The hygiene hypothesis and multiple sclerosis

Immunomodulation of streptozotocin induced Type 1 diabetes mellitus in mouse model by Macrophage migration inhibitory factor-2 (MIF-2) homologue of human lymphatic filarial parasite, Wuchereria bancrofti

Helminth parasites modulate the host immune system to ensure a long-lasting asymptomatic form of infection generally, mediated by the secretion of immunomodulatory molecules and one such molecule is a homologue of human host cytokine, Macrophage migratory Inhibitory Factor (hMIF). In this study, we sought to understand the role of homologue of hMIF from the lymphatic filarial parasite, Wuchereria bancrofti (Wba-MIF2), in the immunomodulation of the Streptozotocin (STZ)-induced Type1 Diabetes Mellitus (T1DM) animal model. Full-length recombinant Wba-MIF2 was expressed and found to have both oxidoreductase and tautomerase activities. Wba-MIF2 recombinant protein was treated to STZ induced T1DM animals, and after 5 weeks pro-inflammatory (IL-1, IL-2, IL-6, TNF-α, IFN-γ) and anti-inflammatory (IL-4, IL-10) cytokines and gene expressions were determined in sera samples and spleen respectively. Pro-inflammatory and anti-inflammatory cytokine levels were significantly (p<0.05) up-regulated and down-regulated respectively, in the STZ-T1DM animals, as compared to treated groups. Histopathology showed macrophage infiltration and greater damage of islets of beta cells in the pancreatic tissue of STZ-T1DM animals, than Wba-MIF2 treated STZ-T1DM animals. The present study clearly showed the potential of Wba-MIF2 as an immunomodulatory molecule, which could modulate the host immune system in the STZ-T1DM mice model from a pro-inflammatory to anti-inflammatory milieu.

Elevated genetic risk for multiple sclerosis emerged in steppe pastoralist populations

Multiple sclerosis (MS) is a neuro-inflammatory and neurodegenerative disease that is most prevalent in Northern Europe. Although it is known that inherited risk for MS is located within or in close proximity to immune-related genes, it is unknown when, where and how this genetic risk originated1. Here, by using a large ancient genome dataset from the Mesolithic period to the Bronze Age2, along with new Medieval and post-Medieval genomes, we show that the genetic risk for MS rose among pastoralists from the Pontic steppe and was brought into Europe by the Yamnaya-related migration approximately 5,000 years ago. We further show that these MS-associated immunogenetic variants underwent positive selection both within the steppe population and later in Europe, probably driven by pathogenic challenges coinciding with changes in diet, lifestyle and population density. This study highlights the critical importance of the Neolithic period and Bronze Age as determinants of modern immune responses and their subsequent effect on the risk of developing MS in a changing environment.

The immunomodulatory effects of the C-type lectin protein of Toxocara canis on experimental autoimmune encephalomyelitis

Toxocara canis is a global zoonosis infection that can cause chronic and long-term toxocariasis in their paratenic host. The excretory-secretory (ES) products of T. canis larvae are considered to be responsible for the Th2 polarization and regulatory immune responses in toxocariasis. The C-type lectin family is one of the most prominent components of ES products of T. canis infective larvae. This study aimed to investigate the ameliorative effect of a T. canis C-type lectin recombinant protein (rCTL), on experimental autoimmune encephalomyelitis (EAE) which is a T-cell-mediated autoimmune disease of the central nervous system. C57BL/6 mice were subcutaneously treated with 30 μg rCTL, three times at an interval of 1 week. EAE was induced by myelin oligodendrocyte glycoprotein 35-55 peptide (MOG35-55 peptide) immunization, and weight and clinical scores were evaluated. Real time polymerase chain reaction was performed to evaluate the expression levels of T-bet, Gata3, and Foxp3 in splenocytes. In addition, the levels of interleukin 4, interferon gamma, and tumour growth factor-β (TGF-β) were quantified by enzyme-linked immunosorbent assay in splenocyte culture supernatants. The results indicated that the rCTL decreased clinical disability scores and delayed the onset of EAE. Furthermore, the data showed that rCTL treatment modulated the immune response, which was associated with upregulation of the mRNA expression of the Foxp3 gene and higher production of TGF-β in rCTL-treated mice. This study demonstrated that rCTL might be a potential agent to ameliorate EAE symptoms by stimulating anti-inflammatory responses.

A target-based discovery from a parasitic helminth as a novel therapeutic approach for autoimmune diseases

BACKGROUND

Regulatory T cells (Tregs) can alleviate the development of autoimmune and inflammatory diseases, thereby proposing their role as a new therapeutic strategy. Parasitic helminths have co-evolved with hosts to generate immunological privilege and immune tolerance through inducing Tregs. Thus, constructing a "Tregs-induction"-based discovery pipeline from parasitic helminth is a promising strategy to control autoimmune and inflammatory diseases.

METHODS

The gel filtration chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC) were used to isolate immunomodulatory components from the egg extracts of Schistosoma japonicum. The extracted peptides were evaluated for their effects on Tregs suppressive functions using flow cytometry, ELISA and T cell suppression assay. Finally, we carried out colitis and psoriasis models to evaluate the function of Tregs induced by helminth-derived peptide in vivo.

FINDINGS

Here, based on target-driven discovery strategy, we successfully identified a small 3 kDa peptide (SjDX5-53) from egg extracts of schistosome, which promoted both human and murine Tregs production. SjDX5-53 presented immunosuppressive function by arresting dendritic cells (DCs) at an immature state and augmenting the proportion and suppressive capacity of Tregs. In mouse models, SjDX5-53 protected mice against autoimmune-related colitis and psoriasis through inducing Tregs and inhibiting inflammatory T-helper (Th) 1 and Th17 responses.

INTERPRETATION

SjDX5-53 exhibited the promising therapeutic effects in alleviating the phenotype of immune-related colitis and psoriasis. This study displayed a screening and validation pipeline of the inducer of Tregs from helminth eggs, highlighting the discovery of new biologics inspired by co-evolution of hosts and their parasites.

FUNDING

This study was supported by the Natural Science Foundation of China (82272368) and Natural Science Foundation of Jiangsu Province (BK20211586).

Gut Microbiota as a Potential Predictive Biomarker in Relapsing-Remitting Multiple Sclerosis

BACKGROUND

The influence of the microbiome on neurological diseases has been studied for years. Recent findings have shown a different composition of gut microbiota detected in patients with multiple sclerosis (MS). The role of this dysbiosis is still unknown.

OBJECTIVE

We analyzed the gut microbiota of 15 patients with active relapsing-remitting multiple sclerosis (RRMS), comparing with diet-matched healthy controls.

