Caspase-12 controls West Nile virus infection via the viral RNA receptor RIG-I.

Caspase-12 has been shown to negatively modulate inflammasome signaling during bacterial infection. Its function in viral immunity, however, has not been characterized. We now report an important role for caspase-12 in controlling viral infection via the pattern-recognition receptor RIG-I. After challenge with West Nile virus (WNV), caspase-12-deficient mice had greater mortality, higher viral burden and defective type I interferon response compared with those of challenged wild-type mice. In vitro studies of primary neurons and mouse embryonic fibroblasts showed that caspase-12 positively modulated the production of type I interferon by regulating E3 ubiquitin ligase TRIM25-mediated ubiquitination of RIG-I, a critical signaling event for the type I interferon response to WNV and other important viral pathogens.

The circadian clock controls toll-like receptor 9-mediated innate and adaptive immunity.

Circadian rhythms refer to biologic processes that oscillate with a period of ~24 hr. These rhythms are sustained by a molecular clock and provide a temporal matrix that ensures the coordination of homeostatic processes with the periodicity of environmental challenges. We demonstrate the circadian molecular clock controls the expression and function of Toll-like receptor 9 (TLR9). In a vaccination model using TLR9 ligand as adjuvant, mice immunized at the time of enhanced TLR9 responsiveness presented weeks later with an improved adaptive immune response. In a TLR9-dependent mouse model of sepsis, we found that disease severity was dependent on the timing of sepsis induction, coinciding with the daily changes in TLR9 expression and function. These findings unveil a direct molecular link between the circadian and innate immune systems with important implications for immunoprophylaxis and immunotherapy.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Gastric Cancer with Peritoneal Carcinomatosis: Multicenter Study of Spanish Group of Peritoneal Oncologic Surgery (GECOP).

BACKGROUND: Gastric cancer (GC) with peritoneal carcinomatosis (PC) is traditionally considered a terminal stage of the disease. The use of a multimodal treatment, including cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), can benefit these patients. Our goal was to evaluate the morbidity and survival outcomes of these patients. METHODS: This is a retrospective, multicenter study from a prospective national database of patients diagnosed with PC secondary to GC treated with CRS and HIPEC from June 2006 to October 2017. RESULTS: Eighty-eight patients from seven specialized Spanish institutions were treated with CRS and HIPEC, with median age of 53 years; 51% were women. Median Peritoneal Cancer Index (PCI) was 6, and complete cytoreduction was achieved in 80 patients (90.9%). HIPEC was administered in 85 cases with 4 different regimens (Cisplatin + Doxorubicin, Mitomycin-C + Cisplatin, Mitomycin-C and Oxaliplatin). Twenty-seven cases (31%) had severe morbidity (grade III-IV) and 3 patients died in the postoperative period (3.4%). Median follow-up was 32 months. Median overall survival (OS) was 21.2 months, with 1-year OS of 79.9% and 3-year OS of 30.9%. Median disease-free survival (DFS) was 11.6 months, with 1-year DFS of 46.1% and 3-year DFS of 21.7%. After multivariate analysis, the extent of peritoneal disease (PCI ≥ 7) was identified as the only independent factor that influenced OS (hazard ratio [HR] 2.37, 95% confidence interval [CI] 1.26-4.46, p = 0.007). CONCLUSIONS: The multimodal treatment, including CRS and HIPEC, for GC with PC can improve the survival results in selected patients (PCI < 7) and in referral centers.

Immunity's fourth dimension: approaching the circadian-immune connection.

The circadian system ensures the generation and maintenance of self-sustained ~24-h rhythms in physiology that are linked to internal and environmental changes. In mammals, daily variations in light intensity and other cues are integrated by a hypothalamic master clock that conveys circadian information to peripheral molecular clocks that orchestrate physiology. Multiple immune parameters also vary throughout the day and disruption of circadian homeostasis is associated with immune-related disease. Here, we discuss the molecular links between the circadian and immune systems and examine their outputs and disease implications. Understanding the mechanisms that underlie circadian-immune crosstalk may prove valuable for devising novel prophylactic and therapeutic interventions.

