Volume 9 Supplement 2
Loss of IL-10 secretion by regulatory B lymphocytes in multiple sclerosis patients
© Michel et al; licensee BioMed Central Ltd. 2011
Published: 23 November 2011
Recently, an alternative role of B cells has emerged. Regulatory B cells have been shown to down-regulate immune responses in mice and humans. These cells control disease progression in several models of human autoimmune diseases, including a model of Multiple Sclerosis (MS). Their regulatory function mostly relies on their capacity to produce IL-10.
Our aim was to explore the frequency, the phenotype and the functional properties of regulatory B cells in MS patients compared to Healthy Volunteers (HV).
All patients suffered from MS and had not received immune drugs since at least 6 months. The frequency and the phenotype of B cell subsets have been analysed using different specific markers: CD19+CD27+ memory B cells, CD19+CD38dimCD24dim mature naïve B cells and CD19+CD24highCD38high transitional B cells. Their capacity to secrete IL-10 was analysed in vitro 48 hours after stimulation by CD40 ligand and CpG ODN.
Thirty-eight MS patients (mean age: 41.55±12.8 yrs) and 21 HV (mean age: 35.4±13.4 yrs, NS) have been included. The patients had different MS forms: Clinically Isolated Syndrome (n=5), Relapsing-Remitting (n=23), Secondary Progressive (n=4) and Primary Progressive (n=6).
No significant difference was found for the frequency of the different B cell subsets in the different subgroups of patients. Particularly, MS patients harbor the same number (in frequency and absolute value) of CD19+CD24highCD38high transitional B cells. However, the frequency of IL-10 secreting B cells was significantly decreased in MS patients (0.9±0.5%, n=9) compared to HV (2±0.95%, n=10, p<0.05, Mann Whitney test).
MS patients display the same frequency of CD19+CD24highCD38high transitional B cells, described as having regulatory properties. Nevertheless, B cells of MS patients present a significant decreased secretion of IL-10, supporting a defect in the B cells regulatory property. If confirmed, these results could have a considerable impact for the development of new therapeutic strategies.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.