Natural Killer Activity In Patients Research Articles

Both CD4+CD25+Foxp3+ Regulatory T Cells and CD3-CD56+ NK Cells Affect the Response of Newly Diagnosed Chronic Myeloid Leukemia Patients to Treatment with a Tyrosine Kinase Inhibitor

Background: Regulatory T cells (Treg) play a role in the maintenance of chronic myeloid leukemia (CML). In contrast, natural killer (NK) cells have spontaneous cytolytic activity against various tumor cells, including leukemic cells, and play an important role in immune surveillance against tumor cells. In this study, we examined changes in the number of circulating Treg and NK cells and the NK activity of patients with CML before and after treatment with a tyrosine kinase inhibitor (TKI). Our goal was to evaluate the clinical significance of this treatment on these two different cell types.Patients and Methods: Treg and NK cells were characterized and quantified by flow cytometry in 13 newly diagnosed CML patients, 5 newly diagnosed patients with other myeloproliferative neoplasms (MPN), and 15 healthy controls. We analyzed all CML patients diagnosed with chronic phase (CP) disease and MPN patients from January 2015 and June 2016. Patients with CML, who were initially treated with TKI between January 2015 and June 2016 and were followed up for more than one year, were enrolled in the study. The mRNA level of the BCR-ABL fusion gene was analyzed by real-time PCR analysis at approximately 6-month intervals during the first year and at 12-month intervals thereafter. After obtaining informed consent, blood was drawn from all patients at initial diagnosis and 12 months after the start of treatment. CD4+CD25+Foxp3+ Treg cells, CD3+CD4+T cells, CD3+CD8+ T cells, and CD3-CD56+ NK cells were analyzed using flow cytometry, and the absolute numbers of these cells were calculated. The NK activity was measured by the standard 51Cr release assay at effector: target (E: T) ratios of 20:1.Results: The median age for CML patients was 65 years (range: 47-84), and 9 of the patients were male. The median period of observation was 543 days. After 12 months, 8 CML patients (MMR-group) had a major molecular response (MMR), and 5 patients (NR-group) did have not a MMR. Before treatment, the absolute number of Treg cells was significantly lower in the MMR-group than that in the NR-group (27.6 ± 10 vs. 50.0 ± 24.0 /μL, p=0.037). Similarly, the absolute number of Treg cells after treatment was significantly lower in both the MMR-group (27.3±10.3 /μL) and the MPN-group (27.6±11.5 /μL) than that in the NR-group (40.0±9.9 /μL, p=0.05, p<0.01, respectively). Treg% values in peripheral lymphocytes before treatment in the NR (7.4±2.1%) were significantly higher than that in MMR group and in the healthy group (4.7±1.7%, 5.5±1.1%, p=0.024, p=0.016, respectively). The absolute number and percentages of CD3-CD56+ NK cells before treatment as well as after treatment did not differ between each group. However, NK activity before treatment in the NR-group (15±1.4%) was significantly lower than that in MMR-group (47.2± 11.6 vs 41.7±4.1%, p<0.01, p<0.01, respectively). With time, the number of CD8+ T cells in the NR group decreased significantly from 940±570 to 348± 167/μL (p=0.040), and the Treg% increased significantly from 0.18± 0.13 to 0.84± 0.29% (p<0.01). The relative percentage of CD3+CD4+ T cells (4.7±4.4%) in the 15 CML patients increased remarkably after treatment (12.8±4.3%, p<0.01) but the absolute number did not change.Conclusions: Treg cell numbers were significantly lower in the CML patients with a MMR compared to that in the patients without a MMR. Although the number of NK cells did not change in the MMR group compared to that in the NR group, the NK activity was significantly higher. While the mechanisms for these changes in cell populations are not completely understood, it is also important to note that we have not yet studied the cellular source and production of cytokines which enhance NK activity. The data suggest that some immunological mechanisms are involved in the response to TKI. Moreover, the increased levels of NK activity in patients with MMR suggest that not only Treg cell numbers but also NK activity may have clinical importance in evaluating the effects of TKI therapy. DisclosuresNo relevant conflicts of interest to declare.

