Campylobacter jejuni lipopolysaccharides from Guillain-Barré syndrome patients induce IgG anti-GM1 antibodies in rabbits

IL-23 Contributes to Campylobacter jejuni-Induced Intestinal Pathology via Promoting IL-17 and IFNγ Responses by Innate Lymphoid Cells

Human pathogen Campylobacter jejuni is a significant risk factor for the development of long-term intestinal dysfunction although the cellular and molecular mechanisms remain scantily defined. IL-23 is an emerging therapeutic target for the treatment of inflammatory intestinal diseases, however its role in C. jejuni-driven intestinal pathology is not fully understood. IL-10 deficient mice represent a robust model to study the pathogenesis of C. jejuni infection because C. jejuni infection of mice lacking IL-10 results in symptoms and pathology that resemble human campylobacteriosis. To determine the role of IL-23 in C. jejuni-driven intestinal inflammation, we studied the disease pathogenesis in IL-23^-/- mice with inhibited IL-10Rα signaling. These mice exhibited reduced intestinal pathology independent from bacterial clearance. Further, levels of IFNγ, IL-17, IL-22, TNF, and IL-6 were reduced and associated with reduced accumulation of neutrophils, monocytes and macrophages in the colon. Flow cytometry analysis revealed reduced production of IL-17 and IFNγ by group 1 and 3 innate lymphoid cells. Thus, our data suggest that IL-23 contributes to intestinal inflammation in C. jejuni infected mice by promoting IL-17 and IFNγ production by innate lymphoid cells.

An update in guillain-barré syndrome

Guillain-Barré syndrome (GBS) was first described in 1916 (Guillain G, 1916) and is approaching its 100th anniversary. Our knowledge of the syndrome has hugely expanded since that time. Once originally considered to be only demyelinating in pathology we now recognise both axonal and demyelinating subtypes. Numerous triggering or antecedent events including infections are recognised and GBS is considered an immunological response to these. GBS is now considered to be a clinical syndrome of an acute inflammatory neuropathy encompassing a number of subtypes with evidence of different immunological mechanisms. Some of these are clearly understood while others remain to be fully elucidated. Complement fixing antibodies against peripheral nerve gangliosides alone and in combination are increasingly recognised as an important mechanism of nerve damage. New antibodies against other nerve antigens such as neurofascin have been recently described. Research databases have been set up to look at factors associated with prognosis and the influence of intravenous immunoglobulin (IvIg) pharmacokinetics in therapy. Exciting new studies are in progress to examine a possible role for complement inhibition in the treatment of the syndrome.

Role of immunologic cross-reactivity in neurological diseases

Although the immune system evolved to protect the host from foreign infection, it can sometimes recognize and attack host tissues, a phenomenon known as autoimmunity. In addition to genetic factors, environmental elements such as viruses and bacteria are thought to play a role in the development of autoimmune diseases. The major hypothesized mechanism by which infection with these agents can lead to autoimmunity is termed molecular mimicry. Here, immune responses initiated against foreign antigens are cross-reactive with self-antigens. This is thought to occur especially if the foreign antigen is similar in structure or amino acid sequence to the self-antigen. In this review, we explore evidence for the role of molecular mimicry in neurological diseases.

Monospecific high-affinity and complement activating anti-GM1 antibodies are determinants in experimental axonal neuropathy

It has been difficult to replicate consistently the experimental model of axonal Guillain-Barré syndrome (GBS). We immunized rabbits with two lipo-oligosaccharides (LOS1 and LOS2) derived from the same C. jejuni strain and purified in a slightly different way. LOS1 did not contain proteins whereas several proteins were present in LOS2. In spite of a robust anti-GM1 antibody response in all animals the neuropathy developed only in rabbits immunized with LOS1. To explain this discrepancy we investigated fine specificity, affinity and ability to activate the complement of anti-GM1 antibodies. Only rabbits immunized with LOS1 showed monospecific high-affinity antibodies which activated more effectively the complement. Although it is not well understood how monospecific high-affinity antibodies are induced these are crucial for the induction of experimental axonal neuropathy. Only a strict adherence to the protocols demonstrated to be successful may guarantee the reproducibility and increase the confidence in the animal model as a reliable tool for the study of the human axonal 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.

