Engagement of the B cell receptor for antigen differentially affects B cell responses to Toll-like receptor-7 agonists and antagonists in BXSB mice.

Nucleic acid sensors of the Toll-like receptor (TLR) family play a well-established role in the pathogenesis of lupus. This is particularly true for a single-stranded RNA-sensing TLR-7 receptor, as lupus mice lacking TLR-7 show ameliorated disease. Cytosine-guanosine dinucleotide (CpG)-DNA-sensing TLR-9, conversely, has a complex regulatory role in systemic lupus erythematosus (SLE). Much less is known about whether signals through the B cell receptor for antigen (BCR) may affect the ability of B cells to respond to suboptimal TLR-7 agonists and antagonists. We studied this question in prediseased BXSB male and female B cells. We found that male B cells responded more vigorously to numerous TLR-7 ligands and this responsiveness was enhanced further upon co-engagement of the BCR. This synergy was seen primarily with the interleukin (IL)-6 secretion. A number of 32-mer inhibitory oligonucleotides (INH-ODNs) with a nuclease-resistant phosphorothioate backbone were capable of blocking TLR-7, but not BCR-induced B cell activation, with an inhibitory concentration (IC)(50) of approximately 100 nm. Surprisingly, while the presence of a single TGC motif at the 5' end of an ODN did not increase its inhibitory capacity, INH-ODNs containing multiple TGC motifs had greater inhibitory potency. When BCR and TLR-7 were co-engaged, INH-ODNs showed a differential effect on B cell activation. Whereas apoptosis protection and G1-M entry completely escaped suppression, IL-6 secretion remained sensitive to inhibition, although with a 10-fold lower potency. Our results suggest that while TLR-7 antagonists may be considered as lupus therapeutics, simultaneous co-engagement of the TLR-7 and BCR might favour autoreactive B cell survival. This hypothesis needs further experimental validation.

B-cell receptor for antigen modulates B-cell responses to complex TLR9 agonists and antagonists: implications for systemic lupus erythematosus.

The capacity to make secondary structures significantly affects the ability of Toll-like receptor 9 (TLR9) agonists and antagonists to either induce or block TLR9-dependent activation in B cells. However, it has a minor impact on TLR9-induced activation in interferon alpha (IFNα)-producing dendritic cells. Based on the ability of inhibitory oligodeoxynucleotides to form predictable secondary structures, we have classified TLR9-antagonists into Class R ('restricted', palindromic) and Class B ('broadly reactive', linear) oligodeoxynucleotides. In non-autoreactive B cells, Class R oligodeoxynucleotides are at least 10-fold less potent TLR9-inhibitors. We wanted to determine whether engagement of the B-cell receptor for antigen could overcome this restriction. Here we show that in non-autoreactive mouse B cells, B-cell receptor for antigen engagement increased the potency of Class R oligodeoxynucleotides for TLR9 activation at least 10-fold, making it equal in potency to linear oligodeoxynucleotides. However, this enhanced potency was selective for TLR9-induced B-cell cycling and apoptosis protection while TLR9-induced IL-6, an event that strongly depends on signaling via late endosomes, still required 10 times more Class R oligodeoxynucleotides. Thus, pathway-specific effects of Class R oligodeoxynucleotides for TLR9/B-cell receptor for antigen co-stimulated B cells may have therapeutic advantages over non-selective targeting of B cells, a strategy that may be seen as a potential therapy for human systemic lupus erythematosus.

Urinary tract status of patients with neurogenic dysfunction presenting with upper tract stone disease.

We treated 71 patients with neurogenic vesical dysfunction between September 1983 and June 1990 for upper tract stones. We studied these patients to determine the time course of stone development and the presence of associated urological abnormalities. There were 44 male and 27 female patients 6 to 72 years old. Lower urinary tract dysfunction resulted from spinal cord injuries in 34 patients (48%), myelodysplasia in 19 (27%), multiple sclerosis in 12 (17%) and other diagnoses in 6 (8%). Of 71 patients 21 (30%) were managed by an ileal loop, 12 (17%) by a Foley catheter, 10 (14%) by a suprapubic tube, 10 (14%) by ureterostomy, 5 (7%) by vesicostomy, 8 (11%) by intermittent catheterization, and 5 (7%) by diaper, Créde's voiding or condom catheterization. Stone disease developed within 1 to 22 years. Patients with an indwelling catheter or supravesical diversion fared worse than those managed by intermittent catheterization or vesicostomy; they had higher rates of renal unit loss, renal parenchymal damage, decreased renal function, hydroureter, and staghorn and bilateral calculi. All of the listed methods of management were contemporaneous, suggesting the continued use of methods proved to be associated with upper tract deterioration.