Intestinal natural killer/T-cell lymphoma presenting as a pancreatic head space-occupying lesion:A case report

BACKGROUND Intestinal natural killer/T-cell lymphoma(NKTCL)is a rare and aggressive non-Hodgkin’s lymphoma,and its occurrence is closely related to Epstein-Barr virus infection.In addition,the clinical symptoms of NKTCL are not obvious,and the specific pathogenesis is still uncertain.While NKTCL may occur in any segment of the intestinal tract,its distinct location in the periampullary region,which leads clinicians to consider mimics of a pancreatic head mass,should also be addressed.Therefore,there remain huge challenges in the diagnosis and treatment of intestinal NKTCL.CASE SUMMARY In this case,we introduce a male who presented to the clinic with edema of both lower limbs,accompanied by diarrhea,and abdominal pain.Endoscopic ultrasound(EUS)showed well-defined homogeneous hypoechoic lesions with abundant blood flow signals and compression signs in the head of the pancreas.Under the guidance of EUS-fine needle biopsy(FNB)with 19 gauge or 22 gauge needles,combined with multicolor flow cytometry immunophenotyping(MFCI)helped us diagnose NKTCL.During treatments,the patient was prescribed the steroid(dexamethasone),methotrexate,ifosfamide,L-asparaginase,and etoposide chemotherapy regimen.Unfortunately,he died of leukopenia and severe septic shock in a local hospital.CONCLUSION Clinicians should enhance their understanding of NKTCL.Some key factors,including EUS characteristics,the right choice of FNB needle,and combination with MFCI,are crucial for improving the diagnostic rate and reducing the misdiagnosis rate.

Immune evasion and therapeutic opportunities based on natural killer cells

Natural killer(NK)cells can elicit an immune response against malignantly transformed cells without recognizing antigens,and they also exhibit cytotoxic effects and immune surveillance functions in tumor immunotherapy.Although several studies have shown the promising antitumor effects of NK cells in immunotherapy,their function is often limited in the tumor microenvironment because tumor cells can easily escape NK cell-induced death.Thus,for efficient tumor immunotherapy,the mechanism by which tumor cells escape NK cell-induced cytotoxicity must be fully understood.Various novel molecules and checkpoint receptors that mediate the disruption of NK cells in the tumor microenvironment have been discovered.In this review,we analyze and detail the major activating and inhibitory receptors on the surface of NK cells to delineate the mechanism by which tumor cells suppress NKG2D ligand expression and increase tumor receptor and inhibitory receptor expression[NKG2A,programmed cell death1(PD-1),and T-cell immunoglobulin and immunoreceptor tyrosine inhibitory motif(TIGIT)]on the NK cell surface,and thus inhibit NK cell activity.We also reviewed the current status of treatments based on these surface molecules.By comparing the therapeutic effects related to the treatment status and bypass mechanisms,we attempt to identify optimal single or combined treatments to suggest new treatment strategies for tumor immunotherapy.

Designing a risk prognosis model based on natural killer cell-linked genes to accurately evaluate the prognosis of gastric cancer

Background:This study was aimed at identifying natural killer(NK)cell-related genes to design a risk prognosis model for the accurate evaluation of gastric cancer(GC)prognosis.Methods:We obtained NK cell-related genes from various databases,followed by Cox regression analysis and molecular typing to identify prognostic genes.Various immune algorithms and enrichment analyses were used to investigate the mutations,immune status,and pathway variations among different genotypes.The key prognostic genes were assessed using the least absolute shrinkage and selection operator(Lasso)regression analysis and univariate Cox regression analysis.Thereafter,the risk score(RS)prognosis model was constructed based on the selected important prognostic genes.A Receiver Operating Characteristics(ROC)curve was plotted for analyzing the robustness of the model.Subsequently,the decision and calibration curves were used for assessing the reliability and prediction accuracy of the proposed model.The‘pRRophetic’R software package was utilized for predicting the half-maximal inhibitory concentration(IC50)of immunotherapy and chemotherapy drugs.Results:We screened 21 prognostic genes and three molecular subtypes and found that the C1 subtype had the worst prognosis.Further,the pathways promoting tumor proliferation,such as epithelial-mesenchymal transition were significantly up-regulated.The results also showed that the macrophages in the M2 stage were significantly infiltrated in the C1 subtype,and there was significant overexpression in the C1 subtype,accompanied by a severe inflammatory reaction.The C1 was highly sensitive to drugs like 5-fluorouracil and paclitaxel.The ROC,calibration curve,and decision curve showed that the risk model was robust and strongly reliable.Conclusion:Overall,our proposed NK cell-related RS model can be used as a more accurate prediction index for GC patients,providing a valuable contribution to personalized medicine.

