Work

Kinetics of Human B Cell Behavior and Amplification of Proliferative Responses following Stimulation with IL-21

Year: 2006

Type: article

Abstract: Although recent studies indicated that IL-21 is an important regulator of human B cell activation, detailed comparison of the effects of IL-21 on distinct B cell subsets have not been performed. Our studies revealed that IL-21R is expressed by naive and germinal center B cells, but not memory or plasma cells. IL-21R was increased on naive and memory B cells following in vitro activation. Investigation into the kinetics and magnitude of responses of human B cells to IL-21 revealed that IL-21 potently augmented proliferation of CD40L-stimulated neonatal, splenic naive, and memory and tonsil germinal center B cells. This response exceeded that induced by IL-4, IL-10, and IL-13, cytokines that also induce B cell proliferation. Remarkably, CD40L/IL-21-stimulated naive B cells underwent the same number of divisions as memory cells and exhibited a greater enhancement in their response compared with CD40L alone than memory B cells. Therefore, IL-21 is a powerful growth factor for naive B cells. This may result from the higher expression of IL-21R on naive, compared with memory, B cells. Stimulation of human B cells with CD40L/IL-21 also induced IL-10 production and activation of STAT3. We propose that IL-21 may have therapeutic application in conditions of immunodeficiency where it could expand naive B cells, the predominant B cell subset in such patients. Conversely, because IL-21 is increased in murine models of lupus, dysregulated IL-21 production may contribute to perturbed B cell homeostasis observed in systemic lupus erythematosus. Thus, antagonizing IL-21 may be a novel strategy for treating Ab-mediated autoimmune diseases.

Source: The Journal of Immunology

DOI: 10.4049/jimmunol.177.8.5236

Authors: Kim L Good, Vanessa L Bryant, Stuart G Tangye

Institutions: The University of Sydney, Garvan Institute of Medical Research, Centenary Institute

Language: English

Topic: T-cell and B-cell Immunology

Subfield: Immunology

Field: Immunology and Microbiology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: bronze

Funders: Cancer Institute NSW, University of Sydney, Medical Research Council, National Health and Medical Research Council