Induction of experimental autoimmune neuritis in CD4-8-C57BL/6J mice.

The C57BL/6J mice strain is known to be reputedly resistant to induction of experimental autoimmune neuritis (EAN), an animal model of Guillain-Barré syndrome in humans. Here we describe the induction of EAN in mice of the C57BL/6J background by transfer into naive syngeneic recipients bovine peripheral nerve myelin (BPM)-primed donor lymph node cells that had been stimulated in vitro with the bovine peripheral nervous system (PNS) myelin P2 protein peptide 57-81 followed by challenge with BPM, Freund's complete adjuvant and pertussis toxin. EAN was more severe, both clinically and histologically, and accompanied by extensive infiltration of inflammatory cells and demyelination in peripheral nerves when examined on day 30 after transfer of primed T cells from CD4- 8- mice into identical naive hosts than after transfer of cells from primed wild type, CD4-/- or CD8-/- mice to corresponding recipient animals. EAN in CD4-8- mice was also associated with elevated numbers of P2 peptide-reactive interferon-y (TFN-gamma) secreting cells and alphabeta T cells were present in lymph nodes and spleens. The data suggest that PNS myelin activated T cells from an EAN-resistant mice strain are capable of homing to the PNS. The expanded CD4-8- alphabeta T cells may have helper and effector functions, related to initiation of EAN in the CD4-8- mice. Lack of CD4+ and CD8+ expressing cells does not prevent the initiation of an autoimmune disease.     

Ginsenoside Rd ameliorates experimental autoimmune encephalomyelitis in C57BL/6 mice

Multiple sclerosis (MS) is a common disabling autoimmune disease without an effective treatment in young adults. Ginsenoside Rd, extracted from Panax notoginseng, has multiple pharmacological effects and potential therapeutic applications in diseases of the central nervous system. In this study, we explore the efficacy of ginsenoside Rd in experimental autoimmune encephalomyelitis (EAE), an established model of MS. EAE was induced by myelin oligodendrocyte glycoprotein 35–55‐amino‐acid peptide. Ginsenoside Rd (10–80 mg/kg/day) or vehicle was intraperitoneally administered on the disease onset day, and the therapy persisted throughout the experiments. The dose of 40 mg/kg/day of ginsenoside Rd was selected as optimal. Ginsenoside Rd effectively ameliorated the clinical severity in EAE mice, reduced the permeability of the blood–brain barrier, regulated the secretion of interferon‐gamma and interleukin‐4, promoted the Th2 shift in vivo (cerebral cortex) and in vitro (splenocytes culture supernatants), and prevented the reduction in expression of brain‐derived neurotrophic factor and nerve growth factor in both cerebral cortex and lumbar spinal cord of EAE mice. This study establishes the potency of ginsenoside Rd in inhibiting the clinical course of EAE. These findings suggest that ginsenoside Rd could be a promising agent for amelioration of neuroimmune dysfunction diseases such as MS. © 2014 Wiley Periodicals, Inc.     

IL-33 blockade suppresses the development of experimental autoimmune encephalomyelitis in C57BL/6 mice

IL-33 is a recently described member of the IL-1 family that has been reported to have a pathogenic role in several inflammatory diseases. In this study, we evaluated the role of IL-33 in a murine model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). We showed that the expression of IL-33 and its receptor, ST2, was markedly elevated in the spinal cord of mice during myelin oligodendrocyte glycoprotein (MOG)(35-55) peptide-induced EAE. Administration of a blocking anti-IL-33 antibody in mice of EAE during the induction phase significantly inhibited the onset and severity of EAE and reduced MOG(35-55)-induced IFN-γ and IL-17 production. In contrast, treatment with recombinant IL-33 worsened the disease course of EAE in association with increased induction of both IFN-γ and IL-17. Furthermore, anti-IL-33 treatment caused a remarkable decrease in expression of IL-17, IFN-γ, T-bet and RORγt, and an upregulation of IL-10 and TGF-β in the spinal cord of EAE mice. These results demonstrate that endogenous IL-33 plays a pivotal role in the pathogenesis of EAE and indicate that blockade of IL-33 has a significant protective effect against EAE.     