Establishment of a prognostic model related to tregs and natural killer cells infiltration in bladder cancer

BACKGROUND Regulatory T cells(Tregs)and natural killer(NK)cells play an essential role in the development of bladder urothelial carcinoma(BUC).AIM To construct a prognosis-related model to judge the prognosis of patients with bladder cancer,meanwhile,predict the sensitivity of patients to chemotherapy and immunotherapy.METHODS Bladder cancer information data was obtained from The Cancer Genome Atlas and GSE32894.The CIBERSORT was used to calculate the immune score of each sample.Weighted gene co-expression network analysis was used to find genes that will have the same or similar expression patterns.Subsequently,multivariate cox regression and lasso regression was used to further screen prognosis-related genes.The prrophetic package was used to predict phenotype from gene expression data,drug sensitivity of external cell line and predict clinical data.RESULTS The stage and risk scores are independent prognostic factors in patients with BUC.Mutations in FGFR3 lead to an increase in Tregs percolation and affect the prognosis of the tumor,and additionally,EMP1,TCHH and CNTNAP3B in the model are mainly positively correlated with the expression of immune checkpoints,while CMTM8,SORT1 and IQSEC1 are negatively correlated with immune checkpoints and the high-risk group had higher sensitivity to chemotherapy drugs.CONCLUSION Prognosis-related models of bladder tumor patients,based on Treg and NK cell percolation in tumor tissue.In addition to judging the prognosis of patients with bladder cancer,it can also predict the sensitivity of patients to chemotherapy and immunotherapy.At the same time,patients were divided into high and low risk groups based on this model,and differences in genetic mutations were found between the high and low risk groups.

Diffuse large B-cell lymphoma successfully treated with amplified natural killer therapy alone: A case report

BACKGROUND The prognosis of patients with advanced diffuse large B-cell lymphoma(DLBCL)is poor,with a 5-year survival rate of approximately 50%.The mainstay of treatment is multidrug combination chemotherapy,which has been associated with serious side effects.Amplified natural killer(ANK)cell therapy amplifies and activates natural killer(NK)cells to attack only malignant tumors.As ANK cells attack programmed death ligand 1(PD-L1)-positive tumor cells,ANK therapy is considered effective against adult T-cell lymphoma and malignant lymphoma.CASE SUMMARY Herein,we report a case of an older patient with advanced DLBCL who was successfully treated with ANK immunotherapy.A 91-year-old female visited our hospital with sudden swelling of the right axillary lymph node in April 2022.The patient was diagnosed with stage II disease,given the absence of splenic involvement or contralateral lymphadenopathy.ANK therapy was administered.Six rounds of lymphocyte sampling were performed on July 28,2022.To reduce the occurrence of side effects,the six samples were diluted by half to obtain 12 samples.Cultured NK cells were administered twice weekly.The treatment efficacy was evaluated by performing computed tomography and serological tests every 1 or 2 mo.The treatment suppressed lesion growth,and the antitumor effect persisted for several months.The patient experienced mild side effects.PD-L1 immunostaining was positive,indicating that the treatment was highly effective.CONCLUSION ANK therapy can be used as a first-line treatment for malignant lymphoma;the PD-L1 positivity rate can predict treatment efficacy.

Effects of acupuncture treatment on natural killer cell activity,pulse rate,and pain reduction for older adults:an uncontrolled,observational study

