Characterization of immune responses induced by N. meningitidis PorB and its us as a vaccine adjuvant

Thesis (Ph.D.)--Boston UniversityVaccines play an essential role in public health. Adjuvants increase immunogenicity for many of these vaccines by stimulating the innate immune system: driving cytokine secretion to induce local and systemic pro-inflammatory states, upregulating costimulatory molecules on antigen presenting cells (APCs), and increasing antigen uptake and presentation to better engage T cell responses. Neisseria meningitidis porin PorB is a Toll-Like Receptor 2 (TLR2) ligand with broad immune stimulating functions and can act as a vaccine adjuvant. Our lab is interested in characterizing how PorB activates the immune system and how these effects relate to its adjuvant activity. An understanding of adjuvant functions will allow for the rational, rather than empiric, design of future vaccines. Here we further investigate the effects of PorB on the innate immune system as it may apply to the adjuvant activity of the porin. In a direct test of adjuvanticity we show that without the presence TLR2 the adjuvant activity of PorB, measured by antigen-specific IgG production, is diminished in immunized mice while loss of MyD88 entirely ablates PorB adjuvant activity. We demonstrate costimulatory molecule upregulation in response to PorB stimulation and its dependence on TLR2. We show that stimulation with PorB increases antigen uptake by APCs and drives APC migration to draining lymph nodes, which appears to be dependent on TLR2 and not on MyD88. Finally, we use systems vaccinology to uncover complex regulatory networks and dynamics. The inclusion of PorB as an adjuvant in a multi-injection vaccine formulation has two major effects on expression profiles in murine splenocytes. Vaccine preparations containing PorB as an adjuvant induce expression in inflammatory and immune signaling networks, in agreement with previous work, and accelerate the kinetics of the immune response, as demonstrated by induction of expression of cell cycle and proliferative genes and regulatory networks at earlier time points as compared to preparations not containing PorB. This systems biology approach reveals previously unappreciated aspects of reaction of the immune system to PorB. Together, these findings deepen our understanding of the immune response to PorB and offer potential insight into the mechanisms behind its adjuvanticity

Seismic and vibration signal analysis and monitoring using LabView

Every year there are around 20 earthquakes of magnitude 7 or above . This kind of seismic events are potentially destructive and can cause several structural damage, economic and human loss. In order to perform an efficient risk management and prevention work geophysics must be equipped with suitable software and hardware tools. Seismic studies comprise not only risk management but earth structure studies that are useful in gas and oil prospections. Vibration monitoring has also turned in a very useful scientific approach to deal with structural safety and maintenance. Among these devices, MEMS accelerometer combines great performance with low costs, characteristics that have made it one of the most popular devices when it comes to this task. Seismic analysis software has been developed using LabVIEW. The software decodes SAC data files and retrieves important seismic parameters like arrival wave times, location and magnitude. The precision and performance reached is acceptable for the scope of this project and it could be used as a domestic seismic analyser but not for its use in a professional seismic station. The seismic data for the system evaluation was retrieved from IRIS database. A vibration DAQ and monitoring module has been designed and implemented. It successfully measures and monitors acceleration versus time and the signal’s spectra. Zooming options were included in order to make easier the background noise and ambient vibration study. An instant and maximum earthquake intensity gauge was programmed to give an idea of the experienced event potential danger. The user can selectively save acceleration time responses in LVM format. An analogue output was implemented. It is capable of reading acceleration versus time responses saved in LVM and SAC files and output them using a DAQ card analogue output function. This voltage can be seen in an oscilloscope or input to other devices. In order to acquire and save the analogue waveforms created with the previous function an analogue input was included as an initial objective in the Scheme of Work. However, it was dropped in the final implementation because it was considered that its function was too similar to the vibration DAQ module and it did not have enough practical application

Upper GI biopsies for adenocarcinoma: how many biopsies should endoscopists take?

