Martin H. Bluth

Sophorolipids and Their Derivatives Are Lethal Against Human Pancreatic Cancer Cells

INTRODUCTIONnWe have previously demonstrated that sophorolipids, a class of easily chemoenzymatically modifiable glycolipids, possess anti-inflammatory effects in vitro and in vivo. Since glycolipids have been shown to have anticancer activity, we investigated the effects of sophorolipids and their derivatives against pancreatic cancer.nnnMATERIALS AND METHODSnHuman pancreatic carcinoma cells were treated with increasing concentrations of sophorolipid natural mixture or select derivatives (ethyl ester, methyl ester, ethyl ester monoacetate, ethyl ester diacetate, acidic sophorolipid [AS], lactonic sophorolipid diacetate [LSD]) for 24 h and assessed for cell necrosis (cytotoxicity-lactate dehydrogenase release). Controls consisted of cells treated with media or vehicle alone and sophorolipid treatment of peripheral blood mononuclear cells.nnnRESULTSnSophorolipids demonstrated anticancer activity against human pancreatic carcinoma cells. Natural mixture mediated consistent cytotoxicity at all doses tested (20 +/- 4%). However, methyl ester derivative mediated much greater levels of cytotoxicity (63 +/- 5%) compared with other derivatives (ethyl ester diacetate, 36 +/- 6%, ethyl ester monoacetate, 18 +/- 7%; P < 0.05). In contrast, LSD- and AS-mediated toxicity was inversely proportional with dose (LSD, 40.3% at 0.5 mg/mL, 3.4% at 2.0 mg/mL; AS, 49% at 0.5 mg/mL, 0% at 2.0 mg/mL). Sophorolipid treatment did not affect peripheral blood mononuclear cells at all doses tested.nnnCONCLUSIONSnThese results suggest that sophorolipids and select derivatives may be effective in treating human pancreatic cancer. Furthermore select derivatives may use different mechanisms toward this end. The ability to chemoenzymatically modify sophorolipids can provide effective lead compounds toward the treatment of pancreatic cancer.

B-Type Natriuretic Peptide: A Biomarker for the Diagnosis and Risk Stratification of Patients With Septic Shock

BACKGROUNDnThe importance of cardiomyocyte damage during sepsis has been a recent subject of interest. The progression of sepsis results in the upregulation of proinflammatory cytokines, which act in concert to damage cardiomyocytes and produce cardiac contractile dysfunction. B-type natriuretic peptide (BNP) is a neurohormone released from the ventricles of the heart in response to myocardial dysfunction. The goal of this study was to examine the relationship between BNP levels and the severity of sepsis independent of congestive heart failure.nnnDESIGNnProspective, nonrandomized control study.nnnSETTINGnUniversity hospital.nnnPATIENTSnForty-nine patients were divided into 3 groups: 13 patients with septic shock, 18 with early sepsis, and 18 age-matched healthy control subjects. We excluded patients with septic shock who had comorbid conditions (congestive heart failure or renal failure); sepsis severity was determined using the Sequential Organ Failure Assessment scoring system. Patients with sepsis were followed up for 21 days.nnnMAIN OUTCOME MEASURESnSerum BNP levels, determined at the time of diagnosis of sepsis and on patient improvement or deterioration.nnnRESULTSnPatients with septic shock had significantly higher BNP levels on admission compared with the other 2 groups (P < .05). The BNP levels were not significantly elevated in patients with early sepsis. Plasma BNP levels for patients with septic shock were positively correlated with Sequential Organ Failure Assessment scores (r(2) = 0.74, P < .05) and prognosticated survival.nnnCONCLUSIONSnThis study confirms the relationship between BNP level elevation and severity of sepsis independent of congestive heart failure. It also supports the utility of BNP level as a marker for mortality in septic shock.

Detection of IgE anti-parvovirus B19 and increased CD23+ B cells in parvovirus B19 infection: relation to Th2 cytokines.