OBJECTIVE： The aim of this study was to examine the changes in natural killer （NK） cell activity, pulse rate, and pain intensity among older adults before and after acupuncture treatment. METHODS： Fifty-six individuals （16 males and 40 females）, aged 60 to 82 years （mean age 72.4 ＋ 5.0）, who were experiencing pain in the shoulder, low back, or knee, participated in the study. NK cell activity, leukocyte differentiation （granulocytes and lymphocytes）, pulse rate, and blood pressure values were obtained. Pain intensity was evaluated by using the visual analog scale （VAS）. The Wilcoxon test was used to analyze NK cell activity, leukocytes （granulocyte counts and granulocyte-to-lymphocyte ratio）, and the VAS score in accordance with the location of pain complaints before and after acupuncture treatment. RESULTS： NK cell activity decreased after acupuncture treatment for pain in the shoulder-pain and knee-pain groups. Further, the lymphocyte and granulocyte counts increased after acupuncture treatment for the shoulder-pain group. Pulse rate decreased for the shoulder-pain, low-back- pain, and knee-pain groups after acupuncture treatment. The VAS score decreased after acupuncture treatment for the shoulder-pain, low-back-pain, and knee-pain groups. CONCLUSION： This study showed that in older adults, acupuncture treatment decreases pulse rate, relieves pain in the shoulder, low back, and knee, and reduces NK-cell activity.

Outcomes of patients treated with SVILE vs.P-GemOx for extranodal natural killer/T-cell lymphoma,nasal type:a prospective,randomized controlled study

Objective:To compare the efficacy and safety of the novel SVILE regimen with the P-GemOx regimen in patients with newly diagnosed extranodal natural killer/T-cell lymphoma,nasal type(ND-ENKTL).Methods:From April 2015 to July 2018,103 patients with ND-ENKTL were randomly assigned to SVILE(experimental group)or P-GemOx(control group)chemotherapy followed by radiotherapy and consolidation chemotherapy.The primary endpoint was the overall response rate after 3 cycles of chemotherapy,and secondary study endpoints were complete response(CR),progression-free survival(PFS),and overall survival(OS).Safety was also evaluated.Results:There were no significant differences in baseline characteristics in the experimentalvs.control groups.In experimental and control groups,respectively,the overall response rates were 91.7%vs.97.0%for stageI/II and 75.0%vs.72.2%for stage III/IV.The CR rates were 83.4%vs.97.0%for stage I/II and 68.8%vs.61.1%for stage III/IV.None of those differences were significant.There was no significant difference in PFS and OS between groups and between patients in stage I/II and stage III/IV.The 3-year PFS and OS in stage I/II were 88.3%vs.93.3%and 88.8%vs.97.0%,respectively.The 3-year PFS and OS in stage III/IV were 46.2%vs.65.7%and 68.8%vs.72.2%,respectively.The common adverse events were hematological toxicity,hepatotoxicity,and coagulation abnormalities,which were found to be reversible with supportive therapy.Conclusions:The novel SVILE regimen has comparable effects to those of P-GemOx in patients with ND-ENKTL and is well tolerated.SVILE is a therapeutic option for ND-ENKTL.

Muscular involvement of extranodal natural killer/T cell lymphoma misdiagnosed as polymyositis: A case report and review of literature

BACKGROUND Natural killer(NK)/T cell lymphoma is a rare and highly aggressive malignant tumor,and is a special form of non-Hodgkin's lymphoma.Although extranodal involvement is frequently found in tissues such as the skin,testicular and gastrointestinal tract etc,its presence in skeletal muscle has scarcely been reported in the literature.CASE SUMMARY We report a case of extranodal NK/T cell lymphoma with muscle swelling as the first clinical manifestation.A 42-year-old man,who initially presented with localized swelling in the double lower extremities,demonstrated gradual facial and eyelid swelling,and his imaging results showed multiple sites of muscle damage throughout the body.The final pathological results suggested NK/T cell lymphoma,and immunohistochemistry showed CD20(-),CD3(+),CD30(+),CD56(-),EBER(+),Ki67(60%),TIA-1(+)and CD68(±)staining.The muscle swelling significantly improved after treatment with chemotherapy regimens.CONCLUSION This disease is difficult to diagnose and highly invasive,and should be included in the differential diagnosis of unexplained muscle swelling.

Aggressive natural killer cell leukemia with skin manifestation associated with hemophagocytic lymphohistiocytosis:A case report

