73 ± 4.64)%] in the peripheral blood in the occurrence group were significantly lower than those in the non-occurrence group ( t = 7.68, 13.10, 4.16, 5.76, all P < 0.001). Univariate analysis showed that preoperative cytotoxic T lymphocytes < 27.47%, preoperative natural killer cells < 21.42%, left ventricular ejection fraction, and low-density lipoprotein may be the risk factors that affect the prognosis of patients with STEMI ( P < 0.000, 0.012, 0.019, 0.033). Cox regression analysis showed that preoperative cytotoxic T lymphocytes < 27.47% and preoperative natural killer cells < 21.42% were independent risk factors affecting the prognosis of patients with STEMI (both P < 0.001). Conclusion:Reduced levels of baseline cytotoxic T lymphocytes and natural killer cells in patients with STEMI suggest an increased risk of poor prognosis.

Efficacy of lenalidomide in treatment of multiple myeloma and its effect on levels of regulatory T cells and natural killer cells of patients / 白血病·淋巴瘤

Objective:To investigate the clinical efficacy of lenalidomide combined with bortezomib and dexamethasone (RVd) regimen in treatment of newly diagnosed multiple myeloma (NDMM) patients and its effect on the levels of regulatory T cells (Treg cells) and natural killer (NK) cells.Methods:Thirty-eight NDMM patients who were admitted to the Second Affiliated Hospital of Bengbu Medical College from September 2019 to May 2022 were selected for a prospective study, and were divided into control group (18 cases) and observation group (20 cases) according to random number table method. The control group was treated with bortezomib+epirubicin+dexamethasone (VAd) regimen, and the observation group was treated with RVd regimen. The efficacy and safety were compared between the two groups. The levels of Treg cells (CD4 + CD25 + FOXP3 +) and NK cells (CD3 - CD56 + CD16 +) before and after treatment in the two groups were detected by flow cytometry, and the results were compared. Results:After 4 courses of treatment, the objective response rate (ORR) of the observation group was 95.0% (19/20), which was higher than that of the control group [77.8% (14/18)], and the difference was statistically significant ( P = 0.016). Before treatment, there was no statistical difference in the levels of Treg cells and NK cells between the two groups ( P values were 0.381 and 0.650). After treatment, the level of Treg cells in the control group increased from (1.5±0.5)% before treatment to (4.7±1.3)% ( P = 0.008), while the level of Treg cells in the observation group increased from (1.4±0.5)% before treatment to (6.8±1.5)% ( P = 0.001), and the level in the observation group was higher than that in the control group ( P = 0.027); the level of NK cells in the control group increased from (16±6)% before treatment to (20±5)% ( P = 0.004), while the level of NK cells in the observation group increased from (16±6)% before treatment to (24±6)% ( P = 0.006), and the level in the observation group was higher than that in the control group ( P = 0.032). The incidence rates of thrombocytopenia and neutropenia in the observation group were higher than those in the control group, and the differences were statistically significant ( P values were 0.012 and 0.027), which was reversible after active treatment. There was no statistical difference in the incidence rates of other adverse reactions (all P>0.05). Conclusions:RVd regimen for NDMM is clinically effective, safe and reliable, and the patients' levels of Treg cells and NK cells elevate after treatment.

Expressions of programmed death 1 and its ligand in acute myeloid leukemia patients and their effect on anti-tumor effect of programmed death receptor 1-positive natural killer cells in vitro / 白血病·淋巴瘤

