Interferon-alpha (IFN-alpha) production by human intestinal mononuclear cells. Response to virus in control subjects and in Crohn's disease

Unexpected Discoveries Should Be Reconsidered in Science-A Look to the Past?

From the past, we know how much “serendipity” has played a pivotal role in scientific discoveries. The definition of serendipity implies the finding of one thing while looking for something else. The most known example of this is the discovery of penicillin. Fleming was studying “Staphylococcus influenzae” when one of his culture plates became contaminated and developed a mold that created a bacteria-free circle. Then he found within the mold, a substance that proved to be very active against the vast majority of bacteria infecting human beings. Serendipity had a key role in the discovery of a wide panel of psychotropic drugs as well, including aniline purple, lysergic acid diethylamide, meprobamate, chlorpromazine, and imipramine. Actually, many recent studies support a step back in current strategies that could lead to new discoveries in science. This change should seriously consider the idea that to further focus research project milestones that are already too focused could be a mistake. How can you observe something that others did not realize before you? Probably, one pivotal requirement is that you pay a high level of attention on what is occurring all around you. But this is not entirely enough, since, specifically talking about scientific discoveries, you should have your mind sufficiently unbiased from mainstream infrastructures, which normally make you extremely focused on a particular endpoint without paying attention to potential “unexpected discoveries”. Research in medicine should probably come back to the age of innocence and avoid the age of mainstream reports that do not contribute to real advances in the curing of human diseases. Max Planck said “Science progresses not because scientists change their minds, but rather because scientists attached to erroneous views die, and are replaced”, and Otto Warburg used the same words when he realized the lack of acceptance of his ideas. This editorial proposes a series of examples showing, in a practical way, how unfocused research may contribute to very important discoveries in science.

Orofacial granulomatosis and erythema multiforme in an adolescent with Crohn's disease

The cutaneous manifestations of Crohn's disease are myriad. A 15-year-old girl presented with recurrent lip swelling and eventual development of diarrhea and targetoid macules on the palms, feet, and back. She was finally diagnosed with Crohn's disease in the setting of a clinical presentation and histopathology consistent with orofacial granulomatosis and erythema multiforme. We review the literature and summarize reported occurrences of these cutaneous diseases in children with Crohn's disease.

Reconstructing the Molecular Function of Genetic Variation in Regulatory Networks

Over the past decade, genetic studies have recognized hundreds of polymorphic DNA loci called response QTLs (reQTLs) as potential contributors to interindividual variation in transcriptional responses to stimulations. Such reQTLs commonly affect the transduction of signals along the regulatory network that controls gene transcription. Identifying the pathways through which reQTLs perturb the underlying network has been a major challenge. Here, we present GEVIN ("Genome-wide Embedding of Variation In Networks"), a methodology that simultaneously identifies a reQTL and the particular pathway in which the reQTL affects downstream signal transduction along the network. Using synthetic data, we show that this algorithm outperforms existing pathway identification and reQTL identification methods. We applied GEVIN to the analysis of murine and human dendritic cells in response to pathogenic components. These analyses revealed significant reQTLs together with their perturbed Toll-like receptor signaling pathways. GEVIN thus offers a powerful framework that renders a comprehensive picture of disease-related DNA loci and their molecular functions within regulatory networks.

Hookworm products ameliorate dextran sodium sulfate-induced colitis in BALB/c mice

BACKGROUND

Several lines of evidence have shown that helminthiasis can significantly reduce disease severity in animal models of intestinal inflammation, airway inflammation/hyperreactivity, diabetes, and multiple sclerosis. Identification and characterization of helminth-derived immunomodulatory molecules that contribute to anticolitis effects could lead to new therapeutic approaches in inflammatory bowel diseases (IBDs) without the need for helminth infection. We evaluated the therapeutic potential of adult human hookworm, Ancylostoma ceylanicum, crude (Aw) and excreted/secreted (ES) products on dextran sulfate sodium (DSS)-induced colitis in BALB/c mice.

METHODS

Colitis was induced by 5% DSS oral administration for 7 days. Clinical disease severity was monitored daily during concomitant intraperitoneal treatment with helminth-derived products. Additionally, several pathways of immunological modulation induced by A. ceylanicum products (MPO, EPO, Th1, Th2, and Th17 cytokine responses) in the inflamed intestinal microenvironment were assessed. Finally, the histopathological profile of the colon was characterized.