Characteristics of lipo-oligosaccharide loci of Campylobacter jejuni isolates associated with Guillain-Barré Syndrome from Hebei, China

Ganglioside mimicry by C.jejuni lipo-oligosaccharides (LOS) could induce the production of autoantibodies against gangliosides and the development of Guillain-Barré syndrome (GBS). The LOS biosynthesis region exhibits significant variation with different strains. Using PCR amplifications of genes from published LOS loci and sequencing the LOS biosynthesis loci, the eight GBS-associated C. jejuni strains from HeBei could be classified into four classes. The expression of sialylated LOS structures (class A) or non-sialylated LOS structures(class F, H and P) in the C. jejuni LOS is considered to be two different factors for the induction of GBS.

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.

The role of infections in autoimmune disease

Autoimmunity occurs when the immune system recognizes and attacks host tissue. In addition to genetic factors, environmental triggers (in particular viruses, bacteria and other infectious pathogens) are thought to play a major role in the development of autoimmune diseases. In this review, we (i) describe the ways in which an infectious agent can initiate or exacerbate autoimmunity; (ii) discuss the evidence linking certain infectious agents to autoimmune diseases in humans; and (iii) describe the animal models used to study the link between infection and autoimmunity.

Immunogenicity and immunoprotection of recombinant PEB1 in Campylobacter-jejuni-infected mice

AIM: To construct a prokaryotic expression vector carrying Campylobacter jejuni peb1A gene and express it in Escherichia coli. Immunoreactivity and antigenicity of rPEB1 were evaluated. The ability of rPEB1 to induce antibody responses and protective efficacy was identified.

METHODS: peb1A gene was amplified by PCR, target gene and prokaryotic expression plasmid pET28a (+) was digested with BamHI and XhoI, respectively. DNA was ligated with T4 DNA ligase to construct recombinant plasmid pET28a(+)-peb1A. The rPEB1 was expressed in E. coli BL21 (DE3) and identified by SDS-PAGE. BALB/c mice were immunized with rPEB1. ELISA was used to detect the specific antibody titer and MTT method was used to measure the stimulation index of spleen lymphocyte transformation.

RESULTS: The recombinant plasmid pET28a (+)-peb1A was correctly constructed. The expression output of PEB1 protein in pET28a (+)-peb1A system was approximately 33% of total proteins in E. coli. The specific IgG antibody was detected in serum of BALB/c mice immunized with rPEB1 protein. Effective immunological protection with a lower sickness incidence and mortality was seen in the mice suffering from massive C. jejuni infection.

CONCLUSION: rPEB1 protein is a valuable candidate for C. jejuni subunit vaccine.

Lewis rats immunized with GM1 ganglioside do not develop peripheral neuropathy

Elevated levels of anti-GM1 antibodies are associated with motor nerve syndromes. Although there is a lot of circumstantial evidence that anti-GM1 antibodies may be causing the disease, their precise role remains unclear. In order to study the role of anti-GM1 antibodies in the pathogenesis of peripheral neuropathy, eight Lewis rats were injected with GM1 ganglioside mixed with keyhole limpet hemocyanin (KLH) and emulsified with Freund's adjuvant and three rats were immunized with GM1 in liposomes. Although IgM class anti-GM1 antibodies were detected in all animals immunized with GM1, none of the animals exhibited overt signs of neuropathy during 6 months after initial immunization. IgG antibody to GM1 was not produced in any of the animals. There was no pathological evidence of nerve damage. These studies suggest that elevated levels of IgM anti-GM1 antibodies by themselves do not cause nerve damage in rats.

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.

Experimental axonopathy induced by immunization with Campylobacter jejuni lipopolysaccharide from a patient with Guillain-Barré syndrome

New Zealand white rabbits were immunized with a lipopolysaccharide (LPS) extracted from a Campylobacter jejuni HS:19 strain isolated from a GBS patient expressing GM1 and GD1a-like epitopes, Freund's adjuvant (group I) and Freund's adjuvant plus keyhole lympet hemocyanin (KLH) (group II). Both groups showed high titers of anti-LPS and anti-GM1 and lower titers of anti-GD1b and anti-GD1a antibodies. Weakness and axonal degeneration in sciatic nerves was detected in 1/11 of group I and 6/7 of group II. This model replicates, at least in part, the pathogenetic process hypothesized in the human axonal GBS with antiganglioside antibodies post C. jejuni infection and indicates that KLH plays an additional role in neuropathy induction.

