This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Mitchell, J P Articles by Tsokos, G C Search for Related Content PubMed PubMed Citation Articles by Mitchell, J P Articles by Tsokos, G C Social Bookmarking                   What's this?

Engagement of complement receptor 2 on the surface of B cells from patients with systemic lupus erythematosus contributes to the increased responsiveness to antigen stimulation

Department of Medicine, Walter Reed Army Medical Center, Washington, DC, USA

E J Enyedy

M P Nambiar

A Lees

Uniformed Services University of the Health Sciences, Bethesda, MD, USA

G C Tsokos

Department of Medicine, Walter Reed Army Medical Center, Washington, DC, USA; Department of Cellular Injury, Walter Reed Army Institute of Research, Silver Spring, MD, USA; WRAIR, Bldg 503, Rm 1A32 gtsokos{at}usa.net

B cells from patients with systemic lupus erythematosus (SLE) display increased responses following cross-linking of the surface antigen receptor. We explored the possibility that the increased responses are at least partially due to simultaneous cross-linking of the complement receptor 2 (CR2). To this end, we stimulated fresh B cells from SLE patients with an anti-IgD antibody conjugated to the Epstein–Barr virus gp350 protein, which binds to CR2, and recorded the free intracytoplasmic calcium response during the first 10 min. Despite the fact that SLE B cells were found to express half as many surface CR2 as normal B cells, both peak responses and the percentage of responding cells were significantly increased in the former. These observations suggest that regulatory molecules such as CR2 are involved in the increased B cell responses in SLE patients. We propose that certain immune complexes that circulate in the sera of SLE patients that have anti-surface immunoglobulin specificities and are decorated with natural ligands of CR2, such as C3d, elicit and promote B cell overactivity.

Key Words: B lymphocytes • B cell receptor • calcium responses • B cell overactivity • complement receptor • Epstein–Barr virus • lymphocyte signaling

Lupus, Vol. 11, No. 5, 299-303 (2002)
DOI: 10.1191/0961203302lu188oa


CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?