RESULTS

Hookworm products are able to modulate the potent proinflammatory response induced by DSS, mainly through the downregulation of Th1 and Th17 cytokines. These proteins also reduce clinical and colonic microscopic inflammation scores as well as EPO and MPO activity.

CONCLUSIONS

Ancylostoma ceylanicum Aw and ES mediators have an important therapeutic potential in experimental colitis in mice, which may provide a more socially acceptable form of therapy for patients with IBDs as opposed to using living worms. Our results support the urgency of further isolation and recombinant expression of active hookworm products responsible for the beneficial effects on colitis.

Control of IFN-alphaA by CD73: implications for mucosal inflammation

Inflammatory diseases influence tissue metabolism, altering regulation of extracellular adenine nucleotides, with a resultant protective influence of adenosine. Ecto-5'-nucleotidase (CD73) is a central surface enzyme generating extracellular adenosine. Thus, we hypothesized that CD73 is protective in mucosal inflammation as modeled by trinitrobenzene sulfonate (TNBS) colitis. Initial studies revealed a >3-fold induction of CD73 mRNA levels after TNBS colitis. Additionally, the severity of colitis was increased, as determined by weight loss and colonic shortening, in cd73(-/-) mice relative to cd73(+/+) controls. Likewise, enteral administration of the selective CD73 inhibitor alpha,beta-methylene ADP to cd73(+/+) mice resulted in a similar increase in severity of TNBS colitis. Gene array profiling of cytokine mRNA expression, verified by real-time PCR, revealed a >90% down-regulation of IFN-alphaA in cd73(-/-) mice and alpha,beta-methylene ADP-treated cd73(+/+) mice, compared with cd73(+/+) mice. Exogenous administration of recombinant IFN-alphaA partially protected TNBS-treated cd73(-/-) mice. Cytokine profiling revealed similar increases in both IFN-gamma and TNF-alpha mRNA in colitic animals, independent of genotype. However, IL-10 mRNA increased in wild-type mice on day 3 after TNBS administration, whereas cd73(-/-) mice mounted no IL-10 response. This IL-10 response was restored in the cd73(-/-) mice by exogenous IFN-alphaA. Further cytokine profiling revealed that this IL-10 induction is preceded by a transient IFN-alphaA induction on day 2 after TNBS exposure. Together, these studies indicate a critical regulatory role for CD73-modulated IFNalphaA in the acute inflammatory phase of TNBS colitis, thereby implicating IFN-alphaA as a protective element of adenosine signaling during mucosal inflammation.

Is interferon-alpha therapy safe and effective for patients with chronic hepatitis C and inflammatory bowel disease? A case-control study

BACKGROUND

Hepatitis C virus infection is more common in patients with inflammatory bowel disease than in general population. Limited data are available as to the safety and efficacy of alpha-interferon therapy for chronic active hepatitis C in patients with concomitant inflammatory bowel disease.

AIM

To evaluate the efficacy and safety of alpha-interferon monotherapy in patients with chronic active hepatitis C and inactive or mildly active inflammatory bowel disease.

METHODS

A total of 513 consecutive inflammatory bowel disease patients at a single centre were tested for antibodies to hepatitis C virus (anti-hepatitis C virus) between 1995 and 2000. Twenty-one patients had detectable anti-hepatitis C virus Ab and were hepatitis C virus-RNA positive with histologically proved chronic active hepatitis. Each of these patients, whose inflammatory bowel disease was in clinical remission or mildly active, was sex- and age-matched to three controls with similar histological grade and stage of chronic hepatitis C virus but without inflammatory bowel disease; and all were treated with human leucocyte alpha-interferon 6 million units given thrice weekly for 12 months. Responses to treatment were classified as follows: complete response--persistently normal alanine aminotransferase and viral clearance (hepatitis C virus-RNA-ve) at the end-of-treatment, incomplete response--alanine aminotransferase normalization without viral clearance (hepatitis C virus-RNA+ve), and sustained response--alanine aminotransferase normalization and hepatitis C virus clearance 12 months after the end-of-treatment.