A small-molecule macrophage migration inhibitory factor antagonist protects against glomerulonephritis in lupus-prone NZB/NZW F1 and MRL/lpr mice.

Autoimmunity leads to the activation of innate effector pathways, proinflammatory cytokine production, and end-organ injury. Macrophage migration inhibitory factor (MIF) is an upstream activator of the innate response that mediates the recruitment and retention of monocytes via CD74 and associated chemokine receptors, and it has a role in the maintenance of B lymphocytes. High-expression MIF alleles also are associated with end-organ damage in different autoimmune diseases. We assessed the therapeutic efficacy of (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), an orally bioavailable MIF antagonist, in two distinct models of systemic lupus erythematosus: the NZB/NZW F1 and the MRL/lpr mouse strains. ISO-1, like anti-MIF, inhibited the interaction between MIF and its receptor, CD74, and in each model of disease, it reduced functional and histological indices of glomerulonephritis, CD74(+) and CXCR4(+) leukocyte recruitment, and proinflammatory cytokine and chemokine expression. Neither autoantibody production nor T and B cell activation were significantly affected, pointing to the specificity of MIF antagonism in reducing excessive proinflammatory responses. These data highlight the feasibility of targeting the MIF-MIF receptor interaction by small-molecule antagonism and support the therapeutic value of downregulating MIF-dependent pathways of tissue damage in systemic lupus erythematosus.

Human innate immunosenescence: causes and consequences for immunity in old age.

The past decade has seen an explosion in research focusing on innate immunity. Through a wide range of mechanisms including phagocytosis, intracellular killing and activation of proinflammatory or antiviral cytokine production, the cells of the innate immune system initiate and support adaptive immunity. The effects of aging on innate immune responses remain incompletely understood, particularly in humans. Here we review advances in the study of human immunosenescence in the diverse cells of the innate immune system, including neutrophils, monocytes, macrophages, natural killer and natural killer T (NKT) cells and dendritic cells-with a focus on consequences for the response to infection or vaccination in old age.

Circadian expression of clock genes in mouse macrophages, dendritic cells, and B cells.

In mammals, circadian and daily rhythms influence nearly all aspects of physiology, ranging from behavior to gene expression. Functional molecular clocks have been described in the murine spleen and splenic NK cells. The aim of our study was to investigate the existence of molecular clock mechanisms in other immune cells. Therefore, we measured the circadian changes in gene expression of clock genes (Per1, Per2, Bmal1, and Clock) and clock-controlled transcription factors (Rev-erbα and Dbp) in splenic enriched macrophages, dendritic cells, and B cells in both mice entrained to a light-dark cycle and under constant environmental conditions. Our study reveals the existence of functional molecular clock mechanisms in splenic macrophages, dendritic cells, and B cells.

Innate immune control of West Nile virus infection.

West Nile virus (WNV), from the Flaviviridae family, is a re-emerging zoonotic pathogen of medical importance. In humans, WNV infection may cause life-threatening meningoencephalitis or long-term neurologic sequelae. WNV is transmitted by Culex spp. mosquitoes and both the arthropod vector and the mammalian host are equipped with antiviral innate immune mechanisms sharing a common phylogeny. As far as the current evidence is able to demonstrate, mosquitoes primarily rely on RNA interference, Toll, Imd and JAK-STAT signalling pathways for limiting viral infection, while mammals are provided with these and other more complex antiviral mechanisms involving antiviral effectors, inflammatory mediators, and cellular responses triggered by highly specialized pathogen detection mechanisms that often resemble their invertebrate ancestry. This mini-review summarizes our current understanding of how the innate immune systems of the vector and the mammalian host react to WNV infection and shape its pathogenesis.

Role of sympathetic nervous system in the entrainment of circadian natural-killer cell function.

