Experimental Campylobacter jejuni infection in the chicken: an animal model of axonal Guillain-Barré syndrome

Antibiotic-induced microbiome depletion promotes intestinal colonization by Campylobacter jejuni in mice

BACKGROUND

To establish a method to induce Campylobacter jejuni colonization in the intestines of C57BL/6 mice through antibiotic-induced microbiome depletion.

RESULTS

Fifty-four female C57BL/6 mice were divided into the normal, control, and experimental groups. The experimental group was administered intragastric cefoperazone sodium and sulbactam sodium (50 mg/mL) for 2 days; then, the experimental and control mice were intragastrically administered 200 µL C. jejuni, which was repeated once more after 2 days. Animal feces were collected, and the HipO gene of C. jejuni was detected using TaqMan qPCR from day 1 to day 14 after modeling completion. Immunofluorescence was used to detect intestinal C. jejuni colonization on day 14, and pathological changes were observed using hematoxylin and eosin staining. Additionally, 16S rDNA analyses of the intestinal contents were conducted on day 14. In the experimental group, C. jejuni was detected in the feces from days 1 to 14 on TaqMan qPCR, and immunofluorescence-labeled C. jejuni were visibly discernable in the intestinal lumen. The intestinal mucosa was generally intact and showed no significant inflammatory-cell infiltration. Diversity analysis of the colonic microbiota showed significant inter-group differences. In the experimental group, the composition of the colonic microbiota differed from that in the other 2 groups at the phylum level, and was characterized by a higher proportion of Bacteroidetes and a lower proportion of Firmicutes.

CONCLUSIONS

Microbiome depletion induced by cefoperazone sodium and sulbactam sodium could promote long-term colonization of C. jejuni in the intestines of mice.

Neuron-Schwann cell interactions in peripheral nervous system homeostasis, disease, and preclinical treatment

Schwann cells (SCs) have a critical role in the peripheral nervous system. These cells are able to support axons during homeostasis and after injury. However, mutations in genes associated with the SCs repair program or myelination result in dysfunctional SCs. Several neuropathies such as Charcot-Marie-Tooth (CMT) disease, diabetic neuropathy and Guillain-Barré syndrome show abnormal SC functions and an impaired regeneration process. Thus, understanding SCs-axon interaction and the nerve environment in the context of homeostasis as well as post-injury and disease onset is necessary. Several neurotrophic factors, cytokines, and regulators of signaling pathways associated with proliferation, survival and regeneration are involved in this process. Preclinical studies have focused on the discovery of therapeutic targets for peripheral neuropathies and injuries. To study the effect of new therapeutic targets, modeling neuropathies and peripheral nerve injuries (PNIs) in vitro and in vivo are useful tools. Furthermore, several in vitro protocols have been designed using SCs and neuron cell lines to evaluate these targets in the regeneration process. SCs lines have been used to generate effective myelinating SCs without success. Alternative options have been investigated using direct conversion from somatic cells to SCs or SCs derived from pluripotent stem cells to generate functional SCs. This review will go over the advantages of these systems and the problems associated with them. In addition, there have been challenges in establishing adequate and reproducible protocols in vitro to recapitulate repair SC-neuron interactions observed in vivo. So, we also discuss the mechanisms of repair SCs-axon interactions in the context of peripheral neuropathies and nerve injury (PNI) in vitro and in vivo. Finally, we summarize current preclinical studies evaluating transgenes, drug, and novel compounds with translational potential into clinical studies.

Th1/Th17-mediated Immunity and Protection from Peripheral Neuropathy in Wildtype and IL10-/- BALB/c Mice Infected with a Guillain-Barré Syndrome-associated Campylobacter jejuni Strain

Campylobacter jejuni is an important cause of bacterial gastroenteritis worldwide and is linked to Guillain-Barré syndrome (GBS), a debilitating postinfectious polyneuropathy. The immunopathogenesis of GBS involves the generation of antibodies that are cross reactive to C. jejuni lipooligosaccharide and structurally similar peripheral nerve gangliosides. Both the C. jejuni infecting strain and host factors contribute to GBS development. GBS pathogenesis is associated with Th2-mediated responses in patients. Moreover, induction of IgG1 antiganglioside antibodies in association with colonic Th2-mediated immune responses has been reported in C. jejuni-infected C57BL/6 IL10-/- mice at 4 to 6 wk after infection. We hypothesized that, due to their Th2 immunologic bias, BALB/c mice would develop autoantibodies and signs of peripheral neuropathy after infection with a GBS patient-derived strain of C. jejuni (strain 260.94). WT and IL10-/- BALB/c mice were orally inoculated with C. jejuni 260.94, phenotyped weekly for neurologic deficits, and euthanized after 5 wk. Immune responses were assessed as C. jejuni-specific and antiganglioside antibodies in plasma and cytokine production and histologic lesions in the proximal colon. Peripheral nerve lesions were assessed in dorsal root ganglia and their afferent nerve fibers by scoring immunohistochemically labeled macrophages through morphometry. C. jejuni 260.94 stably colonized both WT and IL10-/- mice and induced systemic Th1/Th17-mediated immune responses with significant increases in C. jejuni-specific IgG2a, IgG2b, and IgG3 plasma antibodies. However, C. jejuni 260.94 did not induce IgG1 antiganglioside antibodies, colitis, or neurologic deficits or peripheral nerve lesions in WT or IL10-/- mice. Both WT and IL10-/- BALB/c mice showed relative protection from development of Th2-mediated immunity and antiganglioside antibodies as compared with C57BL/6 IL10-/- mice. Therefore, BALB/c mice infected with C. jejuni 260.94 are not an effective disease model but provide the opportunity to study the role of immune mechanisms and host genetic background in the susceptibility to post infectious GBS.