[Antibodies to ganglioside GM1 and Campylobacter jejuni in patients with Guillain-Barré syndrome]

Guillain-Barré syndrome (GBS) is an acute immune mediated neuropathy, polyradiculoneuritis, characterized by rapid onset of symmetric extremity muscle paralysis, areflexia and albuminocytological dissociation in the cerebrospinal fluid (CSF). Recently, the heterogeneity of GBS has been noticed with definition of several GBS variants. The axonal GBS associated with anti-GM1 antibodies is the most important variant with the specific role of Campylobacterjejuni (CJ) in the induction of the disease. The role of our study was to determine the frequency of antecedent infection with CJ in the population of our patients with GBS, the association with anti-GM1 antibodies and the distribution of these antibodies within clinical forms of the disease. The diagnosis of GBS has been established in 17 patients according to clinical, electrophysiological and laboratory (CSF) criteria. The serum antibodies to 63 kDa flagellar protein isolated from CJ serotype 0:19 were determined by ELISA and Western blot and serum anti-GM1 antibodies by ELISA. In relation to the disability score two patients were ambulatory, five were ambulatory with support, seven were bedridden and two patients needed respirator. Five (29%) patients had pure motor, while 12 (71%) had sensorimotor GBS. The cranial nerves were involved in 11 (65%) and 9 (53%) patients had autonomic dysfunction. Electromyoneurography showed primary axonal, predominantly motor neuropathy in 6 (35%) and demyelinating sensorimotor neuropathy in 11 (65%) patients. The CSF protein content ranged from 0.47 to 3.88 g/L. The antecedent infection with CJ was shown by serum antibodies to CJ flagellar protein in 12 (71%) patients. Fifteen (88%) patients had IgG anti-GM1 antibodies. Twelve (71%) patients had both antibodies. In relation to the clinical form, anti-CJ antibodies were found in 8 (73%) out of 11 patients with demyelinating GBS and in 4 (66.6%) out of 6 patients with axonal GBS. The high titer of anti-GM1 antibodies was found in all patients (100%) with axonal and in 9 (82%) out of 11 patients with demyelinating GBS. The association of IgG anti-CJ and IgG anti-GM1 antibodies was found in 4 (66.6%) out of 6 patients with axonal and in 8 (73%) out of 11 patients with demyelinating GBS. The main features of our patients with GBS were high frequency of antecedent infection with CJ, unusually frequent association with anti-GM1 antibodies, and equally frequent association of anti-CJ and anti-GM1 antibodies in both, axonal and demyelinating GBS.

Antibodies induced by ganglioside-mimicking Campylobacter jejuni lipooligosaccharides recognise epitopes at the nodes of Ranvier

Molecular mimicry of gangliosides by Campylobacter jejuni lipooligosaccharides (LOSs) in the induction of anti-ganglioside antibodies has been hypothesised to contribute to GBS development. Rabbits were immunised with ganglioside-mimicking C. jejuni LOSs and anti-LOS responses were analysed using passive haemagglutination, and anti-ganglioside responses by enzyme-linked immunosorbent assay and thin-layer chromatography with immunostaining. High titres of anti-LOS antibodies were demonstrated in rabbit antisera that were cross-reactive with a panel of gangliosides. Non-ganglioside-mimicking C. jejuni HS:3 LOS induced a strong anti-LOS response, but no anti-ganglioside antibodies. Control rabbit antisera had no anti-LOS or -ganglioside responses. Moreover, IgG from a patient treated with parenteral gangliosides, who exhibited Guillain-Barré syndrome, had antibodies reactive with C. jejuni LOS. Biotinylated IgG fractions from the rabbit and the patient sera recognised epitopes at the nodes of Ranvier in sectioned human nerves, whereas fractions from controls did not. This study demonstrates that immunisation with ganglioside-mimicking C. jejuni LOS triggers the production of cross-reactive anti-ganglioside antibodies that recognise epitopes at the nodes of Ranvier.

Functional polymorphisms in LPS receptors CD14 and TLR4 are not associated with disease susceptibility or Campylobacter jejuni infection in Guillain-Barré patients

Guillain-Barré syndrome (GBS) is an acute immune-mediated polyneuropathy preceded by infections. Campylobacter jejuni is the most frequent pathogen and its lipopolysaccharide (LPS) induces antibodies cross-reactive with gangliosides. In this study we assessed whether known functional polymorphisms in the LPS receptors CD14 and Toll-like receptor 4 (TLR4) are associated with an increased susceptibility for GBS or with C. jejuni serology or C. jejuni related clinical and serological features. Comparison of the genotypes of 242 GBS patients and 210 healthy subjects showed that polymorphisms in CD14 and TLR4 did not confer disease susceptibility and were not associated with C. jejuni infection.