Objective:To investigate the expression of programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway in patients with acute myeloid leukemia (AML) and its relationship with clinical features and prognosis, and to examine its effect on PD-1-positive natural killer (NK) cells against AML cells in vitro.Methods:The bone marrow samples of 65 AML patients and the peripheral blood of 32 AML patients diagnosed in Affiliated Cancer Hospital of Zhengzhou University from July 2019 to December 2020 were prospectively collected, and the peripheral blood of 24 healthy people was taken as healthy control. The expression level of PD-L1 in bone marrow tumor cells and expression level of PD-1 in peripheral blood NK cells were detected by flow cytometry. The correlations of PD-1 expression in bone marrow tumor cells and PD-1 expression in NK cells with the clinicopathological features, curative effect and prognosis of patients were analyzed. Flow cytometry was used to detect the expression level of PD-L1 in AML cell line THP-1 (target cells) and the expression level of PD-L1 in NK cell line NKL (effector cells). THP-1 cells treated with and without 25 μmol/L of PD-L1 inhibitor fraxinellone were used as experimental group and control group, and co-cultured with NKL cells at different effector-to-target ratios. The apoptosis of THP-1 cells and the expression of NKG2D in NKL cells were detected by flow cytometry, the cell proliferation status was detected by CCK-8 and the cell proliferation inhibition rate was calculated; the levels of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) in the supernatant of co-culture system were detected by enzyme-linked immunosorbent assay (ELISA).Results:The proportion of AML patients with PD-L1-positive expression in bone marrow tumor cells was higher than that in the healthy control group [38.5% (25/65) vs. 8.3% (2/24), P = 0.029]. The proportion of AML patients with PD-1-positive expression in peripheral blood NK cells was higher than that in the healthy control group [40.6% (13/32) vs. 12.5% (3/24), P = 0.035]. There were no statistical differences in sex, age, hemogram, proportion of primordial cells, risk stratification, chromosomal karyotype, gene mutation (except NPM1 gene), fusion gene and French-American-British cooperative group (FAB) typing between patients with PD-L1 positive and negative in bone marrow tumor cells and between patients with PD-1 positive and negative in peripheral blood NK cells (all P > 0.05). In relapsed/refractory patients, the proportion of patients with PD-L1-positive expression in bone marrow tumor cells was higher than that in newly treated patients [58.8% (10/17) vs. 31.2% (15/48), P = 0.045]. There was no significant difference in the proportion of patients with PD-1-positive expression in peripheral blood NK cells between relapsed/refractory patients and newly treated patients [(38.5% (5/13) vs. 42.1% (8/19), P = 0.837]. There was no statistical difference in complete remission (CR) rate between PD-L1 positive and negative patients [69.6% (16/23) vs. 74.3% (26/35), P > 0.05]. There was no statistical difference in CR rate between PD-1 positive and negative patients [66.7% (8/12) vs. 70.6% (12/17), P > 0.05]. There was no statistical difference in recurrence rate after CR between PD-L1 positive and negative patients [12.5% (2/16) vs. 19.2% (5/26), P > 0.05]. There was no statistical difference in recurrence rate after CR between PD-1 positive and negative patients [25.0% (2/8) vs. 16.7% (2/12), P > 0.05]. Flow cytometry showed that the positive rate of PD-1 in NKL cells was (67±6)% and the positive rate of PD-L1 in THP-1 cells was (85±5)%. After co-culture with NKL cells, the apoptotic rate and proliferation inhibition rate of THP-1 cells were higher in the experimental group compared with the control group, the expression of NKG2D on the surface of NKL cells was elevated, and the levels of IFN-γ and TNF-α in the co-culture supernatant were increased. Conclusions:In AML patients, the expression of PD-L1 in bone marrow tumor cells is high, and the expression of PD-1 in peripheral blood NK cells is also high. The expression of PD-L1 in bone marrow tumor cells of relapsed/refractory AML patients is higher than that of newly treated patients. Inhibition of PD-L1 expression in THP-1 cells can enhance the tumor killing activity of NKL cells in vitro. The mechanism may be that inhibition of PD-L1 expression in THP-1 cells up-regulates the expression of NKL cell activated receptor NKG2D and promotes the secretion of IFN- γ and TNF- α.