P0 protein peptide 180-199 together with pertussis toxin induces experimental autoimmune neuritis in resistant C57BL/6 mice

The C57BL/6 mice strain is known to be reputedly resistant to induction of experimental autoimmune neuritis (EAN), an animal model of Guillain-Barré syndrome in human by bovine peripheral myelin (BPM), and P2 protein or the P2 protein peptide 57-81. The P0 peptide 180-199 is a stronger neuritogenic antigen than the P2 peptide 57-81. We found that this synthetic peptide induced both clinical and pathological characteristics of an acute monophasic EAN in C57BL/6 mice. Only male mice were more sensitive to EAN induction with the P0 peptide 180-199. Intravenously administrated pertussis toxin (PT) had an adjuvant effect that increased the incidence of P0 peptide 180-199-induced EAN as well as the inflammation and demyelination in the peripheral nerves. Spontaneous and P0 peptide 180-199 stimulated proliferation of peripheral T-cells were enhanced by PT-treatment as well. The enhancing effect was lower before onset of the disease (Day 6 post immunization) (p.i.) as compared to the early phase of the disease (Day 22 p.i.). Thus, P0 peptides together with PT are able to break tolerance to myelin in C57BL/6 mice.     

Lymphotoxin-alpha deficiency completely protects C57BL/6 mice from developing clinical experimental autoimmune myasthenia gravis

A complete prevention of clinical experimental autoimmune myasthenia gravis (EAMG) was observed in lymphotoxin (LT)-alpha deficient (LT-alpha(-/-)) mice compared to LT-alpha(+/+) mice when immunized with acetylcholine receptor. However, only a partial prevention of clinical EAMG incidence was observed in LT-beta(-/-) mice compared to LT-beta(+/+) mice. LT-alpha(-/-)and LT-beta(-/-) mice had lower mean titers of total IgG, IgG(1), IgG(2a) and IgG(2b) and higher or equal mean titers of IgM anti-AChR antibodies compared to controls. Therefore, LT-alpha(-/-)and LT-beta(-/-) AChR immunized mice are capable of mounting a primary (IgM) humoral immune response to AChR, but are less capable of switching to the pathogenic anti-AChR IgG isotypes. LT could play a significant role in the pathogenesis of myasthenia gravis.     

Characterization of relapsing–remitting and chronic forms of experimental autoimmune encephalomyelitis in C57BL/6 mice

Multiple sclerosis (MS) is an autoimmune, demyelinating disease of the central nervous system (CNS). Like MS, the animal model experimental autoimmune encephalomyelitis (EAE) is characterized by CNS inflammation and demyelination and can follow a relapsing–remitting (RR) or chronic (CH) disease course. The molecular and pathological differences that underlie these different forms of EAE are not fully understood. We have compared the differences in RR‐ and CH‐EAE generated in the same mouse strain (C57BL/6) using the same antigen. At the peak of disease when mice in both groups have similar clinical scores, CH‐EAE is associated with increased lesion burden, myelin loss, axonal damage, and chemokine/cytokine expression when compared with RR‐EAE. We further showed that inflammation and myelin loss continue to worsen in later stages of CH‐EAE, whereas these features are largely resolved at the equivalent stage in RR‐EAE. Additionally, axonal loss at these later stages is more severe in CH‐EAE than in RR‐EAE. We also demonstrated that CH‐EAE is associated with a greater predominance of CD8⁺ T cells in the CNS that exhibit MOG_35–55 antigen specificity. These studies therefore showed that, as early as the peak stage of disease, RR‐ and CH‐EAE differ remarkably in their immune cell profile, chemokine/cytokine responses, and histopathological features. These data also indicated that this model of CH‐EAE exhibits pathological features of a chronic‐progressive disease profile and suggested that the sustained chronic phenotype is due to a combination of axonal loss, myelin loss, and continuing inflammation. © 2009 Wiley‐Liss, Inc.     

A comparison of the behavior of C57BL/6 and C57BL/10 mice

Selection of an appropriate animal model is a crucial first step in many research programs. The C57BL/6 (B6) mouse is the most widely used inbred mouse strain in biomedical research; this is particularly so in behavioral studies. However, there are several C57BL substrains, all derived from common ancestors. C57BL/10 (B10) mice are superficially almost identical to B6 mice in appearance and behavior and widely used in inflammation and immunology research, yet rarely in behavioral studies. The present study assessed the comparability of behavioral results from these two strains, to determine whether they could be used interchangeably in future behavioral experiments. The results showed that the behavior of B6 mice clearly differed from that of B10 mice: in tests of cognition, species-typical behaviors, and motor coordination the B6 strain performed better. Consequently, B6 mice will probably remain the preferred choice for behavioral studies. Interpretation of results derived from the B10 strain should take into account its particular behavioral characteristics.     