Restoration of natural killer cell activity by interferon-free direct-acting antiviral combination therapy in chronic hepatitis C patients.

Interferon-free direct-acting antiviral (DAA) therapy is an effective treatment for chronic hepatitis C (CH(C)) patients. Activity of natural killer (NK) cells was reported to be impaired in patients with hepatitis C virus infection. The aim of this study was to examine whether DAA therapy could restore NK activity in patients with CH(C). Direct-acting antiviral therapy was given to 31 CH(C) patients as asunaprevir/daclatasvir (ASV/DCV) (n = 15), ledipasvir/sofosbuvir (n = 7), ombitasvir/paritaprevir/ritonavir (n = 6), or elbasvir/grazoprevir (n = 3). Prior to therapy (0M), at the completion of the therapy (EOT), and at 24weeks after completion (AFTER), NK activity and the frequency of CD56dim NK and CD56bright NK cells in peripheral blood were estimated by Cr release assay and flow cytometry. Statistical analysis was carried out by anova and the Mann-Whitney U-test. In one of the ASV/DCV-treated patients, treatment was stopped 12weeks after initiation of therapy because of viral breakthrough. The anova showed that NK activity significantly improved at EOT (vs. 0M, P < 0.01) and at AFTER (vs. 0M, P < 0.001) in 30 patients with sustained virologic response. It also showed that the frequency of CD56dim NK cells was significantly increased at EOT and at AFTER (vs. 0M, P < 0.05). In addition, the NK activity ratio (AFTER/0M) had no significant difference between patient groups with higher and lower Fibrosis-4 scores. Direct-acting antiviral therapy in CH(C) patients could improve NK activity by increasing the frequency of CD56dim NK cells. Additionally, our results might imply that DAAs therapy could reduce the risk of hepatocarcinogenesis by restoring innate immune responses.

In vitro modulation of natural killer activity of human peripheral blood mononuclear cells against prostate tumor cell line

Objective: Natural killer (NK) cells have long been known to be involved in the recognition and lysis of tumor cells but the mechanisms contributing to deficient NK activity in patients with cancer remains unclear. Manipulation of them is likely essential to the success of cancer immunotherapy protocols although optimal stimulation and maintenance of NK activity remains elusive. Here we studied the stimulatory effects of PHA and K562, on NK activity of human peripheral blood mononuclear cells (PBMCs).Materials and methods: The NK activity of PBMCs against DU-145 was determined with 51Cr-release assay. The PBMCs were stimulated with PHA, either on one occasion or repetitively on three occasions (1-PHA-PBMC or 3-PHA-PBMC, respectively), and were incubated with irradiated K562 (iK562). The expression of CD56, NKG2D and MICA/B were detected on PBMCs and cell lines with flow cytometry.Results: PHA stimulation increased the proportion of CD56+ cells and upregulated NKG2D expression on 1-PHA-PBMC and 3-PHA-PBMC, but co-incubation with iK562 decreased NKG2D expression on 1-PHA-PBMC without change of NKG2D expression on the 3-PHA-PBMC. NK activity of 1-PHA-PBMC appeared to decrease with co-incubation with iK562 compared to a significant increase in activity of 3-PHA-PBMC. A similar increase in interferon-γ (IFN-γ) secretion from 3-PHA-PBMC was demonstrated compared to 1-PHA-PBMC.Discussion and conclusion: Our results demonstrated that varying the mitogen exposure to PBMCs affect the influence of iK562 on NK activity. This effect appeared to be unrelated to the subsequent expression of NKG2D or IFN-γ secretion. These results may be beneficial in the development of future cancer immunotherapy protocols.

Defective NATURAL Killer ACTIVITY Improved by IL-2 Stimulation Independent of CD16 and NKG2D Receptors IN PATIENTS with THALASSEMIA MAJOR.