Interferon-α mediating the functional damage of CD56dimCD57+natural killer cells in peripheral blood of systemic lupus erythematosuss / 北京大学学报(医学版)

OBJECTIVE@#To investigate the regulatory effect of interferon-α (IFN-α) on the apoptosis and killing function of CD56dimCD57+ natural killer (NK) cells in systemic lupus erythematosus (SLE) patients, and to explore the specific mechanism.@*METHODS@#A total of sixty-four newly treated SLE patients and sixteen healthy controls (HC) enrolled in the Second Hospital of Dalian Medical University were selected as the research subjects. And the gene expression levels of molecules related to NK cell-killing function were detected by real-time quantitative polymerase chain reaction. CD56dimCD57+ NK cells were co-cultured with the K562 cells, and the apoptotic K562 cells were labeled with Annexin-Ⅴ and 7-amino-actinomycin D. Peripheral blood mononuclear cells were treated with 20, 40, and 80 μmol/L hydrogen peroxide (H2O2), and treated without H2O2 as control, the expression level of perforin (PRF) was detected by flow cytometry. The concentration of IFN-α in serum was determined by enzyme linked immunosorbent assay. The expression levels of IFN-α receptors (IFNAR) on the surface of CD56dimCD57+ NK cells were detected by flow cytometry, and were represented by mean fluorescence intensity (MFI). CD56dimCD57+ NK cells were treated with 1 000 U/mL IFN-α for 24, 48 and 72 h, and no IFN-α treatment was used as the control, the apoptosis and the expression levels of mitochondrial reactive oxygen species (mtROS) were measured by flow cytometry and represented by MFI.@*RESULTS@#Compared with HC(n=3), the expression levels of PRF1 gene in peripheral blood NK cells of the SLE patients (n=3) were decreased (1.24±0.41 vs. 0.57±0.12, P=0.05). Compared with HC(n=5), the ability of peripheral blood CD56dimCD57+ NK cells in the SLE patients (n=5) to kill K562 cells was significantly decreased (58.61%±10.60% vs. 36.74%±6.27%, P < 0.01). Compared with the control (n=5, 97.51%±1.67%), different concentrations of H2O2 treatment significantly down-regulated the PRF expression levels of CD56dimCD57+ NK cells in a dose-dependent manner, the 20 μmol/L H2O2 PRF was 83.23%±8.48% (n=5, P < 0.05), the 40 μmol/L H2O2 PRF was 79.53%±8.56% (n=5, P < 0.01), the 80 μmol/L H2O2 PRF was 76.67%±7.16% (n=5, P < 0.01). Compared to HC (n=16), the serum IFN-α levels were significantly increased in the SLE patients (n=45) with moderate to high systemic lupus erythematosus disease activity index (SLEDAI≥10) [(55.07±50.36) ng/L vs. (328.2±276.3) ng/L, P < 0.001]. Meanwhile, compared with HC (n=6), IFNAR1 expression in peripheral blood CD56dimCD57+ NK cells of the SLE patients (n=6) were increased (MFI: 292.7±91.9 vs. 483.2±160.3, P < 0.05), and compared with HC (n=6), IFNAR2 expression in peripheral blood CD56dimCD57+ NK cells of the SLE patients (n=7) were increased (MFI: 643.5±113.7 vs. 919.0±246.9, P < 0.05). Compared with control (n=6), the stimulation of IFN-α (n=6) significantly promoted the apoptosis of CD56dimCD57+ NK cells (20.48%±7.01% vs. 37.82%±5.84%, P < 0.05). In addition, compared with the control (n=4, MFI: 1 049±174.5), stimulation of CD56dimCD57+ NK cells with IFN-α at different times significantly promoted the production of mtROS in a time-dependent manner, 48 h MFI was 3 437±1 472 (n=4, P < 0.05), 72 h MFI was 6 495±1 089 (n=4, P < 0.000 1), but there was no significant difference at 24 h of stimulation.@*CONCLUSION@#High serum IFN-α level in SLE patients may induce apoptosis by promoting mtROS production and inhibit perforin expression, which can down-regulate CD56dimCD57+ NK killing function.

