High immune cell infiltration predicts improved survival in cholangiocarcinoma.

Background: Antitumoral immune response has a crucial role in constraining cancer. However, previous studies on cholangiocarcinoma (CCA), a rare and aggressive cancer, have reported contradictory findings on the prognostic impact of tumor-infiltrating T-lymphocytes. We aimed to clarify the effect of tumor-infiltrating CD3+ and CD8+ lymphocytes and PD-1/PD-L1 expression on CCA prognosis. Methods: CD3+, CD8+, and PD-1+ lymphocyte densities, as well as PD-L1 expression rate were analyzed from stained tissue microarray samples from the tumor center and invasive margin of 47 cholangiocarcinomas. The association of CD3+ and CD8+ based Immune cell score (ICS) and its components with overall survival was evaluated, adjusting for age, sex, TNM stage, radicality of surgery, tumor location, and PD-L1 expression on immune cells. Results: Low ICS was a strong independent prognostic factor for worse overall survival (Hazard ratio 9.27, 95% confidence interval 2.72-31.64, P<0.001). Among the ICS components, high CD8+ lymphocyte infiltration at the tumor center had the most evident impact on patient outcome. PD-1 and PD-L1 expression on immune cells did not have a significant impact on overall survival alone; however, PD-L1 positivity seemed to impair survival for ICSlow subgroup. Conclusion: Identifying patient subgroups that could benefit from immunotherapy with PD-1/PD-L1 pathway blockade may help improve treatment strategies for this aggressive cancer. Our findings highlight the importance of evaluating the immune contexture in cholangiocarcinoma, as ICS serves as a strong independent prognostic and selective factor for patients who might benefit from immunotherapy.

Association of cephalosporin resistance in intraoperative biliary cultures with surgical site infections in patients undergoing pancreaticoduodenectomy. A retrospective cohort study.

BACKGROUND: The aim of this study was to assess the incidence of bacterobilia at the time of a pancreaticoduodenectomy (PD) and the association of resistant bacteria in bile to surgical site infections (SSI). METHODS: This was a retrospective cohort study including patients undergoing PD in a single center between May 2016 and October 2020. Data of preoperative biliary drainage (PBD), intraoperative biliary cultures (IBC) and postoperative complications were analysed to assess the risk factors for resistant bacteria in IBC and SSIs. RESULTS: Of 361 patients included, 254 (70%) had undergone PBD. Second-generation cephalosporin resistant bacteria were found in IBC of 183 (64%) of all the patients. PBD was the only risk factor for second-generation cephalosporin resistance. The risk for second-generation cephalosporin resistance was more than 20-fold in patients with PBD [n = 170/254 (67%) (OR 22.58 (95% CI, 9.61-53.01), p < 0.001)] compared to patients who did not have PBD (n = 13/107 (12%)). Also, if the time between PBD and surgery was 2 months or more the second-generation cephalosporin resistance in IBC increased the risk for SSIs (OR 4.14 (95% CI, 1.18-14.51), p = 0.027). CONCLUSION: The second-generation cephalosporin resistance in IBC is common in patients who have undergone PBD. Broad-spectrum antibiotics in prophylaxis may be beneficial for these patients.

Development and external validation of DISPAIR fistula risk score for clinically relevant postoperative pancreatic fistula risk after distal pancreatectomy.