METHOD

To determine the composition of the gut microbiota, we performed high-throughput sequencing of the 16S ribosomal RNA gene. The specific amplified sequences were in the V3 and V4 regions of the 16S ribosomal RNA gene.

RESULTS

The gut microbiota of RRMS patients differed from healthy controls in the levels of the Lachnospiraceae, Ezakiella, Ruminococcaceae, Hungatella, Roseburia, Clostridium, Shuttleworthia, Poephyromonas, and Bilophila genera. All these genera were included in a logistic regression analysis to determine the sensitivity and the specificity of the test. Finally, the ROC (receiver operating characteristic) and AUC with a 95% CI were calculated and best-matched for Ezakiella (AUC of 75.0 and CI from 60.6 to 89.4) and Bilophila (AUC of 70.2 and CI from 50.1 to 90.4).

CONCLUSIONS

There is a dysbiosis in the gut microbiota of RRMS patients. An analysis of the components of the microbiota suggests the role of some genera as a predictive factor of RRMS prognosis and diagnosis.

Nematode Orthologs of Macrophage Migration Inhibitory Factor (MIF) as Modulators of the Host Immune Response and Potential Therapeutic Targets

One of the adaptations of nematodes, which allows long-term survival in the host, is the production of proteins with immunomodulatory properties. The parasites secrete numerous homologs of human immune mediators, such as macrophage migration inhibitory factor (MIF), which is a substantial regulator of the inflammatory immune response. Homologs of mammalian MIF have been recognized in many species of nematode parasites, but their role has not been fully understood. The application of molecular biology and genetic engineering methods, including the production of recombinant proteins, has enabled better characterization of their structure and properties. This review provides insight into the current state of knowledge on MIF homologs produced by nematodes, as well as their structure, enzymatic activity, tissue expression pattern, impact on the host immune system, and potential use in the treatment of parasitic, inflammatory, and autoimmune diseases.

The interplay of helminthic neuropeptides and proteases in parasite survival and host immunomodulation

Neuropeptides comprise a diverse and broad group of neurotransmitters in vertebrates and invertebrates, with critical roles in neuronal signal transduction. While their role in controlling learning and memory in the brains of mammals is known, their extra-synaptic function in infection and inflammation with effects on distinct tissues and immune cells is increasingly recognized. Helminth infections especially of the central nervous system (CNS), such as neurocysticercosis, induce neuropeptide production by both host and helminth, but their role in host–parasite interplay or host inflammatory response is unclear. Here, we review the neurobiology of helminths, and discuss recent studies on neuropeptide synthesis and function in the helminth as well as the host CNS and immune system. Neuropeptides are summarized according to structure and function, and we discuss the complex enzyme processing for mature neuropeptides, focusing on helminth enzymes as potential targets for novel anthelminthics. We next describe known immunomodulatory effects of mammalian neuropeptides discovered from mouse infection models and draw functional parallels with helminth neuropeptides. Last, we discuss the anti-microbial properties of neuropeptides, and how they may be involved in host–microbiota changes in helminth infection. Overall, a better understanding of the biology of helminth neuropeptides, and whether they affect infection outcomes could provide diagnostic and therapeutic opportunities for helminth infections.

Epidemiology of multiple sclerosis in Lebanon: A rising prevalence in the middle east

BACKGROUND

The epidemiology of multiple sclerosis (MS) has been studied in many countries of the Middle East but the prevalence and incidence of MS in Lebanon is still unknown.

OBJECTIVES

To determine the incidence and prevalence of MS in Lebanon.

METHODS

Lebanese patients diagnosed with MS between January 2018 and December 2018 were identified using the database of governmental third-party payers. The crude, age- and sex-specific 2018 prevalence and incidence among Lebanese patients were calculated.

RESULTS

2248 MS patients were identified of whom 67.1% were women (female: male ratio 2:1) with a mean age of 41.8 ± 12.96 years. The 2018 prevalence of MS was 62.91 cases per 100,000 persons (95% CI: 60.41 - 65.41). The overall incidence of MS in Lebanon was 8.36 cases per 100,000 (95% CI: 7.45 - 9.27) with a mean age at onset of 34.5 ± 12.5 years.

CONCLUSION

This is the first study to assess prevalence and incidence of MS in Lebanon, confirming that Lebanon is a moderate to high-risk area for MS. Those high rates are commensurate with recently published studies from the Middle East, pointing to a significant rise in incidence and prevalence of this disease in our region.

Gut microbiome and multiple sclerosis: New insights and perspective

The human gastrointestinal microbiota, also known as the gut microbiota living in the human gastrointestinal tract, has been shown to have a significant impact on several human disorders including rheumatoid arthritis, diabetes, obesity, and multiple sclerosis (MS). MS is an inflammatory disease characterized by the destruction of the spinal cord and nerve cells in the brain due to an attack of immune cells, causing a wide range of harmful symptoms related to inflammation in the central nervous system (CNS). Despite extensive studies on MS that have shown that many external and genetic factors are involved in its pathogenesis, the exact role of external factors in the pathophysiology of MS is still unclear. Recent studies on MS and experimental autoimmune encephalomyelitis (EAE), an animal model of encephalitis, have shown that intestinal microbiota may play a key role in the pathogenesis of MS. Therefore, modification of the intestinal microbiome could be a promising strategy for the future treatment of MS. In this study, the characteristics of intestinal microbiota, the relationship between intestine and brain despite the blood-brain barrier, various factors involved in intestinal microbiota modification, changes in intestinal microbial composition in MS, intestinal microbiome modification strategies, and possible use of intestinal microbiome and factors affecting it have been discussed.

Effects of long-term administration of Multi-Strain Probiotic on circulating levels of BDNF, NGF, IL-6 and mental health in patients with multiple sclerosis: a randomized, double-blind, placebo-controlled trial

Background: Mental disorders is one of the main causes of disability and lower life expectancy among patients with Multiple Sclerosis (MS). The present trial aimed to examine the efficacy of multi-strain probiotic supplementation on circulating levels of BDNF, NGF, IL-6 and mental health in patients with MS.Methods: This trial was conducted among 70 patients with MS that referred to the MS Association. Patients were randomized into intervention and control groups to receive 2 multi-strain probiotic capsules or placebo, daily for six months. Serum BDNF, NGF and IL-6 was measured by ELISA kits. Mental health parameters were assessed by valid questionnaires in the baseline and end of the study.Results: Of the 70 patients enrolled in this study, 65 subjects were included in the final analysis. From baseline to 6 months, probiotic supplementation resulted in a significant increase in BDNF and a significant reduction in the IL-6 levels (P < 0.001). Our findings revealed that probiotic supplementation compared to placebo caused a significant improvement in the general health questionnaire-28 (GHQ-28) (-5.31 ± 4.62 vs. -1.81 ± 4.23; P = 0.002), Beck Depression Inventory-II (BDI-II) (-4.81 ± 0.79 vs. -1.90 ± 0.96; P = 0.001), Fatigue Severity Scale (FSS) (-3.81 ± 6.56 vs. 0.24 ± 5.44; P = 0.007) and Pain Rating Index (PRI) (-3.15 ± 4.51 vs. -0.09 ± 3.67; P = 0.004). However, we not found any significant difference between the two groups in other factors (P > 0.05).Conclusion: Overall, six months of probiotic supplementation resulted in greater improvement in mental health parameters.