The immune profile of a parvovirus B19-infected patient (male, 8 years old) was studied on day 0 (initial presentation) and on days 14 and 210 post symptom presentation (psp). Before infection, the patient was skin test positive to various allergens, including ragweed and tree and grass pollens, and had a serum IgE level of 150 IU/mL. On day 0, the patient was diagnosed as parvovirus B19 infected, as judged by the presence of IgG anti-parvovirus Abs in serum (EIA) and presentation of slap cheek rash. The patients serum IgE level increased from 150 IU/mL before infection to 256 IU/mL on day 0, was 233 IU/mL on day 14, and returned to preinfection levels on day 210. In contrast, there was little change in the levels of serum IgM, IgG, or IgA (nephelometry). IgE anti-parvovirus B19 protein (VP-N) was detected in serum (Western blot) on days 0, 14, and 210, despite the decrease in total IgE on day 210. Although there was no increase in total numbers of blood CD23+ B cells on day 0, by day 14 the numbers of these cells increased dramatically (93%), remaining high on day 210. In contrast, there were virtually no changes in total numbers of CD4+ and CD8+ T cells or CD16/56+ NK precursor cells on days 0-210. On day 0, when IgG and IgE anti-parvovirus were detected in serum, patients peripheral blood mononuclear cells (PBMC) expressed mRNA for the Th2 cytokines IL-4 and IL-10, but not for the Th1 cytokines IFN-gamma or IL-2. However, by day 14 psp, PBMC expressed mRNA for the Th1 cytokines IFN-gamma and IL-2, as well as for IL-4 and IL-10. This is the first demonstration of the existence of IgE anti-parvovirus B19 Ab. The presence of IgE anti-parvovirus B19 Ab in serum on day 0 and its persistence in serum 7 months psp suggests that IgE anti-parvovirus may be useful in prognosis of parvovirus B19 infection. Our results reinforce the idea that IgE, in general, may play a major role in anti-viral immunity, perhaps in conjunction with CD23+ cells. The results further suggest that clearance of this infection is accompanied by a switch to Th1 cytokines.

Effect of minocycline and doxycycline on IgE responses

BACKGROUNDnWe have recently found that the tetracycline minocycline suppresses inflammatory responses in serum immunoglobulin (Ig)E-positive asthmatic patients, and that IgE levels can decrease in these patients. The mechanism by which minocycline suppresses these responses is unknown.nnnOBJECTIVEnWe have now investigated the ability of the tetracyclines, minocycline and doxycycline, to regulate IgE responses of peripheral blood mononuclear cells (PBMC) obtained from serum IgE-positive asthmatic patients.nnnMETHODSnThe distributions of CD3+, CD4+, CD8+, and CD19+ lymphocytes in peripheral blood of serum IgE-positive asthmatic patients and IgE-negative nonasthmatic controls, and cytokine-specific mRNA expression by their PBMC were determined by flow cytometry (reverse transcriptase-polymerase chain reaction). Serum Ig levels also were determined (nephelometry, fluoroenzymeimmunoassay, enzyme-linked immunoadsorbent assay; n = 7/group). PBMC (1.5 x 10(6)/mL) were cultured with anti-CD40 monoclonal antibody and recombinant human interleukin-4 in the presence/absence of minocycline or doxycycline (0.1 to 10 microg/mL), and IgE levels in supernatants determined on days 0, 3, and 10 (enzyme-linked immunoadsorbent assay).nnnRESULTSnAsthmatic and nonasthmatic subjects had similar numbers of blood CD4+ T cells (779/mm3 +/- 73 and 766 +/- 115, respectively) and CD19+ B-cells (239/mm3 +/- 35 and 379 +/- 95, respectively); however, CD8+ T cell numbers were decreased in asthmatic compared with nonasthmatic subjects (378/mm3 +/- 66 and 568 +/- 53, respectively; P = 0.045). High IgE levels were detected in supernatants of asthmatic PBMC on day 10 (28 ng/mL +/- 12), whereas control IgE levels did not change (<2.5 ng/mL). When either minocycline or doxycycline was included in culture, IgE production by asthmatic PBMC was strongly suppressed in dose-dependent fashion on day 10 (>80% with 10 microg/mL); control IgE did not change (<2.5 ng/mL).nnnCONCLUSIONSnThe results are consistent with the idea that the therapeutic benefits obtained by asthmatic patients from minocycline may, in part, result from IgE suppression.