Carbohydrate mimicry between human ganglioside GM1 and Campylobacter jejuni lipooligosaccharide causes Guillain-Barre syndrome

Molecular mimicry between microbial and self-components is postulated as the mechanism that accounts for the antigen and tissue specificity of immune responses in postinfectious autoimmune diseases. Little direct evidence exists, and research in this area has focused principally on T cell-mediated, antipeptide responses, rather than on humoral responses to carbohydrate structures. Guillain-Barré syndrome, the most frequent cause of acute neuromuscular paralysis, occurs 1-2 wk after various infections, in particular, Campylobacter jejuni enteritis. Carbohydrate mimicry [Galbeta1-3GalNAcbeta1-4(NeuAcalpha2-3)Galbeta1-] between the bacterial lipooligosaccharide and human GM1 ganglioside is seen as having relevance to the pathogenesis of Guillain-Barré syndrome, and conclusive evidence is reported here. On sensitization with C. jejuni lipooligosaccharide, rabbits developed anti-GM1 IgG antibody and flaccid limb weakness. Paralyzed rabbits had pathological changes in their peripheral nerves identical with those present in Guillain-Barré syndrome. Immunization of mice with the lipooligosaccharide generated a mAb that reacted with GM1 and bound to human peripheral nerves. The mAb and anti-GM1 IgG from patients with Guillain-Barré syndrome did not induce paralysis but blocked muscle action potentials in a muscle-spinal cord coculture, indicating that anti-GM1 antibody can cause muscle weakness. These findings show that carbohydrate mimicry is an important cause of autoimmune neuropathy.

Anti-GM1 IgG antibodies induce leukocyte effector functions via Fcgamma receptors

Guillain-Barré syndrome (GBS) is an immune-mediated neuropathy, in which leukocytes and humoral components of the immune system proposedly initiate localized inflammation. An important pathogenic role for anti-GM1 ganglioside antibodies has been suggested. Therefore, we evaluated anti-GM1 IgG antibody-induced leukocyte effector functions such as degranulation and phagocytosis using serum of 24 GBS patients. Serum without anti-GM1 antibodies of 9 GBS patients as well as pooled serum from healthy individuals served as controls. Ten out of 15 (67%) of anti-GM1 IgG positive sera were capable of inducing leukocyte degranulation, and 8 out of 15 (53%) of anti-GM1 IgG positive sera were capable of inducing phagocytosis of GM1-coated beads. In all of these sera anti-GM1 antibody titers were >or=1:800. No leukocyte degranulation or phagocytosis was observed in control sera. Leukocyte activation was completely abrogated in the presence of IgG receptor (FcgammaR) blocking antibodies, suggesting a crucial role for leukocyte FcgammaR in GBS pathogenesis. No correlation of antibody titers with the extent of leukocyte activation, or severity of disease was observed. These data document the capacity of anti-GM1 IgG antibodies to activate leukocyte inflammatory functions, and suggest an important role for anti-ganglioside IgG antibodies in the pathogenesis of GBS.

Ganglioside mimicry of Campylobacter jejuni lipopolysaccharides determines antiganglioside specificity in rabbits

The core oligosaccharides of Campylobacter jejuni lipopolysaccharides (LPS) display molecular mimicry with gangliosides. Cross-reactive anti-LPS-antiganglioside antibodies have been implicated to show a crucial role in the pathogenesis of the Guillain-Barré and Miller Fisher syndrome. The specificity of the antiganglioside response is thought to depend on the oligosaccharide structure of the ganglioside mimic. To test this hypothesis and to investigate the potential of LPS from Campylobacter strains from enteritis patients to induce an antiganglioside response, we immunized rabbits with purified LPS from eight Campylobacter jejuni reference strains with biochemically well-defined distinct ganglioside mimics and determined the presence of antiganglioside antibodies. All rabbits produced immunoglobulin G (IgM) and IgG anti-LPS antibodies, and the specificity of the cross-reactive antiganglioside response indeed corresponded with the biochemically defined mimic. Most rabbits also had antibody reactivity against additional gangliosides, and there were slight differences in the fine specificity of the antibody response between rabbits that had been immunized with LPS from the same Campylobacter strain. High anti-LPS and antiganglioside titers persisted over a 10-month period. In conclusion, the structure of the LPS only partly determines the antiganglioside specificity. Other strain-specific as well as host-related factors influence the induction and fine-specificity of the cross-reactive anti-LPS-antiganglioside response.

