Endogenously produced catecholamines improve the regulatory function of TLR9-activated B cells

The sympathetic nervous system (SNS) contributes to immune balance by promoting anti-inflammatory B cells. However, whether B cells possess a self-regulating mechanism by which they modulate regulatory B cell (Breg) function is not well understood. In this study, we investigated the ability of B cells to synthesize their own catecholamines upon stimulation with different B cell activators and found that expression of the enzyme tyrosine hydroxylase (TH), required to generate catecholamines, is up-regulated by Toll-like receptor (TLR)9. This TLR9-dependent expression of TH correlated with up-regulation of adrenergic receptors (ADRs), enhanced interleukin (IL)-10 production, and overexpression of the co-inhibitory ligands programmed death ligand 1 (PD-L1) and Fas ligand (FasL). Moreover, concomitant stimulation of ß1-3-ADRs together with a B cell receptor (BCR)/TLR9 stimulus clearly enhances the anti-inflammatory potential of Bregs to suppress CD4 T cells, a crucial population in the pathogenesis of autoimmune diseases, like rheumatoid arthritis (RA). Furthermore, TH up-regulation was also demonstrated in B cells during the course of collagen-induced arthritis (CIA), a mouse model for the investigation of RA. In conclusion, our data show that B cells possess an autonomous mechanism to modulate their regulatory function in an autocrine and/or paracrine manner. These findings help to better understand the function of B cells in the regulation of autoimmune diseases and the interplay of SNS.

The sympathetic nervous system produces neurotransmitters such as catecholamines which contribute to immune balance by promoting anti-inflammatory B cells. This study shows that mouse B cells can themselves synthesize, sense, and transport catecholamines, which in turn modulate regulatory B cell function in an autocrine and/or paracrine manner to suppress T cell proliferation.     

Genome size and chromosomes in marine sponges [Suberites domuncula,Geodia cydonium]

The genome size of the marine sponges Suberites domuncula and Geodia cydonium has been determined by flow cytofluorometric analysis using diamidino-phenylindole [DAPI]. Using human lymphocytes as reference the amount of DNA in cells from S. domuncula has been determined to be 3.7 pg and that of G. cydonium 3.3 pg. While no chromosomes could be identified in G. cydonium, the karyotype of the Suberites domuncula is 32 chromsomes in the diploid state. The size of the chromosomes was between 0.25 and 1.0 μm. No pronounced banding pattern was visible.     

The thoracic muscular system and its innervation in third instar Calliphora vicina Larvae. II. Projection patterns of the nerves associated with the pro‐ and mesothorax and the pharyngeal complex

We describe the anatomy of the nerves that project from the central nervous system (CNS) to the pro‐ and mesothoracic segments and the cephalopharyngeal skeleton (CPS) for third instar Calliphora larvae. Due to the complex branching pattern we introduce a nomenclature that labels side branches of first and second order. Two fine nerves that were not yet described are briefly introduced. One paired nerve projects to the ventral arms (VAs) of the CPS. The second, an unpaired nerve, projects to the ventral surface of the cibarial part of the esophagus (ES). Both nerves were tentatively labeled after the structures they innervate. The antennal nerve (AN) innervates the olfactory dorsal organ (DO). It contains motor pathways that project through the frontal connectives (FC) to the frontal nerve (FN) and innervate the cibarial dilator muscles (CDM) which mediate food ingestion. The maxillary nerve (MN) innervates the sensory terminal organ (TO), ventral organ (VO), and labial organ (LO) and comprises the motor pathways to the mouth hook (MH) elevator, MH depressor, and the labial retractor (LR) which opens the mouth cavity. An anastomosis of unknown function exists between the AN and MN. The prothoracic accessory nerve (PaN) innervates a dorsal protractor muscle of the CPS and sends side branches to the aorta and the bolwig organ (BO) (stemmata). In its further course, this nerve merges with the prothoracic nerve (PN). The architecture of the PN is extremely complex. It innervates a set of accessory pharyngeal muscles attached to the CPS and the body wall musculature of the prothorax. Several anastomoses exist between side branches of this nerve which were shown to contain motor pathways. The mesothoracic nerve (MeN) innervates a MH accessor and the longitudinal and transversal body wall muscles of the second segment. J. Morphol. 271:969–979, 2010. © 2010 Wiley‐Liss, Inc.     

Regulation of cell behaviour by plant receptor kinases: Pattern recognition receptors as prototypical models

In this review we focus on pattern recognition receptors in plants that detect extracellular signals indicative for pathogen attack and injury. We start out with a discussion on FLS2, which binds and responds to bacterial flagellin, and then concentrate on ligand–receptor interactions as initial steps in the molecular receptor activation process. Comparison with other receptor kinases, whether involved in plant immunity or regulation of other cellular programs, might indicate common principles of receptor activation.     

Quantitative detection of siRNA and single-stranded oligonucleotides: relationship between uptake and biological activity of siRNA

The quantitative detection of oligomeric nucleic acids including short double-stranded RNA in cells and tissues becomes increasingly important. Here, we describe a method for the detection of siRNA in extracts prepared from mammalian cells, which is based on liquid hybridization with a ³²P-labelled probe followed by a nuclease protection step. The limit of detection of absolute amounts of siRNA is in the order of 10–100 amol. This methodology is suited to quantitatively follow the spontaneous uptake of siRNA by mammalian cells, i.e. without the use of carrier substances. This protocol may also be used to detect extremely low amounts of other kinds of short nucleic acids, including antisense oligonucleotides.