Reaction of antibodies to Campylobacter jejuni and cytolethal distending toxin B with tissues and food antigens

ARTICLE HIGHLIGHTS

Research background

The bacteria Campylobacter jejuni (C. jejuni) is commonly associated with GBS and IBS, but studies have also linked it with Miller Fisher syndrome, reactive arthritis and other disorders, some of which are autoimmune. It is possible that C. jejuni and its toxins may be cross-reactive with some human tissues and food antigens, potentially leading to autoimmune responses. Cross-reaction between C. jejuni antigens and different transglutaminases may indicate the involvement of C. jejuni not only in the induction of small intestine bacterial overgrowth (SIBO)/irritable bowel syndrome (IBS) but of celiac disease (CD) and nonceliac gluten sensitivity (NCGS) as well. C. jejuni is very often used for the demonstration of the bi-directional signaling that exists between the gastrointestinal tract and the brain. The disruption of the gut-brain axis has been implicated in the etiopathogenesis or manifestation of a diverse range of neurodevelopmental, psychiatric, and neurodegenerative diseases. In turn, common pathophysiological mechanisms have been associated with gastrointestinal comorbidity. Everything is interconnected.

Research motivation

Our earlier research showed that antibodies against amyloid-beta peptide reacted strongly with different tissue and food antigens. Infections have been shown to be involved in the pathogenesis of various disorders. Our earlier study showed that anti-amyloid-beta-42 antibody reacted very strongly with C. jejuni cytolethal distending toxin (Cdt). C. jejuni and its toxins have been shown to be involved not only in IBS, Guillain-Barré syndrome (GBS), SIBO, Miller Fisher syndrome and the like, but in various extragastrointestinal conditions as well, including some that involve the brain. This inspired us to investigate whether perhaps C. jejuni and its toxins were reacting to certain tissues or foods, resulting in food reactivity, molecular mimicry, or even autoimmunity and neurodegenerative disorders. One of the most crucial problems was finding reagents of sufficient quality and purity in order to achieve accurate and reliable results in our study’s testing, and we tried different sources before finally finding and using mouse monoclonal anti-C. jejuni and rabbit affinity-purified anti-C. jejuni Cdt isotypes. This enabled our study to accurately detect and measure antibody levels to a degree that had not previously been possible, and the employment of high quality highly-purified reagents should greatly increase the accuracy of similar lab testing or even lab testing in general in future research. The findings of our study regarding immunoreactivity of C. jejuni and its Cdt antibodies with many human tissues and food antigens may indicate a more widespread role of this bacteria in many autoimmune and neurodegenerative disorders. This deserves the initiation of further studies.

Research objectives

To measure the immune reactivity of C. jejuni and C. jejuni Cdt antibodies with tissue and food antigens to examine their role in autoimmunities.

Research methods

Using enzyme-linked immunosorbent assay (ELISA) methodology, specific antibodies made against C. jejuni and C. jejuni Cdt were applied to a variety of microwell plates coated with 45 tissues and 180 food antigens. The resulting immunoreactivities were compared to reactions with control wells coated with human serum albumin (HSA) which were used as negative controls and with wells coated with C. jejuni lysate or C. jejuni Cdt which served as positive controls.

Research results

Monoclonal antibody made against C. jejuni showed moderate to high reactions with zonulin, somatotropin, acetylcholine receptor, β-amyloid and presenilin. This immune reaction was low with an additional 25 tissue antigens, and the same antibody did not react at all with another 15 tissue antigens. Examining the reaction between C. jejuni antibody and 180 food antigens, we found insignificant reactions with 163 foods but low to high immune reactions with 17 food antigens. Similarly, with C. jejuni Cdt antibody, the reactions with tissues were strongest with zonulin, intrinsic factor and somatotropin, moderate with 9 different tissue antigens including thyroid peroxidase, low with another 10 different antigens, including neuronal antigens, and insignificant with an additional 23 tissue antigens. Between C. jejuni Cdt antibody and different food antigens, 160 out of 180 foods showed insignificant reactions, while 20 foods showed reactions ranging from low to high. Further research with the proper reagents and samples from patients with autoimmune and neurodegenerative disorders can lead to the clinical application of the methods and specific antibody tests used in this study.

Research conclusions

C. jejuni and its toxins are involved in different autoimmune and neurodegenerative disorders beyond the gut. C. jejuni and its toxins play a major role in a variety of autoimmune and neurodegenerative disorders through molecular mimicry. Many investigators have clearly established C. jejuni as the most prevalent cause of food-related enteritis worldwide. It has been associated with a range of gastrointestinal conditions, including inflammatory bowel disease (IBD), Barrett’s esophagus, and colorectal cancer, and has also been reported to be involved in extragastrointestinal manifestations, including bacteremia, lung infections, brain abscesses, meningitis, and reactive arthritis. Monoclonal and affinity-purified antibodies against C. jejuni and its toxins have moderate to strong reactions with a variety of tissue and food antigens. Studies have shown that chronic exposure to C. jejuni and its toxin Cdt could induce epithelial cell damage, facilitating not only bacterial invasion but also the penetration of undigested food antigens into the submucosa and into the circulation. This body exposure to these external triggers may initiate an immune response in which antibody production against the bacterial food toxins and food antigens may result in cross-immunoreactivity with a variety of tissue antigens, thereby setting the stage for multiple autoimmune reactivities beyond the gut. Reaction of antibodies against C. jejuni and its toxins with tissue and food antigens, which has not previously been studied. The reaction of C. jejuni and C. jejuni Cdt with different tissue antigens, including neural tissues, and different food antigens were made possible by finding the proper reagents of high quality and purity. The results of our study confirmed that there is cross-reactivity between C. jejuni and its toxins with other tissue antigens as well as food proteins to which the human body is exposed on a daily basis. This reaction may be due to molecular mimicry and may contribute to the pathogenesis of autoimmune and neurodegenerative disorders. Treatment for C. jejuni should therefore be a part of the strategy for prevention and treatment of autoimmune and neurodegenerative disorders.

Research perspectives

The availability and use of excellent and highly purified reagents such as monoclonal mouse and affinity-purified rabbit antibodies can help us to accurately detect and measure in the blood levels of antibodies that had previously been overlooked or ignored but which may actually have important roles in devastating diseases. The reaction of antibodies made against Campylobacter jejuni with so many human tissues and food antigens encourages future research in the role that this organism may play in multiple autoimmune diseases. Future research should seek to further confirm the involvement of C. jejuni and its toxins in autoimmune and neurodegenerative disorders, and then expand the search to examine the possible involvement of other pathogens. The best method for ensuring the most accurate and reliable results in testing for C. jejuni and other pathogens is to use only specific antibodies that are of high quality and high purity.