Restoring Chimeric Antigen Receptor (CAR) T Cell Function in Chronic Lymphocytic Leukaemia (CLL

PhD ThesisDifferential outcomes for CD19 CAR T cells between chronic lymphocytic leukaemia, lymphoma and acute lymphoblastic leukaemia illustrate unique challenges to overcome in different patient populations. CD19 positive and negative relapses have been described for which different mechanisms of resistance have been proposed. CD19+ relapses could be related to the host microenvironment or T cell fitness. Therefore, there is a need for pre-clinical modelling using immunocompetent mice to explore CAR plus immunotherapy combinations to enhance efficacy. CLL is an ideal disease model to explore as it is associated with a tumour supportive microenvironment and T cells exhibit functional defects, closely recapitulated in Eμ- TCL1 (TCL1) mice, and induced in healthy mice by adoptive transfer (AT) of murine CLL splenocytes. Syngeneic donor CAR T cells were generated after rapid expansion in culture using CD3/CD28 beads and murine IL2. T cells were obtained from the spleens of wild-type mice, mice with CLL or mice with CLL pre-treated with ibrutinib or acalabrutinib. Enriched T cells were transduced with retroviral supernatant from MSGV-1D3-28Z- 1.3mut (CD19-CD28) and expanded before being injected into mice with CLL. Mice recieved lymphodepletion with cyclophosphamide and in some experiments received a PD-L1 antibody. Compared to wild type CAR T cells, CLL derived CAR T cells proliferate less in culture, skew towards CD8 with lower transduction efficiencies in CD8 cells and have higher expression of PD-1. All mice treated with CAR T cells can clear their CLL and normal B cells by D+7 which can reverse their exhausted T cell phenotype. Mice treated with CLL derived CAR T cells were liable to relapse with CD19+ disease, and the addition of PDL1 antibody did not improve this. Pre-treatment of mice with BTK inhibitors resulted in improved T cell ex vivo expansion and a more favourable CAR T cell phenotype, with a long-term efficacy study in progress

Evolutionary responses by native species to major anthropogenic changes to their ecosystems: Pacific salmon in the Columbia River hydropower system

The human footprint is now large in all the Earth’s ecosystems, and construction of large dams in major river basins is among the anthropogenic changes that have had the most profound ecological consequences, particularly for migratory fishes. In the Columbia River basin of the western USA, considerable effort has been directed toward evaluating demographic effects of dams, yet little attention has been paid to evolutionary responses of migratory salmon to altered selective regimes. Here we make a first attempt to address this information gap. Transformation of the free-flowing Columbia River into a series of slackwater reservoirs has relaxed selection for adults capable of migrating long distances upstream against strong flows; conditions now favour fish capable of migrating through lakes and finding and navigating fish ladders. Juveniles must now be capable of surviving passage through multiple dams or collection and transportation around the dams. River flow patterns deliver some groups of juvenile salmon to the estuary later than is optimal for ocean survival, but countervailing selective pressures might constrain an evolutionary response toward earlier migration timing. Dams have increased the cost of migration, which reduces energy available for sexual selection and favours a nonmigratory life history. Reservoirs are a benign environment for many non-native species that are competitors with or predators on salmon, and evolutionary responses are likely (but undocumented). More research is needed to tease apart the relative importance of evolutionary vs. plastic responses of salmon to these environmental changes; this research is logistically challenging for species with life histories like Pacific salmon, but results should substantially improve our understanding of key processes. If the Columbia River is ever returned to a quasinatural, free-flowing state, remaining populations might face a Darwinian debt (and temporarily reduced fitness) as they struggle to re-evolve historical adaptations

Towards Directed Collapsibility

In the directed setting, the spaces of directed paths between fixed initial and terminal points are the defining feature for distinguishing different directed spaces. The simplest case is when the space of directed paths is homotopy equivalent to that of a single path; we call this the trivial space of directed paths. Directed spaces that are topologically trivial may have non-trivial spaces of directed paths, which means that information is lost when the direction of these topological spaces is ignored. We define a notion of directed collapsibility in the setting of a directed Euclidean cubical complex using the spaces of directed paths of the underlying directed topological space relative to an initial or a final vertex. In addition, we give sufficient conditions for a directed Euclidean cubical complex to have a contractible or a connected space of directed paths from a fixed initial vertex. We also give sufficient conditions for the path space between two vertices in a Euclidean cubical complex to be disconnected. Our results have applications to speeding up the verification process of concurrent programming and to understanding partial executions in concurrent programs

