Autoimmunity is a type I interferon-deficiency syndrome corrected by ingested type I IFN via the GALT system

Anti-Inflammatory Agents: An Approach to Prevent Cognitive Decline in Alzheimer's Disease

Systemic inflammation is an organism's response to an assault by the non-self. However, that inflammation may predispose humans to illnesses targeted to organs, including Alzheimer's disease (AD). Lesions in AD have pro-inflammatory cytokines and activated microglial/monocyte/macrophage cells. Up to this point, clinical trials using anti-amyloid monoclonal antibodies have not shown success. Maybe it is time to look elsewhere by combating inflammation. Neuroinflammation with CNS cellular activation and excessive expression of immune cytokines is suspected as the "principal culprit" in the higher risk for sporadic AD. Microglia, the resident immune cell of the CNS, perivascular myeloid cells, and activated macrophages produce IL-1, IL-6 at higher levels in patients with AD. Anti-inflammatory measures that target cellular/cytokine-mediated damage provide a rational therapeutic strategy. We propose a clinical trial using oral type 1 IFNs to act as such an agent; one that decreases IL-1 and IL-6 secretion by activating lamina propria lymphocytes in the gut associated lymphoid tissue with subsequent migration to the brain undergoing inflammatory responses. A clinical trial would be double-blind, parallel 1-year clinical trial randomized 1 : 1 oral active type 1 IFN versus best medical therapy to determine whether ingested type I IFN would decrease the rate of cognitive decline in mild cognitive impairment or mild AD. Using cognitive psychometrics, imaging, and fluid biomarkers (MxA for effective type I IFN activity beyond the gut), we can determine if oral type I IFN can prevent cognitive decline in AD.

Gene expression profiles of germ-free and conventional piglets from the same litter

Germ-free (GF) pigs have clear microbiological backgrounds, and are extensively used as large animal models in the biomedical sciences. However, investigations of the transcriptomic differences between GF and cesarean-derived conventional (CV) piglets are limited. To improve our understanding of GF pigs, and to increase the utility of pigs as an alternative non-rodent model, we used RNA sequencing to profile gene expression in five tissues (the oral mucosae, jejunum, colon, liver, and spleen) of four male GF piglets and four male CV piglets from the same litter. We identified 14 genes that were differentially expressed in all five tissues. Seven of these common differentially expressed genes (DEGs) were interferon-inducible genes, and all 14 were consistently downregulated in the GF piglets as compared to the CV piglets. Compared to the other tissues tested, the expression of transcription factors (TFs) in the colon was most affected by the absence of a microbiota. The expression patterns of immune-related genes were downregulated in the GF piglets as compared to the CV piglets, indicating that the intestinal microbiota influenced gene expression in other tissues besides the gut. Gene Ontology (GO) analysis indicated that, in pigs, the intestinal microbiota affected the expression of genes related to immune system function and development.

Dynamic roles of type I and type II IFNs in early infection with Mycobacterium tuberculosis

Although the protective role of type II IFN, or IFN-γ, against Mycobacterium tuberculosis has been established, the effects of type I IFNs are still unclear. One potential confounding factor is the overlap of function between the two signaling pathways. We used mice carrying null mutations in the type I IFNR, type II IFNR, or both and compared their immune responses to those of wild-type mice following aerosol infection with M. tuberculosis. We discovered that, in the absence of a response to IFN-γ, type I IFNs play a nonredundant protective role against tuberculosis. Mice unable to respond to both types of IFNs had more severe lung histopathology for similar bacterial loads and died significantly earlier than did mice with impaired IFN-γ signaling alone. We excluded a role for type I IFN in T cell recruitment, which was IFN-γ dependent, whereas both types of IFNs were required for optimal NK cell recruitment to the lungs. Type I IFN had a time-dependent influence on the composition of lung myeloid cell populations, in particular by limiting the abundance of M. tuberculosis-infected recruited macrophages after the onset of adaptive immunity. We confirmed that response to IFN-γ was essential to control intracellular mycobacterial growth, without any additional effect of type I IFN. Together, our results imply a model in which type I IFN limit the number of target cells that M. tuberculosis can infect in the lungs, whereas IFN-γ enhances their ability to restrict bacterial growth.