Effects of co-culture of dendritic cells loaded with MAGE-A3 antigen and cytokine-induced killer cells on tumor stem cells and malignant progression of endometrial cancer / 中国临床药理学与治疗学

AIM: To explore the effects of dendritic cells (DC) and cytokine-induced killer cells (CIK) carrying melanoma-associated antigen gene A3 (MAGE-A3) on endometrial cancer tumor stem cells and malignant progression. METHODS: Human peripheral blood was collected to separate mono-nuclear cells, and DC and CIK cells were induced by cytokines, respectively. DCs were incubated with MAGE-A3 and then co-cultured with CIK, and the phenotypes of DC-CIK and MAGE-A3-DC-CIK were detected by flow cytometry; The CD133

Research Progress of Chimeric Antigen Receptor NK Cells in Treatment of Lymphoma / 肿瘤防治研究

Adoptive cell immunotherapy has been a hot spot in tumor research in recent years. Chimeric antigen receptor T cells (CAR-T) have achieved great success in hematological tumors and have changed the current tumor treatment landscape to a certain extent. However, the application of CAR-T therapy in clinics is limited due to its serious side effects and high treatment costs. Natural killer (NK) cells are important immune cells in the body and have native cytotoxicity and well safety. NK cells based on CAR engineering (CAR-NK) have shown powerful anti-tumor activity and safety in preclinical research and could be the next generation of CAR platform-based cellular immunotherapy. This review will systematically introduce the current research status of CAR-NK cells in lymphoma.

Effects of Toxoplasma gondii infection on mouse and human uterine natural killer cells / 中国血吸虫病防治杂志