Axonal degeneration in Guillain-Barré syndrome: a reappraisal

The aim of this review was to analyse the pathophysiology of axonal degeneration in Guillain-Barré syndrome (GBS) with emphasis on early stages (≤ 10 days after onset). An overview of experimental autoimmune neuritis (EAN) models is provided. Originally GBS and acute inflammatory demyelinating polyneuropathy were equated, presence of axonal degeneration being attributed to a "bystander" effect. Afterwards, primary axonal GBS forms were reported, designated as acute motor axonal neuropathy/acute motor-sensory axonal neuropathy. Revision of the first pathological description of axonal GBS indicates the coexistence of active axonal degeneration and demyelination in spinal roots, and pure Wallerian-like degeneration in peripheral nerve trunks. Nerve conduction studies are essential for syndrome subtyping, though their sensitivity is scanty in early GBS. Serum markers of axonal degeneration include increased levels of neurofilament light chain and presence of anti-ganglioside reactivity. According to nerve ultrasonographic features and autopsy studies, ventral rami of spinal nerves are a hotspot in early GBS. In P₂-induced EAN models, the initial pathogenic change is inflammatory oedema of spinal roots and sciatic nerve, which is followed by demyelination, and Wallerian-like degeneration in nerve trunks possessing epi-perineurium; a critical elevation of endoneurial fluid pressure is a pre-requisite for inducing ischemic axonal degeneration. Similar lesion topography may occur in GBS. The repairing role of adaxonal Schwann cytoplasm in axonal degeneration is analysed. A novel pathophysiological mechanism for nerve trunk pain in GBS, including pure motor forms, is provided. The potential therapeutic role of intravenous boluses of methylprednisolone for early severe GBS and intractable pain is argued.

Effects of antibiotic resistance (AR) and microbiota shifts on Campylobacter jejuni-mediated diseases

Campylobacter jejuni is an important zoonotic pathogen recently designated a serious antimicrobial resistant (AR) threat. While most patients with C. jejuni experience hemorrhagic colitis, serious autoimmune conditions can follow including inflammatory bowel disease (IBD) and the acute neuropathy Guillain Barré Syndrome (GBS). This review examines inter-relationships among factors mediating C. jejuni diarrheal versus autoimmune disease especially AR C. jejuni and microbiome shifts. Because both susceptible and AR C. jejuni are acquired from animals or their products, we consider their role in harboring strains. Inter-relationships among factors mediating C. jejuni colonization, diarrheal and autoimmune disease include C. jejuni virulence factors and AR, the enteric microbiome, and host responses. Because AR C. jejuni have been suggested to affect the severity of disease, length of infections and propensity to develop GBS, it is important to understand how these interactions occur when strains are under selection by antimicrobials. More work is needed to elucidate host-pathogen interactions of AR C. jejuni compared with susceptible strains and how AR C. jejuni are maintained and evolve in animal reservoirs and the extent of transmission to humans. These knowledge gaps impair the development of effective strategies to prevent the emergence of AR C. jejuni in reservoir species and human populations.

Matrix metalloproteinases-2 and -9 in Campylobacter jejuni-induced paralytic neuropathy resembling Guillain-Barré syndrome in chickens

Inflammation in Guillain-Barré syndrome (GBS) is manifested by changes in matrix metalloproteinase (MMP) and pro-inflammatory cytokine expression. We investigated the expression of MMP-2, -9 and TNF-α and correlated it with pathological changes in sciatic nerve tissue from Campylobacter jejuni-induced chicken model for GBS. Campylobacter jejuni and placebo were fed to chickens and assessed for disease symptoms. Sciatic nerves were examined by histopathology and immunohistochemistry. Expressions of MMPs and TNF-α, were determined by real-time PCR, and activities of MMPs by zymography. Diarrhea developed in 73.3% chickens after infection and 60.0% of them developed GBS like neuropathy. Pathology in sciatic nerves showed perinodal and/or patchy demyelination, perivascular focal lymphocytic infiltration and myelin swelling on 10th- 20th post infection day (PID). MMP-2, -9 and TNF-α were up-regulated in progressive phase of the disease. Enhanced MMP-2, -9 and TNF-α production in progressive phase correlated with sciatic nerve pathology in C. jejuni-induced GBS chicken model.

The pathogenesis of proventricular dilatation disease

Bornaviruses cause neurologic diseases in several species of birds, especially parrots, waterfowl and finches. The characteristic lesions observed in these birds include encephalitis and gross dilatation of the anterior stomach — the proventriculus. The disease is thus known as proventricular dilatation disease (PDD). PDD is characterized by extreme proventricular dilatation, blockage of the passage of digesta and consequent death by starvation. There are few clinical resemblances between this and the bornaviral encephalitides observed in mammals. Nevertheless, there are common virus-induced pathogenic pathways shared across this disease spectrum that are explored in this review. Additionally, a review of the literature relating to gastroparesis in humans and the control of gastric mobility in mammals and birds points to several plausible mechanisms by which bornaviral infection may result in extreme proventricular dilatation.