Association between shorter leukocyte telomeres and multiple sclerosis

Relative telomere length (TL) is regarded as a biomarker of biological age. Accelerated immune aging, as represented by TL reduction, has been demonstrated in autoimmune diseases, including multiple sclerosis (MS). However, it is still unresolved whether telomere shortening is the cause or the consequence of the pathogenic events underlying autoimmunity. Assessing TL in whole blood DNA samples in 138 MS patients and 120 healthy controls showed reduced TL in patients as compared with controls There seems to be a prelude of accelerated telomere shortening, which may increase the risk for development of MS.

Bacteria-Host Interactions in Multiple Sclerosis

Multiple sclerosis (MS) is caused by a complex interaction of genetic and environmental factors. Numerous causative factors have been identified that play a role in MS, including exposure to bacteria. Mycobacteria, Chlamydia pneumoniae, Helicobacter pylori, and other bacteria have been proposed as risk factors for MS with different mechanisms of action. Conversely, some pathogens may have a protective effect on its etiology. In terms of acquired immunity, molecular mimicry has been hypothesized as the mechanism by which bacterial structures such as DNA, the cell wall, and intracytoplasmic components can activate autoreactive T cells or produce autoantibodies in certain host genetic backgrounds of susceptible individuals. In innate immunity, Toll-like receptors play an essential role in combating invading bacteria, and their activation leads to the release of cytokines or chemokines that mediate effective adaptive immune responses. These receptors may also be involved in central nervous system autoimmunity, and their contribution depends on the infection site and on the pathogen. We have reviewed the current knowledge of the influence of bacteria on MS development, emphasizing the potential mechanisms of action by which bacteria affect MS initiation and/or progression.

The "Gut Feeling": Breaking Down the Role of Gut Microbiome in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the central nervous system with unknown etiology. Recently, the gut microbiota has emerged as a potential factor in the development of MS, with a number of studies having shown that patients with MS exhibit gut dysbiosis. The gut microbiota helps the host remain healthy by regulating various functions, including food metabolism, energy homeostasis, maintenance of the intestinal barrier, inhibition of colonization by pathogenic organisms, and shaping of both mucosal and systemic immune responses. Alteration of the gut microbiota, and subsequent changes in its metabolic network that perturb this homeostasis, may lead to intestinal and systemic disorders such as MS. Here we discuss the findings of recent MS microbiome studies and potential mechanisms through which gut microbiota can predispose to, or protect against, MS. These findings highlight the need of an improved understanding of the interactions between the microbiota and host for developing therapies based on gut commensals with which to treat MS.

Environmental factors in autoimmune diseases and their role in multiple sclerosis

An increase in autoimmune diseases poses a socioeconomic challenge worldwide. Predisposing genetic risk has been identified, yet environmental factors make up a significant part of the risk in disease initiation and propagation. Next to improved hygiene and a gross reduction of infections, changes in dietary habits are one of the most evident Western lifestyle factors potentially associated with the increase in autoimmune diseases. Growing evidence suggests that particularly a typical 'Western diet', rich in saturated fat and salt and related pathologies can have a profound impact on local and systemic immune responses under physiologic and autoimmune conditions such as in multiple sclerosis (MS). In this review, we discuss recent findings on environmental factors influencing autoimmunity with an emphasis on the impact of 'Western diet' on immune homeostasis and gut microbiota in MS.

Multiple sclerosis patients have a distinct gut microbiota compared to healthy controls

Multiple sclerosis (MS) is an immune-mediated disease, the etiology of which involves both genetic and environmental factors. The exact nature of the environmental factors responsible for predisposition to MS remains elusive; however, it’s hypothesized that gastrointestinal microbiota might play an important role in pathogenesis of MS. Therefore, this study was designed to investigate whether gut microbiota are altered in MS by comparing the fecal microbiota in relapsing remitting MS (RRMS) (n = 31) patients to that of age- and gender-matched healthy controls (n = 36). Phylotype profiles of the gut microbial populations were generated using hypervariable tag sequencing of the V3–V5 region of the 16S ribosomal RNA gene. Detailed fecal microbiome analyses revealed that MS patients had distinct microbial community profile compared to healthy controls. We observed an increased abundance of Psuedomonas, Mycoplana, Haemophilus, Blautia, and Dorea genera in MS patients, whereas control group showed increased abundance of Parabacteroides, Adlercreutzia and Prevotella genera. Thus our study is consistent with the hypothesis that MS patients have gut microbial dysbiosis and further study is needed to better understand their role in the etiopathogenesis of MS.

Asymptomatic Helminth Infection in Active Tuberculosis Is Associated with Increased Regulatory and Th-2 Responses and a Lower Sputum Smear Positivity

Background

The impact of intestinal helminth infection on the clinical presentation and immune response during active tuberculosis (TB) infection is not well characterized. Our aim was to investigate whether asymptomatic intestinal helminth infection alters the clinical signs and symptoms as well as the cell mediated immune responses in patients with active TB.

Methodology

Consecutive, newly diagnosed TB patients and healthy community controls (CCs) were recruited in North-west Ethiopia. TB-score, body mass index and stool samples were analyzed. Cells from HIV-negative TB patients (HIV-/TB) and from CCs were analyzed for regulatory T-cells (Tregs) and cytokine responses using flow cytometry and ELISPOT, respectively.

Results

A significantly higher ratio of helminth co-infection was observed in TB patients without HIV (Helm+/HIV-/TB) compared to HIV negative CCs, (40% (121/306) versus 28% (85/306), p = 0.003). Helm+/HIV-/TB patients showed significantly increased IL-5 secreting cells compared to Helm-/HIV-/TB (37 SFU (IQR:13–103) versus 2 SFU (1–50); p = 0.02, n = 30). Likewise, levels of absolute Tregs (9.4 (3.2–16.7) cells/μl versus 2.4 (1.1–4.0) cells/μl; p = 0.041) and IL-10 secreting cells (65 SFU (7–196) versus 1 SFU (0–31); p = 0.014) were significantly higher in Helm+/HIV-/TB patients compared to Helm-/HIV-/TB patients. In a multivariate analysis, a lower rate of sputum smear positivity for acid fast bacilli, lower body temperature, and eosinophilia were independently associated with helminth infection in TB patients.