Objective To examine the effects of Toxoplasma gondii infection on the proportion, quantity, differentiation and function of mouse and human uterine natural killer cells (uNK cells), so as to explore the role of uNK cells in abortion of early pregnancy caused by T. gondii infection. Methods Pregnant mice were injected intraperitoneally with T. gondii tachyzoites on day 6.5 of pregnancy, and the abortion mouse model caused by T. gondii infections was constructed. Mouse uterine lymphocytes were isolated on day 9.5 of pregnancy. Human uterine lymphocytes were isolated from fresh human decidual specimens after abortion in normal early pregnancy and co-cultured with tachyzoites of the T. gondii RH strain for 48 h at T. gondii/uterine lymphocytes ratios of 0.5:1, 1:1 and 2:1. The phenotypes of mouse uNK cells (CD122, NK1.1, DX5) and human uNK cells (CD3, CD56, CD11b, CD27) and the expression of intracellular cytokines interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) were detected by flow cytometry. Mouse and human uNK cells were sorted by magnetic beads, and the cytotoxicity of uNK cells was tested using the lactate dehydrogenase (LDH) release assay at effector/target cell ratios of 1:1, 5:1, 10:1 and 20:1 with mouse or human uNK cells as effector cells and mouse YAC-1 cells or human K562 cells as target cells. Results On day 9.5 of pregnancy, the mouse abortion rate was significantly higher in the infected group than that in the control group (83.02% vs. 3.51%; χ2 = 71.359, P < 0.001). Significantly lower absolute number of uNK cells [(4 547 ± 1 610) cells/mouse vs. (8 978 ± 3 339) cells/mouse; U = 2.000, P < 0.05], lower NK1.1 expression on uNK cell surface [(74.53 ± 8.37)% vs. (93.00 ± 1.11)%; U = 0.000, P < 0.05], higher proportion of NK1.1-DX5-cells [(20.10 ± 8.03)% vs. (5.04 ± 0.68)%; U = 0.000, P < 0.05], lower proportion of NK1.1+ DX5+ cells [(21.70 ± 12.48)% vs. (45.75 ± 2.26)%; U = 0.000, P < 0.05] and higher IFN-γ expression [(16.74 ± 1.36)% vs. (8.13 ± 1.90)%; U = 0.000, P < 0.05] were detected in the infected group than in the control group, while no significant difference was seen in TNF-α expression between the two groups [(67.98 ± 9.20)% vs. (52.93 ± 10.42)%; U = 2.000, P > 0.05]. The mouse uNK cells showed a strong cytotoxicity in the infected group, and the cytotoxicity gradually increased with the effector/target cell ratio. The cytotoxicity of uNK cells against YAC-1 cells was 2.30%, 4.32%, 8.12% and 12.65% in the infected group and 1.21%, 1.63%, 2.51% and 3.22% in the control group at effector/target cell ratios of 1:1, 5:1, 10:1 and 20:1, respectively. Following co-culture of human uterine lymphocytes and tachyzoites of the T. gondii RH strain for 48 h, the proportion [TOX 2:1 group vs. control group: (6.61 ± 1.75)% vs. (17.48 ± 4.81)%; F = 7.307, P < 0.01], and absolute number of human uNK cells in uterine lymphocytes of human uNK cells in uterine lymphocytes [TOX 2:1 group vs. control group: (12 104 ± 5 726) cells/well vs. (65 285 ± 21 810) cells/well; H = 11.540, P < 0.01] were significantly lower in the infected group than in the control group. A lower proportion of CD56brightCD16- NK cells [TOX 2:1 group vs. control group: (25.25 ± 5.90)% vs. (36.03 ± 4.51)%; F = 3.213, P > 0.05] and higher proportion of CD56dimCD16+ NK cells [TOX 2:1 group vs. control group: (11.15 ± 2.15)% vs. (7.09 ± 2.24)%; F = 2.992, P > 0.05] were detected in uNK cells in the infected group than in the control group, and the ratio of CD56brightCD16- cells/CD56dimCD16+ cells was significantly lower in the infected group than in the control group [TOX2:1 group vs. control group: (2.37 ± 0.92) vs. (5.58 ± 2.39); H = 8.228, P < 0.05]. In addition, the proportion of CD11b+CD27- cells in human uNK cells was significantly higher in the infected group than in the control group [TOX 2:1 group vs. control group: (30.28 ± 6.91)% vs. (17.48 ± 4.67)%; H = 6.556, P < 0.05], while no significant differences were found between the two groups in terms of IFN-γ [TOX 2:1 group vs. control group: (14.13 ± 1.28)% vs. (15.19 ± 1.64)%; F = 1.639, P > 0.05] or TNF-α expression [TOX 2:1 group vs. control group: (54.76 ± 10.02)% vs. (50.33 ± 3.67)%; F = 0.415, P > 0.05]. Human uNK cells presented a strong cytotoxicity in the infected group, and the cytotoxicity gradually increased with the effector/target cell ratio. The cytotoxicity of human uNK cells against K562 cells was 11.90%, 28.11%, 49.91% and 73.35% in the infected group and 12.21%, 21.63%, 33.51% and 48.22% in the control group at effector/target cell ratios of 1:1, 5:1, 10:1 and 20:1, respectively. Conclusions T. gondii infection presents diverse effects on the differentiation and secretion ability of mouse and human uNK cells. However, T. gondii infection causes a reduction in the absolute number and enhances the cytotoxicity of both mouse and human uNK cells.

Research Progress of Immune Microenvironment in Multiple Myeloma / 肿瘤防治研究

Multiple myeloma is one type of hematological malignancy, characterized by the proliferation and accumulation of monoclonal plasma cells in bone marrow. Bone marrow microenvironment plays a key supporting role in the proliferation and survival of myeloma cells, where a large number of immune cells exist but are functionally suppressed. Based on the studies of myeloma immune microenvironment in recent years, we summarize the recent advances and existing problems in the treatment of multiple myeloma and put forward some considerations and suggestions, to provide references for researchers in this field.