BACKGROUND: Highly utilized risk scores for clinically relevant postoperative pancreatic fistula (CR-POPF) have guided clinical decision-making in pancreatoduodenectomy. However, none has been successfully developed for distal pancreatectomy. This study aimed to develop and validate a new fistula risk score for distal pancreatectomy. METHODS: Patients undergoing distal pancreatectomy at Helsinki University Hospital, Finland from 2013 to 2021, and at Karolinska University Hospital, Sweden, from 2010 to 2020, were included retrospectively. The outcome was CR-POPF, according to the 2016 International Study Group of Pancreatic Surgery definition. Preoperative clinical demographics and radiological parameters such as pancreatic thickness and duct diameter were measured. A logistic regression model was developed, internally validated with bootstrapping, and the performance assessed in an external validation cohort. RESULTS: Of 668 patients from Helsinki (266) and Stockholm (402), 173 (25.9 per cent) developed CR-POPF. The final model consisted of three variables assessed before surgery: transection site (neck versus body/tail), pancreatic thickness at transection site, and diabetes. The model had an area under the receiver operating characteristic curve (AUROC) of 0.904 (95 per cent c.i. 0.855 to 0.949) after internal validation, and 0.798 (0.748 to 0.848) after external validation. The calibration slope and intercept on external validation were 0.719 and 0.192 respectively. Four risk groups were defined in the validation cohort for clinical applicability: low (below 5 per cent), moderate (at least 5 but below 30 per cent), high (at least 30 but below 75 per cent), and extreme (75 per cent or more). The incidences in these groups were 8.7 per cent (11 of 126), 22.0 per cent (36 of 164), 63 per cent (57 of 91), and 81 per cent (17 of 21) respectively. CONCLUSION: The DISPAIR score after distal pancreatectomy may guide decision-making and allow a risk-adjusted outcome comparison for CR-POPF.

Long-term morbidity and mortality in patients diagnosed with an insulinoma.

OBJECTIVE: Insulinomas are rare functional pancreatic neuroendocrine tumours. As previous data on the long-term prognosis of insulinoma patients are scarce, we studied the morbidity and mortality in the Finnish insulinoma cohort. DESIGN: Retrospective cohort study. METHODS: Incidence of endocrine, cardiovascular, gastrointestinal and psychiatric disorders, and cancers was compared in all the patients diagnosed with an insulinoma in Finland during 1980-2010 (n = 79, including two patients with multiple endocrine neoplasia type 1 syndrome), vs 316 matched controls, using the Mantel-Haenszel method. Overall survival was analysed with Kaplan-Meier and Cox regression analyses. RESULTS: The median length of follow-up was 10.7 years for the patients and 12.2 years for the controls. The long-term incidence of atrial fibrillation (rate ratio (RR): 2.07 (95% CI: 1.02-4.22)), intestinal obstruction (18.65 (2.09-166.86)), and possibly breast (4.46 (1.29-15.39) and kidney cancers (RR not applicable) was increased among insulinoma patients vs controls, P < 0.05 for all comparisons. Endocrine disorders and pancreatic diseases were more frequent in the patients during the first year after insulinoma diagnosis, but not later on. The survival of patients with a non-metastatic insulinoma (n = 70) was similar to that of controls, but for patients with distant metastases (n = 9), the survival was significantly impaired (median 3.4 years). CONCLUSIONS: The long-term prognosis of patients with a non-metastatic insulinoma is similar to the general population, except for an increased incidence of atrial fibrillation, intestinal obstruction, and possibly breast and kidney cancers. These results need to be confirmed in future studies. Metastatic insulinomas entail a markedly decreased survival.

Long-term health-related quality of life in persons diagnosed with an insulinoma in Finland 1980-2010.

OBJECTIVE: Insulinomas are rare pancreatic neoplasms, which can usually be cured by surgery. As the diagnostic delay is often long and the prolonged hyperinsulinemia may have long-term effects on health and the quality of life, we studied the long-term health-related quality of life (HRQoL) in insulinoma patients. DESIGN, PATIENTS AND MEASUREMENTS: The HRQoL of adults diagnosed with an insulinoma in Finland in 1980-2010 was studied with the 15D instrument, and the results were compared to those of an age- and gender-matched sample of the general population. The minimum clinically important difference in the total 15D score has been defined as ±0.015. The clinical characteristics, details of insulinoma diagnosis and treatment, and the current health status of the subjects were examined to specify the possible determinants of long-term HRQoL. RESULTS: Thirty-eight insulinoma patients participated in the HRQoL survey (response rate 75%). All had undergone surgery with a curative aim, a median of 13 (min 7, max 34) years before the survey. The insulinoma patients had a clinically importantly and statistically significantly better mean 15D score compared with the controls (0.930 ± 0.072 vs 0.903 ± 0.039, P = .046) and were significantly better off regarding mobility, usual activities and eating. Among the insulinoma patients, younger age at the time of survey, higher level of education and smaller number of chronic diseases were associated with better overall HRQoL. CONCLUSIONS: In the long term, the overall HRQoL of insulinoma patients is slightly better than that of the general population.

