Activity Of Peripheral Blood NK Cells Research Articles

Phase I study targeting newly diagnosed grade 4 astrocytoma with bispecific antibody armed T cells (EGFR BATs) in combination with radiation and temozolomide

PurposeThe purpose of this study was to determine the safety, feasibility, and immunologic responses of treating grade 4 astrocytomas with multiple infusions of anti-CD3 x anti-EGFR bispecific antibody (EGFRBi) armed T cells (EGFR BATs) in combination with radiation and chemotherapy.MethodsThis phase I study used a 3 + 3 dose escalation design to test the safety and feasibility of intravenously infused EGFR BATs in combination with radiation and temozolomide (TMZ) in patients with newly diagnosed grade 4 astrocytomas (AG4). After finding the feasible dose, an expansion cohort with unmethylated O6-methylguanine-DNA methyltransferase (MGMT) tumors received weekly EGFR BATs without TMZ.ResultsThe highest feasible dose was 80 × 109 EGFR BATs without dose-limiting toxicities (DLTs) in seven patients. We could not escalate the dose because of the limited T-cell expansion. There were no DLTs in the additional cohort of three patients with unmethylated MGMT tumors who received eight weekly infusions of EGFR BATs without TMZ. EGFR BATs infusions induced increases in glioma specific anti-tumor cytotoxicity by peripheral blood mononuclear cells (p < 0.03) and NK cell activity (p < 0.002) ex vivo, and increased serum concentrations of IFN-γ (p < 0.03), IL-2 (p < 0.007), and GM-CSF (p < 0.009).ConclusionTargeting AG4 with EGFR BATs at the maximum feasible dose of 80 × 109, with or without TMZ was safe and induced significant anti-tumor-specific immune responses. These results support further clinical trials to examine the efficacy of this adoptive cell therapy in patients with MGMT-unmethylated GBM.ClinicalTrials.gov Identifier: NCT03344250

Decreased Production of TNF-α and IL-6 Inflammatory Cytokines in Non-Pregnant Idiopathic RPL Women Immunomodulatory Effect of Sildenafil Citrate on the Cellular Response of Idiopathic RPL Women.

Sildenafil citrate (SC), a PDE5 inhibitor, a drug for erectile dysfunction (ED) and pulmonary hypertension (PAH), was found to exert a positive effect on pregnancy outcomes when administered intravaginally before conception. In our previous studies, sildenafil increased endometrial thickness and significantly decreased peripheral blood NK cell activity after the intravaginal administration in women with recurrent pregnancy loss (RPL). No data are available to confirm the effect of sildenafil on maternal T cell populations involved in shaping fetal-maternal tolerance and NK cell activity. Thus, the present study aimed to establish if SC influences NKT cells or the axis of Th17/Treg cells and Th1/Th2 cytokine production. Materials and methods: Twenty-one healthy fertile women and twenty-two nonpregnant women with idiopathic RPL were studied. The ELISA method was used to evaluate the production of cytokines, including IL-2, IL-12p40, IL-4, IL-10, IL-6, IL-17, IL-21, TGF-β, TNF-α, and IFN-γ in PBMC culture supernatants before and after supplementation with the physiological concentration of SC. The percentages of NKT (CD56+CD3+CD44+CD161+), Treg (CD4+CD25+FOXP3+) and Th17 (CD4+CD25+IL-17A+) cells were determined with flow cytometry method. Results: Unexpectedly, we found that the PBMCs of patients with RPL produced a significantly lower level of inflammatory cytokines (TNF-α and IL-6) and a higher level of anti-inflammatory cytokines (TGF-β and IL-10). SC significantly decreased IL-6, IL-12 and increased TGF-β cytokine concentration in fertile women. In the case of RPL patients’ PBMCs, SC improved the production of TNF-α and IL-10. Conclusions: Lower concentration of proinflammatory cytokines in idiopathic RPL women compared to fertile women might suggest the exhaustion of the immune system. The emphasized production of IL-10 by SC partially explains the previously observed downregulation of NK cell activity in RPL patients. The immunomodulatory effect of the drug might be utilized in anti-inflammatory therapies and help achieve positive pregnancy outcomes in women with reproductive failure due to a Th1/Th2 imbalance.

