Interleukin-21 restores immunoglobulin production ex vivo in patients with common variable immunodeficiency and selective IgA deficiency

S Borte, Q Pan-Hammarström, C Liu… - Blood, The Journal …, 2009 - ashpublications.org
S Borte, Q Pan-Hammarström, C Liu, U Sack, M Borte, U Wagner, D Graf, L Hammarström
Blood, The Journal of the American Society of Hematology, 2009ashpublications.org
Abstract Interleukin-21 (IL-21) is an important promoter for differentiation of human B cells
into immunoglobulin (Ig)–secreting cells. The objective of this study was to evaluate an IL-21–
based approach to induce immunoglobulin production in B cells from patients with common
variable immunodeficiency (CVID) or selective IgA deficiency (IgAD). We show that a
combination of IL-21, IL-4, and anti-CD40 stimulation induces class-switch recombination to
IgG and IgA and differentiation of Ig-secreting cells, consisting of both surface IgG+ (sIgG+) …
Abstract
Interleukin-21 (IL-21) is an important promoter for differentiation of human B cells into immunoglobulin (Ig)–secreting cells. The objective of this study was to evaluate an IL-21–based approach to induce immunoglobulin production in B cells from patients with common variable immunodeficiency (CVID) or selective IgA deficiency (IgAD). We show that a combination of IL-21, IL-4, and anti-CD40 stimulation induces class-switch recombination to IgG and IgA and differentiation of Ig-secreting cells, consisting of both surface IgG+ (sIgG+) and sIgA+ B cells and CD138+ plasma cells, in patients with CVID or IgAD. Stimulation with IL-21 was far more effective than stimulation with IL-4 or IL-10. Moreover, spontaneous apoptosis of CD19+ B cells from patients with CVID or IgAD was prevented by a combination of IL-21, IL-4, and anti-CD40 stimulation. Analysis of IL-21 and IL-21 receptor (IL-21R) mRNA expression upon anti-CD3 stimulation of T cells, however, showed no evidence for defective IL-21 expression in CVID patients and sequencing of the coding regions of the IL21 gene did not reveal any mutations, suggesting a regulatory defect. Thus, our work provides an initial basis for a potential therapeutic role of IL-21 to reconstitute immunoglobulin production in CVID and IgAD.
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