Administration of two macrophage-derived interferon-gamma-inducing factors (IL-12 and IL-15) induces a lethal systemic inflammatory response in mice that is dependent on natural killer cells but does not require interferon-gamma

Structural basis for IL-12 and IL-23 receptor sharing reveals a gateway for shaping actions on T versus NK cells

Interleukin-12 (IL-12) and IL-23 are heterodimeric cytokines that are produced by antigen-presenting cells to regulate the activation and differentiation of lymphocytes, and they share IL-12Rβ1 as a receptor signaling subunit. We present a crystal structure of the quaternary IL-23 (IL-23p19/p40)/IL-23R/IL-12Rβ1 complex, together with cryoelectron microscopy (cryo-EM) maps of the complete IL-12 (IL-12p35/p40)/IL-12Rβ2/IL-12Rβ1 and IL-23 receptor (IL-23R) complexes, which reveal "non-canonical" topologies where IL-12Rβ1 directly engages the common p40 subunit. We targeted the shared IL-12Rβ1/p40 interface to design a panel of IL-12 partial agonists that preserved interferon gamma (IFNγ) induction by CD8+ T cells but impaired cytokine production from natural killer (NK) cells in vitro. These cell-biased properties were recapitulated in vivo, where IL-12 partial agonists elicited anti-tumor immunity to MC-38 murine adenocarcinoma absent the NK-cell-mediated toxicity seen with wild-type IL-12. Thus, the structural mechanism of receptor sharing used by IL-12 family cytokines provides a protein interface blueprint for tuning this cytokine axis for therapeutics.

Short bowel syndrome results in increased gene expression associated with proliferation, inflammation, bile acid synthesis and immune system activation: RNA sequencing a zebrafish SBS model

Background

Much of the morbidity associated with short bowel syndrome (SBS) is attributed to effects of decreased enteral nutrition and administration of total parenteral nutrition (TPN). We hypothesized that acute SBS alone has significant effects on gene expression beyond epithelial proliferation, and tested this in a zebrafish SBS model.

Methods

In a model of SBS in zebrafish (laparotomy, proximal stoma, distal ligation, n = 29) or sham (laparotomy alone, n = 28) surgery, RNA-Seq was performed after 2 weeks. The proximal intestine was harvested and RNA isolated. The three samples from each group with the highest amount of RNA were spiked with external RNA controls consortium (ERCC) controls, sequenced and aligned to reference genome with gene ontology (GO) enrichment analysis performed. Gene expression of ctnnb1, ccnb1, ccnd1, cyp7a1a, dkk3, ifng1-2, igf2a, il1b, lef1, nos2b, saa1, stat3, tnfa and wnt5a were confirmed to be elevated in SBS by RT-qPCR.

Results

RNA-seq analysis identified 1346 significantly upregulated genes and 678 significantly downregulated genes in SBS zebrafish intestine compared to sham with Ingenuity analysis. The upregulated genes were involved in cell proliferation, acute phase response signaling, innate and adaptive immunity, bile acid regulation, production of nitric oxide and reactive oxygen species, cellular barrier and coagulation. The downregulated genes were involved in folate synthesis, gluconeogenesis, glycogenolysis, fatty-acid oxidation and activation and drug and steroid metabolism. RT-qPCR confirmed gene expression differences from RNA-Sequencing.

Conclusion

Changes of gene expression after 2 weeks of SBS indicate complex and extensive alterations of multiple pathways, some previously implicated as effects of TPN. The systemic sequelae of SBS alone are significant and indicate multiple targets for investigating future therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-3433-4) contains supplementary material, which is available to authorized users.

Comparison of the Superagonist Complex, ALT-803, to IL15 as Cancer Immunotherapeutics in Animal Models