Previous research in our laboratory has demonstrated robust circadian variations of cytokines and cytolytic factors in enriched NK cells from rat spleen, strongly suggesting these functions may be subject to circadian regulation. The SCN mediates timing information to peripheral tissues by both humoral and neural inputs. In particular, noradrenergic (NE) sympathetic nervous system (SNS) terminals innervate the spleen tissue communicating information between central and peripheral systems. However, whether these immune factors are subject to timing information conveyed through neural NE innervation to the spleen remained unknown. Indeed, we were able to characterize a circadian rhythm of NE content in the spleen, supporting the role of the SNS as a conveyor of timing information to splenocytes. By chemically producing a local splenic sympathectomy through guanethidine treatment, the splenic NE rhythm was abolished or shifted as indicated by a blunting of the expected peak at ZT7. Consequently, the daily variations of cytokine, TNF-α, and cytolytic factors, granzyme-B and perforin, in NK cells and splenocytes were altered. Only time-dependent mRNA expression of IFN-γ was altered in splenocytes, but not protein levels in NK cells, suggesting non-neural entrainment cues may be necessary to regulate specific immune factors. In addition, the rhythms of clock genes and proteins, Bmal1 and Per2, in these tissues also displayed significantly altered daily variations. Collectively, these results demonstrate rhythmic NE input to the spleen acts as an entrainment cue to modulate the molecular clock in NK cells and other spleen cells possibly playing a role in regulating the cytokine and cytolytic function of these cells.

Abrogation of macrophage migration inhibitory factor decreases West Nile virus lethality by limiting viral neuroinvasion.

The flavivirus West Nile virus (WNV) is an emerging pathogen that causes life-threatening encephalitis in susceptible individuals. We investigated the role of the proinflammatory cytokine macrophage migration inhibitory factor (MIF), which is an upstream mediator of innate immunity, in WNV immunopathogenesis. We found that patients suffering from acute WNV infection presented with increased MIF levels in plasma and in cerebrospinal fluid. MIF expression also was induced in WNV-infected mice. Remarkably, abrogation of MIF action by 3 distinct approaches (antibody blockade, small molecule pharmacologic inhibition, and genetic deletion) rendered mice more resistant to WNV lethality. Mif(-/-) mice showed a reduced viral load and inflammatory response in the brain when compared with wild-type mice. Our results also indicate that MIF favors viral neuroinvasion by compromising the integrity of the blood-brain barrier. In conclusion, the data obtained from this study provide direct evidence for the involvement of MIF in viral pathogenesis and suggest that pharmacotherapeutic approaches targeting MIF may hold promise for the treatment of WNV encephalitis.

Intraperitoneal hyperthermic chemotherapy after cytoreduction in patients with peritoneal metastases from endometrial cancer. The next frontier?

BACKGROUND: Endometrial cancer is the most common malignancy of the female genital tract. For cancers detected at an advanced stage or intraperitoneal relapse, the prognosis is poor. Optimal cytoreductive surgery (CRS) is the most accepted treatment; however, patients with advanced intraperitoneal disease might benefit from hyperthermic intraoperative peritoneal chemotherapy (HIPEC). The aim of this study was to analyze recurrence-free survival (RFS) after CRS and HIPEC in a large series of patients with peritoneal metastases from endometrial cancer. METHODS: Patients with a diagnosis of endometrial cancer with primary or recurrent peritoneal dissemination were included. All patients underwent CRS plus HIPEC. Data were prospectively collected in the Spanish Group of Peritoneal Oncological Surgery (GECOP) database. RESULTS: Forty-three patients with endometrial cancer and peritoneal metastasis were included. Fifteen patients (35%) were diagnosed with G3 endometrioid carcinomas and 28 (65%) with other non-endometroid histologies. A completeness of cytoreduction score of CC-0 was achieved in 41 patients (95%). RFS at 5 years was 23%, being factors related to worse RFS: treatment with preoperative chemotherapy (p = 0.027), resection of more than three peritoneal areas (p = 0.010), cytoreduction of the upper abdominal space (p = 0.023), HIPEC treatment with paclitaxel (p = 0.013), and the presence of metastatic lymph nodes (p = 0.029). CONCLUSIONS: Better RFS rates after CRS and HIPEC were observed for patients with the following characteristics: cytoreductive surgery without preoperative chemotherapy, complete surgery performed with limited surgical maneuvers, treated with cisplatin, and no lymph node metastases. SYNOPSIS: Endometrial cancer has a poor prognosis when diagnosed at advance stage. Patients with intraperitoneal metastases from endometrial cancer may benefit from CRS plus HIPEC with improvement in the recurrence-free survival results.