Conclusions

Asymptomatic helminth infection is associated with increased regulatory T-cell and Th2-type responses and a lower rate of sputum smear positivity. Further studies are warranted to investigate the clinical and immunological impact of helminth infection in TB patients.

The effects of helminth infection on chronic infectious diseases such as tuberculosis (TB) merit further characterization. There is limited data regarding the impact of helminth co-infection on clinical and immunological outcomes of TB from clinical field studies in high endemic areas. We tried to address some of these issues in a randomized clinical trial in order to investigate the impact of albendazole treatment on helminth co-infected TB patients. In the present study we focused on the clinical and immunological effects of helminth infection on TB. We found that concomitant asymptomatic helminth infection profoundly affects the immune phenotype of TB patients with a strong leaning towards Th2 types of immune response such as increased regulatory T cells as well as IL-5 and IL-10 secreting cells. Furthermore, helminth co-infection was associated with a significantly lower ratio of sputum smear positivity which correlated to the egg load in helminth positive TB patients. Whether the effect of helminth infection may have an impact on the diagnosis and treatment of active TB remains to be further investigated.

Impact of the environment on multiple sclerosis

BACKGROUND

Epidemiological studies suggest that environmental factors play a significant role in the development of multiple sclerosis. This article presents current knowledge on the impact of the environment on disease risk and disease course.

METHOD

We have conducted searches in PubMed for «multiple sclerosis» combined with «environment» as well as relevant environmental factors.

RESULTS

It is highly likely that an interaction between genetic and environmental factors determines who will develop multiple sclerosis. Epstein-Barr virus infection, smoking, and low vitamin D levels are the environmental factors that have shown the strongest and most consistent association with development of the disease. Low vitamin D levels are also associated with high disease activity. Other risk factors include obesity and high salt intake.

INTERPRETATION

Although epidemiological studies have identified a number of environmental factors with potential aetiological relevance, and the importance of these is supported by experimental studies, there is still insufficient evidence to establish a causal role for these factors in multiple sclerosis.

Sex-Based Differences in Multiple Sclerosis (MS): Part II: Rising Incidence of Multiple Sclerosis in Women and the Vulnerability of Men to Progression of this Disease

It is well known that a number of autoimmune diseases including multiple sclerosis (MS) predominantly affect women and there has been much attention directed toward understanding why this is the case. Past research has revealed a number of sex differences in autoimmune responses that can account for the female bias in MS. However, much less is known about why the incidence of MS has increased exclusively in women over the past half century. The recency of this increase suggests that changing environmental or lifestyle factors are interacting with biological sex to increase MS risk predominantly in females. Indeed, a number of recent studies have identified sex-specific differences in the effect of environmental factors on MS incidence. The first part of this chapter will overview this evidence and will discuss the possible scenarios of how the environment may be interacting with autoimmune mechanisms to contribute to the preferential rise in MS incidence in women. Despite the strong female bias in MS incidence, culminating evidence from natural history studies, and imaging and pathology studies suggests that males who develop MS may exhibit a more rapid decline in disability and cognitive functioning than women. Very little is known about the biological basis of this more rapid deterioration, but some insights have been provided by studies in rodent models of demyelination/remyelination. The second part of this chapter will overview the evidence that males with relapsing-onset MS undergo a more rapid progression of disease than females and will discuss potential biological mechanisms that account for this sex difference.

Blockade of IL-33 release and suppression of type 2 innate lymphoid cell responses by helminth secreted products in airway allergy

Helminth parasites such as the nematode Heligmosomoides polygyrus strongly inhibit T helper type 2 (Th2) allergy, as well as colitis and autoimmunity. Here, we show that the soluble excretory/secretory products of H. polygyrus (HES) potently suppress inflammation induced by allergens from the common fungus Alternaria alternata. Alternaria extract, when administered to mice intranasally with ovalbumin (OVA) protein, induces a rapid (1-48 h) innate response while also priming an OVA-specific Th2 response that can be evoked 14 days later by intranasal administration of OVA alone. In this model, HES coadministration with Alternaria/OVA suppressed early IL-33 release, innate lymphoid cell (ILC) production of IL-4, IL-5, and IL-13, and localized eosinophilia. Upon OVA challenge, type 2 ILC (ILC2)/Th2 cytokine production and eosinophilia were diminished in HES-treated mice. HES administration 6 h before Alternaria blocked the allergic response, and its suppressive activity was abolished by heat treatment. Administration of recombinant IL-33 at sensitization with Alternaria/OVA/HES abrogated HES suppression of OVA-specific responses at challenge, indicating that suppression of early Alternaria-induced IL-33 release could be central to the anti-allergic effects of HES. Thus, this helminth parasite targets IL-33 production as part of its armory of suppressive effects, forestalling the development of the type 2 immune response to infection and allergic sensitization.

Environmental factors in multiple sclerosis

Although genetic susceptibility explains the clustering of multiple sclerosis (MS) cases within families, the changes in MS risk that occur with migration can be explained only by changes in the environment. The strongest known risk factor for MS is infection with Epstein-Barr virus (EBV). Compared with uninfected individuals, the hazard of developing MS is approximately 15-fold higher among individuals infected with EBV in childhood and about 30-fold higher among those infected with EBV in adolescence or later in life. Although the mechanisms underlying this association remain unclear, the data provide strong evidence of a causal relation between EBV infection and MS risk. Relevant aspects of MS epidemiology beyond genetics are not explained by EBV involvement, however, implying the involvement of other factors. Modifiable factors for MS risk include smoking and childhood obesity. Increased risk of MS in individuals with vitamin D insufficiency has been proposed to explain the strong latitude gradient in MS prevalence. Results of case-control studies that relied on prevalent MS cases have been mixed, however, and potentially influenced by selection and recall biases. In a recent case-control study of individuals presenting with a first demyelinating episode, higher levels of vitamin D, sun exposure or actinic damage were found to be associated with reduced MS risk. Two longitudinal studies have thus far been completed. In the first, based on assessment of vitamin D intake from diet and supplements, the risk of MS was found to be 30% lower among women in the highest quintile compared with those in the lowest quintile. In the second study, conducted among young adults in the US military, vitamin D status was assessed by averaging multiple season-adjusted measures of 25-hydroxyvitamin D (25[OH]D). During an average of 5 years' follow-up, MS risk among healthy young adults with serum levels of 25(OH) vitamin D >100 nmol/l was about 60% lower than in individuals of the same age and sex with serum 25(OH) vitamin D levels <100 nmol/l. If confirmed, these findings suggest that a high proportion of MS cases could be effectively prevented by vitamin D supplementation. Furthermore, there is growing evidence that vitamin D insufficiency is a risk factor for conversion from clinically isolated syndrome to MS and for MS progression. Both prevention and treatment trials with vitamin D are needed to confirm these findings and to determine optimal levels of vitamin D.

