Apoptotic B cells: their interactions with macrophages and modulation by rituximab

Apoptotic cells (AC) are able to modulate the immune system, dampening inflammation and triggering anti-inflammatory responses by various immune cells as a consequence of interaction and uptake. Rituximab (RTX) is an anti-CD20 monoclonal antibody used as a treatment in several autoimmune diseases, including rheumatoid arthritis (RA). Treatment results in B cell depletion, with B cell apoptosis known to contribute to RTX-mediated B cell death. However the simple removal of B cells from the system does not seem to account for all the beneficial effects of this biologic. We propose that RTX treatment in RA results in the re-establishment of temporary tolerance to the system, through an apoptotic B cell-dependent mechanism. Initial in vitro and in vivo investigations were undertaken to explore the validity of this hypothesis. The present work sought to examine the immunomodulatory capacity of apoptotic B cells and to determine whether the potential anti-inflammatory effects of apoptotic B cells are modulated by RTX, with both in vitro methods and an in vivo model of autoimmunity utilized in these studies. The results presented in this thesis demonstrate that apoptotic B cells have comparable effects on bone marrow derived macrophage (BMDM) phenotype and function in vitro as previously described AC from other cellular sources. Surprisingly, in the in vitro assay system used, viable cells had the same immunomodulatory effects on BMDM as AC, for all criteria investigated. Preliminary studies indicate this may be a promising avenue of inquiry, however further work is needed before a conclusion can be reached as to the relative level of involvement of apoptotic B cell-mediated tolerance in the improvement seen on RTX treatment in RA

The IκB-protein BCL-3 controls toll-like receptor-induced MAPK activity by promoting TPL-2 degradation in the nucleus

Proinflammatory responses induced by Toll-like receptors (TLRs) are dependent on the activation of the NF-ĸB and mitogen-activated protein kinase (MAPK) pathways, which coordinate the transcription and synthesis of proinflammatory cytokines. We demonstrate that BCL-3, a nuclear IĸB protein that regulates NF-ĸB, also controls TLR-induced MAPK activity by regulating the stability of the TPL-2 kinase. TPL-2 is essential for MAPK activation by TLR ligands, and the rapid proteasomal degradation of active TPL-2 is a critical mechanism limiting TLR-induced MAPK activity. We reveal that TPL-2 is a nucleocytoplasmic shuttling protein and identify the nucleus as the primary site for TPL-2 degradation. BCL-3 interacts with TPL-2 and promotes its degradation by promoting its nuclear localization. As a consequence, Bcl3−/− macrophages have increased TPL-2 stability following TLR stimulation, leading to increased MAPK activity and MAPK-dependent responses. Moreover, BCL-3–mediated regulation of TPL-2 stability sets the MAPK activation threshold and determines the amount of TLR ligand required to initiate the production of inflammatory cytokines. Thus, the nucleus is a key site in the regulation of TLR-induced MAPK activity. BCL-3 links control of the MAPK and NF-ĸB pathways in the nucleus, and BCL-3–mediated TPL-2 regulation impacts on the cellular decision to initiate proinflammatory cytokine production in response to TLR activation

Regulation of the Adaptive Immune Response by the IκB Family Protein Bcl-3

Bcl-3 is a member of the IκB family of proteins and an important regulator of Nuclear Factor (NF)-κB activity. The ability of Bcl-3 to bind and regulate specific NF-κB dimers has been studied in great depth, but its physiological roles in vivo are still not fully understood. It is, however, becoming clear that Bcl-3 is essential for the proper development, survival and activity of adaptive immune cells. Bcl-3 dysregulation can be observed in a number of autoimmune pathologies, and Bcl3-deficient animals are more susceptible to bacterial and parasitic infection. This review will describe our current understanding of the roles played by Bcl-3 in the development and regulation of the adaptive immune response, including lymphoid organogenesis, immune tolerance, lymphocyte function and dendritic cell biology

Using Holograms to Engage Young People with Anatomy

As the need for STEM professionals continues to grow, encouraging young people into STEM fields is crucial. Technology is an efficient means to engage young audiences with learning, and recent advances in 3D visualisation technologies have impacted the approach to teaching many STEM subjects, including anatomy. Anatomy can be a challenging subject to teach children, and the use of novel digital visualisation technologies have been shown to help engage children with the subject material and improve knowledge acquisition. The use of 3D holograms as an educational tool has recently begun to be explored. Hologram technology enables the creation of engaging content that provides the viewer with a 3-dimensional experience that can be seen directly with the naked eye. Without the need for headsets, more people can view and interact with the presented visualisations at once and the potential for user side effects which can arise with the use of headsets is removed. These features may make holography particularly beneficial in a range of environments, such as educational settings. Although holographic technology shows great potential within anatomy education, cost has been identified as one of the main barriers to its use. As such, the development of cost-effective holographic approaches could help to remove the current financial barriers to this novel educational resource. This project utilised innovative visualisation methods to develop a hologram-based anatomy application suitable for educational environments, which allows young audiences to interact with 3D anatomical models using a voice command system. This application runs on an easily reproducible, cost-effective holographic viewer, also developed during this project. These developments represent a step towards increased accessibility of holographic projection in anatomical education, with the aim of enhancing the engagement of young audiences with anatomy