Interleukin-33-induced expression of PIBF1 by decidual B cells protects against preterm labor.
Preterm birth (PTB) is a leading cause of neonatal death worldwide. Intrauterine and systemic infection and inflammation cause 30-40% of spontaneous preterm labor (PTL), which precedes PTB. Although antibody production is a major immune defense mechanism against infection, and B cell dysfunction has been implicated in pregnancy complications associated with PTL, the functions of B cells in pregnancy are not well known. We found that choriodecidua of women undergoing spontaneous PTL harbored functionally altered B cell populations. B cell-deficient mice were markedly more susceptible than wild-type (WT) mice to PTL after inflammation, but B cells conferred interleukin (IL)-10-independent protection against PTL. B cell deficiency in mice resulted in a lower uterine level of active progesterone-induced blocking factor 1 (PIBF1), and therapeutic administration of PIBF1 mitigated PTL and uterine inflammation in B cell-deficient mice. B cells are a significant producer of PIBF1 in human choriodecidua and mouse uterus in late gestation. PIBF1 expression by B cells is induced by the mucosal alarmin IL-33 (ref. 9). Human PTL was associated with diminished expression of the α-chain of IL-33 receptor on choriodecidual B cells and a lower level of active PIBF1 in late gestation choriodecidua. These results define a vital regulatory cascade involving IL-33, decidual B cells and PIBF1 in safeguarding term pregnancy and suggest new therapeutic approaches based on IL-33 and PIBF1 to prevent human PTL.
Huang B, Faucette AN, Pawlitz MD, Pei B, Goyert JW, Zhou JZ, El-Hage NG, Deng J, Lin J, Yao F, Dewar RS 3rd, Jassal JS, Sandberg ML, Dai J, Cols M, Shen C, Polin LA, Nichols RA, Jones TB, Bluth MH, Puder KS, Gonik B, Nayak NR, Puscheck E, Wei WZ, Cerutti A, Colonna M, Chen K. Interleukin-33-induced expression of PIBF1 by decidual B cells protects against preterm labor. Nat Med. 2017 Jan;23(1):128-135. doi: 10.1038/nm.4244. Epub 2016 Dec 5. PMID: 27918564; PMCID: PMC5512431.