Abstract 4746DEFECTIVE NATURAL KILLER ACTIVITY IMPROVED BY IL-2 STIMULATION INDEPENDENT OF CD16 AND NKG2D RECEPTORS IN PATIENTS WITH THALASSEMIA MAJORZeynep Karakaρ1,Belkýs Atasever2, Serap Erdem Kuruca3, Batu Erman2, Agaoglu Leyla11.Istanbul Faculty of Medicine, Department of Pediatrics, Istanbul University, Istanbul, Turkey2.Faculty of Engineering and Natural Sciences, Biological Sciences & Bioengineering Program, Sabanci University, Istanbul, Turkey3 Istanbul Faculty of Medicine, Department of Physiology, Istanbul University, Istanbul, Turkiye BACKGROUNDNatural killer (NK) cells account for up to 15% of blood lymphocytes. Functional NK cells are found in the spleen. The function of NK cells is to recognize and kill virus infected cells and certain tumor cells. The mechanism of recognition is not fully understood, but it involves both activating and inhibitory receptors. CD 16 and NKG2D are receptors involved in two of the activation pathways of NK cells. NK cells use a variety of different mechanism to kill their targets. These include direct cell-cell signalling via surface molecules, and indirect signalling via cytokins. A decreased level of natural killer (NK) activity is one of the various immunological abnormalities in patients with thalassemia major. AIMThis study aims to evaluate the relationship between NK cytotoxicity and CD 16 and NKG2D receptors, and effect of IL-2 stimulation in patients with thalassemia major. PATIENTS AND METHODSThe study includes 26 patients with thalassemia major (TM) with age ranged 7-35 (median age was 18, 17 of them were female and 9 male), and sex and age matched 16 normal healthy subjects as controls. Fourteen of the patients were splenectomized. Patients regulary chelated with deferasirox (n:16), deferipron (n: 8) and desferroxamin (n: 2). NK cells were isolated from PBMC of subjects by using RosetteSep. Before and after the IL2 incubation; CD16, NKG2D receptors are examined in NK cells of both b-thalassemia major patients and controls by flow cytometry and we analyzed cytolytic function of NK cells against K562 cells. The cytotoxic activity of NK cells was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Ratios of NK cells /K562 cells (Efector:Target (E:T)) were 1:1, 10:1 and 20:1. RESULTSNK cytotoxicity was found to be lower at E:T ratios of 1:1 and 10:1 in patients with thalassemia major when compared to controls(p < 0.05). Patients with above 18 years old had significantly lower NK activity than below 18 years old. Sex, presence of splenectomy and chelation type did not effect on NK activity (p>0.05). NK cytotoxicity significantly increased by IL-2 stimulation in 26 patients at E:T ratio of 10:1 (p<0.05). But the increase was still less than the control. There was no significantly statistically difference between CD16 and NKG2D receptor levels compared with patients and controls. Patient's CD 16 receptor levels did not change after incubation with IL-2. NKG2D receptor levels of control NK cells significantly increased after IL-2 incubation (2021.66 / 1675.79/molecule, p<0.003). We detected significantly increased levels of NKG2D after IL-2 incubation in patients with splenectomy than patients without splenectomy (1834.80 / 901.41/molecule, p<0.005). CONCLUSIONIL-2 may have potential therapeutic effect to improve the defective NK activity in patients with thalassaemia major. Increasing effect of IL-2 stimulation on NK activity may be independent than NKG2D receptor pattern. Defective NK cell functions can be partially restored by interleukin IL-2.This study was supported by Istanbul University Research Fund. Disclosures:No relevant conflicts of interest to declare.

Loss of natural killer activity as an indicator of relapse in acute leukaemia

A role for naturally occurring cytotoxic cells in immunosurveillance against malignancy has been presumed in several studies. The natural killer activity (NKA) of peripheral blood mononuclear cells was therefore measured at regular intervals in patients with acute leukaemia and expressed specific cytotoxicity. Sixty controls had a median NKA of 33.6% (range 15.4-71). Seventy-three patients with acute lymphoblastic leukaemia (ALL) and acute non-lymphoblastic leukaemia (ANLL) with untreated or relapsed disease had a median activity of 2.4% (range 0-13.4) (P less than 0.001), while 57 patients who had achieved complete remission had a median activity of 22.7% (range 9.5-64.4). In 15 patients, reductions of NKA were seen prior to 16 episodes of relapse. In ten of these (nine with ANLL and one with ALL), 11 relapses were preceded within 10 weeks by drops in NKA to less than 30% of remission levels. The median NKA of the group prior to the drop in activity was 25.5% and the median first low value was 6.0%. Five patients who relapsed after allogeneic bone marrow transplantation had significant, sustained drops in NKA, 5-9 weeks earlier. The median NKA prior to the drop was 25.6% and the median first low value was 8.0%. We therefore conclude that there was a marked reduction in NKA in patients with active acute leukaemia when compared with healthy blood donors and that this activity substantially improved in complete remission. All patients who relapsed had significantly reduced NKA which in some, significantly preceded the time of relapse. These data suggest that the regular assessment of NKA in patients with acute leukaemia may be a useful diagnostic tool.