Infections and multiple sclerosis

Multiple sclerosis is a chronic inflammatory condition of unknown cause. Increasing evidence suggests that the disease develops as a result of interactions between the environment and the immune system in genetically susceptible individuals. It has long been recognized that infections may serve as environmental triggers for the disease, and a large number of pathogens have been proposed to be associated with multiple sclerosis. Here, we detail the historical basis linking infections to multiple sclerosis and review the epidemiology of the disease, which suggests a possible relationship with infectious agents. We also describe pathophysiologic studies in animals and other human demyelinating diseases that have demonstrated a variety of mechanisms by which infectious agents may induce chronic, relapsing central nervous system disease with myelin damage and relative preservation of axons, similar to multiple sclerosis. In addition, we discuss recent studies in individuals with multiple sclerosis indicating enhanced immune responses to infectious antigens, though not consistently demonstrating evidence for ongoing infection. Taken together, these studies suggest a role for infectious agents in the development of multiple sclerosis. Conclusive evidence, however, remains lacking.

Helminth Therapy for MS

In the last 50 years, environmental factors such as helminth infections have been proposed to explain why autoimmunity is less prevalent in the developing world; this proposal has been termed the hygiene or old friends hypothesis. The epidemiology of MS shows an inverse correlation with helminth infections. Positive effects of helminths in animal models of MS and observational studies in people with MS naturally infected with helminths suggest that those organisms can act as immune regulators and led to clinical trials of helminth therapy. The goal of helminth therapy is to introduce parasitic organisms into people with MS in a controlled and predictable fashion, and to prevent immune-mediated disease without increasing the risk of pathology with high parasite load. This chapter focuses on intestinal worms as they are the current choice as a therapeutic strategy in a number of autoimmune diseases, including MS. Here we review current data regarding the rationale and the current state of research in the field of helminth therapies in MS.

IL-25 prevents T cell-mediated neurotoxicity by decreasing LFA-1 expression

Autoimmune diseases such as multiple sclerosis (MS) are thought to develop due to a dysregulation in the normal T(H)1-T(H)17/T(H)2 immune system balance, where pro-inflammatory responses with a T(H)1/T(H)17 prevalence develop. Some therapeutic treatments in MS promote a shift toward a TH2-prevalent environment and this has been shown to be protective. However, not all patients respond to current immunomodulatory treatments in MS so that new immunomodulatory drugs that can promote a shift of the immune system into an anti-inflammatory T(H)2 status are needed. IL-25 is a cytokine of the IL-17 family with powerful anti-inflammatory properties. This study demonstrates that IL-25 exerts neuroprotective functions by reducing T cell-mediated killing of human fetal neurons. The mechanism of action of this IL-25-mediated neuroprotective effect appears to be linked to reduction in the expression of the adhesion molecule LFA-1, which is relevant in stabilizing the immune synapse during cytotoxicity.

Early life socioeconomic indicators and risk of type 1 diabetes in children and young adults

OBJECTIVE

To examine the potential role of 2 early-life socioeconomic indicators, parental education, and crowding index, on risk of type 1 diabetes (T1DM) in patients up to age 29 years to test heterogeneity by age at onset according to the hygiene hypothesis.

STUDY DESIGN

The study base was 330 950 individuals born from 1967 to 2006 who resided in the city of Turin at any time between 1984 and 2007. Data on their early life socioeconomic position were derived from the Turin Longitudinal Study; 414 incident cases of T1DM up to age 29 years were derived from the Turin T1DM registry.

RESULTS

Socioeconomic indicators had opposing effects on risk of T1DM in different age at onset subgroups. In a Poisson regression model that included both socioeconomic indicators, there was a 3-fold greater risk of T1DM (relative risk 2.91, 95% CI 0.99-8.56) in children age 0-3 years at diagnosis living in crowded houses. In the 4- to 14-year subgroup, a low parental educational level had a protective effect (relative risk 0.50, 95% CI 0.29-0.84), and the effect of crowding nearly disappeared. In the 15- to 29-year subgroup, neither crowding nor parental educational level was clearly associated with the incidence of T1DM.

CONCLUSIONS

We provide evidence of heterogeneity by age at onset of the association between early-life socioeconomic indicators and the risk of T1DM. This finding is consistent with the hypothesis that infectious agents in the perinatal period may increase the risk, whereas in the following years they may become protective factors (hygiene hypothesis).

Helminth infections: therapeutic potential in autoimmune disorders

Knowledge of immunity enables us to predict that the reactions set in response to infection with helminth would prevent concomitant disease driven by an opposing spectrum of immune events. In another way, the immune response generated to combat the helminth infection could counteract the immunopathological reactions that drive autoimmune diseases. Rodent model systems recapitulate many aspects of human autoimmune diseases and have been enormously useful in defining mechanisms of immunopathology after infection. From this theoretical perspective, many researchers have proved that infection with a variety of helminth can ameliorate disease in murine model systems. Thus, helminth-evoked Th2 events were shown to improve disorders in which Th1 events predominated. This raised the question, 'Can this information be translated into therapies for autoimmune diseases in humans via actual infection, cell delivery or drug intervention?' In this review, we will present some experimental trails to treat autoimmune disorders through establishment of some parasitic infections.

Neuroprotective potential beyond immunoregulation of helminth infection as a therapeutic target in multiple sclerosis

Multiple sclerosis (MS) is a common disabling autoimmune disease in young adults which does not have an effective treatment. The prevalence of immune-mediated diseases is higher in developed countries with hygienic environments, suggesting that helminthic infection may protect from autoimmune diseases. Previously, we reported that soluble egg antigens (SEA) from Schistosoma japonicum suppressed experimental autoimmune encephalomyelitis (EAE), an animal model of MS, through up-regulating T helper-2 (Th2) immune responses in both the peripheral and central target organs. Neurotrophins (NTs) are not exclusive to the nervous system. While immune cells, especially Th2 cells, can produce and secrete a variety of NTs resulting in neuroprotective immunity. NTs can also modulate immune responses by augmenting Th2 responses and downregulating Th1 responses. Interestingly, nerve growth factor (NGF) has been found in liver granulomas of Schistosoma mansoni-infected mice. Moreover, in the central nervous system of chronic schistosomiasis, NGF is increased. A hypothesis is hereby proposed - SEA derived from S. japonicum bears neuroprotective properties beyond its immunomodulatory effects. SEA can induce the expression of NTs, which in turn augment Th2 immune responses induced by SEA; whereby a positive regulatory circuit between Th2 responses and NTs comes into being.