Interferon-tau: current applications and potential in antiviral therapy

Interferon-tau (IFN-tau) was initially identified as an ovine pregnancy protein. Produced by the trophoblast, it is important in preventing degradation of the corpus luteum and has been used as an early marker for ovine pregnancy. As a member of the family of type I interferons, IFN-tau has demonstrated promising antiviral activity against human viral infections in vitro. Additionally, it displays high species cross-reactivity despite its absence in humans. To date, IFN-tau has shown efficacy in reducing replication of human immunodeficiency virus, feline immunodeficiency virus, and human papillomavirus. While IFN-tau shares similar antiviral activity to IFN-alpha, the current interferon of choice for treatment of viral infections, it lacks the associated toxicity. This may make IFN-tau an attractive alternative to IFN-alpha for the treatment of viral infections.

Type 1 Diabetes: Etiology, Immunology, and Therapeutic Strategies

Type 1 diabetes (T1D) is a chronic autoimmune disease in which destruction or damaging of the beta-cells in the islets of Langerhans results in insulin deficiency and hyperglycemia. We only know for sure that autoimmunity is the predominant effector mechanism of T1D, but may not be its primary cause. T1D precipitates in genetically susceptible individuals, very likely as a result of an environmental trigger. Current genetic data point towards the following genes as susceptibility genes: HLA, insulin, PTPN22, IL2Ra, and CTLA4. Epidemiological and other studies suggest a triggering role for enteroviruses, while other microorganisms might provide protection. Efficacious prevention of T1D will require detection of the earliest events in the process. So far, autoantibodies are most widely used as serum biomarker, but T-cell readouts and metabolome studies might strengthen and bring forward diagnosis. Current preventive clinical trials mostly focus on environmental triggers. Therapeutic trials test the efficacy of antigen-specific and antigen-nonspecific immune interventions, but also include restoration of the affected beta-cell mass by islet transplantation, neogenesis and regeneration, and combinations thereof. In this comprehensive review, we explain the genetic, environmental, and immunological data underlying the prevention and intervention strategies to constrain T1D.

Ingested (Oral) IFN-α Represses TNF-α mRNA in Relapsing-Remitting Multiple Sclerosis

In a phase II trial in relapsing-remitting multiple sclerosis (RRMS), patients ingesting 10,000 IU, but not 30,000 IU, interferon-alpha (IFN-alpha) showed fewer gadolinium enhancements at months 5 and 6, along with decreased proinflammatory tumor necrosis factor-alpha (TNF-alpha) protein secretion. Therefore, we examined MxA mRNA induction and TNF-alpha mRNA repression after 100, 300, 1,000, 3,000, and 10,000 IU doses of ingested IFN-alpha in 24 RRMS patients to determine the optimal dose for future clinical trials in MS. Maximal TNF-alpha repression occurs at 100, 1,000, and 3,000 IU. These data provide new optimal doses for additional clinical studies using ingested IFN-alpha in MS.

Deficiency of type I interferon contributes toSle2-associated component lupus phenotypes

OBJECTIVE

Studies in mice and humans have implicated type I interferon (IFN-I) in the pathogenesis of lupus. Given that the locus for IFN-I is positioned within the Sle2 murine lupus susceptibility interval on chromosome 4, we undertook this study to investigate whether differences in IFN-I levels might potentially contribute to the phenotypes ascribed to this locus.

METHODS

IFN-I, anti-IFN-I, isotype control antibody, or phosphate buffered saline was administered to C57BL/6 and B6.Sle2 mice, and the serologic and cellular phenotypes were studied. In addition, B6.Sle2 mice were examined for structural and expression polymorphisms in the IFN-I gene.

RESULTS

In both B6.Sle2 congenic mice and C57BL/6 control mice, antibody-mediated blockade of IFN-I augmented serum autoantibody levels and boosted B1a cell numbers. Administration of IFN-I ameliorated these 2 features previously attributed to this disease locus. Importantly, compared with B6 controls, B6.Sle2 mice had reduced levels of IFN-I in their sera and cell culture supernatants, following stimulation. Although several sequence polymorphisms were noted in the Sle2 alleles of various IFN-I genes, it was not established whether any of the noted sequence variations were causally related to the observed phenotypes.

CONCLUSION

Unexpectedly, reduction of IFN-I levels reproduced the serologic and cellular phenotypes previously associated with the Sle2 lupus susceptibility interval. Placing these findings in the context of other studies, the effect of IFN-I on systemic autoimmunity appears to be far more complex than originally perceived.