Dysregulation of TLR3 impairs the innate immune response to West Nile virus in the elderly.

West Nile virus (WNV), a mosquito-borne flavivirus, has recently emerged in North America, and the elderly are particularly susceptible to severe neurological disease and death from infection with this virus. We have investigated the innate immune response of primary human macrophages to WNV in vitro and have found significant differences between the responsiveness of macrophages derived from younger donors and that from older donors. Binding of the glycosylated WNV envelope protein to the C-type lectin dendritic cell-specific intercellular adhesion molecule 3 (ICAM3) grabbing nonintegrin (DC-SIGN) leads to a reduction in the expression of Toll-like receptor 3 (TLR3) in macrophages from young donors via the signal transducer and activator of transcription 1 (STAT1)-mediated pathway. This signaling is impaired in the elderly, and the elevated levels of TLR3 result in an elevation of cytokine levels. This alteration of the innate immune response with aging may contribute to the permeability of the blood-brain barrier and suggests a possible mechanism for the increased severity of WNV infection in older individuals.

Soluble CD30 for the prediction and detection of kidney transplant rejection.

Although safer and more effective immunosuppressants as well as enhanced immunosuppressive protocols are continuously being developed in order to increase graft survival, they come at the steep price of drug-related complications and important side effects. In addition, the value of panel reactive antibodies determination, which at present is the single most used indicator of an increased risk of transplant rejection, is now being reevaluated. Therefore, effective tailoring of immunosuppressive therapy minimizing the above-mentioned pitfalls requires the existence of dependable biomarkers that adequately monitor rejection risk both before and after transplantation. Here we review the data yielded by studies assessing the usefulness of measuring soluble CD30 levels (sCD30) in kidney transplant rejection. These data collectively show that sCD30 serum content has a considerable predictive/diagnostic value for acute rejection of renal grafts, particularly when measured a few days after transplantation.

Beta-endorphin neuronal cell transplant reduces corticotropin releasing hormone hyperresponse to lipopolysaccharide and eliminates natural killer cell functional deficiencies in fetal alcohol exposed rats.

BACKGROUND: Natural killer (NK) cell dysfunction is associated with hyperresponse of corticotropin releasing hormone (CRH) to immune challenge and with a loss of beta-endorphin (BEP) neurons in fetal alcohol exposed animals. Recently, we established a method to differentiate neural stem cells into BEP neurons using cyclic adenosine monophosphate (cAMP)-elevating agents in cultures. Hence, we determined whether in vitro differentiated BEP neurons could be used for reversing the compromised stress response and immune function in fetal alcohol exposed rats. METHODS: To determine the effect of BEP neuron transplants on NK cell function, we implanted in vitro differentiated BEP neurons into the paraventricular nucleus of pubertal and adult male rats exposed to ethanol or control in utero. The functionality of transplanted BEP neurons was determined by measuring proopiomelanocortin (POMC) gene expression in these cells and their effects on CRH gene expression under basal and after lipopolysaccaride (LPS) challenge. In addition, the effectiveness of BEP neurons in activating NK cell functions is determined by measuring NK cell cytolytic activity and interferon-gamma (IFN-gamma) production in the spleen and in the peripheral blood mononuclear cell (PBMC) following cell transplantation. RESULTS: We showed here that when these in vitro differentiated BEP neurons were transplanted into the hypothalamus, they maintain biological functions by producing POMC and reducing the CRH neuronal response to the LPS challenge. BEP neuronal transplants significantly increased NK cell cytolytic activity in the spleen and in the PBMC and increased plasma levels of IFN-gamma in control and fetal alcohol exposed rats. CONCLUSIONS: These data further establish the BEP neuronal regulatory role in the control of CRH and NK cell cytolytic function and identify a possible novel therapy to treat stress hyperresponse and immune deficiency in fetal alcohol exposed subjects.

