Determination of the immunodominant part in the O-antigenic polysaccharide from Escherichia coli O128 by ELISA-inhibition study

Serum anti-Glc(α1,4)Glc(α) antibodies as a biomarker for relapsing–remitting multiple sclerosis

There is an unmet need to develop specific biomarkers for multiple sclerosis (MS) to aid in the diagnosis, improve the management of patients and the monitoring of the effectiveness of treatment. We have screened serum from patients with relapsing-remitting MS (RRMS, n = 107) against a library of glycans on a glycan chip, and have found significantly higher levels of IgM anti-Glc(alpha1,4)Glc(alpha) antibodies (anti-Galpha4Galpha antibodies) than in patients suffering from other neurological diseases (OND, n = 50, p < 0.0001), and other autoimmune diseases (OAD, n = 27, p = 0.02). No significant differences were found relative to patients having primary progressive MS (n = 16). No significant differences were detected between the levels of IgM anti-Galpha4Galpha antibodies in sera from patients with RRMS in relapsing versus remitting state, and in patients treated with immunotherapy versus untreated patients. To test whether the highly significant difference in the levels of IgM anti-Galpha4Galpha between RRMS and OND group is due to general increase in IgM levels, we have measured total serum IgM in a subgroup of 62 MS and 48 OND patients. Although the total IgM was significantly lower in the OND than the RRMS group (p = 0.0007), analysis of covariance (ANCOVA) reveled no statistically significant relationship to the covariate (total IgM). Furthermore, following normalizing the values to total IgM the difference in the levels of IgM anti-Galpha4Galpha between the MS and OND groups was found highly significant (p < < 0.0001). The present findings support further assessment of serum anti-Galpha4Galpha antibodies as a potential biomarker for MS, which may confirm disease diagnosis and aid in its management.

Sequence of Escherichia coli O128 antigen biosynthesis cluster and functional identification of an alpha-1,2-fucosyltransferase

O128 is one of the most common atypical enteropathogenic Escherichia coli isolated from diarrhea patients worldwide. The primary structure of E. coli O128 repeat units has previously been determined as -->3)-beta-D-GalNAc-(1-->4)-alpha-D-Gal-(1-->3)-beta-D-GalNAc-(1-->6)-[alpha-L-Fuc-(1-->2)]-beta-D-Gal-(1--> pentasaccharide. Here we report the complete sequencing of E. coli O128 antigen biosynthesis gene cluster and its flanking regions. Comparative sequence analysis revealed the expected O128 antigen process genes, GDP-fucose biosynthesis genes and four potential glycosyltransferase genes responsible for the assembly of E. coli O128 antigen repeats. WbsJ was shown to encode an alpha-1,2-fucosyltransferase by enzymatic assays and nuclear magnetic resonance spectroscopy analysis.