BACKGROUND Aggressive natural killer cell leukemia(ANKL)is a rare natural killer cell neoplasm characterized by systemic infiltration of Epstein–Barr virus and rapidly progressive clinical course.ANKL can be accompanied with hemophagocytic lymphohistiocytosis(HLH).Here,we report a case of ANKL with rare skin lesions as an earlier manifestation,accompanied with HLH,and review the literature in terms of etiology,clinical manifestation,diagnosis and treatment.CASE SUMMARY A 30-year-old woman from Northwest China presented with the clinical characteristics of jaundice,fever,erythema,splenomegaly,progressive hemocytopenia,liver failure,quantities of abnormal cells in bone marrow,and associated HLH.The immunophenotypes of abnormal cells were positive for CD2,cCD3,CD7,CD56,CD38 and negative for sCD3,CD8 and CD117.The diagnosis of ANKL complicated with HLH was confirmed.Following the initial diagnosis and supplementary treatment,the patient received chemotherapy with VDLP regimen(vincristine,daunorubicin,L-asparaginase and prednisone).However,the patient had severe adverse reactions and complication such as severe hematochezia,neutropenia,and multiple organ dysfunction syndrome,and died a few days later.CONCLUSION This is the first reported case of ANKL with rare skin lesions as an earlier manifestation and associated with HLH.

Primary intestinal extranodal natural killer/T-cell lymphoma, nasal type: A case report

BACKGROUND Primary intestinal extranodal natural killer/T-cell lymphoma,nasal type(PIENKTCL)is a rare non-Hodgkin’s lymphoma(NHL)subtype,and its prognosis is extremely poor.Clinical characteristics of the disease are not obvious and easily misdiagnosed.In this case report,we describe a patient with PI-ENKTCL who presented with intermittent hematochezia.The advantages of positron emission tomography/computed tomography(PET-CT)as a useful diagnostic tool and the role of surgery as an important therapy are highlighted.CASE SUMMARY A 45-year-old man,hospitalized due to intermittent hematochezia,underwent gastroscopy,colonoscopy,biopsy and CT,but no cause was found.Hence,we carried out a multidisciplinary team(MDT)discussion on the causes and treatment of this patient,and it was decided to perform PET-CT imaging with a MDT discussion of the results.PET-CT demonstrated a diagnosis of lymphoma and it was decided to surgically resect the lesion,and a R0 resection was successfully performed.Postoperative pathology showed negative resection margins,and examination of the lesion confirmed the diagnosis of PI-ENKTCL.After surgery,the patient underwent a follow-up period of 6 mo and received 6 cycles of gemcitabine,oxaliplatin and L-asparaginase.No recurrence or metastasis occurred.CONCLUSION PI-ENKTCL is rare,and MDT discussion is required during diagnosis.PET-CT can be performed for imaging diagnosis.Treatment is based on surgical resection,and the best treatment regimen is determined according to postoperative pathological results to improve prognosis and to extend survival in patients.

Combination of atezolizumab and chidamide to maintain long-term remission in refractory metastatic extranodal natural killer/T-cell lymphoma:A case report

BACKGROUND The prognosis of refractory extranodal natural killer/T-cell lymphoma(ENKTL)is poor.Recent data have indicated that immune checkpoint blockade with a programmed cell death protein-1(PD-1)antibody in combination with administration of histone deacetylase inhibitors represents a potentially effective treatment strategy.Compared with PD-1 antibodies,programmed death-ligand 1 antibodies have fewer side effects.Here,we present a rare case of a patient with refractory metastatic ENKTL who achieved sustained remission of approximately 10 mo with minor adverse effects after combination therapy with atezolizumab,chidamide,and radiotherapy.CASE SUMMARY A 56-year-old woman underwent resection of a tumour in her left nasal cavity and was diagnosed with ENKTL(nasal type).Medical examination revealed tumours observed in the bilateral nasal mucosa,the subcutaneous soft tissue of the inner side of the left eye,the soft tissue of the nasopharynx,the bilateral tonsils,and the left preauricular,right hilar,bilateral neck lymph nodes and bone marrow.However,tomography/computed tomography showed increased metabolism of the bilateral nasal mucosa and subcutaneous soft tissue of the inner side of the left eye and newly increased metabolism of the left cervical lymph node after chemotherapy.Therefore,combination therapy with chidamide,atezolizumab,and radiotherapy was performed.Fortunately,the patient achieved a complete response following 10 mo of combination therapy.CONCLUSION The outcome in this case suggests that the combination of atezolizumab,chidamide,and radiotherapy is a promising regimen for treating refractory metastatic ENKTL following chemotherapy treatment failure.