Guillain Barré Syndrome is induced in Non-Obese Diabetic (NOD) mice following Campylobacter jejuni infection and is exacerbated by antibiotics

Campylobacter jejuni is a leading cause of bacterial gastroenteritis linked to several serious autoimmune sequelae such as the peripheral neuropathies Guillain Barré syndrome (GBS) and Miller Fisher syndrome (MFS). We hypothesized that GBS and MFS can result in NOD wild type (WT) mice or their congenic interleukin (IL)-10 or B7-2 knockouts secondary to C. jejuni infection. Mice were gavaged orally with C. jejuni strains HB93-13 and 260.94 from patients with GBS or CF93-6 from a patient with MFS and assessed for clinical neurological signs and phenotypes, anti-ganglioside antibodies, and cellular infiltrates and lesions in gut and peripheral nerve tissues. Significant increases in autoantibodies against single gangliosides (GM1, GQ1b, GD1a) occurred in infected NOD mice of all genotypes, although the isotypes varied (NOD WT had IgG1, IgG3; NOD B7-2^-/- had IgG3; NOD IL-10^-/- had IgG1, IgG3, IgG2a). Infected NOD WT and NOD IL-10^-/- mice also produced anti-ganglioside antibodies of the IgG1 isotype directed against a mixture of GM1/GQ1b gangliosides. Phenotypic tests showed significant differences between treatment groups of all mouse genotypes. Peripheral nerve lesions with macrophage infiltrates were significantly increased in infected mice of NOD WT and IL-10^-/- genotypes compared to sham-inoculated controls, while lesions with T cell infiltrates were significantly increased in infected mice of the NOD B7-2^-/- genotype compared to sham-inoculated controls. In both infected and sham inoculated NOD IL-10^-/- mice, antibiotic treatment exacerbated neurological signs, lesions and the amount and number of different isotypes of antiganglioside autoantibodies produced. Thus, inducible mouse models of post-C. jejuni GBS are feasible and can be characterized based on evaluation of three factors-onset of GBS clinical signs/phenotypes, anti-ganglioside autoantibodies and nerve lesions. Based on these factors we characterized 1) NOD B-7^-/- mice as an acute inflammatory demyelinating polyneuropathy (AIDP)-like model, 2) NOD IL-10^-/- mice as an acute motor axonal neuropathy (AMAN)-like model best employed over a limited time frame, and 3) NOD WT mice as an AMAN model with mild clinical signs and lesions. Taken together these data demonstrate that C. jejuni strain genotype, host genotype and antibiotic treatment affect GBS disease outcomes in mice and that many disease phenotypes are possible.

Pathogenesis of Guillain–Barré syndrome

Guillain-Barre syndrome is a postinfectious disorder caused by an aberrant immune response to an infectious pathogen, resulting in an autoimmune disease. As with other autoimmune diseases of infectious nature, the intricate balance of the numerous factors involved in the immune response may determine the outcome of the interaction between the microbe and host. Recent studies focusing on the role of cytokines and its network of related mediators and receptors suggest that any imbalance may make a significant contribution to the outcome of the infectious disease process. Better understanding of the pathogenesis of Guillain-Barre syndrome may lead to the discovery of newer therapeutics and may also serve as a model for studying other autoimmune diseases.

Role of Campylobacter jejuni infection in the pathogenesis of Guillain-Barré syndrome: an update

Our current knowledge on Campylobacter jejuni infections in humans has progressively increased over the past few decades. Infection with C. jejuni is the most common cause of bacterial gastroenteritis, sometimes surpassing other infections due to Salmonella, Shigella, and Escherichia coli. Most infections are acquired due to consumption of raw or undercooked poultry, unpasteurized milk, and contaminated water. After developing the diagnostic methods to detect C. jejuni, the possibility to identify the association of its infection with new diseases has been increased. After the successful isolation of C. jejuni, reports have been published citing the occurrence of GBS following C. jejuni infection. Thus, C. jejuni is now considered as a major triggering agent of GBS. Molecular mimicry between sialylated lipooligosaccharide structures on the cell envelope of these bacteria and ganglioside epitopes on the human nerves that generates cross-reactive immune response results in autoimmune-driven nerve damage. Though C. jejuni is associated with several pathologic forms of GBS, axonal subtypes following C. jejuni infection may be more severe. Ample amount of existing data covers a large spectrum of GBS; however, the studies on C. jejuni-associated GBS are still inconclusive. Therefore, this review provides an update on the C. jejuni infections engaged in the pathogenesis of GBS.

Gene expression profile of Campylobacter jejuni-induced GBS in Bama miniature pigs

Our aim was to investigate the in vivo gene expression pattern of the Guillain-Barre syndrome (GBS) with DNA microarrays and bioinformatics tools. Oral-infusion model animals mimicking human infection of GBS were analyzed. Tissue samples and body fluids were collected to perform antibody tests and biopsy assays. Gene-expression microarray was conducted with nerve tissues and GBS-related genes were elucidated via bioinformatics tools. Model animals showed typical symptoms of GBS in that mild demyelination was shown by cerebellar white matter and by lumbar enlargement of model animals. Then, 81.25% of the model animals were positive with GM1-IgG antibodies by ELISA. In the microarray analysis, 1,261 genes were identified with statistically different expression (P < 0.05), 21 of which were associated with gene function analysis, gene pathway identification, signal transduction and co-expression network construction. Furthermore, quantitative PCR was used to characterize the gene expression level. We found that genes of HPRT1, PKC and PPARGC-1 were in the core of the network, while the expression of PPARGC-1, SUS2DD and AMPKA2 were significantly inhibited. A total of 21 genes were found to be actively involved in the process of protein transportation, transcriptional regulation, antigen identification and cell cycle regulation during the GBS infection period. The co-expression network indicated an important association between GBS and the 21 genes, especially the down-regulated ones. In conclusion, we demonstrated that GBS-affected hosts had a specific gene expression profile, which may guide the direction of GBS research and therapy.