Effect of Hydrocortisone vs Pasireotide on Pancreatic Surgery Complications in Patients With High Risk of Pancreatic Fistula: A Randomized Clinical Trial.

Importance: Both hydrocortisone and pasireotide have been shown in randomized clinical trials to be effective in reducing postoperative complications of pancreatic surgery, but to date no randomized clinical trial has evaluated the effectiveness of pasireotide compared with hydrocortisone. Objective: To assess the noninferiority of hydrocortisone compared with pasireotide in reducing complications after partial pancreatectomy. Design, Setting, and Participants: A noninferiority, parallel-group, individually randomized clinical trial was conducted at a single academic center between May 19, 2016, and December 17, 2018. Outcome collectors and analyzers were blinded. A total of 281 patients undergoing partial pancreatectomy were assessed for inclusion. Patients younger than 18 years, those allergic to hydrocortisone or pasireotide, patients undergoing pancreaticoduodenectomy with hard pancreas or dilated pancreatic duct, and patients not eventually undergoing partial pancreatectomy were excluded. Modified intention-to-treat analysis was used in determination of the results. Interventions: Treatment included pasireotide, 900 µg, subcutaneously twice a day for 7 days or hydrocortisone, 100 mg, intravenously 3 times a day for 3 days. Main Outcomes and Measures: The primary outcome was the Comprehensive Complication Index (CCI) score within 30 days. The noninferiority limit was set to 9 CCI points. Results: Of the 281 patients (mean [SD] age, 63.8 years) assessed for eligibility, 168 patients (mean [SD] age, 63.6 years) were randomized and 126 were included in the modified intention-to-treat analyses. Sixty-three patients received pasireotide (35 men [56%]; median [interquartile range] age, 64 [56-70] years) and 63 patients received hydrocortisone (25 men [40%]; median [interquartile range] age, 67 [56-73] years). The mean (SD) CCI score was 23.94 (17.06) in the pasireotide group and 30.11 (20.47) in the hydrocortisone group (mean difference, -6.16; 2-sided 90% CI, -11.73 to -0.60), indicating that hydrocortisone was not noninferior. Postoperative pancreatic fistula was detected in 34 patients (54%) in the pasireotide group and 39 patients (62%) in the hydrocortisone group (odds ratio, 1.39; 95% CI, 0.68-2.82; P = .37). One patient in the pasireotide group and 2 patients in the hydrocortisone group died within 30 days. In subgroup analyses of patients undergoing distal pancreatectomy, the CCI score was a mean of 10.3 points lower (mean [SD], 16.03 [11.94] vs 26.28 [21.76]; 2-sided 95% CI, -19.34 to -2.12; P = .03) and postoperative pancreatic fistula rate was lower (37% vs 67%; P = .02) in the pasireotide group compared with the hydrocortisone group. Conclusions and Relevance: In this study, hydrocortisone was not noninferior compared with pasireotide in patients undergoing partial pancreatectomy. Pasireotide may be more effective than hydrocortisone in patients undergoing distal pancreatectomy. Trial Registration: ClinicalTrials.gov identifier: NCT02775227; EudraCT identifier: 2016-000212-16.

Three-dimensional versus two-dimensional high-definition laparoscopy in transabdominal preperitoneal inguinal hernia repair: a prospective randomized controlled study.