Human CD4- CD8- Invariant Natural Killer T Cells Promote IgG Secretion from B Cells Stimulated by Cross-Linking of Their Antigen Receptors

Immunoglobulin (Ig) M production can be induced by the interaction of thymus-independent type-2 (TI-2) antigen (Ag) with B cell Ag receptors (BCRs) without the involvement of conventional T cells;for IgG production through the same process, however, a second signal is required. Previous studies have reported that invariant natural killer T (iNKT) cells may be responsible for the second signal involved in IgG production. In the present study, we addressed whether human iNKT cells could participate in the production of Ig against TI-2 Ag in vitro. Two major distinct subsets of human iNKT cells, CD4+ CD8β- (CD4) and CD4- CD8β- [double negative (DN)] cells, were generated from peripheral blood monocytes from a healthy volunteer. BCR engagement, triggered by anti-IgM antibody stimulation, examined here as a model of BCR engagement triggered by TI-2 Ag, induced abundant IgM production by B cells. Both CD4 and DN iNKT cells reduced IgM production and conversely enhanced IgG production in a dose-dependent manner. In addition, IgG production by CD19+CD27- (naïve) and CD19+CD27+ (memory) B cells was predominantly promoted by DNiNKT cells rather than CD4 iNKT cells;nevertheless, IgM production by both B cell subsets was similarly reduced by either subset of iNKT cells. These results suggest that the DN iNKT subsets may preferentially promote Ig class switching by B cells upon stimulation with TI-2 Ag.

REGULATORY EFFECTS OF HUMAN RECOMBINANT IL-6 ON NATURAL KILLER CELL ACTIVITY OF HUMAN FETAL SPLEENS

In the present study it was proved first that human recombinant interleukin-6(HrIL-6) significantly augmented natural killer(NK) cell activity derived from human fetal spleens against K562 target cells in a 4 hours 51Cr release assay. The enhancement of NK activity with 24 hours preincubation in HrlL-6 was dose-dependent, and significantly higher than that of fresh NK cells and controls cultured with RPMI-1640 medium alone (P<0.001). We also found that IL-6 was able to augment NK activity from different fetal spleens at 20 to 40 weeks of gestation (up to 2.24 to 2.78 times), and no difference of NK activity of fetal splenocytes treated by HrIL-6 was observed between different fetal age (32.3% to 45.4%, P>0.05). Furthermore, IL-6-augmented NK activity of fetal splenocytes was very similar to adult levels (P>0.05). These finding strongly indicated that IL-6 plays an important role in the development of NK cell function during the gestational period, suggesting that IL-6 may be of importance in the regulation of host defense mechanisms against malignancies and viral diseases.

Tumor immunotherapy: New aspects of natural killer cells

A group of impressive immunotherapies for cancer treatment, including immune checkpoint-blocking antibodies,gene therapy and immune cell adoptive cellular immunotherapy, have been established, providing new weapons to fight cancer. Natural killer（NK） cells are a component of the first line of defense against tumors and virus infections. Studies have shown dysfunctional NK cells in patients with cancer. Thus, restoring NK cell antitumor functionality could be a promising therapeutic strategy. NK cells that are activated and expanded ex vivo can supplement malfunctional NK cells in tumor patients. Therapeutic antibodies, chimeric antigen receptor（CAR）, or bispecific proteins can all retarget NK cells precisely to tumor cells. Therapeutic antibody blockade of the immune checkpoints of NK cells has been suggested to overcome the immunosuppressive signals delivered to NK cells.Oncolytic virotherapy provokes antitumor activity of NK cells by triggering antiviral immune responses. Herein,we review the current immunotherapeutic approaches employed to restore NK cell antitumor functionality for the treatment of cancer.

Distribution of natural killer cells and T-lymphocyte subsets in peripheral blood,gallbladder cancer and surrounding tissue