Aims: There is evidence that 4 or 5 gastric cancer biopsies are required for accurate HER2 interpretation. However, the number of biopsies that need to be taken to reach this number of viable cancer biopsies is without evidence. This study aimed to address this gap by assessing the number of biopsies required to get at least 4 viable biopsies containing cancerMethods and results: 105 consecutive biopsy cases of gastric and oesophageal adenocarcinoma were retrieved from file. Only definite cancer diagnoses were included; missed cancers or unproven cases were not considered. The cases were reviewed and the number of biopsies taken, and the number containing viable tumour was recorded. In total, 667 biopsies were taken of which 471 had viable tumour (70.6%) 70/105 cases (67%) had 4 viable tumour biopsies but only 47/105 (45%) had 5 viable tumour biopsies. In order to have a >90% chance of having 4 viable tumour biopsies, 7 biopsies needed to be taken, while 10 or more biopsies were required for a >90% chance of 5 viable tumour biopsies. Mathematically, using a 0.7 probability for a single biopsy, 8 biopsies would be required for a 94% chance of at least 4 viable tumour biopsies.Conclusion: In our large upper GI cancer centre, many biopsy cases do not contain sufficient material for adequate HER2 assessment. In order to meet the 4 biopsy requirement for adequate HER2 assessment in >90% of cases, at least 8 biopsies need to be taken, while 10 biopsies would be required for the 5 cancer biopsy threshold

Chronic rejection of mouse kidney allografts

Chronic rejection of mouse kidney allografts.BackgroundChronic renal allograft rejection is the leading cause of late graft failure. However, its pathogenesis has not been defined.MethodsTo explore the pathogenesis of chronic rejection, we studied a mouse model of kidney transplantation and examined the effects of altering the expression of donor major histocompatibility complex (MHC) antigens on the development of chronic rejection.ResultsWe found that long-surviving mouse kidney allografts develop pathological abnormalities that resemble chronic rejection in humans. Furthermore, the absence of MHC class I or class II antigens did not prevent the loss of graft function nor alter the pathological characteristics of chronic rejection. Expression of transforming growth factor-β (TGF-β), a pleiotropic cytokine suggested to play a role in chronic rejection, was markedly enhanced in control allografts compared with isografts. However, TGF-β up-regulation was significantly blunted in MHC-deficient grafts. Nonetheless, these differences in TGF-β expression did not affect the character of chronic rejection, including intrarenal accumulation of collagens.ConclusionsReduced expression of either class I or II direct allorecognition pathways is insufficient to prevent the development of chronic rejection, despite a reduction in the levels of TGF-β expressed in the allograft. This suggests that the severity of chronic rejection is independent of the level of MHC disparity between donor and recipient and the level of TGF-β expression within the allograft

Array-based evolution of DNA aptamers allows modelling of an explicit sequence-fitness landscape

Mapping the landscape of possible macromolecular polymer sequences to their fitness in performing biological functions is a challenge across the biosciences. A paradigm is the case of aptamers, nucleic acids that can be selected to bind particular target molecules. We have characterized the sequence-fitness landscape for aptamers binding allophycocyanin (APC) protein via a novel Closed Loop Aptameric Directed Evolution (CLADE) approach. In contrast to the conventional SELEX methodology, selection and mutation of aptamer sequences was carried out in silico, with explicit fitness assays for 44 131 aptamers of known sequence using DNA microarrays in vitro. We capture the landscape using a predictive machine learning model linking sequence features and function and validate this model using 5500 entirely separate test sequences, which give a very high observed versus predicted correlation of 0.87. This approach reveals a complex sequence-fitness mapping, and hypotheses for the physical basis of aptameric binding; it also enables rapid design of novel aptamers with desired binding properties. We demonstrate an extension to the approach by incorporating prior knowledge into CLADE, resulting in some of the tightest binding sequences

Robust Operation of Tendon-Driven Robot Fingers Using Force and Position-Based Control Laws

A robotic system includes a tendon-driven finger and a control system. The system controls the finger via a force-based control law when a tension sensor is available, and via a position-based control law when a sensor is not available. Multiple tendons may each have a corresponding sensor. The system selectively injects a compliance value into the position-based control law when only some sensors are available. A control system includes a host machine and a non-transitory computer-readable medium having a control process, which is executed by the host machine to control the finger via the force- or position-based control law. A method for controlling the finger includes determining the availability of a tension sensor(s), and selectively controlling the finger, using the control system, via the force or position-based control law. The position control law allows the control system to resist disturbances while nominally maintaining the initial state of internal tendon tensions

The BACE1 inhibitor LY2886721 improves diabetic phenotypes of BACE1 knock-in mice

Acknowledgements The authors would like to acknowledge University of Aberdeen PhD studentship to RD and Alzheimer’s Research UK grant to BP and MD (ARUK-PG2017B-11). The authors also thank David Riddell and David McKinzie at Eli Lilly for involvement with sample handling for Aβ determination.Peer reviewedPostprin