Immunopathology and Th1/Th2 immune response of Campylobacter jejuni-induced paralysis resembling Guillain-Barré syndrome in chicken

Immunopathogenesis of Campylobacter jejuni-associated Guillain-Barré syndrome (GBS) is not yet well established probably due to lack of experimental model. Therefore, we studied the Th1/Th2 immune response and pathological changes in C. jejuni-induced chicken model for GBS. C. jejuni (5 × 10(9) CFU/ml) and placebo were fed to 30 chickens each. Stools of all birds were negative for C. jejuni by culture and PCR before experiment. The birds were regularly assessed for disease symptoms up to 30 days. Sciatic nerves from all chickens were examined at 5 days intervals by histopathology and immunohistochemistry, and also for the expression of Th1/Th2 cytokines. Twenty-two chickens (73.3%) developed diarrhea after C. jejuni infection; 18 (60.0%) experimental chickens developed GBS-like paralytic neuropathy. Pathology in the sciatic nerves of these chickens included perinodal and/or patchy demyelination, perivascular focal lymphocytic infiltration, myelin swelling and presence of macrophages within the nerve fibers on 10th-20th post-infection day (PID). Cytokines (IFN-γ, IL-1β, TNF-α, IL-6 and IL-2) were elevated in early phase (5th-15th PID) and TGF-β2, IL-10 and IL-4 in the recovery phase (25th-30th PID) of the disease. The study provides evidence that C. jejuni infection in the chicken can provide an experimental animal model of GBS.

Campylobacter jejuni DNA-binding protein from starved cells in Guillain-Barré syndrome patients

Campylobacter jejuni enteritis is frequently associated with an axonal form of Guillain-Barré syndrome (GBS) and C. jejuni DNA-binding protein from starved cells (C-Dps) induces paranodal myelin detachment and axonal degeneration through binding with sulfatide in vivo. Here we investigated the invasion of C-Dps into hosts with C. jejuni-related GBS. Our analyses of patient sera found that both C-Dps and anti-C-Dps antibodies were most commonly detected in sera from C. jejuni-related GBS patients (5/27, 14.8% and 15/24, 62.5%; respectively). These findings suggest that C-Dps invades the host and may potentially contribute to the peripheral nerve damage in C. jejuni-related GBS.

Host factors determine anti-GM1 response following oral challenge of chickens with Guillain-Barré syndrome derived Campylobacter jejuni strain GB11

Background

Anti-ganglioside antibodies with a pathogenic potential are present in C. jejuni-associated Guillain-Barré syndrome (GBS) patients and are probably induced by molecular mimicry. Immunization studies in rabbits and mice have demonstrated that these anti-ganglioside antibodies can be induced using purified lipo-oligosaccharides (LOS) from C. jejuni in a strong adjuvant.

Methodology/Principal Findings

To investigate whether natural colonization of chickens with a ganglioside-mimicking C. jejuni strain induces an anti-ganglioside response, and to investigate the diversity in anti-ganglioside response between and within genetically different chicken lines, we orally challenged chickens with different C. jejuni strains. Oral challenge of chickens with a C. jejuni strain from a GBS patient, containing a LOS that mimics ganglioside GM1, induced specific IgM and IgG anti-LOS and anti-GM1 antibodies. Inoculation of chickens with the Penner HS:3 serostrain, without a GM1-like structure, induced anti-LOS but no anti-ganglioside antibodies. We observed different patterns of anti-LOS/ganglioside response between and within the five strains of chickens.

Conclusions

Natural infection of chickens with C. jejuni induces anti-ganglioside antibodies. The production of antibodies is governed by both microbial and host factors.

The role of endotoxin in infection: Helicobacter pylori and Campylobacter jejuni

Both Helicobacter pylori and Campylobacter jejuni are highly prevalent Gram-negative microaerophilic bacteria which are gastrointestinal pathogens of humans; H. pylori colonizes the gastroduodenal compartment and C. jejuni the intestinal mucosa. Although H. pylori causes chronic gastric infection leading to gastritis, peptic ulcers and eventually gastric cancer while C. jejuni causes acute infection inducing diarrhoeal disease, the endotoxin molecules of both bacterial species contrastingly contribute to their pathogenesis and the autoimmune sequelae each induces. Compared with enterobacterial endotoxin, that of H. pylori has significantly lower endotoxic and immuno-activities, the molecular basis for which is the underphosphorylation and underacylation of the lipid A component that interacts with immune receptors. This induction of low immunological responsiveness by endotoxin may aid the prolongation of H. pylori infection and therefore infection chronicity. On the other hand, this contrasts with acute infection-causing C. jejuni where overt inflammation contributes to pathology and diarrhoea production, and whose endotoxin is immunologically and endotoxically active. Futhermore, both H. pylori and C. jejuni exhibit molecular mimicry in the saccharide components of their endotoxins which can induce autoreactive antibodies; H. pylori expresses mimicry of Lewis and some ABO blood group antigens, C. jejuni mimicry of gangliosides. The former has been implicated in influencing the development of inflammation and gastric atrophy (a precursor of gastic cancer), the latter is central to the development of the neurological disorder Guillain-Barré syndrome. Both diseases raise important questions concerning infection-induced autoimmunity awaiting to be addressed.