BACKGROUND: The patient with malignant tumor always show immunologic function drawback and ingravescent with tumor development, especially in the aspect of cell-mediated immunity. This study was undertaken to define the relationship between the immune function of local cells and cancer development by investigating the distribution of natural killer (NK) cells and T-lymphocyte subsets in peripheral blood, the cancer tissue and the tissue surrounding gallbladder carcinoma. METHODS: The numbers of CD4(+) and CD8(+) T-lymphocytes and NK cells were measured by flow cytometry in samples taken from gallbladder cancer tissue, the surrounding tissues and peripheral blood of 38 patients, and compared with the numbers in the peripheral blood and gallbladder tissue of 30 patients with cholecystitis as controls. RESULTS: The numbers of CD4(+) and CD8(+) T-cells and NK cells in gallbladder cancer tissues were significantly higher than those in the surrounding tissue and gallbladder with gallstone. However, the ratio of CD4(+)/CD8(+) was lower in the cancer tissue than that in the surrounding tissue and tissue from gallbladders with gallstones. The distribution of CD4(+) and CD8(+) T-cells and NK cells in mucous membrane of cholecystitis gallbladder and that in the tissue surrounding gallbladder cancer were significantly different. CONCLUSIONS: Disproportionate and imbalanced distribution of NK cells and subsets of T-lymphocytes occurs in the mucous membrane proper of gallbladder cancer and surrounding tissue. Although gallbladder cancer tissue has higher expressions of CD4(+), CD8(+) and NK cells, the immune function is low or in an inhibited state. In gallbladder cancer immunization therapy, local cellular immunological function should be enhanced and the protective barrier improved.

Synchronous adenocarcinoma and extranodal natural killer/T-cell lymphoma of the colon:A case report and literature review

Extranodal natural killer/T-cell lymphoma(ENKTL) is a distinct subtype of non-Hodgkin's lymphoma and is rare in the colon.Synchronous adenocarcinoma and ENKTL of the colon has not been reported in the literature.In the present study,we report a 63-year-old male who suffered from intermittent bloody stools for 2 mo.He did not have fever,body weight loss or night sweat.Endoscopic and imaging studies revealed a 4.5-cm ulcerative mass in the ascending colon and a 3.0-cm polypoid,easy bleeding mass in the sigmoid colon,respectively.Thought to have double carcinoma of the colon,he received simultaneous right hemicolectomy and sigmoidectomy.The pathological diagnosis was a synchronous ENKTL(ascending colon) and adenocarcinoma(sigmoid colon).The literature on synchronous adenocarcinoma and malignant lymphoma of the colon was also reviewed.

Human natural killer cells for targeting delivery of gold nanostars and bimodal imaging directed photothermal/photodynamic therapy and immunotherapy

Objective:To construct a novel nanoplatform GNS@CaCO3/Ce6-NK by loading the CaCO3-coated gold nanostars(GNSs)with Chlorin e6 molecules(Ce6)into human peripheral blood mononuclear cells(PBMCs)-derived NK cells for tumor targeted therapy.Methods:GNS@CaCO3/Ce6 nanoparticles were prepared and characterized by TEM and UV-vis.The cell surface markers and cytokines secretion of NK cells before and after loading the GNS@CaCO3/Ce6 nanoparticles were detected by Flow Cytometry(FCM)and ELISA.Effects of the GNS@CaCO3/Ce6-NK cells on A549 cancer cells was determined by FCM and CCK-8.Intracellular fluorescent signals of GNS@CaCO3/Ce6-NK cells were detected via Confocal laser scanning microscopic(CLSM)and FCM at different time points.Intracellular ROS generation of GNS@CaCO3/Ce6-NK cells under laser irradiation were examined by FCM.The distribution of GNS@CaCO3/Ce6-NK in A549 tumor-bearing mice were observed by fluorescence imaging and PA imaging.The combination therapy of GNS@CaCO3/Ce6-NK under laser irradiation were investigated on tumor-bearing mice.Results:The coated CaC03 shell on the surface of GNSs exhibited prominent delivery and protection effect of Ce6 during the cellular uptake process.The as-prepared multifunctional GNS@CaCO3/Ce6-NK cells possessed bimodal functions of fluorescence imaging and photoacoustic imaging.The as-prepared multifunctional GNS@CaCO3/Ce6-NK cells could actively target tumor tissues with the enhanced photothermal/photodynamic therapy and immunotherapy.Conclusions:The GNS@CaCO3/Ce6-NK shows effective tumor-targeting ability and prominent therapeutic efficacy toward lung cancer A549 tumor-bearing mice.Through fully utilizing the features of GNSs and NK cells,this new nanoplatform provides a new synergistic strategy for enhanced photothermal/photodynamic therapy and immunotherapy in the field of anticancer development in the near future.