Detailed Analysis of Peripheral Blood Natural Killer Cells in Women with Repeated IVF Failure

To analyse the peripheral blood NK cells in women with repeated IVF failure (RIF) and a fertile control group to determine which parameters best differentiate the two populations. Peripheral blood from the luteal phase of 171 women with RIF and 33 fertile controls was analysed by four-colour flow cytometry for NK cell concentration, subset differentiation and the activation marker CD69. Women with RIF had significantly increased NK cell numbers as determined by concentration (P < 0.05) and percentage of lymphocytes (P < 0.001), increased concentration of the CD56(dim) subtype (P < 0.05), and increased concentration of activated CD56(dim) CD69(+) cells (P = 0.0001). There was no correlation between any NK cell parameters with the length of infertility or number of embryo transfer cycles. Peripheral blood NK cell activity is significantly higher in women with RIF than in fertile controls. Future trials of immune therapy in women undergoing IVF should target those with high NK activity.

Immunophenotype of Peripheral Blood Mononuclear Cells and NK Cell Activity after Allogeneic Bone Marrow Transplantation Using Recombinant Human Granulocyte Colony-Stimulating Factor

Immunophenotype of Peripheral Blood Mononuclear Cells and NK Cell Activity after Allogeneic Bone Marrow Transplantation Using Recombinant Human Granulocyte Colony-Stimulating Factor

Suppression of intestinal mucosal natural killer cells by corticosteroids.

Corticosteroid therapy of patients with inflammatory bowel disease can give rise to systemic side-effects. Budesonide is a topically acting corticosteroid with low systemic bioavailability and is efficacious in the treatment of inflammatory bowel disease. Natural killer cells were previously found to be altered, both systemically and locally, in patients with inflammatory bowel disease. Modulatory effects of budesonide, prednisolone, dexamethasone, and cortisol on peripheral blood NK cells have already been described, but have never been assessed on mucosal NK cells from the intestine. The effect of the synthetic corticosteroids prednisolone and budesonide, the endogenous corticosteroid cortisol, and adrenocorticotropic hormone was analysed on NK cells isolated from the lamina propria of human intestinal resection specimens. The three corticosteroids suppressed intestinal NK cell activity, not only during the cytotoxicity assay, but also after pre-incubation of the lamina propria mononuclear cells. ACTH, however, did not affect the activity of intestinal NK cells. We previously showed that corticosteroid-suppressed peripheral blood NK cell activity could be restored in vivo, but not in vitro, by the administration of ACTH. In the present study, the in vitro incubation of budesonide- or prednisolone-suppressed mucosal NK cells with cortisol, alone or combined with ACTH, did not revert the suppressed NK cell activity. These findings are similar to our previous observations with peripheral blood NK cells. Intestinal mucosal NK cells can be suppressed by systemically as well as locally acting corticosteroids. This suppression in NK cell activity is not reversed by incubation with cortisol and/or ACTH.

In vitro effect of budesonide, prednisolone, cortisol, and ACTH on peripheral blood NK cell activity of Crohn's disease patients and controls

In vitro effect of budesonide, prednisolone, cortisol, and ACTH on peripheral blood NK cell activity of Crohn's disease patients and controls

Effect of ranitidine and low-dose interleukin-2 in vitro on NK-cell activity in peripheral blood from patients with liver metastases from colorectal cancer

Peripheral venous blood from 12 patients with colorectal cancer and eight healthy volunteers was used to identify the lowest in vitro dose of human, recombinant interleukin-2 (rIL-2) with immunoactivity on NK-cell lysis of K562 tumour cells. Subsequently, this dosage of 200 units/ml rIL-2, which may respond to 10(6) units in vivo, was used alone or in combination with ranitidine (0.02 mg/ml, which may correspond to 100 mg in vivo) to improve in vitro NK-cell activity in peripheral blood from 25 patients with liver metastases from colorectal cancer. A standard 4-hour Cr51-release assay of K562 tumour cells was used for the analyses. Spontaneous NK-cell activity was 19.0% (6.5-33.2), while ranitidine-induced NK-cell activity was 23.6% (7.8-46.2), and without statistical difference from spontaneous activity. Recombinant IL-2-induced NK-cell activity was 37.1% (11.1-71.7) (P < 0.05 compared to spontaneous activity), and rIL-2 plus ranitidine-induced NK-cell activity was 52.7% (18.9-85.6) (P < 0.05 compared to spontaneous and to rIL-2-induced activity, respectively). These results suggest a synergistic increase of low-dose rIL-2-induced NK-cell activity by ranitidine. Therefore, the combination of low-dose rIL-2 and ranitidine may be beneficial to improve post-operative immune competence, and should be considered in future adjuvant treatment regimens of cancer patients.