Topology and patch-clamp analysis of the sodium channel in relationship to the anti-lipid a antibody in campylobacteriosis

An infecting strain VLA2/18 of Campylobacter jejuni was obtained from an individual with campylobacteriosis and used to prepare chicken sera by experimental infection to investigate the role of serum anti-ganglioside antibodies in Guillain-Barré syndrome. Both sera of the patient and chicken contained anti-ganglioside antibodies and anti-Lipid A (anti-Kdo2-Lipid A) antibodies directed against the lipid A portion of the bacterial lipooligosaccharide. The anti-Kdo2-Lipid A activities inhibited voltage-gated Na (Nav) channel of NSC-34 cells in culture. We hypothesized that anti-Kdo2-Lipid A antibody acts on the functional inhibition of Nav1.4. To test this possibility, a rabbit peptide antibody (anti-Nav1.4 pAb) against a 19-mer peptide (KELKDNHILNHVGLTDGPR) on the alpha subunit of Nav1.4 was produced. Anti-Nav1.4 pAb was cross-reactive to Kdo2-Lipid A. Anti-Kdo2-lipid A antibody activity in the chicken serum was tested for the Na(+) current inhibition in NSC-34 cells in combination with mu-Conotoxin and tetrodotoxin. Contrary to our expectations, the anti-Kdo2-Lipid A antibody activity was extended to Nav channels other than Nav1.4. By overlapping structural analysis, it was found that there might be multiple peptide epitopes containing certain dipeptides showing a structural similarity with v-Lipid A. Thus, our study suggests the possibility that there are multiple epitopic peptides on the extracellular domains of Nav1.1 to 1.9, and some of them may represent target sites for anti-Kdo2-Lipid A antibody, to induce neurophysiological changes in GBS by disrupting the normal function of the Nav channels.

Ganglioside mimicry and peripheral nerve disease

Four criteria must be satisfied to conclude that a given microorganism causes Guillain-Barré (GBS) or Fisher (FS) syndrome associated with anti-ganglioside antibodies: (1) an epidemiological association between the infecting microbe and GBS or FS; (2) isolation in the acute progressive phase of illness of that microorganism from GBS or FS patients with associated anti-ganglioside IgG antibodies; (3) identification of a microbial ganglioside mimic; and (4) a GBS or FS with associated anti-ganglioside antibodies model produced by sensitization with the microbe itself or its component, as well as with ganglioside. Campylobacter jejuni is a definitive causative microorganism of acute motor axonal neuropathy and may cause FS and related conditions. Haemophilus influenzae and Mycoplasma pneumoniae are possible causative microorganisms of acute motor axonal neuropathy or FS. Acute and chronic inflammatory demyelinating polyneuropathies may be produced by mechanisms other than ganglioside mimicry.

Human and chicken antibodies to gangliosides following infection by Campylobacter jejuni

Campylobacteriosis is frequently associated with Guillain-Barré syndrome. Poultry are frequently highly colonized with Campylobacter jejuni and are a major foodborne vehicle for campylobacteriosis. In this study, high titer anti-GM1 antibodies were found in the serum of a laboratory worker who developed campylobacteriosis. The microbiologically confirmed strain VLA2/18 (non-serotyped) was isolated from the worker and subsequently inoculated into chickens, resulting in high titers of serum antibodies to GM1. However, none of the immunized chickens in our study showed any noticeable neurological symptoms, such as paralysis or cramping. High titer anti-GM1 antibodies in chicken and human sera strongly inhibited spontaneous muscle action potential in an in vitro system of spinal cord and muscle cell co-culture. In addition, infection of chickens with C. jejuni strains 81116 (HS6) and 99/419 (HS21) or immunization with purified GM1, GM2, and GM3 resulted in elevation of serum anti-ganglioside antibodies with an inhibitory effect on spontaneous muscle action potential. Immunoabsorption studies demonstrated that this inhibitory activity is due to anti-ganglioside antibodies. On the other hand, anti-GM1 is the only specific human serum antibody to induce an inhibitory effect on neuromuscular junctions. Chicken anti-GM1 antibodies showed a strong inhibitory effect, but anti-GM2 and -GM3 had weaker activities. Taken together, our data suggest that campylobacteriosis in chickens may provide a strong link between infection and the development of anti-ganglioside antibody-mediated peripheral nerve dysfunctions.

Molecular mimicry: sensitization of Lewis rats with Campylobacter jejuni lipopolysaccharides induces formation of antibody toward GD3 ganglioside

Recently we have reported cases of demyelinating inflammatory neuropathy showing elevated titers of anti-GD3 antibodies, which occurs rarely in Guillain-Barré syndrome. To examine the correlation between the anti-GD3 antibody titer and Campylobacter jejuni infection, we sensitized female Lewis rats with lipopolysaccharides (LPSs) from serotype HS19 of C. jejuni and examined changes in nerve conduction velocity and nerve conduction block (P/D ratio). After 16 weeks of sensitization, animals revealed decreases of nerve conduction velocity and conduction block (P/D ratio) and high titer of anti-GD3 antibodies. These anti-GD3 antibodies also blocked transmission in neuromuscular junctions of spinal cord-muscle cells cocultures. The GD3 epitope was verified to be located on the Schwann cell surface and nodes of Ranvier in rat sciatic nerve. To determine the target epitope for GD3 antibodies in causing nerve dysfunction, the LPS fraction containing the GD3 epitope was purified from the total LPS by using an anti-GD3 monoclonal antibody-immobilized affinity column. Subsequently, chemical analysis of the oligosaccharide portion was performed and confirmed the presence of a GD3-like epitope as having the following tetrasaccharide structure: NeuAcalpha2-8NeuAc2-3Galbeta1-4Hep. Our data thus support the possibility of a contribution of GD3 mimicry as a potential pathogenic mechanism of peripheral nerve dysfunction.

