Altered humoral immunity to mycobacterial antigens in Japanese patients affected by inflammatory demyelinating diseases of the central nervous system

Mycobacterium avium subsp. paratuberculosis Antigens Elicit a Strong IgG4 Response in Patients with Multiple Sclerosis and Exacerbate Experimental Autoimmune Encephalomyelitis

Neuroinflammation can be triggered by microbial products disrupting immune regulation. In this study, we investigated the levels of IgG1, IgG2, IgG3, and IgG4 subclasses against the heat shock protein (HSP)70_533-545 peptide and lipopentapeptide (MAP_Lp5) derived from Mycobacterium avium subsp. paratuberculosis (MAP) in the blood samples of Japanese and Italian individuals with relapsing remitting multiple sclerosis (MS). Additionally, we examined the impact of this peptide on MOG-induced experimental autoimmune encephalomyelitis (EAE). A total of 130 Japanese and 130 Italian subjects were retrospectively analyzed using the indirect ELISA method. Furthermore, a group of C57BL/6J mice received immunization with the MAP_HSP70_533-545 peptide two weeks prior to the active induction of MOG_35-55 EAE. The results revealed a significantly robust antibody response against MAP_HSP70_533-545 in serum of both Japanese and Italian MS patients compared to their respective control groups. Moreover, heightened levels of serum IgG4 antibodies specific to MAP antigens were correlated with the severity of the disease. Additionally, EAE mice that were immunized with MAP_HSP70_533-545 peptide exhibited more severe disease symptoms and increased reactivity of MOG_35-55-specific T-cell compared to untreated mice. These findings provide evidence suggesting a potential link between MAP and the development or exacerbation of MS, particularly in a subgroup of MS patients with elevated serum IgG4 levels.

Bacillus Calmette-Guérin Tokyo-172 vaccine provides age-related neuroprotection in actively induced and spontaneous experimental autoimmune encephalomyelitis models

Multiple sclerosis is the most common immune-mediated disorder affecting the central nervous system in young adults but still has no cure. Bacillus Calmette-Guérin (BCG) vaccine is reported to have non-specific anti-inflammatory effects and therapeutic benefits in autoimmune disorders including multiple sclerosis. However, the precise mechanism of action of BCG and the host immune response to it remain unclear. In this study, we aimed to investigate the efficacy of the BCG Tokyo-172 vaccine in suppressing experimental autoimmune encephalomyelitis (EAE). Groups of young and mature adult female C57BL/6J mice were BCG-vaccinated 1 month prior or 6 days after active EAE induction using myelin oligodendrocyte glycoprotein (MOG)35-55 peptide. Another group of 2D2 TCRMOG transgenic female mice was BCG-vaccinated before and after the onset of spontaneous EAE. BCG had an age-associated protective effect against active EAE only in wild-type mice vaccinated 1 month before EAE induction. Furthermore, the incidence of spontaneous EAE was significantly lower in BCG vaccinated 2D2 mice than in non-vaccinated controls. Protection against EAE was associated with reduced splenic T-cell proliferation in response to MOG35-55 peptide together with high frequency of CD8+ interleukin-10-secreting T cells in the spleen. In addition, microglia and astrocytes isolated from BCG-vaccinated mice showed polarization to anti-inflammatory M2 and A2 phenotypes, respectively. Our data provide new insights into the cell-mediated and humoral immune mechanisms underlying BCG vaccine-induced neuroprotection, potentially useful for developing better strategies for the treatment of MS.