Diversity and dialogue in immunity to helminths

The vertebrate immune system has evolved in concert with a broad range of infectious agents, including ubiquitous helminth (worm) parasites. The constant pressure of helminth infections has been a powerful force in shaping not only how immunity is initiated and maintained, but also how the body self-regulates and controls untoward immune responses to minimize overall harm. In this Review, we discuss recent advances in defining the immune cell types and molecules that are mobilized in response to helminth infection. Finally, we more broadly consider how these immunological players are blended and regulated in order to accommodate persistent infection or to mount a vigorous protective response and achieve sterile immunity.

Probiotic helminth administration in relapsing-remitting multiple sclerosis: a phase 1 study

BACKGROUND

Probiotic treatment strategy based on the hygiene hypothesis, such as administration of ova from the non-pathogenic helminth, Trichuris suis, (TSO) has proven safe and effective in autoimmune inflammatory bowel disease.

OBJECTIVE

To study the safety and effects of TSO in a second autoimmune disease, multiple sclerosis (MS), we conducted the phase 1 Helminth-induced Immunomodulatory Therapy (HINT 1) study.

METHODS

Five subjects with newly diagnosed, treatment-naive relapsing-remitting multiple sclerosis (RRMS) were given 2500 TSO orally every 2 weeks for 3 months in a baseline versus treatment control exploratory trial.

RESULTS

The mean number of new gadolinium-enhancing magnetic resonance imaging (MRI) lesions (n-Gd+) fell from 6.6 at baseline to 2.0 at the end of TSO administration, and 2 months after TSO was discontinued, the mean number of n-Gd+ rose to 5.8. No significant adverse effects were observed. In preliminary immunological investigations, increases in the serum level of the cytokines IL-4 and IL-10 were noted in four of the five subjects.

CONCLUSION

TSO was well tolerated in the first human study of this novel probiotic in RRMS, and favorable trends were observed in exploratory MRI and immunological assessments. Further investigations will be required to fully explore the safety, effects, and mechanism of action of this immunomodulatory treatment.

Chronic helminth infection promotes immune regulation in vivo through dominance of CD11cloCD103- dendritic cells

Gastrointestinal helminth infections are extremely prevalent in many human populations and are associated with downmodulated immune responsiveness. In the experimental model system of Heligmosomoides polygyrus, a chronic infection establishes in mice, accompanied by a modulated Th2 response and increased regulatory T cell (Treg) activity. To determine if dendritic cell (DC) populations in the lymph nodes draining the intestine are responsible for the regulatory effects of chronic infection, we first identified a population of CD11c(lo) nonplasmacytoid DCs that expand after chronic H. polygyrus infection. The CD11c(lo) DCs are underrepresented in magnetic bead-sorted preparations and spared from deletion in CD11c-diptheria toxin receptor mice. After infection, CD11c(lo) DCs did not express CD8, CD103, PDCA, or Siglec-H and were poorly responsive to TLR stimuli. In DC/T cell cocultures, CD11c(lo) DCs from naive and H. polygyrus-infected mice could process and present protein Ag, but induced lower levels of Ag-specific CD4(+) T cell proliferation and effector cytokine production, and generated higher percentages of Foxp3(+) T cells in the presence of TGF-β. Treg generation was also dependent on retinoic acid receptor signaling. In vivo, depletion of CD11c(hi) DCs further favored the dominance of the CD11c(lo) DC phenotype. After CD11c(hi) DC depletion, effector responses were inhibited dramatically, but the expansion in Treg numbers after H. polygyrus infection was barely compromised, showing a significantly higher regulatory/effector CD4(+) T cell ratio compared with that of CD11c(hi) DC-intact animals. Thus, the proregulatory environment of chronic intestinal helminth infection is associated with the in vivo predominance of a newly defined phenotype of CD11c(lo) tolerogenic DCs.

Paradigms in multiple sclerosis: time for a change, time for a unifying concept

It has recently been suggested that, rather than being an autoimmune disease, multiple sclerosis (MS) is an example of a neurocristopathy, a pathological process resulting from a faulty development of the neural crest. Whilst several characteristics of the disease suggest a neurocristopathy, other aetiological factors require consideration, including hygiene-related factors that alter the immune responses to common pathogens resulting in an eclipse of immune reactivity that could protect against MS, the possible role of human endogenous retroviruses (HERVs) in pathogenesis and autoimmune phenomena, HLA polymorphism, vitamin D levels before and after birth and immune repair mechanisms. A postulated aetiological factor in MS, associated with altered vitamin D metabolism and abnormal HERV expression, is a long-lasting disturbed redox regulation in the biosynthesis of a melanoma-like melanin pigment. Although intensive further studies on melanin pigments in nerve tissue in MS are required, the known properties of a pathological form of such pigments in melanoma could explain a number of observations in MS, including the impact of light, UV-light, and vitamin D, and could explain the clinical manifestations of MS on the basis of an oscillating process of oxidative charge and discharge of the pigments and a threshold phenomenon with a change of the quasi-catalytic function of the pigment from destroying reactive oxygen radicals or species to transforming them to more harmful long-persisting highly reactive species. Taken together with the consequences of an adaptive process in partly demyelinated neurons, resulting in an increase in number of mitochondria, and the impact of stressful life events, these conditions are necessary and sufficient to explain the disease process of MS with its spatial (plaques) and temporal (attacks and remissions) characteristics. This suggested unifying concept of the pathogenesis of MS may open perspectives for prevention, diagnosis and therapy. In particular, prevention may be achieved by vaccinating against Epstein-Barr virus in early childhood.

Regulatory T cells in infection

Infectious agents have intimately co-evolved with the host immune system, acquiring a portfolio of highly sophisticated mechanisms to modulate immunity. Among the common strategies developed by viruses, bacteria, protozoa, helminths, and fungi is the manipulation of the regulatory T cell network in order to favor pathogen survival and transmission. Treg activity also benefits the host in many circumstances by controlling immunopathogenic reactions to infection. Interestingly, some pathogens are able to directly induce the conversion of naive T cells into suppressive Foxp3-expressing Tregs, while others activate pre-existing natural Tregs, in both cases repressing pathogen-specific effector responses. However, Tregs can also act to promote immunity in certain settings, such as in initial stages of infection when effector cells must access the site of infection, and subsequently in ensuring generation of effector memory. Notably, there is little current information on whether infections selectively drive pathogen-specific Tregs, and if so whether these cells are also reactive to self-antigens. Further analysis of specificity, together with a clearer picture of the relative dynamics of Treg subsets over the course of disease, should lead to rational strategies for immune intervention to optimize immunity and eliminate infection.