Lipooligosaccharide of Campylobacter jejuni prevents myelin-specific enteral tolerance to autoimmune neuritis—a potential mechanism in Guillain-Barré syndrome?

Campylobacter jejuni-induced enteritis is the most common infection preceding Guillain-Barre syndrome (GBS), an immune-mediated polyradiculoneuritis. The acute autoimmune attack is thought to be based on C. jejuni antigens which may mimick antigens of the peripheral nervous system. Additional pathomechanisms, like disturbance of natural T cell immunoregulation by C. jejuni, have not been evaluated so far. In experimental autoimmune neuritis (EAN), a T lymphocyte-mediated animal model of human GBS, tolerance to myelin-derived autoantigens can be induced by oral feeding of the respective antigen. Here we investigated whether the lipooligosaccharide (LOS) fraction of C. jejuni may directly alter immunologic tolerance through gastrointestinal pathways. While EAN, actively induced by immunization with bovine peripheral nerve myelin could be ameliorated by precedent feeding of myelin, feeding of C. jejuni LOS along with the myelin antigen not only prevented the tolerizing effects of oral myelin but even accelerated the onset of overt EAN and augmented the myelin-specific B cell response. These findings provide evidence that LOS of C. jejuni, as produced in the gut during C. jejuni-induced enteritis, can disturb natural tolerance to definite proteins which may be or may mimic peripheral nerve antigens. In human patients this may be one of the potential mechanisms to explain why C. jejuni enteritis is a common trigger of GBS.

Antiglycolipid antibodies in Guillain-Barré syndrome and related diseases: Review of clinical features and antibody specificities

Guillain-Barré syndrome (GBS) is an acute inflammatory polyradiculoneuropathy that usually develops following a respiratory or intestinal infection. Although the pathogenic mechanisms of GBS have not been fully established, both humoral and cell-mediated immune factors have been shown to contribute to the disease process. Several antiglycosphingolipid (anti-GSL) antibodies have been found in the sera of patients with GBS or related diseases. Measurements of these antibody titers are very important in the diagnosis of GBS and in evaluating the effectiveness of treatments in clinical trials. The most common treatment strategies for these disorders involve plasmapheresis and the use of steroids for reducing anti-GSL antibody titers to ameliorate patients' clinical symptoms. Administration of intravenous immunoglobulin may also be beneficial in the treatment of neuropathies by suppressing the immune-mediated processes that are directed against antigenic targets in myelin and axons. In certain demyelinating neuropathies, the destruction or malfunctioning of the blood-nerve barrier, which results in the leakage of circulating antibodies into the peripheral nerve parenchyma, has been considered to be an initial step in development of the disease process. In addition, anti-GSL antibodies, such as anti-GM1, may cause nerve dysfunction and injury by interfering with the ion channel function at the nodes of Ranvier, where carbohydrate epitopes of glycoconjugates are located. These malfunctions thus contribute to the pathogenic mechanisms of certain demyelinating neuropathies.

Blood ?? T cells,Campylobacter jejuni, and GM1 titers in Guillain-Barr� syndrome

The gammadelta T cells participate in microbial defense, are prevalent in intestinal epithelia, and are activated in autoimmune diseases. We studied whether peripheral blood gammadelta cells and gammadelta subsets are increased in Guillain-Barré syndrome (GBS) and whether elevations are associated with Campylobacter jejuni infection or GM1 elevations. In 20 GBS patients, we performed serial flow cytometry studies of blood gammadelta, Vdelta1, and Vdelta2 cells (+/- CD8+), C jejuni, and ganglioside titers. There was no significant difference in median gammadelta T-cell percentages between GBS patients and controls at onset and at convalescence. However, 5 patients had marked Vdelta1/CD8+ elevations. Elevated Vdelta1 or Vdelta1/CD8+ cells occurred in 3 of 6 patients with C jejuni or GM1 titer elevations. A minority of GBS patients have elevations of Vdelta1/CD8+ cells, possibly associated with elevated C jejuni or GM1 titers. The gammadelta T cells may have a cytotoxic (or suppressor) role in the disease.

Sialosyl-galactose: a common denominator of Guillain-Barré and related disorders?

The immune reactivity implicated in the pathogenesis of Guillain-Barré syndrome (GBS) and related diseases, which occur following infection with specific strains of Campylobacter jejuni bearing sialylated lipopolysaccharide structures that cross-react with specific gangliosides, is consistent with provocation of inflammation via molecular mimicry. In this review, we have focused upon microbial characteristics and structures, the fine structure of the essential carbohydrate determinants, and the application of our proposed criteria, modified from those of Koch for causation of infectious and of Witebsky for autoimmune diseases, to the circumstance of infectious induction of autoimmune disorder.

Chronic effects of Campylobacter infection

Campylobacter jejuni is one of the most common causes of bacterial gastroenteritis and chronic sequelae, such as reactive arthritis and Guillain-Barré syndrome (GBS), are known to follow uncomplicated infections. While little is known about reactive arthritis following Campylobacter infection, our knowledge on the pathogenesis of Campylobacter-induced GBS is expanding rapidly and is summarized in this review.