Mycobacterium paratuberculosis zoonosis is a One Health emergency

A singular pathogen has been killing animals, contaminating food and causing an array of human diseases. Mycobacterium avium subspecies paratuberculosis (MAP) is the cause of a fatal enteric infectious disease called Johne's (Yo'-nees), a disorder mostly studied in ruminant animals. MAP is globally impacting animal health and imparting significant economic burden to animal agriculture. Confounding the management of Johne's disease is that animals are typically infected as calves and while commonly not manifesting clinical disease for years, they shed MAP in their milk and feces in the interval. This has resulted in a "don't test, don't tell" scenario for the industry resulting in greater prevalence of Johne's disease; furthermore, because MAP survives pasteurization, the contaminated food supply provides a source of exposure to humans. Indeed, greater than 90% of dairy herds in the US have MAP-infected animals within the herd. The same bacterium, MAP, is the putative cause of Crohn's disease in humans. Countries historically isolated from importing/exporting ruminant animals and free of Johne's disease subsequently acquired the disease as a consequence of opening trade with what proved to be infected animals. Crohn's disease in those populations became a lagging indicator of MAP infection. Moreover, MAP is associated with an increasingly long list of human diseases. Despite MAP scientists entreating regulatory agencies to designate MAP a "zoonotic agent," it has not been forthcoming. One Health is a global endeavor applying an integrative health initiative that includes the environment, animals and humans; One Health asserts that stressors affecting one affects all three. Recognizing the impact MAP has on animal and human health as well as on the environment, it is time for One Health, as well as other global regulatory agencies, to recognize that MAP is causing an insidious slow-motion tsunami of zoonosis and implement public health mitigation.

Efficacy of BCG vaccine in animal models of neurological disorders

The Bacillus Calmette-Guerin (BCG) vaccine can modulate the immune response via antigen-specific immune response, but also it can confer nonspecific protection and therapeutic benefits in several neurological conditions through different heterologous effects of vaccination. However, the precise mechanism of action of BCG remains unclear. In this review, different mechanisms underlying BCG-mediated immunity will be explained in animal models that reflects characteristic feature of neuroinflammatory and neurodegenerative disorders such as multiple sclerosis, Alzheimer's and Parkinson's diseases. Furthermore, evidence for a beneficial effect of the BCG on neuropsychiatric disorders, will be also discussed.

Infections and Multiple Sclerosis: From the World to Sardinia, From Sardinia to the World

Multiple Sclerosis (MS) is an inflammatory disease of the central nervous system. Sardinia, an Italian island, is one of the areas with the highest global prevalence of MS. Genetic factors have been widely explored to explain this greater prevalence among some populations; the genetic makeup of the Sardinians appears to make them more likely to develop autoimmune diseases. A strong association between MS and some infections have been reported globally. The most robust evidence indicating the role of infections is MS development concerns the Epstein-Barr virus (EBV). Anti-EBV antibodies in patients once infected by EBV are associated with the development of MS years later. These features have also been noted in Sardinian patients with MS. Many groups have found an increased expression of the Human endogenous retroviruses (HERV) family in patients with MS. A role in pathogenesis, prognosis, and prediction of treatment response has been proposed for HERV. A European multi-centre study has shown that their presence was variable among populations, ranging from 59% to 100% of patients, with higher HERV expression noted in Sardinian patients with MS. The mycobacterium avium subspecies paratuberculosis (MAP) DNA and antibodies against MAP2694 protein were found to be associated with MS in Sardinian patients. More recently, this association has also been reported in Japanese patients with MS. In this study, we analysed the role of infectious factors in Sardinian patients with MS and compared it with the findings reported in other populations.

Prediction of molecular mimicry between antigens from Leishmania sp. and human: Implications for autoimmune response in systemic lupus erythematosus

Pathogens and humans share an intrinsic relation related to molecular mimicry in their antigens. Interactions between immune system and pathogenic antigens result in a production of antibodies that could protect against infection, but develop autoreactive responses mediated by autoantibodies that react to pathogenic and human antigens because they share epitopes. In this study, a pipeline of bioinformatic tools was used to explore the repertory of autoantigens implicated in the develop of Systemic Lupus Erythematosus and their homologous in Leishmania sp. With this, we screened and selected 33 molecular mimicry candidates. In 17 autoantigens from lupus was possible to perform epitope prediction and was found that, at least one potential cross epitope. Some of autoantigens with molecular mimicry were Aquaporin 4, nuclear autoantigens such as: Ubiquitin-related modifier 1 and Small nuclear ribonucleoprotein Sm. Also, mitochondrial, and ribosomal autoantigens were found to share molecular mimicry with antigens from Leishmania sp. In conclusion, this is the first study that provide evidence of molecular mimicry between antigens from Leishmania sp. and human. Implications for the develop of SLE and clinical manifestation deserve more study.