BACKGROUND: Three-dimensional (3D) laparoscopy improves technical efficacy in laboratory environment, but evidence for clinical benefit is lacking. The aim of this study was to determine whether the 3D laparoscopy is beneficial in transabdominal preperitoneal laparoscopic inguinal hernia repair (TAPP). METHOD: In this prospective, single-blinded, single-center, superior randomized trial, patients scheduled for TAPP were randomly allocated to either 3D or two-dimensional (2D) TAPP laparoscopic approaches. Patients were excluded if secondary operation was planned, the risk of conversion was high, or the surgeon had less than five previous 3D laparoscopic procedures. Patients were operated on by 13 residents and 3 attendings. The primary endpoint was operation time. The study was registered in ClinicalTrials.gov (NCT02367573). RESULTS: Total 278 patients were randomized between 5th February 2015 and 23rd October 2017. Median operation time was shorter in the 3D group (56.0 min vs. 68.0 min, p < 0.001). 10 (8%) patients in 3D group and 6 (5%) patients in 2D group had clinically significant complications (Clavien-Dindo 2 or higher) (p = 0.440). Rate of hernia recurrence was similar between groups at 1-year follow-up. In the subgroup analyses, operation time was shorter in 3D laparoscopy among attendings, residents, female surgeons, surgeons with perfect stereovision, surgeons with > 50 3D laparoscopic procedures, surgeons with any experience in TAPP, patients with body mass indices < 30, and bilateral inguinal hernia repairs. CONCLUSION: 3D laparoscopy is beneficial and shortens operation time but does not affect safety or long-term outcomes of TAPP.

Three-dimensional versus two-dimensional high-definition laparoscopy in cholecystectomy: a prospective randomized controlled study.

BACKGROUND: While 3D laparoscopy increases surgical performance under laboratory conditions, it is unclear whether it improves outcomes in real clinical scenarios. The aim of this trial was to determine whether the 3D laparoscopy can enhance surgical efficacy in laparoscopic cholecystectomy (LCC). METHOD: This prospective randomized controlled study was conducted between February 2015 and April 2017 in a day case unit of an academic teaching hospital. Patients scheduled for elective LCC were assessed for eligibility. The exclusion criteria were: (1) planned secondary operation in addition to LCC, (2) predicted to be high-risk for conversion, and (3) surgeons with less than five previous 3D laparoscopic procedures. Patients were operated on by 12 residents and 3 attendings. The primary endpoint was operation time. All surgeons were tested for stereoaquity (Randot® stereotest). The study was registered in ClinicalTrials.gov (NCT02357589). RESULTS: A total of 210 patients were randomized; 105 to 3D laparoscopy and 104 to 2D laparoscopy. Median operation time as similar in the 3D and 2D laparoscopy groups (49 min vs. 48 min, p = 0.703). Operation times were similar in subgroup analyses for surgeon's sex (male vs. female), surgeon's status (resident vs. attending), surgeon's stereovision (stereopsis 10 vs. less than 10), surgeon's experience (performed 200 LCCs or below versus over 200 LCCs), or patient's BMI (≤ 25 vs. 25-30 vs. > 30). No differences in intra- or postoperative complications were noted between the 3D and 2D groups. CONCLUSION: 3D laparoscopy did not show any advantages over 2D laparoscopy in LCC.

Characteristics and Outcomes of 79 Patients with an Insulinoma: A Nationwide Retrospective Study in Finland.

OBJECTIVE: Insulinomas are rare pancreatic tumours. Population-based data on their incidence, clinical picture, diagnosis, and treatment are almost nonexistent. The aim of this study was to clarify these aspects in a nationwide cohort of insulinoma patients diagnosed during three decades. DESIGN AND METHODS: Retrospective analysis on all adult patients diagnosed with insulinoma in Finland during 1980-2010. RESULTS: Seventy-nine patients were diagnosed with insulinoma over the research period. The median follow-up from diagnosis to last control visit was one (min 0, max 31) year. The incidence increased from 0.5/million/year in the 1980s to 0.9/million/year in the 2000s (p = 0.002). The median diagnostic delay was 13 months and did not change over the study period. The mean age at diagnosis was 52 (SD 16) years. The overall imaging sensitivity improved from 39% in the 1980s to 98% in the 2000s (p < 0.001). Seventy-one (90%) of the patients underwent surgery with a curative aim, two (3%) had palliative surgery, and 6 (8%) were inoperable. There were no significant differences in the types of surgical procedures between the 1980s, 1990s, and 2000s; tumour enucleations comprised 43% of the operations, distal pancreatic resections 45%, and pancreaticoduodenectomies 12%, over the whole study period. Of the patients who underwent surgery with a curative aim, 89% had a full recovery. Postoperative complications occurred in half of the patients, but postoperative mortality was rare. CONCLUSIONS: The incidence of insulinomas has increased during the past three decades. Despite the improved diagnostic options, diagnostic delay has remained unchanged. To shorten the delay, clinicians should be informed and alert to consider the possibility of hypoglycemia and insulinoma, when symptomatic attacks are investigated in different sectors of the healthcare system. Developing the surgical treatment is another major target, in order to lower the overall complication rate, without compromising the high cure rate of insulinomas.