HIV Type 1-Specific IgE in Serum of Long-Term Surviving Children Inhibits HIV Type 1 Production in Vitro

We previously identified a group of long-term pediatric survivors who had acquired HIV-1 through maternal transmission; had not received antiretroviral therapy; are now >8 years old, in good health, and with no opportunistic infections; and have not failed to thrive, although they have greatly decreased numbers of blood CD4+ T cells (<500/mm(3)). All the children have elevated total serum IgE levels (210-2475 IU/ml) and make anti-HIV-1 IgE or IgE directed against non-HIV-1 specificities (radioimmunoassay, Western blot assay); they have no detectable antigenemia. We have now studied the ability of anti-HIV-1 IgE in serum obtained from these children to regulate (1) production of HIV-1 by interleukin 2/phytohemagglutinin (IL-2/PHA)-stimulated peripheral blood mononuclear cells (PBMCs) taken from HIV-1-seronegative donors and infected with a T cell-tropic clone of HIV-1, and (2) transmission of a primary HIV-1 strain from adult AIDS patients to uninfected IL-2/PHA-stimulated PBMCs (p24 core antigen production). High levels of HIV-1 production were observed when PBMCs were cultured for 5 days in the presence of HIV-1-seronegative donor serum that was either IgE positive or IgE negative (IgE, >100 or <100 IU/ml, respectively). HIV-1 production also was observed when PBMCs were cultured with HIV-1-infected donor serum that either contained IgE directed against non-HIV-1 specificities or was IgE negative; these levels were 40% less than those seen with sera from the HIV-1-seronegative donors. Far greater inhibition of virus production was observed if the serum in culture contained anti-HIV-1 IgE (>95%). Virus neutralization did not appear to account for the inhibition obtained with anti-HIV-1 IgE-containing serum because virus production was not suppressed in cultures to which serum was added immediately preinfection (<10%), but was strongly suppressed when serum was added 1.5 hr postinfection (>95%). The inhibition of virus production obtained with serum containing anti-HIV-1 IgE was reversed when (1) serum was depleted of IgE (immunoaffinity), but not when it was depleted of IgG (protein G-Sepharose) before inclusion in culture postinfection, (2) anti-IgE, but not anti-IgG, was included in culture, or (3) serum was heat treated before culture. The results indicate that serum from certain HIV-1-infected pediatric long-term survivors contains agents that inhibit HIV-1 production in vitro, and that these agents include anti-HIV-1 IgE. They suggest that a cytotoxic event, rather than virus neutralization, plays an important role in anti-HIV-1 IgE-mediated inhibition of virus production.

Use of Gene Expression Profiles in Cells of Peripheral Blood to Identify New Molecular Markers of Acute Pancreatitis