Progress in pathogenesis of autoantibody-related congenital heart block / 中华围产医学杂志

Autoantibody-related congenital heart block (ACHB) is a passively acquired autoimmune disease developing in fetuses after exposuring to maternal anti-Ro/Sj?gren's syndrome type A (SSA) antibody and/or anti-La/SSB antibody transported across the placenta, which contributes to fetal heart conduction system damage and signal conduction block at the atrioventricular node. However, fetal atrioventricular block does not necessarily occur with the presence of maternal autoantibodies, indicating its complex pathogenesis. This review focuses on the theories of calcium channels and apoptosis, the influence of other maternal factors and environmental changes on ACHB and the roles of natural killer cells and human leukocyte antigen in ACHB, aiming to provide reference for further study on the pathogenesis.

Role of liver-resident natural killer cells in the development and progression of hepatocellular carcinoma / 临床肝胆病杂志

Liver-resident natural killer (LrNK) cells, as a type of newly discovered tissue-resident natural killer cells, have a strong immune killing function. During the development and progression of hepatocellular carcinoma (HCC), the function of LrNK cells is impaired and such cells may promote the progression of HCC by upregulating the expression of related immune checkpoints. Based on the latest research, this article reviews the immune function of LrNK cells and their role in the development and progression of HCC, in order to explore the application prospect of these cells in HCC immunotherapy.

Features of acquired immune properties in innate immune cells and its roles in transplant rejection / 中华消化外科杂志

Transplant rejection involves natural immune cells and acquired immune cells. For decades, acquired immune cells have been dominating the study of transplant immunity. Researchers have found the surprising new features of innate immune cells, including immune memory, which may be of great significance to further improve graft survival. The short-term survival rate of grafts is very good, but the long-term graft outcomes are less so and most transplants are eventually lost to chronic rejection in the clinic. In animal models and clinical studies, innate immune cells, especially macrophages and natural killer cells, often predominate the chronic rejection process which lead grafts lost. Recent studies suggest that innate immune cells are capable of acquiring adaptive features in that they either directly recognize the allografts or become "trained" in the allogeneic milieu to further acquire features of memory and donor specificity. In selected transplant models, targeting the adaptive features of innate immune cells has been shown to promote long-term graft survival. Clearly, these findings highlight new therapeutic opportunities in further improvement of transplant outcomes as well as in treatment of cancers and autoimmune diseases in the clinic. The authors summarize the literature reports, introduce the recent acquired response characteristics of natural immune cells, and stimulate researchers to carry out more exploration in this field by fully discussing the heterogeneity and plasticity of natural immune cell types and the outstanding problems in related field.

Immune characterization of a Colombian family cluster with SARS-CoV-2 infection / Caracterización inmunológica de un grupo familiar colombiano con infección por SARS-CoV-2

Abstract | Introduction: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARS- CoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited. Objective: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection. Materials and methods: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay. Results: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin. Conclusion: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells could be associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.

Resumen | Introducción. Se han descrito diferentes marcadores inmunológicos durante la COVID-19, los cuales persisten incluso después de la convalecencia y se asocian con los estadios clínicos de la infección. Sin embargo, aún son pocos los estudios orientados al análisis exhaustivo de las alteraciones del sistema inmunológico en el curso de la infección. Objetivo. Evaluar la producción de citocinas proinflamatorias, la reacción de anticuerpos, y el fenotipo y la función de las células NK y los linfocitos T en una familia colombiana con infección por SARS-CoV-2. Materiales y métodos. Se evaluaron las citocinas proinflamatorias mediante RT-PCR y ELISA; la frecuencia, el fenotipo y la función de las células NK (en cocultivos con células K562) y linfocitos T CD8+ (estimulados con péptidos spike/RdRp) mediante citometría de flujo, y los anticuerpos anti-SARS-CoV-2, mediante inmunofluorescencia indirecta y prueba de neutralización por reducción de placa. Resultados. Durante la COVID-19 hubo una producción elevada de citocinas proinflamatorias, con disminución de las células NK CD56 bright y reacción citotóxica. Comparados con los controles sanos, los individuos infectados presentaron con gran frecuencia linfocitos T CD8+ disfuncionales CD38+HLA-DR-. Además, en los linfocitos T CD8+ estimulados con péptidos virales, predominó una reacción monofuncional con gran producción de IL-10 durante la fase aguda y una reacción bifuncional caracterizada por la coexpresión de CD107a y granzima B o perforina durante la convalecencia. Conclusión. Aunque la reacción inflamatoria caracteriza la infección por SARS-CoV-2, hay otras alteraciones fenotípicas y funcionales en células NK y linfocitos T CD8+ que podrían asociarse con la progresión de la infección. Se requieren estudios adicionales para entender estas alteraciones y guiar futuras estrategias de inmunoterapia.

