Reports from National Institute of Arthritis and Musculoskeletal and Skin Disease highlight recent research in immunology
2007 NOV 20 -- Fresh data on immunology are presented in the report 'Essential role of IL-21 in B cell activation, expansion, and plasma cell generation during CD4+ T cell-B cell collaboration.' According to recent research published in the Journal of Immunology, "During T cell-B cell collaboration, plasma cell (PC) differentiation and Ig production are known to require T cell-derived soluble factors. However, the exact nature of the cytokines produced by activated T cells that costimulate PC differentiation is not clear." "Previously, we reported that costimulation of purified human B cells with IL-21 and anti-CD40 resulted in efficient PC differentiation. In this study, we addressed whether de novo production of IL-21 was involved in direct T cell-induced B cell activation, proliferation, and PC differentiation. We found that activated human peripheral blood CD4(+) T cells expressed mRNA for a number of cytokines, including IL-21, which was confirmed at the protein level. Using a panel of reagents that specifically neutralize cytokine activity, we addressed which cytokines are essential for B cell activation and PC differentiation induced by anti-CD3-activated T cells. Strikingly, neutralization of IL-21 with an IL-21R fusion protein (IL-21R-Fc) significantly inhibited T cell-induced B cell activation, proliferation, PC differentiation, and Ig production. Inhibition of PC differentiation was observed even when the addition of IL-21R-Fc was delayed until after initial B cell activation and expansion had occurred. Importantly, IL-21 was found to be involved in PC differentiation from both naive and memory B cells. Finally, IL-21R-Fc did not inhibit anti-CD3-induced CD4(+) T cell activation, but rather directly blocked T cell-induced B cell activation and PC differentiation," wrote S. Kuchen and colleagues, National Institute of Arthritis and Musculoskeletal and Skin Disease. The researchers concluded: "These data are the first to document that B cell activation, expansion, and PC differentiation induced by direct interaction of B cells with activated T cells requires IL-21." Kuchen and colleagues published their study in the Journal of Immunology (Essential role of IL-21 in B cell activation, expansion, and plasma cell generation during CD4+ T cell-B cell collaboration. Journal of Immunology, 2007;179(9):5886-96). For additional information, contact S. Kuchen, National Institutes of Health, Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892 USA.. The publisher's contact information for the Journal of Immunology is: American Association Immunologists, 9650 Rockville Pike, Bethesda, MD 20814, USA. Keywords: United States, Bethesda, Immunology. This article was prepared by Life Science Weekly editors from staff and other reports. Copyright 2007, Life Science Weekly via NewsRx.com.
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