Early IFN-γ production together with decreased expression of TLR3 and TLR9 characterizes EAE development conditional on the presence of myelin

Delimiting MOGAD as a disease entity using translational imaging

The first formal consensus diagnostic criteria for myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) were recently proposed. Yet, the distinction of MOGAD-defining characteristics from characteristics of its important differential diagnoses such as multiple sclerosis (MS) and aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder (NMOSD) is still obstructed. In preclinical research, MOG antibody-based animal models were used for decades to derive knowledge about MS. In clinical research, people with MOGAD have been combined into cohorts with other diagnoses. Thus, it remains unclear to which extent the generated knowledge is specifically applicable to MOGAD. Translational research can contribute to identifying MOGAD characteristic features by establishing imaging methods and outcome parameters on proven pathophysiological grounds. This article reviews suitable animal models for translational MOGAD research and the current state and prospect of translational imaging in MOGAD.

Analysis of Differential TLR Activation in a Mouse Model of Multiple Sclerosis

Multiple sclerosis (MS) is a neurodegenerative and autoimmune disease affecting the central nervous system (CNS). The precise etiology of MS is still undeciphered, and signs and symptoms of the disease are varied and complex, ranging from axonal degeneration, synaptic, and neuronal loss to demyelination. Inflammation plays a critical role in determining the onset and the progression of MS, but there is still a lot of information missing before scientists come to understand what are the factors that contribute to the establishment of the neuroinflammation. Thus, various murine models, each representative of a specific hallmark of MS, are used to study the processes underlying the pathogenetic mechanisms of the disease in an attempt to find effective drugs for its treatment. Among the many causes of MS, viral infections appear to be one of the most prominent ones. In this scenario, the comprehension of the role of receptors activated upon the recognition of viral, and in general microbial, components in determining onset and progression of the neuroinflammation is of paramount importance. Toll-like receptors (TLRs) are evolutionarily conserved receptors that recognize several pathogen-associated molecular patterns (PAMPs), common structures of the pathogens, or the damage caused by the pathogens within the host. TLRs are thus directly involved in the regulation of inflammatory reactions and in the activation of the innate and, subsequently, the adaptive immune responses crucial for the elimination of infectious pathogens. The role of TLR activation in the development of MS is widely studied in various murine models of MS, as well as in MS patients. In this chapter, we will summarize the current knowledge about the contribution of TLRs to the development or progression of MS, and we will illustrate different methods commonly used for the investigation of the role of different TLRs in various murine models of the disease.

A new lipophilic amino alcohol, chemically similar to compound FTY720, attenuates the pathogenesis of experimental autoimmune encephalomyelitis by PI3K/Akt pathway inhibition

Experimental autoimmune encephalomyelitis (EAE) is one of the main animal models used for the study of Multiple Sclerosis (MS). Long-chain lipophilic amino alcohols with immunoregulatory activities have already been studied in some models of inflammatory diseases, but the action of these compounds in EAE and MS is still unknown. In this study, we investigated whether the lipophilic amino alcohol 4b would act to improve the clinical signs of EAE and reduce the demyelination process and the neuroinflammatory parameters in the spinal cord, as well as the inflammatory process in the inguinal lymph nodes, of C57Bl/6 mice induced with EAE after stimulation with MOG_35-55 and pertussis toxin. The 4b treatment (1.0 mg/kg/day) was orally administered, starting on the day of onset of clinical signs of the disease (10th) and ending on the 20th day after immunization. This treatment was able to reduce the cell count on the inguinal lymph nodes, the migration of inflammatory cells into the central nervous system (CNS), as well as the processes of microgliosis, astrogliosis, and the production of chemokines and pro-inflammatory cytokines, thus increasing the IL-10 anti-inflammatory cytokine levels in EAE mice. The inhibition of Akt phosphorylation in the CNS of EAE mice after treatment with 4b indicates that the immunoregulatory action of 4b is related to the PI3K/Akt signaling pathway. Our results indicate the immunoregulatory efficacy of the new compound 4b in the control of some inflammatory parameters and in the glial proliferation. In addition, 4b was able to reduce the demyelination of neurons and the worsening of clinical signs of EAE as effectively as the compound FTY720, the first oral drug approved by the FDA for the treatment of MS.