Mellow yellow: An experiment in amber

Amber natron glasses were produced from at least the Hellenistic period and continued to be produced into the early second century CE. However, as with other strong colours used for Roman vessel production, this colour gradually declined in popularity as colourless and blue-green glass came to dominate. Whilst the colouring mechanisms for blue-green glasses are relatively well understood, the cause of the distinctive amber colour is more complex and can be attributed to the iron sulphur chromophore. This paper demonstrates, using analytical data and model glasses, that the amber colour develops during primary production, and that the sulphate-rich natron is key. The analytical data show that most natron amber glass was probably produced in the Levant alongside the more common blue-green glasses, however, its composition is different. Whilst many glass colours were made in a secondary stage, by adding colourants and opacifiers to a blue-green or colourless glass base, amber glass was not made this way since it required a slightly different set of raw materials and melting technologies. These findings suggest that the production of the glass required specialist knowledge, and particularly skilled furnace operation, in order to produce repeatable results. Skilled specialists would also be required to work amber glass whilst retaining the same clear amber hue, especially for complex wares, such as mosaic vessels, where the glass would be reheated more than once

Calculi for Synchrony and Asynchrony

AbstractA calculus for distributed computation is studied, based upon four combinators. A central idea is an Abelian group of actions which models the interfaces between components of a distributed computing agent. Using a notion of bisimulation, congruence relations are defined over computing agents, and thence an algebraic theory is derived. The calculus models both synchronous and asynchronous computation. In particular, it is shown that the author's Calculus of Communicating Systems (1980), which is an asynchronous model, is derivable from the calculus presented here

Effective bridging therapy can improve CD19 CAR-T outcomes while maintaining safety in patients with large B-cell lymphoma

The impact of bridging therapy (BT) on CD19-directed chimeric antigen receptor T-cell (CD19CAR-T) outcomes in large B-cell lymphoma (LBCL) is poorly characterised. Current practice is guided by physician preference rather than established evidence. Identification of effective BT modalities and factors predictive of response could improve CAR-T intention to treat and clinical outcomes. We assessed BT modality and response in 375 adult LBCL patients in relation to outcomes following axicabtagene ciloleucel (Axi-cel) or tisagenlecleucel (Tisa-cel). The majority of patients received BT with chemotherapy (57%) or radiotherapy (17%). We observed that BT was safe for patients, with minimal morbidity/mortality. We showed that complete or partial response to BT conferred a 42% reduction in disease progression and death following CD19CAR-T therapy. Multivariate analysis identified several factors associated with likelihood of response to BT, including response to last line therapy, the absence of bulky disease, and the use of Polatuzumab-containing chemotherapy regimens. Our data suggested that complete/partial response to BT may be more important for Tisa-cel than Axi-cel, as all Tisa-cel patients with less than partial response to BT experienced frank relapse within 12 months of CD19CAR-T infusion. In summary, BT in LBCL should be carefully planned towards optimal response and disease debulking, to improve CD19CAR-T patient outcomes. Polatuzumab-containing regimens should be strongly considered for all suitable patients, and failure to achieve complete/partial response to BT pre-Tisa-cel may prompt consideration of further lines of BT where possible

Organ complications after CD19 CAR T-cell therapy for large B cell lymphoma: a retrospective study from the EBMT transplant complications and lymphoma working party.

We investigated ≥ grade 3 (CTC-AE) organ toxicities for commercial CD19 chimeric antigen receptor T cell (CAR-T cell) products in 492 patients (Axi-Cel; n = 315; Tisa-Cel; n = 177) with Large B-cell Lymphoma in the European Society for Blood and Marrow Transplantation (EBMT) CAR-T registry. The incidence of ≥ grade 3 organ toxicities during the first 100 days after CAR-T was low and the most frequent were: renal (3.0%), cardiac (2.3%), gastro-intestinal (2.3%) and hepatic (1.8%). The majority occurred within three weeks after CAR-T cell therapy. Overall survival was 83.1% [79.8-86.5; 95% CI] at 3 months and 53.5% [49-58.4; 95% CI] at one year after CAR-T. The most frequent cause of death was tumour progression (85.1%). Non-relapse mortality was 3.1% [2.3-4.1; 95% CI] at 3 months and 5.2% [4.1-6.5; 95% CI] at one year after CAR-T. The most frequent causes of non-relapse mortality were cell-therapy-related toxicities including organ toxicities (6.4% of total deaths) and infections (4.4% of total deaths). Our data demonstrates good safety in the European real-world setting