Tumor-like Chronic Pancreatitis Is Often Autoimmune Pancreatitis.

BACKGROUND: Distinguishing between pancreatic cancer and chronic pancreatitis (CP) is often difficult. Certain (5-6%) CP cases are autoimmune in nature, and these patients respond to corticosteroid treatment, making surgery avoidable. Our aim was to evaluate the incidence of autoimmune pancreatitis (AIP) among patients operated on for a pancreatic mass with a final histology of CP. PATIENTS AND METHODS: A total of 33 patients were operated on at the Tampere or Helsinki University Hospital for suspicion of cancer, but with final histopathological diagnosis of CP. The median age was 58 (31-81) years; 26 patients (79%) were male. There were 28 pancreaticoduodenectomes and five left pancreatic resections. Surgical specimens were re-evaluated by experienced pathologists, with representative samples chosen for immunohistochemistry Each sample was scored as positive or negative for immunoglobulin G4 (IgG4) independently by two pathologists. Honolulu consensus criteria served for AIP sub-typing. RESULTS: Out of the 33 specimens, 10 (30%) were positive for IgG4. Histopathological re-evaluation of these revealed all to be type 1 AIP. CONCLUSION: The proportion of AIP, according to IgG4-positive immunohistochemistry and histological re-evaluation, was much higher than expected. This suggests that by focusing on diagnosis of AIP preoperatively, certain patients might be treated with corticosteroids and possibly avoid unnecessary surgery.

[Intraductal papillary mucinous neoplasm of the pancreas, IPMN]. / Haiman intraduktaalinen papillaarinen musinoosinen neoplasia eli IPMN--pitäisikö leikata vai seurata?

With the development and increasing use of imaging techniques, intraductal papillary mucinous neoplasm (IPMN) is being detected with increasing frequency. Two forms of the disease are distinguished, the rare main duct form and the common accessory pancreatic duct form. The former often progresses to malignancy, the latter only seldom. The mixed form of IPMN exhibits features of both forms. In main duct IPMN, mucin production obstructs the pancreatic duct causing its dilatation and often symptoms typical of chronic pancreatitis. Main duct IPMN is always an indication for surgery, whereas monitoring is often sufficient for side duct IPMN.

IFN-alpha regulates Toll-like receptor-mediated IL-27 gene expression in human macrophages.

IL-27 is a novel member of the IL-12 cytokine family. IL-27 has pro- and anti-inflammatory properties, and it controls the responses of adaptive immunity. It promotes the differentiation of naïve Th cells and suppresses the effector functions of Th17 cells. Biologically active IL-27 is a heterodimer composed of EBV-induced gene 3 (EBI3) and p28 proteins. We report that TLR-dependent expression of IL-27 in human macrophages is mediated by IFN-alpha. Stimulation of macrophages with agonists for TLR3 {polyinosinic:polycytidylic acid [poly(I:C)]}, TLR4 (LPS), or TLR7/8 (R848) results in concurrent expression of EBI3 and p28. The p28 expression is inhibited with neutralizing anti-IFN-alpha antibodies. Unlike poly(I:C), LPS, and R848, TLR2 agonist (S)-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-N-palmitoyl-(R)-Cys-(S)-Ser(S)-Lys4-OH trihydrochloride does not stimulate macrophages to produce IFN-alpha, and therefore, it is not able to turn on the expression of p28. There is an IFN-stimulated response element (ISRE) in the p28 gene promoter. IFN-alpha enhances the expression of IFN regulatory factor 1 (IRF-1) in macrophages and induces binding of IRF-1 to the p28 ISRE site. The data provide a mechanistic basis for the IFN-alpha-mediated activation of IL-27. The data emphasize a role of IFN-alpha in immune responses, which rely on the recognition of pathogens by TLRs.