To B or not to B: B cells and the Th2-type immune response to helminths

Similar T helper (Th)2-type immune responses are generated against different helminth parasites, but the mechanisms that initiate Th2 immunity, and the specific immune components that mediate protection against these parasites, can vary greatly. B cells are increasingly recognized as important during the Th2-type immune response to helminths, and B cell activation might be a target for effective vaccine development. Antibody production is a function of B cells during helminth infection and understanding how polyclonal and antigen-specific antibodies contribute should provide important insights into how protective immunity develops. In addition, B cells might also contribute to the host response against helminths through antibody-independent functions including, antigen presentation, as well as regulatory and effector activity. In this review, we examine the role of B cells during Th2-type immune response to these multicellular parasites.

Infection of non-encapsulated species of Trichinella ameliorates experimental autoimmune encephalomyelitis involving suppression of Th17 and Th1 response

Epidemiological and experimental studies have indicated that helminth infections can ameliorate autoimmune diseases. The present study investigated the amelioration effect of the Trichinella pseudospiralis infection on experimental autoimmune encephalomyelitis (EAE), a T-cell-mediated autoimmune disease of central nervous system (CNS), and expression kinetics of Th17 and Th1 cytokine which play a crucial role in the pathogenesis of EAE. The results indicated that the infection of helminth T. pseudospiralis obviously ameliorated clinical severity and greatly delayed the onset of EAE induced by myelin oligodendrocyte glycoprotein (MOG) immunization. Infection caused much lesser inflammatory infiltration and demyilination in the CNS of infected EAE mice than uninfected EAE mice. The reduced infiltration was also suggested by the expressions of the inflammation cytokines, IL-17, IL-6, IL-1β, IFN-γ, and TNF-α, which were high in the spinal cords of the uninfected EAE mice, but was nearly normal or low in the infected EAE mice. The increased production of MOG-induced IL-17 and IFN-γ and the expression of IL-6, IL-1β, TGF-β in splenocytes after restimulation with MOG was inhibited in the infected EAE mice. On the other hand, the greatly induced Th2 response was observed in the splenocytes of the infected EAE mice. The present study showed that T. pseudospiralis infection can suppresses EAE by reducing the inflammatory infiltration in CNS, likely associated with the suppression of Th17 and Th1 responses by the infection.

Helminth-induced CD19+CD23hi B cells modulate experimental allergic and autoimmune inflammation

Numerous population studies and experimental models suggest that helminth infections can ameliorate immuno-inflammatory disorders such as asthma and autoimmunity. Immunosuppressive cell populations associated with helminth infections include Treg and alternatively-activated macrophages. In previous studies, we showed that both CD4⁺CD25⁺ Treg, and CD4^– MLN cells from Heligmosomoides polygyus-infected C57BL/6 mice were able to transfer protection against allergic airway inflammation to sensitized but uninfected animals. We now show that CD4^–CD19⁺ MLN B cells from infected, but not naïve, mice are able to transfer a down-modulatory effect on allergy, significantly suppressing airway eosinophilia, IL-5 secretion and pathology following allergen challenge. We further demonstrate that the same cell population can alleviate autoimmune-mediated inflammatory events in the CNS, when transferred to uninfected mice undergoing myelin oligodendrocyte glycoprotein_(p35–55)-induced EAE. In both allergic and autoimmune models, reduction of disease was achieved with B cells from helminth-infected IL-10^−/− donors, indicating that donor cell-derived IL-10 is not required. Phenotypically, MLN B cells from helminth-infected mice expressed uniformly high levels of CD23, with follicular (B2) cell surface markers. These data expand previous observations and highlight the broad regulatory environment that develops during helminth infections that can abate diverse inflammatory disorders in vivo.

Vitamin D and multiple sclerosis

The hypothesis that adequate vitamin D nutrition can contribute to the prevention of multiple sclerosis (MS) was originally proposed to explain the geographical distribution of MS, but only recently has the relation between various measures of vitamin D (eg, sun exposure, dietary sources, and serum concentrations of 25-hydroxyvitamin D) and risk of developing MS been rigorously investigated. Overall, the results of these studies support a protective effect of vitamin D, but there are uncertainties and many unanswered questions, including how vitamin D exerts a protective effect, how genetic variations modify the effect, and whether vitamin D can influence the course of MS progression.

99th Dahlem conference on infection, inflammation and chronic inflammatory disorders: symbionts and immunopathology in chronic diseases: insights from evolution

Immunological aetiologies of disease are not generally well understood, but have been attributed to intrinsic immunological imbalances, infectious triggers or persistent infections. Evolutionary considerations lead to the formulation of three feasible categories of immunopathology for common diseases. One category of hypotheses presumes that the immune system is exposed to environmental conditions to which the individual is not well adapted. One hypothesis within this category, often referred to as the hygiene hypothesis, proposes that new more hygienic environmental conditions have generated compositions of symbionts that differ from those to which humans have been adapted. A second category of hypotheses proposes that infectious agents act as triggers of immunopathology by shifting the immune system into a self-destructive state. A third category proposes that infectious agents keep the immune in a self-destructive state by causing persistent infections. To evaluate disease causation rigorously and to determine the appropriate interventions, these three categories of causation need to considered for every disease that involves immunopathology. Assessment of the progress in understanding oncogenesis and other chronic diseases emphasizes the value of such integrated assessments.

Epidemiology of Multiple Sclerosis

This chapter discusses the environmental factors associated to epidemiology of multiple sclerosis. The epidemiologic evidence points to three environ­mental risk factors—infection with the Epstein-Barr virus (EBV), low levels of vitamin D, and cigarette smoking—whose association with multiple sclerosis (MS) seems to satisfy in varying degrees most of the criteria that support causality, including temporality, strength, consis­tency, biologic gradient, and plausibility. None of these associations, however, has been tested experimentally in humans and only one––vitamin D deficiency is presently amenable to experimental interventions. The evidence, albeit more sparse and inconsistent, linking other environmental factors to MS risk are summarized. Epidemiologic clues to the hypothetical role of infection in MS are com­plex and often seem to point in opposite directions. The ecological studies, database/linkage analyses, and longitudinal studies of sunlight exposure and vitamin D are reviewed. Biologic mechanisms for smoking and increased risk of MS could be neuro­toxic, immunomodulatory, vascular, or they could involve increased frequency and duration of respiratory infections. Some other possible risk factors include––diet and hepatitis B vaccine.