The Effect of Cardiovascular Drugs on Pro-Inflammatory Cytokine Secretion and Natural Killer Activity of Peripheral Blood Mononuclear Cells of Patients with Chronic Heart Failure in vitro

Recent studies have shown that patients with heart failure over-express pro-inflammatory cytokines which enhance natural killer (NK) activity and negatively influence contractility and contribute to the remodeling of myocardium. The question is that how cardiovascular drugs influence on the cytokines of Peripheral Blood Mononuclear Cells (PBMCs) in Chronic Heart Failure (CHF). To study the effect of cardiovascular drugs on PBMCs-cytokines and NK activity of CHF patients. PBMCs of CHF patients/normal controls collected by Ficoll-paque density centrifugation. NK activity against K562 target cell was measured with MTT colorimetric assay. PBMCs were cultivated in RPMI/FCS, stimulated with phytohaemaglutinin (PHA). Tumor necrosis factor (TNF)-alpha interleukin (IL)-6, IL-2 and IL-1beta of culture supernatants after 24 h incubation with/without furosemide, captopril and digoxin were measured with sandwitch ELISA. Patients had higher NK activity than controls (56.9% +/- 1.6 vs 50.9% +/- 1.2, p < 0.05). NK activity of patients who already consumed Captopril/Furosemide didn't show difference with controls. Captopril (3, 1, 0.3 microg mL(-1)) and Furosemide (5, 2.5, 1.25 microg mL(-1)) caused a dose dependent inhibition in TNF-alpha compared with control (329 +/- 23, 427 +/- 15, 519 +/- 19 and 343 +/- 19, 430 +/- 14, respectively vs. 562 +/- 24 pg mL(-1) p < 0.05). Furosemide caused a dose dependent decrease in IL-6 (421 +/- 31, 534 +/- 33 vs. 662 +/- 41 pg mL(-1) p < 0.05). Captopril and Furosemide didn't show any significant effect on IL-1beta/IL-2. Digoxin had no significant effect on PBMCs-cytokines. These data suggest that the immunomodulatory effects of Captopril and Furosemide may contribute to their beneficial and no long-term adverse effects on PBMCs.

IN VITRO EFFECTS OF VITAMIN C AND SELENIUM ON NK ACTIVITY OF PATIENTS WITH β -THALASSEMIA MAJOR

In this study, the in vitro effects of vitamin C and selenium on natural killer (NK) cell activity of β-thalassemia major patients was investigated. At first, significant decreased NK activity was found at E:T ratios of 1:1, 5:1, and 10:1 in whole thalassemia patients. Low-dose selenium treatment enhanced NK activity in patients but there was no change in the control group. High-dose selenium decreased NK activity significantly in splenectomized patients. Different doses vitamin C enhanced NK activity significantly in both splenectomized and unsplenectomized patients. According to these results, selenium dosage should be arranged carefully in thalassemia patients, whereas vitamin C can be used confidently.

Preconception Peripheral Natural Killer Cell Activity as a Predictor of Pregnancy Outcome in Patients with Unexplained Infertility

Preconception high peripheral natural killer (NK) cell activity in women with recurrent spontaneous abortion can predict subsequent miscarriages. We have examined prospectively, for the first time, the pregnancy rate in patients with unexplained infertility by measuring the peripheral NK activity. We tested the peripheral NK activity of 94 infertile women who despite treatment were unable to conceive for 6 or more months (mean; 2.4 years). Peripheral NK activity was measured by a chromium-51 release cytotoxicity assay. Women were followed for 2 years and assessed. In 77 patients who were followed for 2 years, 28 had conceived but 49 did not. The peripheral NK activity of the group that became pregnant (mean +/- S.D.; 34.5 +/- 13.8%) was significantly lower than that of non-conception group (42.3 +/- 13.3%, P = 0.017). Our finding suggests that elevated peripheral NK activity in patients with unexplained infertility is a risk factor for attaining pregnancy success.