Genes involved in fatty acid partitioning and binding, lipolysis, monocyte/macrophage recruitment, and inflammation are overexpressed in the human fatty liver of insulin-resistant subjects.

OBJECTIVE: The objective of this study is to quantitate expression of genes possibly contributing to insulin resistance and fat deposition in the human liver. RESEARCH DESIGN AND METHODS: A total of 24 subjects who had varying amounts of histologically determined fat in the liver ranging from normal (n = 8) to steatosis due to a nonalcoholic fatty liver (NAFL) (n = 16) were studied. The mRNA concentrations of 21 candidate genes associated with fatty acid metabolism, inflammation, and insulin sensitivity were quantitated in liver biopsies using real-time PCR. In addition, the subjects were characterized with respect to body composition and circulating markers of insulin sensitivity. RESULTS: The following genes were significantly upregulated in NAFL: peroxisome proliferator-activated receptor (PPAR) gamma 2 (2.8-fold), the monocyte-attracting chemokine CCL2 (monocyte chemoattractant protein [MCP]-1, 1.8-fold), and four genes associated with fatty acid metabolism (acyl-CoA synthetase long-chain family member 4 [ACSL4] [2.8-fold], fatty acid binding protein [FABP]4 [3.9-fold], FABP5 [2.5-fold], and lipoprotein lipase [LPL] [3.6-fold]). PPARgamma coactivator 1 (PGC1) was significantly lower in subjects with NAFL than in those without. Genes significantly associated with obesity included nine genes: plasminogen activator inhibitor 1, PPARgamma, PPARdelta, MCP-1, CCL3 (macrophage inflammatory protein [MIP]-1 alpha), PPAR gamma 2, carnitine palmitoyltransferase (CPT1A), FABP4, and FABP5. The following parameters were associated with liver fat independent of obesity: serum adiponectin, insulin, C-peptide, and HDL cholesterol concentrations and the mRNA concentrations of MCP-1, MIP-1 alpha, ACSL4, FABP4, FABP5, and LPL. CONCLUSIONS: Genes involved in fatty acid partitioning and binding, lipolysis, and monocyte/macrophage recruitment and inflammation are overexpressed in the human fatty liver.

Treatment of abdominal compartment syndrome with subcutaneous anterior abdominal fasciotomy in severe acute pancreatitis.

BACKGROUND: Managing the abdominal compartment syndrome associated with severe acute pancreatitis by the open abdomen method is associated with considerable morbidity and resource utilization. METHODS: A technique of subcutaneous anterior abdominal fasciotomy is described for the first time in two patients with severe acute pancreatitis. RESULTS: Following the procedure, the intra-abdominal pressure decreased from 30 mmHg immediately to 23 mmHg and to a sustained level of 12-14 mmHg in the first patient, and from 35 mmHg immediately to 23 mmHg and to a sustained level of 14-19 mmHg in the second patient. CONCLUSIONS: The subcutaneous anterior abdominal fasciotomy is a promising method for safe and effective abdominal decompression with sustained effect and avoiding the morbidity associated with the alternative open abdomen techniques.

Retinoic acid inducible gene-I and mda-5 are involved in influenza A virus-induced expression of antiviral cytokines.