Melatonin exerts a more potent effect than S-adenosyl-l-methionine against iron metabolism disturbances, oxidative stress and tissue injury induced by obstructive jaundice in rats.

Melatonin and S-adenosyl-l-methionine (SAMe) prevent oxidative stress and tissue dysfunction in obstructive jaundice (OJ). Lipid peroxidation is exacerbated in the presence of trace amounts of iron (Fe). The study investigated the regulation by melatonin and SAMe the induction of oxidative stress, iron metabolism disturbances and tissue injury in an experimental model of OJ. Different parameters of lipid peroxidation, antioxidant status, tissue injury and Fe metabolism were determined in liver and blood. OJ induced Fe accumulation in liver, and increased transferrin (Tf) saturation and loosely bound Fe content in blood. Melatonin, and SAMe at lesser extent, enhanced protein Tf content in liver and blood, that reduced loosely bound Fe content in blood. Melatonin and SAMe did not affect ferritin (FT) and Tf mRNA expression, but reduced Tf receptor (TfR) mRNA expression in liver. In conclusion, the effect of melatonin and SAMe on Fe metabolism may be included in the beneficial properties of these agents on lipid peroxidation and tissue injury induced by OJ.

Evaluation of a novel nested PCR for the routine diagnosis of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV).

Laboratory diagnosis of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) usually involves both viruses, as the clinical signs are similar and coinfection may occur. Serological methods may not represent an accurate diagnosis: maternal antibodies or cross-reactions may give false positive results to FIV, and false negative results may occur in latent FeLV status, or in certain FIV infection stages. A nested polymerase chain reaction (PCR) technique was designed to detect FeLV, FIV and feline endogenous retrovirus simultaneously. The detection of endogenous sequences was considered indicative of successful DNA extraction. The technique was used to diagnose FIV and FeLV in the blood cells of 179 cats. The kappa value with the serological data was 0.69 for FeLV and 0.87 for FIV. The joint detection of FeLV and FIV by this novel nested PCR is sensitive, specific, fast and convenient, and its applicability for clinical diagnosis is promising, as the direct evidence of the presence of the virus is more realistic than the indirect data provided by the serological detection.

The circadian gene mPer2 regulates the daily rhythm of IFN-gamma.

Circadian and daily rhythms regulate many aspects of physiology and behavior. Although a growing number of studies suggest that circadian disruptions may render organisms more susceptible to infection and cancer, the molecular links between the circadian system and the immune system are largely unknown. Here we report that mice carrying a loss-of-function mutation in the Per2 gene, a key component of the molecular circadian clock, lacked the physiologic daily rhythm of interferon-gamma (IFN-gamma) mRNA and protein expression in the spleen. These observations were associated with a significant alteration in the expression of canonical clock genes. In addition, Per2 mutant mice failed to show a daily rhythm in IFN-gamma serum levels, which were significantly lower than those determined in wild-type mice during the early light period. These findings provide novel evidence for a direct circadian regulation of IFN-gamma, a critical cytokine modulating the immune response.

Evolution of specific antibodies and proviral DNA in milk of small ruminants infected by small ruminant lentivirus.