HYPOTHESISnBlood leukocytes play a major role in mediating local and systemic inflammation during acute pancreatitis. We hypothesize that peripheral blood mononuclear cells (PBMCs) in circulation exhibit unique changes in gene expression and could provide a reporter function that reflects the inflammatory response in the pancreas with acute pancreatitis.nnnDESIGNnTo determine specific changes in blood leukocytes during acute pancreatitis, we studied the gene transcription profile in PBMCs in a rat model of experimental pancreatitis (sodium taurocholate). Normal rats, saline controls, and a model of septic shock were used as a controls. Complementary RNA obtained from PBMCs of each group (n = 3 in each group) were applied to Affymetrix rat genome DNA GeneChip arrays. Main Outcome Measure Changes in gene expression.nnnRESULTSnFrom the 8799 rat genes analyzed, 140 genes showed unique significant changes in their expression in PBMCs during the acute phase of pancreatitis, but not in sepsis. Among the 140 genes, 57 were up-regulated, while 69 were down-regulated. Platelet-derived growth factor receptor, prostaglandin E(2) receptor, and phospholipase D(1) were among the top up-regulated genes. Others included genes involved in G protein-coupled receptor and transforming growth factor beta-mediated signaling pathways, while genes associated with apoptosis, glucocorticoid receptors, and even the cholecystokinin receptor were down-regulated.nnnCONCLUSIONSnMicroarray analysis in transcriptional profiling of PBMCs showed that genes that are uniquely related to molecular and pancreatic function display differential expression in acute pancreatitis. Profiling genes obtained from an easily accessible source during severe pancreatitis may identify surrogate markers for disease severity.

PANCREATIC REGENERATING PROTEIN I IN CHRONIC PANCREATITIS AND AGING IMPLICATIONS FOR NEW THERAPEUTIC APPROACHES TO DIABETES

Objectives: We investigated the relationship of pancreatic regenerating protein (reg) in models of acinar cell atrophy and aging, and the effect of reg I protein replacement on glucose tolerance. Methods: Rats underwent pancreatic duct ligation (PDL) and were followed through 12 months. Aging rats were studied at 12 and 20 months. Intraperitoneal glucose tolerance tests (IPGTTs) were performed, pancreatic reg I, reg I receptor, insulin gene expression, and reg I protein levels were measured. Pancreatic duct ligation and aged animals were treated with exogenous reg I protein and assessed for glucose metabolism. Results: After PDL, chronic atrophic pancreatitis developed, with a progressive loss of acinar cells and pancreatic reg I. During aging, a similar depression of reg I gene expression was also noted. The reg I levels correlated with pancreatic insulin levels. Twelve months after PDL, IPGTT results were abnormal, which were significantly improved by administration of reg I protein. Aged animals demonstrated depressed IPGTT, which marginally improved after reg I administration. Anti-reg antibody administration to young rats depressed IPGTT to elderly levels. Conclusions: Depletion of the acinar product reg I is associated with the pathogenesis of impaired glucose tolerance of pancreatitis-associated diabetes and aging, and replacement therapy could be useful in these patients. Reg I is an acinar cell product, which affects islet function.

Small-interference RNA gene knockdown of pancreatitis-associated proteins in rat acute pancreatitis.

Objectives: Pancreatitis-associated proteins (PAPs) are induced in acute pancreatitis and antisense-mediated gene knockdown of PAP decreased PAP gene expression and worsened pancreatitis. Here, we investigated the effect of a more stable inhibition of PAP using small-interference RNA gene knockdown in vitro and in an in vivo model of experimental pancreatitis. Methods: Pancreatitis-associated protein-specific siRNA was administered to AR42J cell cultures or rats induced with pancreatitis. Controls included administration of scrambled siRNA or vehicle alone. After 24 hours, cells and pancreata were harvested and assessed for PAP (PAP 1, PAP 2, PAP 3) gene expression and pancreatitis severity. Results: In vitro, PAP protein, and mRNA levels were reduced (PAP 1, 76%; PAP 2, 8%; PAP 3, 24%) in cells treated with PAP siRNA. In vivo, PAP 1, and PAP 3 expressions were reduced (PAP 1, 36%; PAP 3, 66%) in siRNA-treated rats; there was no difference in PAP 2 isoform mRNA expression and serum protein levels. Serum amylase and lipase levels decreased (≥50%) after administration of siRNA; interleukin (IL) 1&bgr;, IL-4, and IL-6 increased, whereas C-reactive protein and tumor necrosis factor-&agr; decreased when compared with vehicle control. Administration of PAP siRNA correlated with worsening histopathology. Conclusions: siRNA-mediated gene knockdown of PAP worsens pancreatitis. Differences in gene knockdown technology may provide different approaches to study gene function.

