Soluble BAFF-R produced by decidual stromal cells plays an inhibitory role in monocytes and macrophages

Abstract

A sophisticated immunological regulation between decidual stromal cells (DSC) and monocytes and macrophages is essential for the successful symbiosis of the mother and her fetus, but the mechanisms remain incompletely understood. The mRNA and proteins of B lymphocyte stimulator (BAFF, also known as BLys) and its receptor, BAFF-R (also known as BR3, CD268 or TNFRSF17), have been detected in both first-trimester and term placentas, but whether BAFF or BAFF-R participates in the cross-talk between DSC and monocytes and macrophages in the first-trimester pregnancy has not been described. This study found that purified DSC extensively shed BAFF-R and that polyinosinic:polycytidylic acid (poly(I:C); a synthetic toll-like receptor (TLR) 3 agonist) dramatically up-regulated BAFF-R secretion, suggesting that release of these soluble proteins was an inherent property of DSC and its induction might have relevance to TLR-3-mediated signal transduction. When monocytes were cultured with the supernatants of resting DSC or poly(I:C)-treated DSC, the proliferation of CD14(+)HLA-DR(+) monocytes (P=0.025 and 0.045) and the secretion levels of tumour necrosis factor α (P=0.035 and 0.031) and interleukin 6 (P=0.021 and 0.035) were significantly increased after the BAFF-R was blocked. Soluble BAFF-R may play inhibitory roles in monocytes and macrophages.

Analysis of serum B cell‐activating factor from the tumor necrosis factor family (BAFF) and its soluble receptors in systemic lupus erythematosus

“…The same group showed that sBCMA can also be shed by plasmacytoid dendritic cells via a similar γ‐secretase‐dependent cleavage . One study has reported the existence of sBAFF‐R, a soluble form of the receptor released by human decidual stromal cells ex vivo , and an inhibitory role in the regulation of interleukin (IL)‐6 and TNF secretion by monocytes has been suggested . Some published studies have reported the presence of soluble forms of BAFF receptors in human serum.…”

“…9 One study has reported the existence of sBAFF-R, 10 a soluble form of the receptor released by human decidual stromal cells ex vivo, and an inhibitory role in the regulation of interleukin (IL)-6 and TNF secretion by monocytes has been suggested. 10 Some published studies have reported the presence of soluble forms of BAFF receptors in human serum. All three soluble BAFF receptors have been reported in rheumatoid arthritis, 11 and sTACI and sBCMA have been described in multiple sclerosis, multiple myeloma and patients with chronic lymphocytic leukaemia.…”

Physiological Changes in the Levels of Anti-Cytokine Autoantibodies in Early Pregnancy Are Missing in Pregnant Women with Hashimoto’s Thyroiditis

“…It has recently been reported that the placenta secretes BAFF. Both in early and term pregnancies BAFF accompanied by its receptor could be detected in the placenta [45]. Trophoblasts and stromal cells of the decidua were shown to express BAFF.…”

“…Trophoblasts and stromal cells of the decidua were shown to express BAFF. Furthermore, BAFF-R secretion was suggested to be an inherent property of decidual stromal cells [45], and this soluble BAFF-R might inhibit the functions of macrophages. Therefore, the BAFF system might play a vital role in the successful pregnancies.…”