Regulation of type 1 diabetes, tuberculosis, and asthma by parasites

Helminth infection is a worldwide health problem. In addition to directly causing disease, helminthic infection also affects the incidence and progression of other diseases by exerting immune modulatory effects. In animal models, infection with helminthic parasites can prevent autoimmune diseases and allergic inflammatory diseases, but worsens protective immunity to certain infectious pathogens. In this review, we summarize current findings regarding the effects of helminth infection on type 1 diabetes, tuberculosis, and asthma and discuss possible mechanisms through which helminthic parasites modulate host immunity. Investigating these mechanisms could lead to treatment strategies that specifically modulate the immune response as well as address fundamental questions in immunobiology.

Allergy and multiple sclerosis: a population-based case-control study

BACKGROUND

Epidemiological studies on the association between allergic disorders, T-helper type 2 (Th2) mediated, and multiple sclerosis (MS), a T-helper type 1 (Th1)/Th17-mediated disease, provided conflicting results.

OBJECTIVE

The aim of this study was to further examine the association between allergic disorders and MS.

METHODS

The association between MS and previous medical history of any type of allergy has been investigated in a population-based case-control study conducted in Northern Italy, based on telephone interviews to 423 cases and 643 population controls (refusal rates 3.7% and 9.4%, respectively). Controls were a random sample of the general population.

RESULTS

A history of atopic allergies seems to confer protection against MS (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.38-0.89; P = 0.012). In particular, the prevalence of allergic asthma was 4.9% in people with MS and 12% in control subjects (OR = 0.38; 95% CI 0.22-0.66, P < 0.01). No association was found between MS and nonatopic allergies.

CONCLUSIONS

Our findings are confirmatory of the putative protective effect of Th2-mediated disorders on Th1 immune responses associated with MS. A unifying theory on the mechanisms by which previous history of atopic allergies may modify the risk of MS is still lacking.

Is the risk of multiple sclerosis related to the 'biography' of the immune system?

Multiple sclerosis (MS) with onset in childhood offers a unique opportunity to study the infectious background of this disease but the immune reactions against infectious agents in such children have only recently been investigated. These and other epidemiological studies strongly implicate involvement of one or more infectious agents in the aetiology of MS, with Epstein-Barr virus (EBV) being the prime candidate. Rather than being the actual cause of MS, it is more probable that these agents are involved in the development of immunoregulatory pathways. These pathways, if disturbed by hygiene-related factors including an altered sequence of infections, may generate and maintain a deficit within the immunological network that facilitates, to particular early events in the development of MS, preceding the onset of MS disease by years or a decade. A framework that can serve as a guide for further epidemiological, immunologic and molecular biologic investigations is formulated. This approach may shed light on the complex natural history of MS and may lead to rational preventive and therapeutic strategies. It is possible that, in the future, MS could be prevented by vaccination against EBV in early childhood; the framework is of relevance to the design of an appropriate type of vaccine.

Helminths and the IBD hygiene hypothesis

Helminths are parasitic animals that have evolved over 100,000,000 years to live in the intestinal track or other locations of their hosts. Colonization of humans with these organisms was nearly universal until the early 20th century. More than 1,000,000,000 people in less developed countries carry helminths even today. Helminths must quell their host's immune system to successfully colonize. It is likely that helminths sense hostile changes in the local host environment and take action to control such responses. Inflammatory bowel disease (IBD) probably results from an inappropriately vigorous immune response to contents of the intestinal lumen. Environmental factors strongly affect the risk for IBD. People living in less developed countries are protected from IBD. The "IBD hygiene hypothesis" states that raising children in extremely hygienic environments negatively affects immune development, which predisposes them to immunological diseases like IBD later in life. Modern day absence of exposure to intestinal helminths appears to be an important environmental factor contributing to development of these illnesses. Helminths interact with both host innate and adoptive immunity to stimulate immune regulatory circuitry and to dampen effector pathways that drive aberrant inflammation. The first prototype worm therapies directed against immunological diseases are now under study in the United States and various countries around the world. Additional studies are in the advanced planning stage.

An update on the use of helminths to treat Crohn's and other autoimmunune diseases

This review updates our previous one (Reddy and Fried, Parasitol Research 100: 921-927, 2007) on Crohn's disease and helminths. The review considers the most recent literature on Trichuris suis therapy and Crohn's and the significant literature on the use of Necator americanus larvae to treat Crohn's and other autoimmune disorders. The pros and cons of helminth therapy as related to autoimmune disorders are discussed in the review. We also discuss the relationship of the bacterium Campylobacter jejuni and T. suis in Crohn's disease. The significant literature on helminths other than N. americanus and T. suis as related to autoimmune diseases is also reviewed.

Antibodies against fetal brain in sera of mothers with autistic children

Serum antibodies in 100 mothers of children with autistic disorder (MCAD) were compared to 100 age-matched mothers with unaffected children (MUC) using as antigenic substrates human and rodent fetal and adult brain tissues, GFAP, and MBP. MCAD had significantly more individuals with Western immunoblot bands at 36 kDa in human fetal and rodent embryonic brain tissue. The density of bands was greater in fetal brain at 61 kDa. MCAD plus developmental regression had greater reactivity against human fetal brain at 36 and 39 kDa. Data support a possible complex association between genetic/metabolic/environmental factors and the placental transfer of maternal antibodies in autism.

Soluble egg antigen from Schistosoma japonicum modulates the progression of chronic progressive experimental autoimmune encephalomyelitis via Th2-shift response

Soluble egg antigen (SEA) is strongly antigenic and inherently induces Th2-biased immune responses. In this study, we tested whether SEA from Schistosoma japonicum is able to prevent experimental autoimmune encephalomyelitis (EAE) induced by MOG(35-55) peptide, an established animal model of multiple sclerosis (MS). Intraperitoneal administration with SEA before EAE induction and in the preclinical phase after EAE induction successfully ameliorated the severity and progression of EAE on mice compared with phosphate buffered saline (PBS) controls, while no protective effect was shown when SEA immunization began after disease onset. This effect was associated with reduced interferon gamma (IFN-gamma) production and/or increased interleukin 4 (IL-4) production in spleen and central nervous system (CNS) even at the chronic stage. Similarly, we observed reduced inflammation and demyelination in spinal cords of SEA pretreated EAE mice compared with controls. Our data indicate that immunization with SEA from S. japonicum induces a preestablished Th2-biased microenvironment that provides preventive immune-modulating effects on EAE progression. This study may have important implications for its promising therapeutic use in MS and other autoimmune diseases.