A model of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice for the characterisation of intervention therapies

Multiple sclerosis (MS) and its different forms are studied in the animal model experimental autoimmune encephalomyelitis (EAE). Relapsing-remitting MS, the most common form of the disease can be induced in mice where clinical symptoms fluctuate in severity over time. However, the animal model does not experience periods of recovery where clinical signs are absent, unlike the human disease. We have developed a novel model of relapsing-remitting EAE in C57BL/6 mice immunised with myelin oligodendrocyte glycoprotein (MOG) peptide and Quil A as adjuvant. These animals have relapses that are followed by periods of recovery, during which time the animals do not exhibit illness. Furthermore, administration of the PPARgamma agonist pioglitazone prior to a predicted relapse prevents the expected development of symptoms in a dose-dependent fashion. Immune cell infiltration into white matter of the CNS and decreased production of inflammatory cytokine IFN-gamma in treated animals were also observed. Our model will be a valuable tool in assessing intervention therapies for RR-MS sufferers.     

Observational learning in C57BL/6j mice

The ability of mice to solve a complex task by observational learning was investigated with C57BL/6j mice. Four female demonstrators were trained to reliably perform a sequence that consisted in pushing a piece of food into a tube attached to the side of a puzzle box, and recovering it by opening a drawer in front of the box. They then performed this sequence in front of naive mice assigned to individual cubicles in a box with a wire mesh front arranged in a row facing the demonstrators. A total of 25 naive mice (13 males and 12 females) were used. Fifteen mice observed 14 demonstrations a day for 5 days; 10 control mice were placed in similar cubicles, but behind a plastic screen which prevented them from observing the demonstrators. The mice were post-tested in the demonstrator situation, and 6 of 15 observers immediately reproduced the complete task successfully, but none of the naive or control mice were able to solve the task. The observers and controls were then subjected to a five level individual learning schedule. Observers learned the individual task significantly faster than the controls. No sex difference was found. These results suggest that observational learning processes at work were based on stimulus enhancement and observational conditioning.     

Sociability and brain development in BALB/cJ and C57BL/6J mice

Sociability—the tendency to seek social interaction—propels the development of social cognition and social skills, but is disrupted in autism spectrum disorders (ASD). BALB/cJ and C57BL/6J inbred mouse strains are useful models of low and high levels of juvenile sociability, respectively, but the neurobiological and developmental factors that account for the strains’ contrasting sociability levels are largely unknown. We hypothesized that BALB/cJ mice would show increasing sociability with age but that C57BL/6J mice would show high sociability throughout development. We also hypothesized that littermates would resemble one another in sociability more than non-littermates. Finally, we hypothesized that low sociability would be associated with low corpus callosum size and increased brain size in BALB/cJ mice. Separate cohorts of C57BL/6J and BALB/cJ mice were tested for sociability at 19-, 23-, 31-, 42-, or 70-days-of-age, and brain weights and mid-sagittal corpus callosum area were measured. BALB/cJ sociability increased with age, and a strain by age interaction in sociability between 31 and 42 days of age suggested strong effects of puberty on sociability development. Sociability scores clustered according to litter membership in both strains, and perinatal litter size and sex ratio were identified as factors that contributed to this clustering in C57BL/6J, but not BALB/cJ, litters. There was no association between corpus callosum size and sociability, but smaller brains were associated with lower sociability in BALB/cJ mice. The associations reported here will provide directions for future mechanistic studies of sociability development.     

MBP-PLP fusion protein-induced EAE in C57BL/6 mice

Gene knock-out and knock-in mice are becoming increasingly indispensable for mechanism-oriented studies of EAE. Most gene-modified mice are on the C57BL/6 background, for which presently there are only two EAE models available, the MOG peptide 35-55 and the PLP 178-191 peptide induced disease. However, because MS is not a single pathogenic entity, different EAE models are required to reproduce and study its various features. Here we are introducing MBP-PLP fusion protein (MP4)-induced EAE for C57BL/6 mice. B cell- and CD8+ T cell-dependence, as well as multi-determinant recognition are among the unique features of this demyelinating EAE.     