Antibody response to homologous epitopes of Epstein-Barr virus, Mycobacterium avium subsp. paratuberculosis and IRF5 in patients with different connective tissue diseases and in mouse model of antigen-induced arthritis

Background

Improved knowledge of different biomarkers is crucial for early diagnosis of rheumatic diseases and to provide important insights for clinical management. In this study, we evaluated the seroreactivity of patients with different connective tissue diseases (CTDs) (rheumatoid arthritis, RA; systemic lupus erythematosus, SLE; systemic sclerosis, SSc; and Sjogren’s syndrome, SSj) to interferon regulatory factor 5 (IRF5) peptide and homologs derived from Epstein-Barr virus (EBV) and Mycobacterium avium subsp. paratuberculosis (MAP). Antigen-induced arthritis (AIA) experiments have been performed in control and IRF5 conditional knockout mice to reinforce the hypothesis that antibodies generated against the three homologous peptides are cross-reactive.

Methods

Reactivity against wild-type (wt) and citrullinated (cit) IRF5 (IRF5_424-434), MAP (MAP_4027_18-32) and EBV (BOLF1_305-320) peptides were tested by indirect ELISA in sera from 100 RA patients, 54 patients with other CTDs (14 SLE, 28 SSc and 12 SSj) and 100 healthy subjects (HCs). Antibody responses to the same wt peptides have been tested in AIA mouse sera after immunization with complete Freud’s adjuvant (CFA) and methylated bovine serum albumin (mBSA) to induce arthritis in the knee joint.

Results

BOLF1, MAP_4027 and IRF5 peptides triggered different antibody responses in CTD diseases with a stronger reactivity in RA (p=0.0001). Similar trends were observed in AIA mice with significantly higher reactivity after 7 days from induction of arthritis. We also found statistically significant differences in antibody responses between SSc and HCs for BOLF1 (p=0.003), MAP_4027 (p=0.0076) and IRF5 (p=0.0042). Peripheral reactivity to cit peptides was lower compared to their wt counterparts, except for cit-MAP_4027_18-32, which induced stronger responses in RA than wt-MAP_4027_18-32 (46% vs. 26%, p=0.0170).

Conclusion(s): Our results show differential antibody responses to BOLF1, MAP_4027 and IRF5 peptides among CTDs, highlighting their potential as diagnostic biomarkers in these diseases. Experiments performed in IRF5 conditional knockout mice support the hypothesis of cross-reactivity between the investigated homologous antigens.

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Serum IgG anti-BOLF1, MAP_4027 and IRF5 Abs responses are significantly higher in RA than in other rheumatic conditions.

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Antibody responses to epitopes of EBV, IRF5 and MAP in AIA mouse model is comparable to results obtained in humans.

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Antigens present in the CFA are homologous to MAP, EBV and IRF5 peptides trigger cross-reactive responses.

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MAP might be a possible triggering factor in the etiology of systemic sclerosis and RA.