Campylobacter jejuni infection during pregnancy: long-term consequences of associated bacteremia, Guillain-Barré syndrome, and reactive arthritist

Campylobacter jejuni infections are the main cause of foodborne gastroenteritis in the United States and other developed countries. Generally, C. jejuni infections are self-limiting and treatment is not necessary; however, infections caused by this organism can lead to potentially dangerous long-term consequences for some individuals. Bacteremia, Guillain-Barré syndrome (GBS; an acute flaccid paralytic disease), and reactive arthritis (ReA) are the most serious of the long-term consequences of C. jejuni infections. During pregnancy, foodborne infections may be hazardous to both the woman and the fetus. C. jejuni-induced bacteremia during pregnancy may lead to intrauterine infection of the fetus, abortion, stillbirth, or early neonatal death. Infection of a newborn by the mother during the birth process or shortly after birth may lead to neonatal enteritis, bacteremia, and/or meningitis. C. jejuni enteritis is the inducing antecedent infection in approximately 30% of cases of GBS. Thus, pregnant women infected with C. jejuni may contract GBS. GBS during pregnancy does not affect fetal or infant development and does not increase spontaneous abortion or fetal death; however, it may induce spontaneous delivery during the third trimester in severe cases. Reactive arthritis occurs in approximately 2% of C. jejuni enteritis cases and leads to the impaired movement of various joints. Pregnant women with C. jejuni-induced reactive arthritis can be expected to deliver a normal infant. A pregnant patient with GBS or ReA may be unable to care for a newborn infant because of the physical impairment induced by these diseases. Since C. jejuni infections put both fetuses and pregnant women at risk, pregnant women must take special care in food handling and preparation to prevent such infections.

Guillain-Barré syndrome serum and anti-Campylobacter antibody do not exacerbate experimental autoimmune neuritis

To investigate whether antibodies are pathogenic in Guillain-Barré syndrome (GBS), we injected pre-treatment serum from 11 GBS patients intraperitoneally into rats in which the blood-nerve barrier had been opened by induction of mild adoptive transfer experimental autoimmune neuritis. There was no significant clinical, neurophysiological or pathological difference between rats receiving GBS serum compared with those receiving control serum, except that GBS serum caused minor excess weight loss. Murine monoclonal antibody to Campylobacter jejuni and gangliosides also did not exacerbate disease. This experiment failed to show antibody-mediated disease exacerbation and so does not support an antibody-mediated mechanism in GBS.

Axonal Guillain-Barré syndrome: a critical review

Axonal Guillain-Barré Syndrome (GBS) was first described by Feasby et al. in 1986, challenging the existent notion of GBS being a primarily demyelinating disease. The severe course and slow recovery commonly seen in these patients was ascribed to axonal degeneration. Other authors challenged this claim on several grounds. Amidst these controversies, epidemics of a similar illness were reported from China, which were given the acronym AMAN, having exclusive motor involvement in contrast to the cases already described in which both motor and sensory involvement were present (AMSAN). Pathologically, Wallerian degeneration, minimal lymphocytic response, absent demyelination or inflammation and periaxonal macrophages are prominent features. Ultrastructural studies have revealed node of Ranvier to be the prime target of immune attack. A frequent occurrence of antecedent Campylobacter jejuni infection and a strong association between elevated titres of IgG GM1 and axonal GBS on a background of preceding C. jejunii infection has been observed and molecular mimicry between lipopolysaccharides of C. jejuni and neural epitopes has been proposed as a mechanism of injury. Clinically axonal variant is similar to AIDP, but a more severe course, with frequent respiratory involvement, ventilator dependence and significant residue may be seen. Diagnosis is essentially electrophysiological. Treatment is similar to AIDP, preferential benefit of either IVIG or plasmapheresis needs to be further evaluated. A critical review of existing literature in axonal GBS is presented.

Molecular mimicry in Campylobacter jejuni and Helicobacter pylori lipopolysaccharides: contribution of gastrointestinal infections to autoimmunity

Molecular mimicry of host structures by the saccharide portion of lipopolysaccharides (LPS) of the gastrointestinal pathogens Campylobacter jejuni and Helicobacter pylori is thought to be associated with the development of autoimmune sequelae. C. jejuni, a leading cause of gastroenteritis, is the most common antecedent infection in Guillain-Barré syndrome (GBS), an inflammatory neuropathy. Chemical analyses of the core oligosaccharides of neuropathy-associated C. jejuni strains have revealed structural homology with human gangliosides. Serum antibodies against gangliosides are found in one third of GBS patients but are generally absent in enteritis cases. Collective data suggest that the antibodies are induced by antecedent infection with C. jejuni, and subsequently react with nerve tissue causing damage. The O-chains of most H. pylori strains express Lewis blood group antigens which are thought to have a role in camouflage of the bacterium as these antigens are also present on human gastric epithelial cells. In chronic H. pylori infections, bacterial expression of Lewis antigens is suggested to be involved in the induction of autoantibodies against the Lewis antigen-expressing gastric proton pump. Many aspects of the autoimmune mechanisms in C. jejuni -associated GBS and H. pylori -induced atrophic gastritis remain unclear, such as the involvement of T cells and the role of host factors.