High affinity as a disease determinant factor in anti-GM(1) antibodies: comparative characterization of experimentally induced vs. disease-associated antibodies

Elevated titers of serum anti-GM(1) antibodies of IgG isotype are found frequently in patients with Guillain-Barré syndrome. Much evidence indicates that these autoantibodies are involved in disease progression, but their exact function and the mechanism of their appearance are still unclear. In an attempt to reproduce "ganglioside syndrome", the experimental model of neuropathy developed by Nagai et al. (Neurosci. Lett. 2 (1976) 107), rabbits were intensively immunized with GM(1) in complete Freund adjuvant (CFA). High titers of anti-GM(1) antibodies were produced, with class switch and affinity maturation indicating an elaborate immune response. Unexpectedly, the rabbits did not show any clinical symptoms of neuropathy. Relatively affinities of both IgM and IgG antibodies were significantly lower than those of similar antibodies from neuropathy patients. These results suggest the existence of a threshold value above which affinity of anti-GM(1) antibodies becomes an important factor in disease induction. The absence of neuropathy symptoms in rabbits may be explained by absence of these high-affinity anti-GM(1) antibodies.

Acquired canine peripheral neuropathies

Accurate diagnosis of the many causes of acute and chronic peripheral neuropathy in the dog presents a challenging prospect for any clinician. Being able to accurately localize the observed neurologic signs to the peripheral nervous system is the first challenge. Once this is accomplished, a logical series of diagnostic steps should be pursued so as to have the best chance of reaching a final etiologic diagnosis. Specific therapy can then be instituted to attempt to halt or, in some cases, reverse the peripheral nerve dysfunction.

Infectious origins of, and molecular mimicry in, Guillain-Barré and Fisher syndromes

Guillain-Barré syndrome (GBS), characterised by limb weakness and areflexia, is the prototype of postinfectious autoimmune diseases, and Campylobacter jejuni is the most frequent antecedent pathogen. GBS subsequent to C jejuni enteritis is associated with a severe, pure motor axonal variant and IgG antibodies against GM1, GM1b, GD1a, or GalNAc-GDla, gangliosides expressed in human peripheral nerves. Lipopolysaccharides of C jejuni isolated from GBS patients have ganglioside-like epitopes. Cytomegalovirus is the most common viral antecedent infection. Patients with demyelinating GBS who have had a recent CMV infection have severe sensory deficits and anti-GM2 IgM antibody. CMV-infected fibroblasts express the GM2 epitope. Fisher syndrome (FS), characterised by ophthalmoplegia, ataxia, and areflexia, is a GBS variant associated with anti-GQ1b IgG antibody. GQ1b is enriched in the cranial nerves that innervate the extraocular muscles. Some patients develop FS after C jejuni infection, and the lipopolysaccharide present bears the GQ1b epitope. Molecular mimicry is a possible cause of GBS and FS.

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.

Guillain-Barré syndrome- and Miller Fisher syndrome-associated Campylobacter jejuni lipopolysaccharides induce anti-GM1 and anti-GQ1b Antibodies in rabbits

Campylobacter jejuni infections are thought to induce antiganglioside antibodies in patients with Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS) by molecular mimicry between C. jejuni lipopolysaccharides (LPS) and gangliosides. We used purified LPS fractions from five Campylobacter strains to induce antiganglioside responses in rabbits. The animals that received injections with LPS from GBS-associated strains developed anti-GM1 and anti-GA1 antibodies. Animals injected with LPS from one MFS-related C. jejuni strain produced anti-GQ1b antibodies. Rabbits that were injected with Penner O:3 LPS had a strong anti-LPS response, but no antiganglioside reactivity was observed. The antiganglioside specificity in the rabbits reflected the specificity in the patients from whom the strains were isolated. In conclusion, our results indicate that an immune response against GBS- and MFS-associated C. jejuni LPS results in antiganglioside antibodies. These results provide strong support for molecular mimicry as a mechanism in the induction of antiganglioside antibodies following infections.