Natural killer cell activity and distant metastasis in rectal cancers treated surgically with and without neoadjuvant chemoradiotherapy.

We investigated whether impaired preoperative natural killer (NK) cell activity correlates with asynchronous distant metastasis after curative surgery for rectal cancers. In addition, we examined if preoperative chemoradiotherapy for rectal cancers impairs NK cell activity and contributes to the induction of distant metastasis. Preoperative NK cell activity was examined in 174 rectal cancer patients. All patients were enrolled in this study and followed until asynchronous distant metastasis occurred. The mean NK activity in patients with stage IV disease (n = 20) was significantly lower than seen in other stages. There were no differences among stage I to stage III patients. In stage III patients, the cumulative distant metastasis-free rate after curative surgery was significantly lower in cases with NK activity of 25% or less than those with more than 25%. Preoperative chemoradiotherapy for stage I to III patients significantly impaired NK cell activity (n = 39), and the metastasis-positive ratio significantly increased among patients with stage II or stage III diseases (n = 30). Multivariate analysis indicated that dichotomized NK cell activity was a significant risk factor that is associated with distant metastasis as well as nodal involvement. In primary rectal cancers, NK cell activity is not necessarily impaired in accordance with the disease progression. It is considered an important background factor for developing asynchronous distant metastases in stage III rectal cancers. Neoadjuvant chemoradiotherapy impaired NK cell activity in selected patients, suggesting the necessity of concurrent immunotherapy for better outcomes.

Immunosuppressive effect of chenodeoxycholic acid on natural killer cell activity in patients with biliary atresia and hepatitis C virus-related liver cirrhosis.

Patients with severe liver diseases, such as liver cirrhosis and biliary atresia, have low natural killer (NK) cell activity. The relations between NK activity and measures of liver function, including serum levels of total bilirubin, total bile acids, bile acid components, aspartate aminotransferase, and alanine aminotransferase, and platelet count were examined in patients with biliary atresia (6 boys and 6 girls; mean age, 4.8+/-5.7 years) and patients with liver cirrhosis due to hepatitis C virus infection (10 men and 2 women; mean age, 54.3+/-13.8 years). Univariate analysis showed that platelet count was positively correlated with NK activity in patients with biliary atresia (r = 0.611, P < 0.05). Serum levels of free chenodeoxycholic acid were negatively correlated with NK activity both in patients with biliary atresia (r = -0.647, P < 0.05) and in patients with hepatitis C virus-related liver cirrhosis (r = -0.876, P < 0.01). None of the other free bile acids or conjugated bile acids or other indicators of liver function were correlated with NK activity. Multiple stepwise regression analysis showed that only levels of free chenodeoxycholic acid were independently correlated with NK activity. All patients with biliary atresia underwent liver transplantation from living related donors. NK activity had increased significantly two months after transplantation (from 24.1+/-20.2% to 49.2+/-12.5%, P < 0.01). In contrast, levels of free chenodeoxycholic acid in transplant recipients had decreased significantly two months after transplantation (from 1.22+/-1.16 to 0.26+/-0.21 micromol/l, P < 0.05). In conclusion, in patients with biliary atresia or liver cirrhosis, NK activity in peripheral blood decreases, mostly because of free chenodeoxycholic acid.

Natural killer cell activity in patients with Graves' disease and Hashimoto's thyroiditis.