Genetic changes in rat proximal nerve stumps after sciatic nerve transection

Background

Peripheral nerves can self-regenerate after traumatic injury, although their self-regeneration ability is limited after severe nerve injury. After peripheral nerve injury, the distal nerve stumps undergo Wallerian degeneration while the proximal nerve stumps undergo a regeneration process.

Methods

Here, to decipher genetic changes and involved biological processes in the proximal nerve stumps after peripheral nerve injury, microarray data (GSE30165) were analyzed. Differentially expressed genes in the proximal nerve stumps at 0.5 h, 1 h, 3 h, 6 h, 9 h, 1 d, 4 d, 7 d, and 14 d after rat sciatic nerve transection were subjected to Ingenuity pathway analysis (IPA) bioinformatic analysis.

Results

Cytokine signaling, cellular immune response, nuclear receptor signaling, disease-specific pathways, and organismal growth and development were significantly activated in the proximal nerve stumps after nerve transection. Organ development, inflammation and immune response, diseases and organ abnormalities, and cellular behavior-related biological functions were highly involved.

Conclusions

The expression levels of differentially expressed genes in biological function "Organismal Injury and Abnormalities" were displayed and validated. Our current study helps to obtain a better understanding of the biological processes of peripheral nerve regeneration, especially the regeneration process in the proximal nerve stumps, and thus may help to discover new therapeutic methods that can promote nerve regeneration.

Herpes Simplex Virus Type 1 Infection of the Central Nervous System: Insights Into Proposed Interrelationships With Neurodegenerative Disorders

Herpes simplex virus type 1 (HSV-1) is highly prevalent in humans and can reach the brain without evident clinical symptoms. Once in the central nervous system (CNS), the virus can either reside in a quiescent latent state in this tissue, or eventually actively lead to severe acute necrotizing encephalitis, which is characterized by exacerbated neuroinflammation and prolonged neuroimmune activation producing a life-threatening disease. Although HSV-1 encephalitis can be treated with antivirals that limit virus replication, neurological sequelae are common and the virus will nevertheless remain for life in the neural tissue. Importantly, there is accumulating evidence that suggests that HSV-1 infection of the brain both, in symptomatic and asymptomatic individuals could lead to neuronal damage and eventually, neurodegenerative disorders. Here, we review and discuss acute and chronic infection of particular brain regions by HSV-1 and how this may affect neuron and cognitive functions in the host. We review potential cellular and molecular mechanisms leading to neurodegeneration, such as protein aggregation, dysregulation of autophagy, oxidative cell damage and apoptosis, among others. Furthermore, we discuss the impact of HSV-1 infection on brain inflammation and its potential relationship with neurodegenerative diseases.

Autoimmunity in 2016

The number of peer-reviewed articles published during the 2016 solar year and retrieved using the "autoimmunity" key word remained stable while gaining a minimal edge among the immunology articles. Nonetheless, the quality of the publications has been rising significantly and, importantly, acquisitions have become available through scientific journals dedicated to immunology or autoimmunity. Major discoveries have been made in the fields of systemic lupus erythematosus, rheumatoid arthritis, autoimmunity of the central nervous system, vasculitis, and seronegative spondyloarthrithritides. Selected examples include the role of IL17-related genes and long noncoding RNAs in systemic lupus erythematosus or the effects of anti-pentraxin 3 (PTX3) in the treatment of this paradigmatic autoimmune condition. In the case of rheumatoid arthritis, there have been reports of the role of induced regulatory T cells (iTregs) or fibrocytes and T cell interactions with exciting implications. The large number of studies dealing with neuroimmunology pointed to Th17 cells, CD56(bright) NK cells, and low-level TLR2 ligands as involved in multiple sclerosis, along with a high salt intake or the micriobiome-derived Lipid 654. Lastly, we focused on the rare vasculitides to which numerous studies were devoted and suggested that unsuspected cell populations, including monocytes, mucosal-associated invariant T cells, and innate lymphoid cells, may be crucial to ANCA-associated manifestations. This brief and arbitrary discussion of the findings published in 2016 is representative of a promising background for developments that will enormously impact the work of laboratory scientists and physicians at an exponential rate.