New concepts of Guillain-Barré syndrome

Guillain-Barré syndrome is an acute autoimmune polyradiculoneuropathy with a clinical presentation of flaccid paralysis with areflexia, variable sensory disturbance, and elevated cerebrospinal fluid protein without pleocytosis. Although Guillain-Barré syndrome previously had been viewed as a unitary disorder with variations, it currently is viewed as a group of syndromes with several distinctive subtypes. These include the principal subtype prevalent in the Western world (acute inflammatory demyelinating polyradiculoneuropathy, and others, each with distinctive electrodiagnostic and pathologic features, including acute motor axonal neuropathy), acute motor-sensory axonal neuropathy, Miller Fisher syndrome, and perhaps others. The clinical and pathologic features of these Guillain-Barré syndrome subtypes are reviewed, and the role of antecedent infections, particularly Campylobacter jejuni gastroenteritis, and the role of antiganglioside antibody responses are reviewed with respect to pathogenesis. Treatment of Guillain-Barré syndrome includes both important supportive measures and immunotherapies, specifically high-dose intravenous immunoglobulin and plasma exchange.

Pathogenesis of Guillain-Barré syndrome

Recent neurophysiological and pathological studies have led to a reclassification of the diseases that underlie Guillain-Barré syndrome (GBS) into acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor and sensory axonal neuropathy (AMSAN) and acute motor axonal neuropathy (AMAN). The Fisher syndrome of ophthalmoplegia, ataxia and areflexia is the most striking of several related conditions. Significant antecedent events include Campylobacter jejuni (4-66%), cytomegalovirus (5-15%), Epstein-Barr virus (2-10%), and Mycoplasma pneumoniae (1-5%) infections. These infections are not uniquely associated with any clinical subtype but severe axonal degeneration is more common following C. jejuni and severe sensory impairment following cytomegalovirus. Strong evidence supports an important role for antibodies to gangliosides in pathogenesis. In particular antibodies to ganglioside GM1 are present in 14-50% of patients with GBS, and are more common in cases with severe axonal degeneration associated with any subtype. Antibodies to ganglioside GQ1b are very closely associated with Fisher syndrome, its formes frustes and related syndromes. Ganglioside-like epitopes exist in the bacterial wall of C. jejuni. Infection by this and other organisms triggers an antibody response in patients with GBS but not in those with uncomplicated enteritis. The development of GBS is likely to be a consequence of special properties of the infecting organism, since some strains such as Penner 0:19 and 0:41 are particularly associated with GBS but not with enteritis. It is also likely to be a consequence of the immunogenetic background of the patient since few patients develop GBS after infection even with one of these strains. Attempts to match the subtypes of GBS to the fine specificity of anti-ganglioside antibodies and to functional effects in experimental models continue but have not yet fully explained the pathogenesis. T cells are also involved in the pathogenesis of most or perhaps all forms of GBS. T cell responses to any of three myelin proteins, P2, PO and PMP22, are sufficient to induce experimental autoimmune neuritis. Activated T cells are present in the circulation in the acute stage, up-regulate matrix metalloproteinases, cross the blood-nerve barrier and encounter their cognate antigens. Identification of the specificity of these T cell responses is still at a preliminary stage. The invasion of intact myelin sheaths by activated macrophages is difficult to explain according to a purely T cell mediated mechanism. The different patterns of GBS are probably due to the diverse interplay between antibodies and T cells of differing specificities.

Campylobacter species and Guillain-Barré syndrome

Since the eradication of polio in most parts of the world, Guillain-Barré syndrome (GBS) has become the most common cause of acute flaccid paralysis. GBS is an autoimmune disorder of the peripheral nervous system characterized by weakness, usually symmetrical, evolving over a period of several days or more. Since laboratories began to isolate Campylobacter species from stool specimens some 20 years ago, there have been many reports of GBS following Campylobacter infection. Only during the past few years has strong evidence supporting this association developed. Campylobacter infection is now known as the single most identifiable antecedent infection associated with the development of GBS. Campylobacter is thought to cause this autoimmune disease through a mechanism called molecular mimicry, whereby Campylobacter contains ganglioside-like epitopes in the lipopolysaccharide moiety that elicit autoantibodies reacting with peripheral nerve targets. Campylobacter is associated with several pathologic forms of GBS, including the demyelinating (acute inflammatory demyelinating polyneuropathy) and axonal (acute motor axonal neuropathy) forms. Different strains of Campylobacter as well as host factors likely play an important role in determining who develops GBS as well as the nerve targets for the host immune attack of peripheral nerves. The purpose of this review is to summarize our current knowledge about the clinical, epidemiological, pathogenetic, and laboratory aspects of campylobacter-associated GBS.

Human autoimmune neuropathies

Peripheral nerve diseases are among the most prevalent disorders of the nervous system. Because of the accessibility of the peripheral nervous system (PNS) to direct physiological and pathological study, neuropathies have traditionally played a unique role in developing our understanding of basic mechanism of nervous system injury and repair. At present they are providing new insight into the mechanisms of immune injury to the nervous system. A rapidly growing catalogue of PNS disorders are now suspected to be immune-mediated, and in the best understood of these disorders, the molecular and cellular targets of immune attack are known, and the pathophysiology follows directly from the specific immune injury. This review summarizes the immunologically relevant features of the PNS, then considers selected immune-mediated neuropathies, focusing on pathogenetic mechanisms. Finally, the PNS is providing a testing ground for new immunotherapies and approaches to protection and regeneration, including the use of trophic factors. The current status of treatment and implications for future approaches is reviewed.