Natural killer (NK) cell activity of peripheral blood lymphocytes (PBL) against k562 human tumor cell targets was studied in patients with Graves' disease and Hashimoto's thyroiditis. NK activity was measured in a standard 4-hour 51chromium (Cr) release assay. Cytotoxicity was expressed as lytic units (LU)/10(6) PBL. Significantly decreased NK cell activity was demonstrated in both groups of patients, with mean (+/- SE) lytic units of 10.3 (+/- 9.1) and 13.3 (+/- 10.3) for patients with Graves' disease and Hashimoto's thyroiditis, respectively, compared with 36.0 (+/- 26.3) for age- and sex-matched normal subjects. When patients with Graves' disease were analyzed according to their thyroid status; NK activity was significantly depressed in (1) hyperthyroid patients before treatment; (2) hyperthyroid patients receiving antithyroid therapy; and (3) euthyroid patients receiving antithyroid therapy, compared with normal subjects. Graves' disease patients who were hypothyroid after radioactive iodine therapy or thyroidectomy had normal NK activity. No significant differences between hyperthyroid and euthyroid patients or between hypothyroid patients and normal subjects were demonstrated. NK activity in patients with Graves' disease did not correlate with serum levels of thyroxine, the presence or severity of ophthalmopathy, or titers of serum thyroid antibodies. In patients with Hashimoto's thyroiditis there was no correlation between NK activity and goiter size, titers of antithyroid antibodies, or thyroid status. These findings suggest that depression of NK activity in both disorders is secondary to abnormalities of thyroid hormone secretion, although an effect of the underlying autoimmune reactions has not been excluded.

Ursodeoxycholic acid corrects defective natural killer activity by inhibiting prostaglandin E2 production in primary biliary cirrhosis

We evaluated the effect of ursodeoxycholic acid on the defective natural killer activity in primary biliary cirrhosis. Administration of ursodeoxycholic acid (600 mg daily) for one month significantly increased natural killer activity in patients with primary biliary cirrhosis (P < 0.05). Ursodeoxycholic acid also enhanced the in vitro natural killer activity of lymphocytes from healthy volunteers, while other hydrophobic bile acids depressed it. Furthermore, ursodeoxycholic acid reduced the prostaglandin E2 concentration in culture supernatants of lymphocytes from healthy volunteers to a lower level than that in culture incubated with chenodeoxycholic acid (P < 0.05) or control cultures (P < 0.01). Urosdeoxycholic acid normalized the defective natural killer activity in primary biliary cirrhosis by reducing the levels of other hydrophobic bile acids and inhibiting prostaglandin E2 production, suggesting that it may be a useful immunomodulating agent for primary biliary cirrhosis.

Relationship of curative surgery on natural killer cell activity in colorectal cancer.

Aim of this study has been to evaluate natural killer (NK) activity in patients with colorectal tumors before and after curative surgery. Forty colorectal cancer patients without distant metastases were stratified according to American Joint Committee on Cancer/International Union Against Cancer staging system into three categories: Stage I (n = 12), Stage II (n = 15), and Stage III (n = 13). All of them underwent curative resection, and there were no major postoperative complications. Venous blood samples were obtained preoperatively, at surgical wound closure, and on the 1st, 7th, and 21st postoperative days. Mononuclear cells were isolated over Ficoll-Hypaque (Lymphoprep, Nycomed Pharma AS, Oslo, Norway) gradients, and NK activity was assayed by evaluation of cytotoxic response against K562 cells. Normal NK activity was achieved from 15 healthy donors. Percentage relative increments in relation to preoperative levels were calculated for every postoperative sample, and t-test was used for statistical evaluation. Before surgery, Stages II and III patients had lower levels of NK activity than healthy people (P < 0.05 and P < 0.001, respectively). NK activity always fell after surgery (Stage I: -18.48 +/- 11.42; Stage II: -16.93 +/- 13.57; Stage III: -35.29 +/- 12.03, at day 1 postsurgery) and appeared to rise slightly by the 21st postoperative day in Stage I patients (+4.87 +/- 12.41). Stage II, and especially Stage III, patients did show a significant recovery by the 21st postoperative day (+23.63 +/- 9.36 and +43.19 +/- 13.34, respectively). At this time, NK activity in these two groups was not significantly lower than in normal subjects (P > 0.05). NK activity is depressed in colorectal cancer patients in relation to progression of illness, even at locoregional stages. Curative resection of tumors at Stages II and III has promoted a recovery of NK activity in patients with uneventful postoperative courses.