T cell and antibody responses in remitting-relapsing experimental autoimmune encephalomyelitis in (C57BL/6 x SJL) F1 mice

To characterize T cell and antibody responses in remitting-relapsing experimental autoimmune encephalomyelitis (RR-EAE), we compared myelin oligodendrocyte glycoprotein (MOG)-induced RR-EAE in C57BL/6 (B6) x SJL (F1) mice and chronic-progressive EAE (CP-EAE) in B6 mice at week 8 p.i. when clinical scores were comparable. Although these two strains exhibited similar inflammation/demyelination pattern and MOG-induced T cell responses, RR-EAE mice produced significantly higher levels of anti-MOG IgG1/IgG2a antibodies. Further, lymphocytes of RR-EAE mice proliferated vigorously to the secondary epitope myelin basic protein (MBP) 1-11. These results support a potential involvement of anti-MOG antibodies and epitope spreading in T cell responses in the development of MOG-induced RR-EAE model.     

P0(106-125) is a neuritogenic epitope of the peripheral myelin protein P0 and induces autoimmune neuritis in C57BL/6 mice

The present study describes a new model of autoimmune neuritis in C57BL/6 mice induced by immunization with the novel neuritogenic epitope P0(106-125), derived from mouse peripheral myelin protein P0. Immunization with this peptide in combination with pertussis toxin induced high levels of peptide-specific CD4+ T cells in spleen and popliteal lymph nodes. Clinical symptoms of autoimmune neuritis started with a flaccid tail at day 10 postimmunization (p.i.), progressed to moderate paraparesis at day 15 p.i., declining thereafter with undetectable symptoms at day 40 p.i. Clinical disease activity paralleled decreased sciatic nerve motor conduction and histopathologic alterations of sciatic nerves. These included inflammatory infiltrates, mainly consisting of inducible nitric oxide synthase (iNOS)+ macrophages and CD4+ T cells. These data fit into the pathogenetic concept of murine autoimmune neuritis as a CD4+ TH1 cell-mediated disease. Our new mouse model provides an attractive tool to identify critical factors that regulate the severity of autoimmune responses in the peripheral nervous system.     

Tripchlorolide protects against MPTP-induced neurotoxicity in C57BL/6 mice

Many current studies of Parkinson's disease (PD) suggest that inflammation is involved in the neurodegenerative process. Tripchlorolide (TW397), a traditional Chinese herbal compound with anti-inflammatory and immunosuppressive properties, has been shown to protect dopaminergic neurons against, and restore their function after, the neurotoxicity induced by 1-methyl-4-phenylpyridinium ions in vitro. This study was designed to investigate the effect of TW397 in vivo in the PD model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned C57BL/6 mice. In the animals that received vehicle-only (i.e., no TW397) treatment with MPTP i.p. injection, the survival ratios of tyrosine hydroxylase-immunoreactive (TH-IR) neurons in the substantia nigra pars compacta and TH-IR fibres in the striatum were only 59 and 13%, respectively, compared with the normal controls. Intriguingly, in conjunction with MPTP, treatment with TW397, 1 microg/kg for 16 days, once per day, dramatically improved the survival rate of the TH-IR neurons and TH-IR fibres to 80 and 43% of the control. The treatment with TW397 also significantly improved the level of dopamine in the substantia nigra and striatum to 157 and 191%, respectively, of the MPTP- plus vehicle-treated group. In addition, in MPTP-treated animals the rota-rod performances of those treated with 0.5 or 1 microg/kg TW397 were significantly improved, by approximately 2- and 3-fold, respectively, relative to vehicle-treated animals. The neuroprotective effect of TW397 was coincident with an attenuated astroglial response within the striatum. These data demonstrate a neuroprotective action of TW397 in vivo against MPTP toxicity, with important implications for the treatment of PD.     

Acetylcholinesterase molecular forms in C57BL/6J dystrophic mice

Acetylcholinesterase (AChE) was extracted from normal and dystrophic C57BL/6J mouse hindlimb muscles and its molecular forms fractionated by sucrose density gradient ultracentrifugation. In the soleus muscles from 6- to 7-week-old mice an increase in the 3 Svedberg unit (S) and a decrease in the 16S AChE molecular forms was observed in dystrophic animals compared to controls. At 12-13 weeks of age, no major significant differences in the relative proportions of AChE molecular forms were noted. In the extensor digitorum longus (EDL) muscles of 6- to 7-week-old dystrophic mice a significant decrease in the proportion of the 10S AChE molecular form and an increase in the 3S and 5S forms was observed. At 12-13 weeks, the dystrophic EDL muscles again displayed a decrease in the 10S form; however, the increase in the 3S and 5S AChE forms, while still apparent, was not significant. These results provide evidence for a biochemical abnormality in the distribution of specific AChE molecular forms, and a differential expression of this abnormality in the soleus and EDL muscles.     