IL15, a potent stimulant of CD8(+) T cells and natural killer (NK) cells, is a promising cancer immunotherapeutic. ALT-803 is a complex of an IL15 superagonist mutant and a dimeric IL15 receptor αSu/Fc fusion protein that was found to exhibit enhanced biologic activity in vivo, with a substantially longer serum half-life than recombinant IL15. A single intravenous dose of ALT-803, but not IL15, eliminated well-established tumors and prolonged survival of mice bearing multiple myeloma. In this study, we extended these findings to demonstrate the superior antitumor activity of ALT-803 over IL15 in mice bearing subcutaneous B16F10 melanoma tumors and CT26 colon carcinoma metastases. Tissue biodistribution studies in mice also showed much greater retention of ALT-803 in the lymphoid organs compared with IL15, consistent with its highly potent immunostimulatory and antitumor activities in vivo. Weekly dosing with 1 mg/kg ALT-803 in C57BL/6 mice was well tolerated, yet capable of increasing peripheral blood lymphocyte, neutrophil, and monocyte counts by >8-fold. ALT-803 dose-dependent stimulation of immune cell infiltration into the lymphoid organs was also observed. Similarly, cynomolgus monkeys treated weekly with ALT-803 showed dose-dependent increases of peripheral blood lymphocyte counts, including NK, CD4(+), and CD8(+) memory T-cell subsets. In vitro studies demonstrated ALT-803-mediated stimulation of mouse and human immune cell proliferation and IFNγ production without inducing a broad-based release of other proinflammatory cytokines (i.e., cytokine storm). Based on these results, a weekly dosing regimen of ALT-803 has been implemented in multiple clinical studies to evaluate the dose required for effective immune cell stimulation in humans.

NK cells in hepatitis B virus infection: a potent target for immunotherapy

Viruses, including hepatitis B virus (HBV), are the most prevalent and infectious agents that lead to liver disease in humans. Hepatocellular carcinoma (HCC) and cirrhosis of the liver are the most serious complications arising from prolonged forms of hepatitis B. Previous studies demonstrated that patients suffering from long-term HBV infections are unable to eradicate HBV from hepatocytes completely. The mechanisms responsible for progression of these forms of infection have not yet been clarified. However, it seems that there are differences in genetic and immunological parameters when comparing patients to subjects who successfully clear HBV infections, and these may represent the causes of long-term infection. Natural killer (NK) cells, the main innate immune cells that target viral infections, play important roles in the eradication of HBV from hepatocytes. NK cells carry several stimulatory and inhibitor receptors, and binding of receptors with their ligands results in activation and suppression of NK cells, respectively. The aim of this review is to address the recent information regarding NK cell phenotype, functions and modifications in hepatitis B. This review addresses the recent data regarding the roles of NK cells as novel targets for immunotherapies that target hepatitis B infection. It also discusses the potential to reduce the risk of HCC or cirrhosis of the liver by targeting NK cells.

Natural killer cell is a major producer of interferon gamma that is critical for the IL-12-induced anti-tumor effect in mice

Although the anti-tumor effect of IL-12 is mediated mostly by IFNgamma, which cell types most efficiently produce IFNgamma and therefore initiate or promote the anti-tumor effect of IL-12 has not been clearly determined. In the present study, we demonstrated hydrodynamic injection of the IL-12 gene led to prolonged IFNgamma production, NK-cell activation and complete inhibition of liver metastasis of CT-26 colon cancer cells in wild-type mice, but not in IFNgamma knockout mice. NK cells expressed higher levels of STAT4 and upon IL-12 administration displayed stronger STAT4 phosphorylation and IFNgamma production than non-NK cells. Adoptive transfer of wild-type NK cells into IFNgamma knockout mice restored IL-12-induced IFNgamma production, NK-cell activation and anti-tumor effect, whereas transfer of the same number of wild-type non-NK cells did not. In conclusion, NK cells are predominant producers of IFNgamma that is critical for IL-12 anti-tumor therapy.

Early evaluation of natural killer activity in post-transplant acute myeloid leukemia patients

The focus of this study was to investigate NK cell reconstitution early after hematopoietic stem cell transplantation (HSCT). We were particularly interested in acute myeloid leukemia (AML) since patients with this disease may display an altered NK cell function. The function and the phenotype of donor-derived NK cells obtained from 35 allografted patients 30 and 60 days after HSCT for AML or other-than-AML hematological malignancies has been assessed. NK functional status was investigated by measuring the degranulation capacity (externalization of CD107a) of NK cells against human K562. We also concomitantly determined the concentration of selected cytokines known to modulate NK function and/or receptor expression. At day 30, donor-derived AML and non-AML NK cells could efficiently degranulate when exposed to leukemic K562 targets. At day 60, we observed a reduced NK degranulation potential in AML patients only. Decreased NK activity in AML patients was concomitant to NKp46 and NKp30 down-regulation. AML NK cells were chronically exposed to low IL-2 levels following HSCT. TGF-beta(1) was undetectable in all patients. In AML, the functional activity of donor-derived NK cells is remarkable at day 30 but may strongly decrease two months after HSCT. Therefore, in this condition, early NK immune-modulation might improve HSCT outcome.