Immune-mediated genesis of multiple sclerosis

Multiple sclerosis (MS) is widely acknowledged to be an autoimmune disease affecting the neuronal myelin structure of the CNS. Autoantigens recognized as the target of this autoimmune process are: myelin basal protein, anti-proteolipid protein, antimyelin-associated glycoprotein and antimyelin-based oligodendrocytic basic protein. Ample evidence supports the idea of a dysregulation of immunological tolerance towards self-antigens of neuronal myelin structure triggered by one or more viral or bacterial microbial agents in predisposed HLA gene subjects. Genetic predisposition to MS has been highlighted by numerous studies associating the disease to specific HLA haplotypes. Moreover, a wide range of evidence supports the fact that MS may be consequence of one or more viral or bacterial infections such as measles virus, EBV, HHV6, HZV, Chlamydia pneumoniae, Helicobacter Pylori, and other microbial agents. Microbiota elements also seems to have a role on the determinism of the disease as a pathogenic or protective factor. The autoimmune pathogenetic process could arise when a molecular mimicry between a foreign microbial antigen and an auto-antigen occurs in an HLA gene subject competent for that particular antigen. The antigen-presenting cells in this case would induce the activation of a specific Th clone causing a cross-reaction between a foreign antigen and an autoantigen resulting in an autoimmune response.

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A multifactorial ethiopathogenetic model based on immunomediation is a reliable hypothesis for multiple sclerosis.

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Evidence found in the scientific literature makes it possible to reconstruct this etiopathogenetic hypothesis for MS.

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HLA gene predisposition, correlation with infections, molecular mimicry and other immunological data are reported.

Infections, Vaccines and Autoimmunity: A Multiple Sclerosis Perspective

Background: Multiple sclerosis (MS) is a chronic neuroinflammatory and neurodegenerative disease that is associated with multiple environmental factors. Among suspected susceptibility events, studies have questioned the potential role of overt viral and bacterial infections, including the Epstein Bar virus (EBV) and human endogenous retroviruses (HERV). Furthermore, the fast development of immunomodulatory therapies further questions the efficacy of the standard immunization policies in MS patients. Topics reviewed: This narrative review will discuss the potential interplay between viral and bacterial infections and their treatment on MS susceptibility and disease progression. In addition, the review specifically discusses the interactions between MS pathophysiology and vaccination for hepatitis B, influenza, human papillomavirus, diphtheria, pertussis, and tetanus (DTP), and Bacillus Calmette-Guerin (BCG). Data regarding potential interaction between MS disease modifying treatment (DMT) and vaccine effectiveness is also reviewed. Moreover, HERV-targeted therapies such as GNbAC1 (temelimab), EBV-based vaccines for treatment of MS, and the current state regarding the development of T-cell and DNA vaccination are discussed. Lastly, a reviewing commentary on the recent 2019 American Academy of Neurology (AAN) practice recommendations regarding immunization and vaccine-preventable infections in the settings of MS is provided. Conclusion: There is currently no sufficient evidence to support associations between standard vaccination policies and increased risk of MS. MS patients treated with immunomodulatory therapies may have a lower benefit from viral and bacterial vaccination. Despite their historical underperformance, new efforts in creating MS-based vaccines are currently ongoing. MS vaccination programs follow the set back and slow recovery which is widely seen in other fields of medicine.

PtpA and PknG Proteins Secreted by Mycobacterium avium subsp. paratuberculosis are Recognized by Sera from Patients with Rheumatoid Arthritis: A Case-Control Study

Purpose

Rheumatoid arthritis (RA) can result from complex interactions between the affected person’s genetic background and environment. Viral and bacterial infections may play a pathogenetic role in RA through different mechanisms of action. We aimed to evaluate the presence of antibodies (Abs) directed against two proteins of Mycobacterium avium subsp. paratuberculosis (MAP) in sera of RA subjects, which are crucial for the survival of the pathogen within macrophages. Moreover, we analyzed the correlation of immune response to both proteins with the following homologous peptides: BOLF1_305–320, MAP_4027_18–32 and IRF5_424–434 to understand how the synergic role of Epstein–Barr virus (EBV) and MAP infection in genetically predisposed subjects may lead to a possible deregulation of interferon regulatory factor 5 (IRF5).