Lesion-induced DA supersensitivity in aging C57BL/6J mice

Lesion-induced dopaminergic supersensitivity was investigated in 4-, 10-, and 28-month-old C57BL/6J mice. Apomorphine-induced rotational behavior was examined 5, 10, and 20 days after destruction of the dopamine-containing nigro-striatal pathway by intrastriatal infusion of 6-OHDA. No major differences between ages were observed in the extent or rate of development of contralateral rotation. It is concluded that age-differences in dopaminergic supersensitization are dependent upon the nature and/or severity of the sensitizing stimulus.     

Naked mole-rats: behavioural phenotyping and comparison with C57BL/6 mice

Naked mole-rats (NMR) live underground in large eusocial colonies in East Africa. They are extremely long-lived, some individuals having a lifespan of over 30 years. This has attracted research into longevity and possibly neurodegenerative disorders. However, very little is known about their basic behaviour, particularly in tests commonly used to characterise the behaviour of the laboratory rat and mouse, for which there is an enormous database. Recently the authors carried out comprehensive behavioural phenotyping on NMRs, comparing them on most tasks directly with C57BL/6 mice, the strain for which there is the largest behavioural database. The NMR colony had been obtained from the wild originally, but housed in an animal facility for about two years. Large inter-species differences in behaviour were seen between the mice and the NMRs. The latter had generally poor sensorimotor function, including cutaneous sensation, strength and even grasp reflexes. They were often reluctant to enter or head-dip into small holes that mice readily entered. Their vision (generally considered to be very poor) was sufficient to distinguish the two zones of a light-dark box. Although, as expected, the NMRs were capable of burrowing and digging, when individually housed they did not shred cotton material to make nests. Shredding was seen in a colony cage containing a queen, but no nests were made there even when a nesting box was provided. In cognitive testing, although, unlike mice and rats, they did not spontaneously alternate in a T-maze, they learnt rewarded alternation and a cued position task well. This study demonstrates how behaviour uniquely reflects the natural environment in which these unusual animals have evolved and live, and provides baseline data for future work.     

Treatment and prevention of experimental autoimmune neuritis with superagonistic CD28-specific monoclonal antibodies

Two distinct CD28-specific mAb were used in treatment of active or adoptive transfer (AT)-experimental autoimmune neuritis (EAN): “superagonistic” JJ316 activates T cells without T cell receptor (TCR) occupancy, and conventional JJ319 activates T cells only in the presence of TCR-stimulation. Treatment with JJ316 during induction phase of active and adoptive-transfer experimental autoimmune encephalomyelitis (AT-EAN) dramatically reduced disease severity and improved nerve function as revealed by electrophysiology. JJ316 given 1 week before immunization had a preventive effect. By immunohistology, JJ316 markedly reduced TC infiltration of the sciatic nerve in active and AT-EAN. JJ319 was less effective. Ex vivo, JJ316 therapy reduced P2-specific proliferation and interferon-γ (IFN-γ) production of lymph node cells. We demonstrate preventive and therapeutic effects of a “superagonistic” mAb-mediated, TCR-independent CD28 stimulation in EAN, possibly with implications for therapy of autoimmune-inflammatory disorders.     

Behavioral and neuroreceptor differences in C57BL/6 and BALB/c mice

We studied spontaneous behavior in the cross-maze test and differences in neuroreceptors in inbred C57BL/6 and BALB/c mice. Correlation and factor analysis of behavioral data showed that the indices of exploratory behavior and anxiety in a novel context were rather independent from each other. The densities of NMDA receptors (B _max, fmol/mg of protein) in the hippocampus and benzodiazepine receptors in the prefrontal cortex were higher in C57BL/6 mice. Our data demonstrate the opportunity for selective pharmacological regulation of cognitive behavior and anxiety using nootropic and anxiolytic drugs.     

A deficiency of axonal regeneration in C57BL/6J mice

Axonal regeneration within peripheral nerves and dorsal spinal roots was investigated in inbred strains of mice with known differences in macrophage recruitment and inflammatory functions. During the second week after sciatic nerve crush, counts of regenerating newly myelinated fibres were significantly lower in C57BL/6J mice than in 4 other strains. After dorsal root crush with or without concomitant sciatic nerve transection to enhance regeneration, fibre counts in roots of C57BL/6J were one-fifth of those in A/J mice. Axonal regeneration is subnormal in C57BL/6J mice but this defect appears not to be linked to known deficiencies in macrophage function.