Saccharomyces cerevisiae, the Baker's Yeast, suppresses the growth of Ehrlich carcinoma-bearing mice

This study was undertaken to evaluate the effectiveness and mechanisms of anti-tumor activity of Baker's yeast, Saccharomyces cerevisiae, in immunocompetent mice. Swiss albino mice were inoculated intramuscularly in the right thigh with Ehrlich Ascites Carcinoma (EAC) cells. At day 8, mice bearing Solid Ehrlich Carcinoma tumor (SEC) were intratumorally (IT) injected with killed S. cerevisiae (10 x 10(6) and 20 x 10(6) cells) for 35 days. Histopathology of yeast-treated mice showed extensive tumor degeneration, apoptosis, and ischemic (coagulative) and liquefactive necrosis. These changes are associated with a tumor growth curve that demonstrates a significant antitumor response that peaked at 35 days. Yeast treatment (20 x 10(6) cells) three times a week resulted in a significant decrease in tumor volume (TV) (67.1%, P < 0.01) as compared to PBS-treated mice. The effect was determined to be dependent on dose and frequency. Yeast administered three and two times per week induced significant decrease in TV as early as 9 and 25 days post-treatment, respectively. Administration of yeast significantly enhanced the recruitment of leukocytes, including macrophages, into the tumors and triggered apoptosis in SEC cells as determined by flow cytometry (78.6%, P < 0.01) at 20 x 10(6) cells, as compared to PBS-treated mice (42.6%). In addition, yeast treatment elevated TNF-alpha and IFN-gamma plasma levels and lowered the elevated IL-10 levels. No adverse side effects from the yeast treatment were observed, including feeding/drinking cycle and life activity patterns. Indeed, yeast-treated mice showed significant final body weight gain (+21.5%, P < 0.01) at day 35. These data may have clinical implications for the treatment of solid cancer with yeast, which is known to be safe for human consumption.

Stress molecules in sepsis and systemic inflammatory response syndrome

During sepsis, microbial derived products ("pathogen-associated molecular patterns", PAMPs) are recognized as exogenous danger signals by specific sensors of the host ("pattern recognitions receptors", PRRs). This interaction leads to the release of numerous stress proteins that are a prerequisite to fight infection, though their overzealous production can contribute to tissue damage, organ dysfunction and eventually death. In critically ill patients, translocation of PAMPs can occur from the gut, and injured tissues and cells release endogenous danger signals called "alarmins" (e.g. High mobility group box-1); that share some properties with PAMPs. Thus, numerous similarities occur during infectious and non-infectious systemic inflammation.

INTRANASAL EXPOSURE TO STAPHYLOCOCCAL ENTEROTOXIN B ELICITS AN ACUTE SYSTEMIC INFLAMMATORY RESPONSE

Staphylococcus aureus produces a variety of superantigen exotoxins, including staphylococcal enterotoxin B (SEB). Little is known regarding the pathogenesis of SEB entering through the intranasal route. Intranasal exposure to SEB might occur because of nasal packing following surgical procedure, biologic warfare, or even S. aureus colonization. We evaluated the local and systemic effects of intranasally delivered SEB using a series of human leukocyte antigen (HLA) class II transgenic mice as conventional mice expressing endogenous class II molecules mount a poor immune response to SEB. Gene expression profiling using microarrays showed robust up-regulation of genes involved in several proinflammatory pathways as early as 3 h post-intranasal challenge with SEB in HLA class II transgenic mice. This was accompanied by a several hundred-fold increase in serum levels of pro-inflammatory cytokines such as IL-12, IL-6, TNF-alpha, IFN-gamma, as well as MCP-1 in HLA class II transgenic mice but not in C57BL/6 mice; CD4 or CD8 T-cells independently contributed to the systemic cytokine response. Defective IL-12 or IL-4 receptor signaling significantly decreased or increased serum IFN-gamma, respectively. Intranasal exposure to SEB resulted in neutrophil influx into bronchoalveolar lavage fluid and caused expansion of both CD4 and CD8 T-cells expressing TCR V beta 8 in the spleen. This was accompanied by mononuclear cell infiltration in the liver reminiscent of the systemic inflammatory response syndrome. Thus, we have shown, for the first time, that intranasal administration of SEB can cause systemic immune activation.