Materials and methods

The presence of Abs against protein tyrosine phosphatase A (PtpA) and protein kinase G (PknG) in sera from Sardinian RA patients (n=84) and healthy volunteers (HCs, n=79) was tested by indirect ELISA.

Results

RA sera showed a remarkably high frequency of reactivity against PtpA in comparison to HCs (48.8% vs 7.6%; p<0.001) and lower but statistically significant responses towards PknG (27.4% vs 10.1%; p=0.0054). We found a significant linear correlation between the number of swollen joints and the concentrations of antibodies against PtpA (p=0.018). Furthermore, a significant bivariate correlation between PtpA and MAP MAP_4027_18–32 peptide has been found, suggesting that MAP infection may induce a secondary immune response through cross-reaction with IRF5 (R²=0.5).

Conclusion

PtpA and PknG are strongly recognized in RA which supports the hypothesis that MAP infection may be involved in the pathogenesis of RA.

Practice guideline update summary: Vaccine-preventable infections and immunization in multiple sclerosis

Objective

To update the 2002 American Academy of Neurology (AAN) guideline regarding immunization and multiple sclerosis (MS).

Methods

The panel performed a systematic review and classified articles using the AAN system. Recommendations were based on evidence, related evidence, principles of care, and inferences according to the AAN 2011 process manual, as amended.

Major recommendations (Level B except where indicated)

Clinicians should discuss the evidence regarding immunizations in MS with their patients and explore patients' opinions, preferences, and questions. Clinicians should recommend that patients with MS follow all local vaccine standards, unless there are specific contraindications and weigh local vaccine-preventable disease risks when counseling patients. Clinicians should recommend that patients with MS receive the influenza vaccination annually. Clinicians should counsel patients with MS about infection risks associated with specific immunosuppressive/immunomodulating (ISIM) medications and treatment-specific vaccination guidance according to prescribing information (PI) and vaccinate patients with MS as needed at least 4–6 weeks before initiating patients' ISIM therapy. Clinicians must screen for infections according to PI before initiating ISIM medications (Level A) and should treat patients testing positive for latent infections. In high-risk populations, clinicians must screen for latent infections before starting ISIM therapy even when not specifically mentioned in PI (Level A) and should consult specialists regarding treating patients who screen positive for latent infection. Clinicians should recommend against using live-attenuated vaccines in people with MS receiving ISIM therapies. Clinicians should delay vaccinating people with MS who are experiencing a relapse.

Anti-Mycobacterial Antibodies in Paired Cerebrospinal Fluid and Serum Samples from Japanese Patients with Multiple Sclerosis or Neuromyelitis Optica Spectrum Disorder

Local synthesis of antibodies and presence of oligoclonal bands in the cerebrospinal fluid (CSF) are hallmarks of multiple sclerosis (MS). We investigated the frequency of antibodies against mycobacterial and relevant human epitopes in the CSF of patients with MS or neuromyelitis optica spectrum disorder (NMOSD) and whether these antibodies differed from those present in the serum. Matched serum and CSF samples from 46 patients with MS, 42 patients with NMOSD, and 29 age-matched and sex-matched control subjects were screened retrospectively for the presence of antibodies against Mycobacterium avium subsp. paratuberculosis (MAP) pentapeptide (MAP_5p), MAP_2694_295–303, and myelin basic protein (MBP)_85–98 peptides by using indirect ELISA. Serum levels of anti-MAP_5p and anti-MAP_2694_295–303 antibodies were highly prevalent in patients with MS when compared to patients with NMOSD and controls. Several patients with MS had detectable anti-MAP_5p and anti-MAP_2694_295–303 antibodies in the CSF. Furthermore, a group of patients with MS showed intrathecally restricted production of antibodies against these peptides. Women appeared to mount a stronger humoral response to mycobacterial peptides than men. No significant difference in the frequency of anti-MBP_85–98 antibodies was found between patients with MS and those with NMOSD. These data highlight the zoonotic potential of MAP, which suggests its involvement in MS etiopathogenesis.

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.