Functional distinction of rat liver natural killer cells from spleen natural killer cells under normal and acidic conditions in vitro

BACKGROUND: The microenvironment within solid tumors has often been shown to exhibit an acidic extracellular pH. Although the morphologic and functional differences in natural killer (NK) cells of the liver and spleen have been reported previously under physiological conditions, the difference under acidic conditions is still unclear. This study was to investigate the differences in the morphological and functional characteristics between rat liver and spleen NK cells under normal and acidic conditions in vitro. METHODS: Liver and spleen NK cells were isolated and purified from Sprague-Dawley rats by density gradient centrifugation and the Dynabeads FlowComp TM Flexi system, and stimulated for 4 days with or without IL-2 or treated with low pH or control for different times. Morphology was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), cell death and proliferation assays were performed by flow cytometry, IFN-γ production was tested by ELISA, and cytotoxic activity was evaluated by lactate dehydrogenase (LDH) release assay. RESULTS: Liver NK cells had significantly higher levels of cytotoxic activity than spleen NK cells under normal and acidic conditions, and the maximum difference was observed at pH 5.6. Further analysis revealed that the cytotoxic activity of NK cells was correlated with morphology, cell death, proliferative activity and IFN-γ production. By TEM, liver NK cells contained a greater number of electron-dense granules per cell at pH 5.6.Moreover, a modest elevation of cell death and reduction of proliferation of liver NK cells occurred within a range of 5.6-7.2. Interestingly, an acidic extracellular pH only marginally, and not significantly, suppressed IFN-γ production by liver NK cells. CONCLUSION: The sharp morphological and functional differences shown by the two types of NK cells in vitro indicate that liver NK cells are unexpectedly resistant to pH shock.

Research on stress-induced apoptosis of natural killer cells and the alteration of their killing activity in mouse liver

AIM:To investigate the stress-induced apoptosis of natural killer(NK)cells and the changes in their killing activity in mouse livers.METHODS:A restraint stress model was established in mice.Flow cytometry was employed to measure the percentage of NK cells and the changes in their absolute number in mouse liver.The cytotoxicity of hepatic and splenic NK cells was assessed against YAC-1 target cells via a 4 h 51Cr-release assay.RESULTS:The restraint stress stimulation induced the apoptosis of NK cells in the liver and the spleen,which decreased the cell number.The number and percentage of NK cells in the spleen decreased.However,the number of NK cells in the liver decreased,whereas the percentage of NK cells was significantly increased.The apoptosis of NK cells increased gradually with prolonged stress time,and the macrophage-1(Mac-1)+NK cells were more susceptible to apoptosis than Mac-1-NK cells.Large numbers of Mac-1-NK cells in the liver,which are more resistant to stress-induced apoptosis,were observed than the Mac-1-NK cells in the spleen.The stress stimulation diminished the killing activity of NK cells in the spleen was significantly decreased,but the retention of numerous Mac-1-NK cells in the liver maintained the killing ability.CONCLUSION:Significant stress-induced apoptosis was observed among Mac-1+NK cells,but not Mac-1-NK cells in the mouse liver.Stress stimulation markedly decreased the killing activity of NK cells in the spleen but remained unchanged in the liver.

Effects of Intraoperative Administration of Dexmedetomidine on the Percentage of T-Lymphocyte Subsets and Natural Killer Cells in Patients with Colorectal Cancer

Study Objective: To observe the effect of dexmedetomidine (DEX) on T-lymphocyte subsets and natural killer (NK) cells in the peripheral blood of perioperative patients with colorectal cancer. Design: A random double-blind control clinical study. Setting: A university hospital. Patients: Forty patients with colorectal cancer, ASA I-П. Interventions: All patients were randomly divided into a DEX group (n = 20) and a control group (n = 20). Before induction of anesthesia, epidural catheters were placed in the L1-L2 or T12-L1 intervertebral spaces. The DEX group received 1 μg/kg of DEX (200 μg/50 ml) intravenously for 15 min prior to the surgery, which was then infused at a rate of 0.5 μg/kg/h until 30 min before the end of the surgery. The control group received an intravenous infusion of saline (50 ml) instead of DEX during the same periods as the DEX group. All patients received routine anesthesia and postoperative analgesia. Measurements: Blood samples from all patients were collected at the following time points: before anesthesia (T0), 24 h after surgery (T1), 48 h after surgery (T2) and 72 h after surgery (T3). Changes in T-lymphocyte subsets (CD3+, CD4+, CD8+, CD4+/CD8+) and NK cells were determined by flow cytometry. Main Results: Compared with the control group, the percentages of CD3+ and CD4+ cells and the CD4+/CD8+ ratio in the DEX group increased significantly from T1 to T3