Activation of host cell antiviral responses is mediated by pattern recognition receptors. Cytoplasmic RNA helicases, retinoic acid inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (mda-5) have been identified to function as receptors for double-stranded RNA. Here we show that interferon (IFN)-alpha pretreatment enhances influenza A virus-induced expression of IFN-alpha, IFN-beta, interleukin (IL)-28 and IL-29 genes in human dendritic cells and epithelial cell lines. Both IFN-alpha and IFN-beta strongly enhanced RIG-I and mda-5 mRNA and protein expression in these cell types. Expression of RIG-I and mda-5 gene constructs, but not that of TLR3, lead to a dramatic enhancement of IFN-beta promoter driven transcription in influenza A virus-infected epithelial cells. Furthermore, dominant negative RIG-I gene construct inhibited influenza A virus-induced IFN-beta promoter activity. In conclusion, our results show that in epithelial cells influenza A virus-induced antiviral cytokine gene expression is triggered by RIG-I and mda-5, whose expression is positively regulated by IFN-alpha.

The interferon-inducible RNA helicase, mda-5, is involved in measles virus-induced expression of antiviral cytokines.

Activation of host cell antiviral responses is mediated by receptors detecting the presence of viruses. Here we have studied the role of double-stranded RNA (dsRNA) binding molecules melanoma differentiation-associated gene 5 (mda-5), retinoic acid inducible gene I (RIG-I), and Toll-like receptor 3 (TLR3) in measles virus (MV)-induced expression of antiviral cytokines and chemokines in human A549 lung epithelial cells and human umbilical vein endothelial cells (HUVECs). We show that MV infection results in the activation of mda-5, RIG-I, and TLR3 gene expression that is followed by high expression of interferon (IFN)-beta, interleukin (IL)-28 and IL-29, CCL5, and CXCL10 genes. We also demonstrate that IFN-alpha and IFN-beta upregulate mda-5, RIG-I, and TLR3 gene expression in epithelial and endothelial cell lines. Forced expression of mda-5, but not that of RIG-I or TLR3, leads to enhanced IFN-beta promoter activity in MV-infected A549 cells. Our results suggest that IFN-inducible mda-5 is involved in MV-induced expression of antiviral cytokines.

Induction of cytokine expression by herpes simplex virus in human monocyte-derived macrophages and dendritic cells is dependent on virus replication and is counteracted by ICP27 targeting NF-kappaB and IRF-3.

Macrophages and dendritic cells (DCs) play essential roles in host defence against microbial infections. In the present study, it is shown that human monocyte-derived macrophages and DCs express both type I and type III interferons (IFNs) [IFN-alpha, IFN-beta and interleukin 28 (IL-28), IL-29, respectively], tumour necrosis factor alpha and the chemokines CCL5 and CXCL10 after herpes simplex virus 1 (HSV-1) infection. The cytokine-inducing activity of HSV-1 was dependent on viability of the virus, because UV-inactivated virus did not induce a cytokine response. Pretreatment of the cells with IFN-alpha or IL-29 strongly enhanced the HSV-1-induced cytokine response. Both IFN-alpha and IL-29 decreased viral immediate-early (IE) gene infected-cell protein 27 (ICP27) transcription, suggesting that IL-29 possesses antiviral activity against HSV-1 comparable to that of IFN-alpha. Macrophage infection with HSV-1 lacking functional ICP27 (d27-1 virus) resulted in strongly enhanced cytokine mRNA expression and protein production. In contrast, viruses lacking functional IE genes ICP0 and ICP4 induced cytokine responses comparable to those of the wild-type viruses. The activation of transcription factors IRF-3 and NF-kappaB was strongly augmented when macrophages were infected with the ICP27 mutant virus. Altogether, the results demonstrate that HSV-1 both induces and inhibits the antiviral response in human cells and that the type III IFN IL-29, together with IFN-alpha, amplifies the antiviral response against the virus. It is further identified that viral IE-gene expression interferes with the antiviral response in human macrophages and ICP27 is identified as an important viral protein counteracting the early innate immune response.

Tumor necrosis factor alpha enhances influenza A virus-induced expression of antiviral cytokines by activating RIG-I gene expression.

