MAP3738c and MptD are specific tags of Mycobacterium avium subsp. paratuberculosis infection in type I diabetes mellitus

Mycobacterium avium subsp. paratuberculosis (Map) is the causative agent of Johne's disease, a chronic inflammation of ruminants' intestine. Recent studies have linked Map to type I Diabetes mellitus (T1DM). We searched the presence of antibodies against two specific proteins of Map (MptD and MAP3738c) in sera of patients affected by T1DM and type II Diabetes mellitus (T2DM). MptD protein (MAP3733c) has been recognized as a Map virulent factor whereas MAP3738c has not yet been studied. Both proteins are encoded by genes belonging to a Map specific pathogenicity island. Forty three T1DM patients' sera, 56 T2DM patients' sera and 48 healthy subjects' sera were screened by ELISA to evaluate the immunoresponse against MptD or MAP3738c recombinant proteins. Results showed a positive response to both proteins in T1DM patients whereas no difference with controls was found for T2DM patients. Results suggest a potential relation between T1DM and the bacterial infection.

Research highlights► Antibodies against MAP3733c and MAP3738c in T1DM and T2DM sera were searched. ► Both proteins are species-specific and belong to a MAP pathogenicity island. ► Sera from 43 T1DM patients, 56 T2DM patients and 48 healthy subjects were evaluated ► A significative response was observed in T1DM patients but not in T2DM ► A MAP specific humoral response in T1DM but not in T2DM patients was observed