Vehicle control mice delivered 64·5 hr post injection and LPS-tre

Vehicle control mice delivered 64·5 hr post injection and LPS-treated mice delivered 7·7 hr post injection (P < 0·001) (Fig. 4a). Co-injection of LPS and Pyl A augmented delivery to 5·8 hr (mean) post injection

(Fig. 4a). This effect was more pronounced with a higher dose of Pyl A (500 μg) and lower dose of LPS (10 μg), shortening delivery time from 14·7 to 8·7 hr post injection (P < 0·01) (Fig. 4b). Although at 250 μg Pyl A alone did not induce labour, at 500 μg labour was induced at 44·8 hr post injection from 64·6 hr in the vehicle control group. None of the vehicle control-treated mice delivered preterm. We then determined if the CRTH2 agonist Pyl A maintained the same feto-protective effect as 15dPGJ2 by NVP-BEZ235 price examining fetal wellbeing at 4·5 hr post intrauterine injection of LPS with vehicle or Pyl A. Mice were anaesthetized and underwent a caesarean section. Fetuses were assessed click here for viability by assessment of colour and movement with or without mechanical stimulus.

A significant improvement in fetal viability was observed when LPS-treated mice were co-injected with Pyl A compared with LPS and vehicle control. There was a clear difference in the appearance between both groups, in that the LPS-treated mice were clearly dead with no respiratory effort, whereas the LPS/Pyl A-treated mice were pink, moved spontaneously or with stimulus, and had respiratory effort. Fetal survival was increased from 20% in LPS-treated mice to

100% in LPS/Pyl A-treated mice, (P < 0·0001) (Fig. 5a). However, Resminostat following spontaneous labour no pups were viable in the LPS-treated and LPS/Pyl A-treated groups (Fig. 5b). To explore the mechanisms behind Pyl A-augmented LPS-induced preterm labour, key mediators of inflammation in the myometrium were investigated. Myometrium and pup brain were harvested at 4·5 hr post intrauterine injection and Western blotting was used to detect whole cell phospho-p65 and COX-2. Administration of LPS did not lead to an increase in NF-κB in the myometrium; however, an increase was seen with co-administration of LPS and Pyl A (P < 0·05) (Fig. 6a). A reduction was seen in NF-κB in pup brain with LPS compared with vehicle control, with no increase with co-administration with Pyl A (Fig. 6b). No significant difference in COX-2 protein expression was seen between treatment groups in the myometrium or pup brain at this time-point (Fig. 6c,d). However, the messenger RNA of COX-2 was increased in the myometrium of dams treated with Pyl A and LPS compared with other treatment groups (Fig. 6e). We next sought to determine whether activation of NF-κB resulted in downstream activation of pro-inflammatory cytokines. As the CRTH2 agonist PGD2 induces the production of the Th2 cytokines IL-10 and IL-4 in human T cells,[22] we anticipated that Pyl A would lead to an increase in these anti-inflammatory cytokines and an inhibition of the pro-inflammatory cytokines.

This BAFF-R+ BM B-cell population shows higher levels of surface

This BAFF-R+ BM B-cell population shows higher levels of surface IgM expression and decreased RAG-2 transcripts than BAFF-R– immature B cells. When cultured, mouse BAFF-R–, but not BAFF-R+ immature B cells spontaneously undergo B-cell receptor editing. However, BAFF-R+ immature B cells cultured in the presence of an anti-κ light chain antibody are induced to undergo receptor editing. This receptor editing correlates with down-modulation of surface BAFF-R expression

and the up-regulation of RAG-2 at the RNA level. B-cell receptor (BCR) cross-linking on splenic T1 B cells results in down-modulation see more of the BAFF-R, and receptor editing and RAG-2 up-regulation in a minor fraction of B cells. BCR cross-linking on splenic T2/3 B cells results in partly down and partly up-modulation of BAFF-R expression and no evidence for receptor editing. Overall, our data indicate that BAFF-R expression is tightly regulated during B-cell development in mouse and human and its expression is correlated with positive selection. The random assembly of V, D and J immunoglobulin

(Ig) gene segments in developing lymphocytes results in the formation of an immense number of different B-cell receptors (BCRs) capable of recognizing a diverse antigen repertoire. However, this random assembly of BCRs can lead to the formation of Ig receptors that are either auto-reactive or functionally impaired. In general, such cells are excluded from the mature find more B-cell pool by negative selection. Receptor editing is an important salvage mechanism to eliminate cells bearing potentially auto-reactive or signaling-incompetent receptors, while at the same time preventing unnecessary deletion of cells. B cells expressing an inappropriate BCR can undergo secondary Ig gene rearrangements forming a BCR with a new specificity 1, 2. Thus, receptor editing plays a major role in both positive and negative selection 3. Knock-in experiments performed by the group of Nussenzweig 4 showed that about 25% of the mature B-cell pool is

derived from B cells that have undergone receptor editing. The main selection checkpoint for B cells seems to take place at the immature stage, Palbociclib cell line even though a first selection occurs already at the pre-B I cell stage. Appropriate signaling by the pre-BCR, which consists of μH and surrogate light (SL) chains, is important for the survival of pre-B I cells and their developmental progression to cycling large pre-B II cells, whereas insufficient pre-BCR signaling results in their developmental arrest 5. Ig light chain (LC) locus rearrangement takes place at the pre-B II cell stage, and the first cells expressing a complete BCR are newly formed immature B cells. Analyses of production and turnover rates revealed severe cell losses among immature B cells 6, 7. From the approximately 20 million immature B cells produced per day in the BM, only about 20% enters the periphery 6, 7. These findings indicate that strong selection takes place at the immature B-cell stage.