Epithelial cells of the lung are the primary targets for respiratory viruses. Virus-carried single-stranded RNA (ssRNA) can activate Toll-like receptors (TLRs) 7 and 8, whereas dsRNA is bound by TLR3 and a cytoplasmic RNA helicase, retinoic acid-inducible protein I (RIG-I). This recognition leads to the activation of host cell cytokine gene expression. Here we have studied the regulation of influenza A and Sendai virus-induced alpha interferon (IFN-alpha), IFN-beta, interleukin-28 (IL-28), and IL-29 gene expression in human lung A549 epithelial cells. Sendai virus infection readily activated the expression of the IFN-alpha, IFN-beta, IL-28, and IL-29 genes, whereas influenza A virus-induced activation of these genes was mainly dependent on pretreatment of A549 cells with IFN-alpha or tumor necrosis factor alpha (TNF-alpha). IFN-alpha and TNF-alpha induced the expression of the RIG-I, TLR3, MyD88, TRIF, and IRF7 genes, whereas no detectable TLR7 and TLR8 was seen in A549 cells. TNF-alpha also strongly enhanced IKK epsilon mRNA and protein expression. Ectopic expression of a constitutively active form of RIG-I (deltaRIG-I) or IKK epsilon, but not that of TLR3, enhanced the expression of the IFN-beta, IL-28, and IL-29 genes. Furthermore, a dominant-negative form of RIG-I inhibited influenza A virus-induced IFN-beta promoter activity in TNF-alpha-pretreated cells. In conclusion, IFN-alpha and TNF-alpha enhanced the expression of the components of TLR and RIG-I signaling pathways, but RIG-I was identified as the central regulator of influenza A virus-induced expression of antiviral cytokines in human lung epithelial cells.

Severe acute respiratory syndrome coronavirus fails to activate cytokine-mediated innate immune responses in cultured human monocyte-derived dendritic cells.

Activation of host innate immune responses was studied in severe acute respiratory syndrome coronavirus (SCV)-infected human A549 lung epithelial cells, macrophages, and dendritic cells (DCs). In all cell types, SCV-specific subgenomic mRNAs were seen, whereas no expression of SCV proteins was found. No induction of cytokine genes (alpha interferon [IFN-alpha], IFN-beta, interleukin-28A/B [IL-28A/B], IL-29, tumor necrosis factor alpha, CCL5, or CXCL10) or IFN-alpha/beta-induced MxA gene was seen in SCV-infected A549 cells, macrophages, or DCs. SCV also failed to induce DC maturation (CD86 expression) or enhance major histocompatibility complex class II expression. Our data strongly suggest that SCV fails to activate host cell cytokine gene expression in human macrophages and DCs.

Gene expression and antiviral activity of alpha/beta interferons and interleukin-29 in virus-infected human myeloid dendritic cells.

Dendritic cells (DCs) respond to microbial infections by undergoing phenotypic maturation and by producing multiple cytokines. In the present study, we analyzed the ability of influenza A and Sendai viruses to induce DC maturation and activate tumor necrosis factor alpha (TNF-alpha), alpha/beta interferon (IFN-alpha/beta), and IFN-like interleukin-28A/B (IFN-lambda2/3) and IL-29 (IFN-lambda1) gene expression in human monocyte-derived myeloid DCs (mDC). The ability of influenza A virus to induce mDC maturation or enhance the expression of TNF-alpha, IFN-alpha/beta, interleukin-28 (IL-28), and IL-29 genes was limited, whereas Sendai virus efficiently induced mDC maturation and enhanced cytokine gene expression. Influenza A virus-induced expression of TNF-alpha, IFN-alpha, IFN-beta, IL-28, and IL-29 genes was, however, dramatically enhanced when cells were pretreated with IFN-alpha. IFN-alpha priming led to increased expression of Toll-like receptor 3 (TLR3), TLR7, TLR8, MyD88, TRIF, and IFN regulatory factor 7 (IRF7) genes and enhanced influenza-induced phosphorylation and DNA binding of IRF3. Influenza A virus also enhanced the binding of NF-kappaB to the respective NF-kappaB elements of the promoters of IFN-beta and IL-29 genes. In mDC IL-29 induced MxA protein expression and possessed antiviral activity against influenza A virus, although this activity was lower than that of IFN-alpha or IFN-beta. Our results show that in human mDCs viruses can readily induce the expression of IL-28 and IL-29 genes whose gene products are likely to contribute to the host antiviral response.