Comparison of a classical Th1 bacteria versus a Th17 bacteria as adjuvant in the induction of experimental autoimmune encephalomyelitis

Insights into microbiome research 5: Mapping is first but function must come next

Several efforts identifying differential bacterial prevalence in the gut of multiple sclerosis (MS) patients have been reported and many more are underway. While these are critical first steps in determining the involvement of gut microbes in MS pathogenesis, functional assays (both in vitro and in vivo) are needed to explore the mechanisms underlying the observed changes and ultimately implementing interventional strategies to counter severity, progression or even reduce the chance that it develops in the first place.

Serum Neuroinflammatory Disease-Induced Central Nervous System Proteins Predict Clinical Onset of Experimental Autoimmune Encephalomyelitis

There is an urgent need in multiple sclerosis (MS) patients to develop biomarkers and laboratory tests to improve early diagnosis, predict clinical relapses, and optimize treatment responses. In healthy individuals, the transport of proteins across the blood–brain barrier (BBB) is tightly regulated, whereas, in MS, central nervous system (CNS) inflammation results in damage to neuronal tissues, disruption of BBB integrity, and potential release of neuroinflammatory disease-induced CNS proteins (NDICPs) into CSF and serum. Therefore, changes in serum NDICP abundance could serve as biomarkers of MS. Here, we sought to determine if changes in serum NDICPs are detectable prior to clinical onset of experimental autoimmune encephalomyelitis (EAE) and, therefore, enable prediction of disease onset. Importantly, we show in longitudinal serum specimens from individual mice with EAE that pre-onset expression waves of synapsin-2, glutamine synthetase, enolase-2, and synaptotagmin-1 enable the prediction of clinical disease with high sensitivity and specificity. Moreover, we observed differences in serum NDICPs between active and passive immunization in EAE, suggesting hitherto not appreciated differences for disease induction mechanisms. Our studies provide the first evidence for enabling the prediction of clinical disease using serum NDICPs. The results provide proof-of-concept for the development of high-confidence serum NDICP expression waves and protein biomarker candidates for MS.

Bacterial toxin's DNA vaccine serves as a strategy for the treatment of cancer, infectious and autoimmune diseases

DNA vaccination -a third generation vaccine-is a modern approach to stimulate humoral and cellular responses against different diseases such as infectious diseases, cancer and autoimmunity. These vaccines are composed of a gene that encodes sequences of a desired protein under control of a proper (eukaryotic or viral) promoter. Immune response following DNA vaccination is influenced by the route and the dose of injection. In addition, antigen presentation following DNA administration has three different mechanisms including antigen presentation by transfected myocytes, transfection of professional antigen presenting cells (APCs) and cross priming. Recently, it has been shown that bacterial toxins and their components can stimulate and enhance immune responses in experimental models. A study demonstrated that DNA fusion vaccine encoding the first domain (DOM) of the Fragment C (FrC) of tetanus neurotoxin (CTN) coupled with tumor antigen sequences is highly immunogenic against colon carcinoma. DNA toxin vaccines against infectious and autoimmune diseases are less studied until now. All in all, this novel approach has shown encouraging results in animal models, but it has to go through adequate clinical trials to ensure its effectiveness in human. However, it has been proven that these vaccines are safe, multifaceted and simple and can be used widely in organisms which may be of advantage to public health in the near future. This paper outlines the mechanism of the action of DNA vaccines and their possible application for targeting infectious diseases, cancer and autoimmunity.

Rotarod motor performance and advanced spinal cord lesion image analysis refine assessment of neurodegeneration in experimental autoimmune encephalomyelitis

BACKGROUND

Experimental autoimmune encephalomyelitis (EAE) is a commonly used experimental model for multiple sclerosis (MS). Experience with this model mainly comes from the field of immunology, while data on its use in studying the neurodegenerative aspects of MS is scarce.

NEW METHOD

The aim of this study is to improve and refine methods to assess neurodegeneration and function in EAE. Using the rotarod, a tool used in neuroscience to monitor motor performance, we evaluated the correlation between motor performance, disease severity as measured using a clinical scale and area covered by inflammatory lesions.

RESULTS

The included parameters are highly correlated in a non-linear manner, with motor performance rapidly decreasing in the intermediate values of the clinical scale. The relation between motor performance and histopathological damage is exclusively determined by lesions in the ventral and lateral columns, based on a new method of analysis of the entire spinal cord. Using a set of definitions for distinct disease milestones, we quantified disease duration as well as severity.

COMPARISON WITH EXISTING METHODS

The rotarod measures motor performance in a more objective and quantitative manner compared to using a clinical score. The outcome shows a strong correlation to the surface area of inflammatory lesions in the motor systems of the spinal cord.

CONCLUSIONS

These results provide an improved workflow for interpreting the outcome of EAE from a neurological point of view, with the eventual goal of dissecting neurodegeneration and evaluating neuroprotective drugs in EAE for application in MS.

Remyelination by Resident Oligodendrocyte Precursor Cells in a Xenopus laevis Inducible Model of Demyelination

We have generated a Xenopus laevis transgenic line, MBP-GFP-NTR, allowing conditional ablation of myelin-forming oligodendrocytes. In this transgenic line the transgene is driven by the proximal portion of the myelin basic protein regulatory sequence, specific to mature oligodendrocytes. The transgene protein is formed by the green fluorescent protein reporter fused to the Escherichia coli nitroreductase (NTR) selection enzyme. The NTR enzyme converts the innocuous prodrug metronidazole (MTZ) to a cytotoxin. Ablation of oligodendrocytes by MTZ treatment of the tadpole induced demyelination, and here we show that myelin debris are subsequently eliminated by microglial cells. After cessation of MTZ treatment, remyelination proceeded spontaneously. We questioned the origin of remyelinating cells. Our data suggest that Sox10+ oligodendrocyte precursor cells (OPCs), which are already present in the optic nerve prior to the experimentally induced demyelination, are responsible for remyelination, and this required only minimal (if any) cell division of OPCs.

PFA-fixed Hsp60sp-loaded dendritic cells as a vaccine for the control of mouse experimental allergic encephalomyelitis

We have shown that Hsp60sp-loaded immature dendritic cells (DC/sp) can protect mice from the induction of experimental allergic encephalomyelitis (EAE) by inducing Qa-1-restricted CD8(+) T regulatory (Treg) cells. The binding half-life between Qa-1 and Hsp60sp is particularly short and leads to an unstable Qa-1/peptide complex that significantly decreases the efficacy of this vaccination. To prevent Qa-1/Hsp60sp complex dissociation, we utilized paraformaldehyde (PFA) fixation to stabilize the formation of the Qa-1/Hsp60sp complex and maximize the function of DC/sp as a vaccine to control autoimmune diseases. Compared with the non-fixed DC/sp, the fixed DC/sp (FDC/sp) showed an enhanced ability to activate Qa-1-restricted Hsp60sp-specific CD8(+)T cells in vitro and prevented EAE in vivo. Importantly, the FDC/sp maintained immune activity following cryopreservation for 1 week or after storage for 72 h at 4 °C. These results indicate that PFA fixation can sustain or increase the efficacy of DC/sp by improving the stability of the Qa-1/Hsp60sp complex on the surface of the DC/sp. In addition, PFA fixation creates a time window for DC/sp storage, transport and application. Our data suggest a potential clinical use of FDC/sp as a vaccine for the prevention and treatment of autoimmune disease.