Interferon beta enhances the natural killer activity of patients with bladder carcinoma.

We have investigated the effect of interferon beta (INF beta) on the natural killer (NK) cytotoxic activity of peripheral blood mononuclear cells (PBMC) from patients with superficial and infiltrative transitional-cell carcinoma of the bladder (TCC) against both NK-sensitive and NK-resistant target cells. The normal NK activity found in PBMC from these patients can be significantly enhanced by short-term incubation (18 h) with INF beta (P < 0.05). The depressed NK cytotoxic activity found in PBMC from patients with infiltrative TCC can also be significantly enhanced, but not normalized, by short-term incubation with INF beta (P < 0.05). In kinetic studies we found that the maximal levels of the INF beta-promoted cytotoxic activity against NK-sensitive and against NK-resistant target cells in PBMC from TCC patients were reached after 18 h of culture. Short-term-INF beta-incubated PBMC from patients with TCC of the bladder also showed marked cytotoxic activity against NK-resistant target cells. The effector cells of the INF beta-induced cytotoxic activity in PBMC from patients with TCC were CD16+ CD3- NK cells. This cytotoxic inducer effect of INF beta synergized with that of interleukin-2. In conclusion, INF beta can enhance the NK activity of PMBC from patients with TCC of the bladder.

Interferon as adjunctive treatment for non-metastatic renal cell carcinoma

To investigate the effect of recombinant alpha 2b-interferon therapy on natural killer (NK) activity and antibody-dependent cell-mediated cytotoxicity (ADCC) in the peripheral blood in patients with renal cell carcinoma who had undergone radical nephrectomy. Between January 1988 and June 1989, 20 patients (14 men and six women, mean age 59 years, range 43-80) received interferon (IFN) therapy following radical nephrectomy for renal cell carcinoma. Thirteen patients had stage I disease, one had stage II and six had stage III; none had metastases. There was a significant increase in NK activity at 5 and 7 months after starting IFN therapy but there was no increase in ADCC. Low doses of IFN administered long-term increased NK activity in patients with renal cell carcinoma. This finding should be helpful in designating protocols for randomized studies of post-operative IFN administration as adjuvant therapy.

Interferon ? enhances the natural killer activity of patients with bladder carcinoma

Interferon ? enhances the natural killer activity of patients with bladder carcinoma

Depressed natural killer cell activity in schizophrenic patients.

Factors that suppress natural killer (NK) cell activity were examined in a random sample of 73 schizophrenic patients. NK activity in these patients were compared with 25 healthy age, sex and race matched controls. The mean percent of NK activity was 21% in the schizophrenic group compared with 30% percent in the controls. The difference between these two groups was statistically significant. The mean percent of NK activity in the chronic undifferentiated schizophrenic subgroup and schizoaffective subgroup were 20% and 22% respectively. The degree of suppression of NK activity in the chronic undifferentiated subgroup was higher than in the schizoaffective one, but the difference was not statistically significant. The two subgroups were comparable regarding other immune related variables such as total white cell count, neutrophils, lymphocytes, total protein, albumin, globulin, immunoglobulins and stress. The lower impairment of NK activity in the schizoaffective subgroup may be due to their exposure to lithium which can enhance immune functions. Factors associated with significant suppression of NK activity in schizophrenic patients were physical restraint, number of psychotropic medications, number of chronic non-psychiatric diagnoses and race. Psychosocial stressors were associated with suppression of NK activity but it was not statistically significant. Our results identify factors associated with reduced NK activity observed in certain schizophrenic patients and NK activity in these patients may be the result of interaction between various factors.

Endometriotic tissues produce immunosuppressive factors.