Approved and future pharmacotherapy for multiple sclerosis

BACKGROUND

Pharmacotherapy for relapsing-remitting multiple sclerosis (MS) advanced with the demonstration that interferon beta and glatiramer acetate improve the clinical course of this disease. Mitoxantrone is the first drug approved by the Food and Drug Administration for treatment of secondary progressive MS. Despite this progress, the agents presently available are only partially effective, are difficult to administer, and may have significant side effects. Several orally administered immunomodulatory agents are presently being evaluated for treatment of MS. One class of drugs, HMG CoA inhibitors (statins), is safe and well-tolerated and could become another mainstay of MS therapy.

REVIEW SUMMARY

This article reviews the clinical evidence for approved MS therapies and discusses their mechanisms of action. Furthermore, the clinical and laboratory data suggesting a potential role for statins in MS therapy are discussed.

CONCLUSIONS

Although treatment with interferon beta, glatiramer acetate, and mitoxantrone, the approved therapies, provide important treatment options for patients with relapsing-remitting MS and secondary progressive MS, the potential benefits of other medications, including statins, should be explored in controlled clinical trials.

Induction of blood 2',5'-oligoadenylate synthetase activity in mice by gastric administration of ovine IFN-tau

Interferon-tau (IFN-tau) is a member of the type I IFN family. Although its distribution is restricted to ruminants, IFN-tau is active against cells of humans and mice. It has been reported that oral administration of ovine IFN-tau (OvIFN-tau) prevents both acute and chronic relapsing forms of murine experimental allergic encephalomyelitis (EAE). Here, we examined the effect in mice of peroral gastric administration of OvIFN-tau on the induction of 2',5'-oligoadenylate synthetase (OAS) activity in whole blood. Before administration, mice were deprived of food and drink for 6 h, and IFN was given by either intraperitoneal (i.p.) injection or per-oral gastric administration. When administered gastrically, IFN was introduced directly into the upper part of the stomach using an oral feeding needle. OAS activity in whole blood increased dependent on dose (0-105 U) and time (0-24 h), with no significant difference in the level of activity between the two routes. An increase in the activity of OAS in blood following administration of OvIFN-tau was observed in ICR, BALB/c, C57BL/6, NZW/N, and SJL/J mice, although the extent of the increase varied with the strain. Blood OAS levels also increased on administration of murine IFN-alpha (MuIFN-alpha). However, higher levels were detected after i.p. injection than after gastric administration.

Ingested IFN-alpha preserves residual beta cell function in type 1 diabetes

Type 1 diabetes mellitus is a chronic disorder that presumably results from an autoimmune destruction of the insulin-producing pancreatic beta cells. The therapeutic potential of interventions aimed at preventing type 1 diabetes can be assessed in newly diagnosed patients. Because there is a historical experience of a low incidence of spontaneous remission in type 1 diabetes mellitus, interventions preserving beta cell function have been used to identify positive therapeutic outcomes. We treated 10 newly diagnosed type 1 diabetes patients with 30,000 IU ingested interferon-alpha (IFN-alpha) within 1 month of diagnosis and examined the difference between baseline and Sustacal-induced (Mead Johnson Nutritionals, Evansville, IN) C-peptide responses, respectively, at 0, 3, 6, 9, and 12 months. Eight of the ten patients showed preserved beta cell function, with at least a 30% increase in stimulated C-peptide levels at 0, 3, 6, 9, and 12 months after initiation of treatment. There was no discernible chemical or clinical toxicity associated with ingested IFN-alpha. Our results support the potential of ingested IFN-alpha to preserve residual beta cell function in recent onset type 1 diabetes mellitus and the testing of IFN-alpha in a placebo-controlled trial.

Global immune disregulation in multiple sclerosis: from the adaptive response to the innate immunity

Increasing evidences show a global immune disregulation in multiple sclerosis (MS). The possible involvement of myelin and non-myelin (auto-)antigens in the autoaggressive process as well as the disregulation of both adaptive and innate immunity challenge the concept of specific immunotherapy. T cells at the boundary between innate and adaptive immunity, whose immunoregulatory role is becoming increasingly clear, have recently been shown to bear relevance for MS pathogenesis. Global immune interventions (and type I interferons may be considered as such) aimed at interfering with both innate and acquired immune responses seem to be a most promising therapeutic option in MS.