The diagnosis of Small Ruminant Lentivirus (SRLV) is based on clinical signs, pathological lesions and laboratory testing. No standard reference test for the diagnosis of maedi visna has been validated up to the present, and it is puzzling that tests which detect antibodies against the virus and tests which detect the proviral genome may render opposite results. The aim of this study was to evaluate the presence in milk throughout a lactation period of specific antibodies by ELISA and of SRLV proviral DNA by a PCR of the highly conserved pol region. A six-month study was conducted with the milk of 28 ewes and 31 goats intensively reared. The percentage of animals with antibodies against SRLV increased throughout the study period. Seroprevalence in sheep was 28% at the beginning of the study and by the end it had increased up to 52.4%. In goats, initial seroprevalence of 5.6% increased to 16%. The percentage of PCR positive ewes was stable throughout the study period. Of the positive sheep, 21.4% were PCR-positive before antibodies could be detected and most of them became PCR-negative shortly after the first detection of antibodies. This might suggest that antibodies have a neutralizing effect. In addition, an equal percentage of sheep were always PCR-negative but either became ELISA-positive or was always ELISA-positive, which might support this hypothesis. On the other hand, the PCR results in goats did not follow any pattern and oscillated between 35.3% and 55.6% depending on the month. Most goats positive by PCR failed to develop antibodies in the 6 months tested. We may conclude that the infection and the antibody response to it follow a different trend in sheep and goats.

Improvement of capecitabine antitumoral activity by melatonin in pancreatic cancer.

OBJECTIVE: The purpose of our study was to evaluate the effects of the addition of melatonin and capecitabine on experimental pancreatic cancer. METHODS: Fifty Syrian hamsters were randomized in 5 groups: group 1: no tumor induction (control group); group 2: tumor induction with BOP [N-nitrosobis(2-oxopropyl) amine]; group 3: tumor induction with BOP and melatonin administration; group 4: tumor induction with BOP and capecitabine administration; and group 5: tumor induction with BOP and administration of combined capecitabine and melatonin therapy. The evaluation of pathological tumor evolution and oxidative stress markers in pancreatic tissue was carried out. RESULTS: All animals under BOP exposure presented poorly or moderately differentiated pancreatic adenocarcinoma associated with increased lipoperoxide levels and decreased antioxidant activity in pancreatic tissue. Pancreatic cancer was shown in only 66% of the capecitabine-treated group and 33% of melatonin-treated group (P < 0.05), most of them moderately differentiated adenocarcinoma. When capecitabine and melatonin were combined, a well-differentiated pancreatic adenocarcinoma was observed in 10% of animals. The beneficial effect was associated with a decrease in lipoperoxide levels and increased antioxidant activity in pancreatic tissue. CONCLUSIONS: The combined administration of capecitabine and melatonin provided an improvement in antioxidant status as well as a synergistic antitumoral effect in experimental pancreatic cancer.

The role of hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) in the treatment of peritoneal carcinomatosis in recurrent ovarian cancer.

BACKGROUND AND OBJECTIVES: Peritoneal carcinomatosis in women frequently has an ovarian origin. Hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) along with radical surgery/peritonectomy could present a new therapeutic approach with curative intention. The purpose of this research is to evaluate the role of the administration of HIPEC. METHODS: A series of patients (N=26) diagnosed with peritoneal carcinomatosis for recurrent epithelial ovarian cancer (stage III) from January 1997 to December 2004 submitted to radical surgery/peritonectomy with optimal cytoreduction (R0-R1) were included in this study, 14 treated with HIPEC and 12 without HIPEC. RESULTS: The variables age, histologic type, peritonectomy procedures, peritoneal cancer index (PCI) and lymph node affectation were similar in both groups. The 5-year global survival was 58% and 17% (p=0.046), and 67% and 29% in patients with maximal cytoreduction (R0) (p=0.264), in the HIPEC- and non-HIPEC-treated patients, respectively. In patients with optimal cytoreduction and partial peritonectomy, 5-year global survival was also superior in the HIPEC group (75% vs. 11%, p=0.011). Average time free of disease was superior in the HIPEC group (48+/-42 vs. 24+/-21 months), with less reinterventions due to a new reappearance during the first three evolutionary years (2/14 vs. 4/12). Postoperative morbidity did not show substantial differences in both groups and there was no surgical mortality. CONCLUSIONS: HIPEC is a complement to radical surgery/ peritonectomy, which has been shown to be a surgical procedure with high tolerability, low morbimortality, enhanced survival and prolonged disease-free interval in patients with peritoneal carcinomatosis for recurrent ovarian cancer.