Regulation of NK cell functions by TGF-beta 1.

The contribution of exogenous and endogenous TGF-beta 1 to human peripheral blood NK cell proliferation and activity in vitro was investigated. Exogenous bioactive TGF-beta 1 inhibited NK cell DNA synthesis and production of IFN-gamma, TNF-alpha, and granulocyte-macrophage CSF (GM-CSF) by NK cultures consisting of > 98% CD56+ cells. The cytotoxic activity of NK cells was also weakly inhibited by exogenous TGF-beta 1. All TGF-beta 1-induced inhibitory effects occurred in the absence and presence of the NK cell-activating cytokines IFN-alpha, IL-2, and IL-12. Unstimulated NK cell cultures expressed steady state TGF-beta 1 mRNA detected by Northern blot analysis and produced TGF-beta protein (1.6 ng/ml), as determined by ELISA. When NK cell proliferation was induced by IL-2, IL-12, IFN-alpha, or a combination of IL-2 and IL-12, expression of TGF-beta 1 mRNA and protein was moderately and consistently reduced by approximately 20%, as compared with unstimulated control cultures. Unstimulated and rapidly proliferating NK cell cultures secreted primarily latent TGF-beta into their culture medium, as determined by the Mv1Lu bioassay. These results indicate that, in vitro, endogenous NK cell-derived TGF-beta 1 has no negative autocrine effect upon activation of NK cells by various cytokines.

MAJOR-HISTOCOMPATIBILITY-COMPLEX RESTRICTED AND NONRESTRICTED AUTOIMMUNE EFFECTOR MECHANISMS IN BB RATS

To investigate whether the immunologic mechanisms of autoimmune pancreatic beta-cell destruction are MHC restricted, we examined the relative vulnerability of islet allografts from a panel of MHC-compatible and -incompatible donors to autoimmune damage after transplantation to spontaneously diabetic BB recipients. To circumvent a potentially confounding allograft response to the foreign islet graft, we utilized two strategies: (1) pretransplant in vitro culture of islets to delete intraislet APCs; and (2) induction of islet donor-specific immunologic tolerance in diabetes-prone BB rats. Experiments employing organ culture to prevent rejection demonstrated that MHC-incompatible grafts were significantly less vulnerable to autoimmunity than MHC-compatible grafts. In contrast, when we used the model of immunologic tolerance to exclude rejection, both MHC-compatible and -incompatible islet grafts were equally susceptible to autoimmune damage. The reason for this discrepancy has not been defined fully but may be related to our observation that tolerant BB animals exhibit increased peripheral blood NK-cell activity. NK cells are known to be cytotoxic to islets in vitro and could play a role in a non-MHC-restricted diabetogenic response in vivo. We conclude that both MHC-restricted and nonrestricted mechanisms are capable of contributing to anti-beta-cell autoimmunity in BB rats.

Effect of repeated oral administration of tobacco snuff on natural killer-cell activity in the rat

The possible immune effect of oral snuff was investigated. In male adult rats, oral snuff given for 15 weeks significantly decreased NK-cell activity in peripheral blood against murine NK cell-sensitive target cells (YAC-1 lymphoma).

Supernatant derived from a human hepatocellular carcinoma cell line (PLC/PRF/5) depresses natural killer (NK) cell activity.

Harvest fluid derived from a human primary hepatocellular carcinoma cell line (PLC/PRF/5) inhibited normal peripheral blood NK-cell activity when either PLC/PRF/5 or K562 cells were employed as targets. MN cells incubated with the PLC/PRF/5 supernatant for only 6 h demonstrated depressed NK-cell activity, which was partially reversible if the cells were washed and incubated in fresh medium for 24 h. Enriched NK cells obtained on discontinuous Percoll gradients employing human tonsillar cells also showed depressed cytotoxicity when treated directly with the tumour harvest fluid. Furthermore, the binding of these cells to the tumour targets could be inhibited by prior treatment of the NK cells with the tumour supernatant. It is suggested that materials produced by tumours may inhibit NK-cell activity by blocking a receptor site on the effector cell, thereby allowing the tumour to proliferate.