In order to study the possible role of the immune functions in the pathogenesis of endometriosis, effects of supernatants from endometrial and endometriotic tissue cultures on the natural killer (NK) activity were examined by determining the lymphocyte cytotoxicity toward an erythroleukemic cell line (K562). Endometrial and endometriotic tissues were obtained at the time of operation from patients with ectopic endometriosis or uterine myoma. The normal peritoneum and myoma tissues were used as controls. The supernatants obtained by culturing the ectopic endometriotic tissues for 24-48 h had significant (p < 0.01) suppressive effects on NK activity of peripheral blood lymphocytes (PBL) from a healthy woman, compared to the supernatants from the normal peritoneum and the myoma tissues. There was no significant difference between NK activities of PBL from patients with ectopic endometriosis and age-matched healthy women. However, the NK activity in patients with low NK status before surgery was significantly elevated after surgery while that in patients with normal NK status before surgery was not changed. Although PBL from the same healthy women could significantly lyse the endometrial cells, the ability was about-one-third the level at which they could lyse K562 cells. These results suggest that the immunosuppressive factors secreted by endometriotic tissues may be involved in the local implantation and development of ectopic endometriosis.

Suppression of natural killer cell activity by granulocytes in patients with aplastic anemia: role of granulocyte colony-stimulating factor

Patients with aplastic anemia were tested for natural killer (NK) activity, and the roles of granulocytes and granulocyte colony-stimulating factor (G-CSF) in the regulation of cytotoxicity were evaluated. Blood lymphocytes showed low or no NK activity against K562 targets. The depression of NK activity was more frequently recorded for patients who were not in remission and those who received G-CSF administration. Granulocytes of aplastic anemia patients with impaired NK activity suppressed the lytic activity of NK cells. By contrast, granulocytes from normal controls and aplastic anemia patients with normal NK activity had no suppressive activity. There was a good correlation between NK activity of lymphocytes and suppressive activity of granulocytes. Blocking of direct contact of suppressor and effector cells by cell chambers abolished suppression of cytotoxicity. NK suppression by granulocytes was resistant to treatment with catalase or superoxide dismutase. In vitro stimulation with G-CSF of granulocytes that naturally had no suppressive activity resulted in development of suppressive function, whereas granulocytes with natural suppressive activity were not further stimulated in vitro by G-CSF to express augmented activity. These results suggest that the presence of suppressor granulocytes in the blood could be one cause of the impaired NK activity in patients with aplastic anemia.

Interferon-alpha-2b enhances the natural killer activity of patients with transitional cell carcinoma of the bladder.

Transitional cell carcinoma (TCC) of the bladder is associated with alterations in the immune system of the host. The authors demonstrated that in patients with bladder carcinoma there is a negative correlation between the levels of natural killer (NK) activity and the clinical evolution and pathologic stages of disease. The authors investigated the effect of various doses of recombinant interferon-alpha-2b (IFN-alpha-2b) for variable periods of culture on the nonmajor histocompatibility-restricted cytotoxic activity of peripheral blood mononuclear cells (PBMNC) with or without CD16 and CD3-depleted populations from patients with superficial (confined to the mucosa or lamina propria) and infiltrative (those infiltrating beyond the lamina propria) TCC of the bladder using 4-hour 51-sodium chromate (51Cr)-release cytotoxicity assays against both NK-sensitive (K562) and NK-resistant (JY) tumor target cells. The normal NK activity detected in PBMNC from patients with superficial TCC of the bladder can be significantly enhanced by short-term (18-hour) incubation with recombinant IFN-alpha (P < 0.05). The depressed NK cytotoxic activity found in PBMNC from patients with infiltrative TCC can also be significantly enhanced, but not normalized, by short-term (18-hour) incubation with recombinant IFN-alpha (P < 0.05). Short-term recombinant IFN-alpha-incubated PBMNC from patients with superficial, but not infiltrative, TCC of the bladder also showed marked cytotoxic activity against NK-resistant target cells. By selection with CD16 or CD3 monoclonal antibodies and complement, it was also found that the precursor and effector lymphocytes of this recombinant IFN-alpha-promoted cytotoxicity belong to NK lineage. In kinetic studies, it was found that the maximal levels of the recombinant IFN-alpha-promoted cytotoxic activity against NK-sensitive and NK-resistant target cells in PBMNC from patients with TCC were reached after 18 hours of culture. Recombinant IFN-alpha can enhance the nonmajor histocompatibility-restricted cytotoxic activity of PBMNC from patients with TCC of the bladder.