Web supplement to

Proteome analysis of B-cell maturation

Johanna M. Salonen ¹ , Leena Valmu ² , Gunilla Rönnholm ² , Nisse Kalkkinen ² , Mauno Vihinen ^{1 3 *}

¹ Institute of Medical Technology, University of Tampere, Tampere, Finland
² Institute of Biotechnology, University of Helsinki, Helsinki, Finland
³ Research Unit, Tampere University Hospital, Tampere, Finland

e-mail: Mauno Vihinen ( mauno.vihinen@uta.fi )

* Correspondence to

Mauno Vihinen, Institute of Medical Technology, University of Tampere, FI-33014 Tampere, Finland Fax: +358-3-35517710

Keywords :

B-cell maturation, Immunology, Ramos, Two-dimensional gel electrophoresis

Abstract

Proteins affected by anti-mIgM stimulation during B-cell maturation were identified using 2-DE-based proteomics. We investigated the proteome profiles of stimulated and nonstimulated Ramos B-cells at eight time points during 5 d and compared the obtained proteomic data to the corresponding data from DNA-microarray studies. Anti-mIgM stimulation of the cells resulted in significant differences ( twofold) in the protein abundance close to 100 proteins and differences in post-translational protein modifications. Forty-eight up- or down-regulated proteins were identified by mass spectrometric methods and database searches. The identities of a further nine proteins were revealed by comparing their positions to the known proteins in other lymphocyte 2-DE databases. Several of the proteins are directly related to the functional and morphological characteristics of B-cells, such as cytoskeleton rearrangement and intracellular signalling triggered by the crosslinking of B-cell receptors. In addition to proteins known to be involved in human B-cell maturation, we identified several proteins that were not previously linked to lymphocyte differentiation. The results provide deeper insights into the process of B-cell maturation and may lead to novel therapeutic strategies for immunodeficiencies. An interactive 2-DE reference map is available at http://bioinf.uta.fi/BcellProteome.

PROTEOMICS, Volume 6, Issue 19 (p 5152-5168)
DOI 10.1002/pmic.200600156