Diverse functions of IL-2, IL-15, and IL-7 in lymphoid homeostasis

IL-2, IL-15, and IL-7 are cytokines that are critical for regulating lymphoid homeostasis. These cytokines stimulate similar responses from lymphocytes in vitro, but play markedly divergent roles in lymphoid biology in vivo. Their distinct physiological functions can be ascribed to distinct signaling pathways initiated by proprietary cytokine receptor chains, differential expression patterns of the cytokines or their receptor chains, and/or signals occurring in distinct physiological contexts. Recently, the discovery of a novel mechanism of cytokine signaling, trans-presentation, has provided further insights into the different ways these cytokines function. Trans-presentation also raises several novel cell biological and cellular implications concerning how cytokines support lymphoid homeostasis.

Primary infection of mice with high titer inoculum respiratory syncytial virus: characterization and response to antiviral therapy

Intranasal infection of BALB/c mice with respiratory syncytial virus (RSV)-A2 (0.5 x 10(8) - 2.0 x 10(8) plaque-forming units, PFU) produced disease characterized by weight loss (2-3 g) and mortality (60%-100%) with the mean day of death ranging from 6-7 d after infection. The extent of RSV disease was inoculum titer-dependent and required a replication competent virus. Lung titers of virus peaked at 0.5-1 x 10(6) PFU/g wet weight. Bronchoalveolar lavage fluid (BALF) levels of IL-1beta, TNF-alpha, INF-gamma IL-12, IL-6, MIP-1alpha, RANTES, and protein were elevated, whereas IL-2, IL-4, IL-5, IL-13, and IL-10 were unchanged. Histological assessment of lungs revealed marked inflammatory pathology characterized by bronchiolitis, vasculitis, and interstitial pneumonia. Whole-body plethysmography revealed significant disease-associated deficits of respiratory function. Therapy with ribavirin administered either by the intranasal, subcutaneous, or oral route significantly reduced disease in a dose-dependent manner. Delaying the initiation of therapy resulted in a loss of activity for ribavirin. Synagis administered either intramuscularly as a single dose in prophylaxis or intranasally in prophylaxis, followed by therapy, also significantly reduced disease in a dose-dependent manner. Infection of mice with a high titer inoculum of RSV-A2 resulted in severe and fatal pulmonary disease that was responsive to treatment. This model may be useful to characterize the in vivo activity of experimental therapies for RSV infection.

Alpha phenyl-tert-butyl nitrone (PBN) protects syngeneic marrow transplant recipients from the lethal cytokine syndrome occurring after agonistic CD40 antibody administration

Administration of agonistic monoclonal antibodies or recombinant cytokines is a potential approach to enhance antitumor immunity in bone marrow (BM) transplant recipients, but is complicated by toxicity due to proinflammatory cytokine-mediated vital organ damage. We used a murine syngeneic bone marrow transplant (BMT) model, in which administration of anti-CD40 antibody early after BMT results in overproduction of interleukin-12 (IL-12) and interferon-γ (IFN-γ), and lethal gut toxicity to examine the protective effect of the spin trap inhibitor, alpha phenyl-tert-butyl nitrone (PBN). Administration of PBN protected transplant recipients from mortality by significantly attenuating gut toxicity, but did not effect a reduction in the levels of proinflammatory cytokines (IL-12, IFN-γ, tumor necrosis factor α [TNF-α], or nitrate/nitrite). Moreover, PBN did not compromise anti-CD40 antibody-mediated antitumor effects in a nontransplantation lymphoma model. Collectively, these data suggest that PBN administration may represent a novel approach for reduction of toxicity without compromise of antitumor effects resulting from administration of therapeutic antibodies in both transplantation and nontransplantation settings. (Blood. 2005;105:428-431)

Pre-transplant elevations of interleukin-12 and interleukin-10 are associated with acute rejection after renal transplantation

BACKGROUND

Methods for predicting patients at higher risk for rejection before transplantation may help improve outcomes. We hypothesized that pre-transplant elevations of serum interleukin-12 (IL-12), a pro-inflammatory cytokine, would predict acute rejection, while pre-transplant IL-10, an immunoregulatory cytokine, would be down-regulated in patients subsequently experiencing acute rejection.

MATERIALS AND METHODS

Thirty patients experiencing acute rejection after cadaveric renal allograft transplantation and a control group of 30 patients, undergoing the same procedure but without the occurrence of rejection, were identified. Serum samples taken before transplantation from each patient were then analyzed quantitatively for IL-12 and IL-10 using ELISA assays.