Is malaria immunity a possible protection against severe symptoms and outcomes of COVID-19?

Malaria-endemic areas of the world are noted for high morbidity and mortality from malaria. Also noted in these areas is the majority of persons in the population having acquired malaria immunity. Though this acquired malaria immunity does not prevent infection, it resists the multiplication of Plasmodium parasites, restricting disease to merely uncomplicated cases or asymptomatic infections. Does this acquired malaria immunity in endemic areas protect against other diseases, especially outbreak diseases like COVID-19? Does malaria activation of innate immunity resulting in trained or tolerance immunity contribute to protection against COVID-19? In an attempt to answer these questions, this review highlights the components of malaria and viral immunity and explores possible links with immunity against COVID-19. With malaria-endemic areas of the world having a fair share of cases of COVID-19, it is important to direct research in this area to evaluate and harness any benefits of acquired malaria immunity to help mitigate the effects of COVID-19 and any possible future outbreaks

Application of lymphocytes test in peripheral blood of patients with systemic sclerosis during the treatment / 北京大学学报(医学版)

OBJECTIVE@#To explore the significance of lymphocytes in systemic sclerosis (SSc), by detecting the levels of T lymphocytes, B lymphocytes and natural killer (NK) cells, and analyzing the correlation between the lymphocytes and clinical laboratory indexes.@*METHODS@#The numbers and proportion of T, CD4+T, CD8+T, B, and NK cells were detected by flow cytometry in peripheral blood of 32 SSc patients who had taken immunosuppressive drugs and 30 healthy controls (HC). The comparison of the lymphocyte subsets in SSc with them in the HC groups, and the correlation between the lymphocytes and other clinical and laboratory indicators were analyzed by the relevant statistical analysis.@*RESULTS@#Compared with the HC group, the numbers of T, CD4+T, CD8+T, and NK cells in peripheral blood of SSc group, who had taken immunosuppressive drugs, were significantly decreased (P < 0.05). More-over, the proportion of NK cells in peripheral blood of the SSc group was also significantly lower than that in the HC group (P=0.004). In addition, all the lymphocyte subsets were decreased in peripheral blood of more than 65% of the SSc patients who had taken immunosuppressive drugs. Compared with CD4+T normal group, the positivity of Raynaud's phenomenon, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) was significantly increased in CD4+T reduction group, respectively (P＝0.024, P < 0.001, P=0.018). ESR was higher in CD8+T reduction group than CD8+T normal group (P＝0.022). The prevalence of fingertip ulcer was significantly increased in B cell decrease group (P=0.019). Compared with NK cell normal group, the prevalence of fingertip ulcer was significantly increased in NK cell lower group (P=0.033), IgM was remarkablely decreased yet (P=0.049). The correlation analysis showed that ESR was negatively correlated with the counts of T lymphocytes (r＝－0.455, P＝0.009), CD4+T lymphocytes (r＝－0.416, P＝0.018), CD8+T lymphocytes (r＝－0.430, P=0.014), B cells (r＝－0.366, P＝0.039).@*CONCLUSION@#The number of CD4+T, CD8+T, B, and NK cells significantly decreased in peripheral blood of SSc patients who had used immunosuppressive drugs, some lymphocyte subsets might be related with Raynaud's phenomenon and fingertip ulcer, and reflected the disease activity by negatively correlated with ESR and CRP; the numbers of lymphocyte subsets in peripheral blood should be detected regularly in SSc patients who had taken immunosuppressive drugs.