RESULTS

Twenty-one patients with chronic active hepatitis C and inflammatory bowel disease (10 with Crohn's disease and 11 with ulcerative colitis) and 63 sex- and age-matched controls with chronic hepatitis C virus alone received alpha-interferon monotherapy. Response rates to interferon were similar for inflammatory bowel disease patients compared with controls [CR 42% vs. 35% and SR 24% vs. 18% (P, not significant), respectively]. None of the 21 inflammatory bowel disease patients had severe adverse effects and the mild ones observed were comparable with those seen in the control group. No patients developed an inflammatory bowel disease relapse during the interferon treatment period or in the 12 months thereafter.

CONCLUSIONS

The biochemical and virological response to a 12-month human leucocyte alpha-interferon treatment in patients with chronic active hepatitis C are similar to that observed in matched controls with chronic hepatitis C virus without inflammatory bowel disease. Adverse effects are similar in both groups of patients and unrelated to the underlying inflammatory bowel condition. This provides hepatologists with evidence that alpha-interferon can be safely administered to patients with chronic hepatitis C virus and inflammatory bowel disease provided that the inflammatory bowel condition is in clinical remission.

The biological relevance of polykaryons in the immune response

Peripheral blood monocyte-derived multinucleated giant cells are a well-known feature of chronic inflammatory conditions. Similarly, virus-induced syncytia derived from CD4+ cells are considered to be typical of human immunodeficiency virus infection under culture conditions. Here, Stefano Fais and colleagues summarize recent experimental results comparing the mechanisms underlying the formation and fate of these two different polykaryons, discussing their putative role in the immune response.

Prospective evaluation of interferon-alpha in treatment of chronic active Crohn's disease

Several case reports suggested good effects of interferon-alpha in patients with Crohn's disease. In addition, a decreased production of interferon-alpha in Crohn's disease has been shown in vitro. Treatment with interferon-alpha may activate intestinal natural killer cells and down-regulate the overproduction of inflammatory cytokines like interleukin-6 in Crohn's disease. To evaluate the clinical efficacy of interferon-alpha, we treated 12 patients with a chronic active course of Crohn's disease with recombinant human interferon-alpha prospectively for 24 weeks. Prednisolone was continuously tapered and discontinued at week 12. The end point of the study was the prevention of worsening of clinical symptoms defined with the Crohn's disease activity index and was monitored by acute-phase proteins, interleukin-6 serum concentrations, and endoscopy. The biochemical activity of interferon-alpha was measured by 2',5'-oligo adenylate serum levels. The end point of the study was reached in four patients (33%). In these patients the final Crohn's disease activity index was above 150, which means that they did not achieve clinical remission. All other patients (66%) did not respond to interferon-alpha and had to be withdrawn prematurely. Interferon-alpha did not show any beneficial effect on interleukin-6 or acute-phase protein concentrations and on endoscopic activity. The 2',5'-oligo adenylate levels continuously increased during interferon therapy. Considerable side effects were noted. These results fail to demonstrate a therapeutic role of interferon-alpha in chronic active Crohn's disease.

Interferon expression in Crohn's disease patients: increased interferon-gamma and -alpha mRNA in the intestinal lamina propria mononuclear cells

The in vivo interferon (IFN) activation in Crohn's disease was evaluated by measuring the relative amounts of IFN-alpha and -gamma mRNA in freshly isolated human lamina propria mononuclear cells (LPMC) from patients with Crohn's disease and controls. Both IFN-gamma and IFN-alpha mRNA, as estimated by dot blot analysis, were increased in Crohn's disease (LPMC), although the relative amounts of IFN mRNA appeared to differ among patients. Appreciable amounts of IFN-gamma mRNA were found in Crohn's disease peripheral blood mononuclear cells (PBMC) extracts, whereas the same cells were negative for IFN-alpha mRNA. Only minute amounts of IFN-gamma RNA were found sporadically in control LPMC while no IFN-alpha was detected. Control PBMC were shown to be virtually negative for both IFN-alpha and IFN-gamma mRNA. These data suggest that IFN induction in the normal human gut is a well-controlled function and that in Crohn's disease tissues, both IFN-gamma and IFN-alpha production are dysregulated. The increased IFN activity may represent a major feature in the induction and perpetuation of the chronic inflammatory process in Crohn's disease.