Mycobacterium avium subsp. paratuberculosis Antigens Elicit a Strong IgG4 Response in Patients with Multiple Sclerosis and Exacerbate Experimental Autoimmune Encephalomyelitis

Abstract

Neuroinflammation can be triggered by microbial products disrupting immune regulation. In this study, we investigated the levels of IgG1, IgG2, IgG3, and IgG4 subclasses against the heat shock protein (HSP)70533–545 peptide and lipopentapeptide (MAP_Lp5) derived from Mycobacterium avium subsp. paratuberculosis (MAP) in the blood samples of Japanese and Italian individuals with relapsing remitting multiple sclerosis (MS). Additionally, we examined the impact of this peptide on MOG-induced experimental autoimmune encephalomyelitis (EAE). A total of 130 Japanese and 130 Italian subjects were retrospectively analyzed using the indirect ELISA method. Furthermore, a group of C57BL/6J mice received immunization with the MAP_HSP70533–545 peptide two weeks prior to the active induction of MOG35–55 EAE. The results revealed a significantly robust antibody response against MAP_HSP70533–545 in serum of both Japanese and Italian MS patients compared to their respective control groups. Moreover, heightened levels of serum IgG4 antibodies specific to MAP antigens were correlated with the severity of the disease. Additionally, EAE mice that were immunized with MAP_HSP70533–545 peptide exhibited more severe disease symptoms and increased reactivity of MOG35–55-specific T-cell compared to untreated mice. These findings provide evidence suggesting a potential link between MAP and the development or exacerbation of MS, particularly in a subgroup of MS patients with elevated serum IgG4 levels.

Epstein–Barr Virus and Human Endogenous Retrovirus in Japanese Patients with Autoimmune Demyelinating Disorders

“…To perform the peptide-based indirect ELISA, we employed the Imject maleimideactivated bovine serum albumin (BSA) spin kit from Thermo Fisher Scientific, Waltham, MA, USA, as previously published [19]. This kit was selected to ensure that antigenic epitopes remain accessible for antibody binding, preventing any masking effect.…”

“…It has been hypothesized that the EBV, a globally widespread γ-herpes virus capable of establishing latent infection with periodic reactivation, contributes to the pathogenesis of MS, either directly by infecting B cells [17] or indirectly by interacting with other genetic and environmental factors, such as the activation of neuropathogenic human endogenous retroviruses [18]. In a recent study conducted on Japanese and Sardinian subjects, we identified antibodies showing cross-reactivity between EBNA1 386-405 and a peptide belonging to Mycobacterium avium paratuberculosis heat shock protein 70 [19]. M. paratuberculosis is a bacterium endemic in the Sardinian Island, which has been proposed as a potential risk factor for MS in susceptible individuals, and its encephalitogenic potential in experimental autoimmune encephalomyelitis (EAE) has been demonstrated [19].…”

“…In a recent study conducted on Japanese and Sardinian subjects, we identified antibodies showing cross-reactivity between EBNA1 386-405 and a peptide belonging to Mycobacterium avium paratuberculosis heat shock protein 70 [19]. M. paratuberculosis is a bacterium endemic in the Sardinian Island, which has been proposed as a potential risk factor for MS in susceptible individuals, and its encephalitogenic potential in experimental autoimmune encephalomyelitis (EAE) has been demonstrated [19].…”