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Dieser Beitrag soll aufzeigen, dass eine chthonische und eschatologische Dimension der dionysischen Göttlichkeit in verschiedenen Riten und Kulten des Gottes nachgewiesen werden kann und dabei keinesfalls mysterienexklusiv ist. Dazu soll der archäologische Befund, der Dionysos mit dem Jenseits und eschatologischen Ho nungen in Verbindung bringt, vorgestellt und untersucht werden. Darauf aufbauend soll belegt werden, dass diese jenseitige Dimension sich sowohl in Riten mit privatem Kern, hier am Beispiel der Oreibasia, als auch in Kultfeiern des ö entlichen Festkanons, wie den Anthesterien, zeigt. Abschließend soll dann Dionysos‘ Funktion in den eleusinischen Mysterien untersucht werden. This paper aims to show that a chthonic and eschatological dimension of dionysiac divinity can be found in various rites and cults of the god and that this is not exclusive for the mysteries. Recent archaeological evidence connecting Dionysos with the afterlife and eschatological expectations will be introduced and analyzed. is dimension manifests itself in rites with a private intent (e.g. the Oreibasia) as well as public celebrations of the festival calendar (e.g. the Anthesteria). An analysis of Dionysos’ function in the eleusinian mysteries concludes the overview.

Abstract Ligation of the B cell antigen receptor (BCR) initiates humoral immunity. However, BCR signaling without appropriate co-stimulation commits B cells to death rather than to differentiation into immune effector cells. How BCR activation depletes potentially autoreactive B cells while simultaneously primes for receiving rescue and differentiation signals from cognate T lymphocytes remains unknown. Here, we use a mass spectrometry-based proteomic approach to identify cytosolic/nuclear shuttling elements and uncover transcription factor EB (TFEB) as a central BCR-controlled rheostat that drives activation-induced apoptosis, and concurrently promotes the reception of co-stimulatory rescue signals by supporting B cell migration and antigen presentation. CD40 co-stimulation prevents TFEB-driven cell death, while enhancing and prolonging TFEB’s nuclear residency, which hallmarks antigenic experience also of memory B cells. In mice, TFEB shapes the transcriptional landscape of germinal center B cells. Within the germinal center, TFEB facilitates the dark zone entry of light-zone-residing centrocytes through regulation of chemokine receptors and, by balancing the expression of Bcl-2/BH3-only family members, integrates antigen-induced apoptosis with T cell-provided CD40 survival signals. Thus, TFEB reprograms antigen-primed germinal center B cells for cell fate decisions.

The generation, differentiation, survival and activation of B cells are coordinated by signals emerging from the B cell antigen receptor (BCR) or its precursor, the pre-BCR. The adaptor protein SLP65 (also known as BLNK) is an important signaling factor that controls pre-B cell differentiation by down-regulation of PI3K signaling. Here, we investigated the mechanism by which SLP65 interferes with PI3K signaling. We found that SLP65 induces the activity of the small GTPase RHOA, which activates PTEN, a negative regulator of PI3K signaling, by enabling its translocation to the plasma membrane. The essential role of RHOA is confirmed by the complete block in early B cell development in conditional RhoA-deficient mice. The RhoA-deficient progenitor B cells showed defects in activation of immunoglobulin gene rearrangement and fail to survive both in vitro and in vivo. Reconstituting the RhoA-deficient cells with RhoA or Foxo1, a transcription factor repressed by PI3K signaling and activated by PTEN, completely restores the survival defect. However, the defect in differentiation can only be restored by RhoA suggesting a unique role for RHOA in B cell generation and selection. In full agreement, conditional RhoA-deficient mice develop increased amounts of autoreactive antibodies with age. RHOA function is also required at later stage, as inactivation of RhoA in peripheral B cells or in a transformed mature B cell line resulted in cell loss. Together, these data show that RHOA is the key signaling factor for B cell development and function by providing a crucial SLP65-activated link between BCR signaling and activation of PTEN. Moreover, the identified essential role of RHOA for the survival of transformed B cells offers the opportunity for targeting B cell malignancies by blocking RHOA function.

Epitope tags are widely used in various applications, but often lack versatility. Here, the authors introduce a small, alpha helical tag, which is recognized by a high affinity nanobody and can be used in a range of different applications, from protein purification to super-resolution imaging and in vivo detection of proteins.

Signalling of the B cell receptor (BCR) is pivotal for survival and activation of naïve B cells. Here the authors show, using super-resolution microscopy techniques, that BCRs exist primarily as monomers and dimers in resting B cells, and oligomerize only on stimulation, thereby implicating a function of BCR clustering patterns on B cell biology.