RESULTS

The mean pre-transplant serum IL-12 level was higher in patients who subsequently underwent acute rejection vs. those who did not (181 +/- 143 pg/mL vs. 81.2 +/- 71.5 pg/mL, respectively, p = 0.007). Unexpectedly, pre-transplant serum IL-10 levels were also elevated in patients who underwent rejection (559 +/- 293 pg/mL vs. 332 +/- 163 pg/mL, respectively, p = 0.002). Multivariate analysis demonstrated that elevations of IL-12 and IL-10 were independent risk factors for rejection when adjusted for confounding variables.

CONCLUSIONS

Pre-transplant elevations of IL-12 and, unexpectedly, IL-10 are associated with acute rejection after cadaveric renal transplantation and may be useful in predicting which patients are at increased immunological risk at the time of transplantation. Further studies are necessary to assess the role of occult systemic inflammation in contributing to poor outcomes after transplantation.

Serum Levels of Prolactin, Growth Hormone, and Cortisol in Burn Patients: Correlations with Severity of Burn, Serum Cytokine Levels, and Fatality

In this study, we measured serum prolactin (PRL), cortisol, growth hormone, interleukin (IL)-1beta, IL-6, IL-8, IL-10, IL-12, and tumor necrosis factor-alpha in patients admitted with small-to-moderate burn injuries. Serum samples were obtained at the time of admission from 49 adult male burn patients with ages ranging from 18 to 91 years and TBSA ranging from 0.001 to 60%. The levels of serum PRL, IL-8, IL-6, and IL-1beta correlated positively with the TBSA, whereas only serum IL-8 levels correlated positively with fatality. Each of these factors were increased at least 2-fold at the higher burn severity. Not surprisingly, there was a large degree of variability in the hormone and cytokine levels in this patient population, which presumably reflects individual levels of stress, as well as other physiological variables. We also studied relationships between serum hormone levels and serum cytokine levels in this context. Linear regression analysis revealed a significant positive correlation between the serum PRL level and the levels of IL-10, IL-6, and IL-8. These results indicate that PRL responds to burn injury at early time points and that a subset of cytokines are involved in the early response to burn injury.

STAT4 signal pathways regulate inflammation and airway physiology changes in allergic airway inflammation locally via alteration of chemokines

Mice homozygous for the STAT4-null mutation were sensitized to cockroach Ag, challenged intratracheally 21 days later, and compared with STAT4-competent allergic mice. The STAT4(-/-) mice showed significant decreases in airway hyperreactivity (AHR) and peribronchial eosinophils compared with wild-type controls. In addition, pulmonary levels of chemokines were decreased in the STAT4(-/-) mice, including CC chemokine ligand (CCL)5, CCL6, CCL11, and CCL17. However, levels of Th2-type cytokines, such as IL-4 and IL-13, as well as serum IgE levels were similar in the two groups. Transfer of splenic lymphocytes from sensitized wild-type mice into sensitized STAT4(-/-) mice did not restore AHR in the mutant mice. Furthermore, chemokine production and peribronchial eosinophilia were not restored during the cellular transfer experiments. Thus, it appears that STAT4 expression contributes to a type 2 process such as allergen-induced chemokine production and AHR. In additional studies, competent allergic mice were treated with anti-IL-12 locally in the airways at the time of allergen rechallenge. These latter studies also demonstrated a decrease in AHR. Altogether, these data suggest that STAT4-mediated pathways play a role locally within the airway for the exacerbation of the allergen-induced responses.

Delivery to macrophages and toxic action of etoposide carried in mouse red blood cells

Erythrocytes could be used as physiological carriers of active compounds. Several substances can be loaded into erythrocytes by hypotonic dialysis methods. Furthermore, carrier erythrocyte membrane can be chemically modified in order to promote increased arrival of the loaded compound to macrophages. In this work, we have prepared erythrocytes loaded with etoposide. We found conditions to obtain high etoposide encapsulation yields with minor alteration of some cell parameters of these carrier erythrocytes. Etoposide loaded into erythrocytes is mainly localised in the cytoplasmic compartment. Membrane modification of etoposide-loaded erythrocytes with band 3 crosslinkers produces an increased incorporation of the drug into macrophages mainly by phagocytosis process. The toxic effect of etoposide conveyed in these carrier erythrocytes determined as DNA fragmentation in macrophages was higher than that shown by free etoposide added at the same concentration in the culture medium to macrophages. These results seem to indicate the usefulness of this model to deliver this anti-tumour compound to macrophages, which might be useful in therapy.