Tetracycline-mediated IgE isotype-specific suppression of ongoing human and murine IgE responses in vivo and murine memory IgE responses induced in vitro

We previously reported that minocycline treatment of allergic asthmatic patients had oral steroid sparing effects and improved their clinical status and that minocycline suppressed in vitro induction of IgE responses by their PBMC. The effect of minocycline on human or animal IgE responses in vivo has not been studied. Allergic asthmatics (serum IgE: 505 +/- 535 IU ml(-1)) were given minocycline (150 mg po to 250 mg po BID) as add-on therapy to standard care for up to 10 months; control subjects (IgE: 405 +/- 472 IU ml(-1)) received standard care (n = 6 per group). Serum immunoglobulin (IgM, IgG, IgE and IgA) levels were determined monthly (Nephelometry, Unicap Total IgE Fluoroenzyme immunoassay). BALB/c mice (n = 6 per group) were injected intraperitoneally with benzylpenicilloyl(14)-Keyhole limpet hemocyanin (BPO(14)-KLH) in alum on days 0, 21 and 42, fed with minocycline or doxycycline (10-100 mg kg(-1)) on day 44 and numbers of BPO-specific IgG(1), IgE and IgA antibody-forming cell (AFC) in mesenteric LN and spleen and serum immunoglobulin levels were determined on days 46-70 (enzyme-linked immunosorbent spot assay, ELISA). The ability of minocycline or doxycycline to suppress in vitro induction of murine memory IgE responses also was investigated. Minocycline strongly suppressed serum IgE levels of allergic asthmatics (9% per month) (P = 0.012). Minocycline (and doxycycline) also strongly suppressed peak murine IgE AFC and serum IgE responses (>95, approximately 75%, respectively) and in vitro induction of memory IgE responses by murine mesenteric LN and spleen cells (>95%). Tetracycline suppression of all human and murine IgE responses was IgE isotype specific. Suppression of murine IgE responses in vivo was dose dependent and lasted 5-7 days.

Long-term persistence of IgE anti-influenza A HIN1 virus antibodies in serum of children and adults following influenza A vaccination with subsequent H1N1 infection: a case study.

Background and methods The role of immunoglobulin (Ig) E in immunity against influenza A H1N1 has not been studied. Total serum IgE and specific IgE and IgG anti-H1N1 virus responses were studied in children and adults (n = 2) who received influenza virus vaccination (Flumist® or Fluzone® ) in autumn 2008 and 2009, and then subsequently became infected with the H1N1 virus in spring 2009. Twelve months after infection, antibodies in their serum were compared with those in the serum of subjects who were either vaccinated but not infected (n = 4) or nonvaccinated and noninfected subjects (n = 2), using UniCAP total IgE fluoroenzyme immunoassay, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and Western blotting. Band sizes for the influenza virus (58, 56, 40, 30, 25, and 17 kDa) and H1N1 viral proteins (58, 56, 25, and 17 kDa) were determined, using sodium dodecyl sulfate polyacrylamide gel electrophoresis and Coomassie brilliant blue. Results We found that the serum of vaccinated and subsequently infected children and adults contained IgE and IgG antibodies to both H1N1 and influenza virus, with a strong IgE and IgG band intensity at 56 kDa. Interestingly, in subjects who were vaccinated but not infected, band intensity at 56 kDa was lowered by approximately two-fold. Serum of nonvaccinated and noninfected subjects had no detectable IgE or IgG antibodies to influenza virus or H1N1. Conclusion This is the first description of IgE anti-influenza A H1N1 antibodies in human serum and the first demonstration of their long-term persistence. The decreased intensity of the 56 kDa band in vaccinated noninfected subjects compared with vaccinated infected subjects suggests augmented IgE and IgG antibody responses to influenza A H1N1.