Periodic Reporting for period 2 - QuanTII (Quantitative T cell Immunology and Immunotherapy)
Periodo di rendicontazione: 2020-09-01 al 2023-08-31
The specific training objectives of QuanTII are to provide an inspiring and supportive environment for the training of 15 ESRs, and to establish a broad programme of challenging research projects that are multidisciplinary and intersectoral, and lead to lasting, fruitful collaboration between ETN partners.
ESRs carried out research projects in immunological memory, immune repertoires, cancer and immunotherapies. Experimental approaches included sequencing and labelling of thymocytes and stem-cell memory T cells. Theoretical approaches included deterministic models of signalling, of T-cell subsets in exhaustion, and of the effect of checkpoint inhibitors. ESRs developed stochastic models of cell division and death, of the correlation structure of cell fates, and of the maintenance of product cell populations from progenitor cells, probabilistic repertoire models and agent-based models of heterogeneous populations. Modern algebraic and statistical techniques including Bayesian analysis were a feature. Once travel restrictions were relaxed, ESRs were able to undertake secondments and attend network meetings again. We are grateful that all QuanTII academic and industrial partners remained with the network from start to finish, participating in supervision of training and research, organising network events and hosting secondments.
ESR 2 was involved in modelling normal and autonomous thymii, seeding rates of thymic progenitors, and Bayesian computation to determine mutation and selection parameters from sequencing data.
ESR 3 has made use of novel algebraic methods to study IL-7R binding models to obtain analytical expressions of the steady state, amplitude and EC50 of the dose response.
ESR 4 obtained murine data from bone marrow and skin, and by studying memory T cells in human and a more natural mouse model they found relations and similarities between both species.
ESR 5 quantified antigen-specific CD8 T memory subpopulations from combined skin and muscle HIV trial vaccine study samples, and found the correlation between the T stem cell memory pool generated at early timepoints and the rate of decay of memory.
ESR 6 studied mathematical models for the cell cycle, with a particular interest in multi-stage representation for cell proliferation via Erlang distributions.
ESR 7 investigated the lifespan and maintenance of memory T cells in human bone marrow and skin, adipose tissues, and blood by using in vivo heavy water labelling.
ESR 8 made improvements to the differential equations models used to estimate the life span of T cells in the human body from heavy-water labelling experiments.
ESR 9 performed an analysis to predict immunogenicity of somatic mutations that arise from different cancer mutation signatures.
ESR 10 developed a stochastic model of T-cell populations in homeostasis including cross-reactivity and multiple self-pMHC complexes.
ESR 11 validated a computational model of TCR probability in the periphery, and also applied the method to B cell receptors to check its wide applicability.
ESR 12 studied the relevance of the iKIR-HLA receptor-ligand system in cancer and autoimmunity and analyse the mechanisms by which iKIRs influence T cells.
ESR 13 considered the maintenance of 'product' cell populations from 'progenitor' cells via a sequence of one or more cell types, or compartments, where each cell's fate is chosen stochastically. ESR 13 defined an ODE model of T-cell exhaustion states and studied structural identifiability.
ESR 14 explored agent-based and stochastic models and their combination with ordinary differential equations, to model heterogeneity of cancer cell populations, the effect of different therapeutic options and the tumour-immune cell interaction. The reinforcement algorithm was employed to optimize parameters.
ESR 15 developed the Cyton2 model, that encapsulates features of inheritance correlation structure of cell fates.
In work package 2, T cell clonotypes can be identified by their unique TCRs, and with current NGS technologies, T cell repertoires can be identified in various tissues for naive and memory T cell subsets. An improved quantitative understanding of the in vivo TCR repertoire diversity and clonal distributions of the different naive and memory T cell populations in blood and tissues, in health and disease, as well as the overlap between and cross-reactivity of these TCR repertoires is needed, and ESRs in WP2 have worked to obtain the best clinical outcome, and also to tailor individual patient T cell immunotherapies.
ESRs in WP3 have worked to improve our current quantitative understanding of T cell based immunotherapies, by carrying out research projects to develop novel theoretical methods. Adoptive T cell therapies for the treatment of cancer and immunodeficiencies rely on appropriate selection of T cells from the patient, ex vivo clonal expansion through the provision of activating stimuli and, possibly, ex vivo genetic modifications that result in T cells expressing chimeric antigen receptors (CARs). In trials, these CARs are directly engineered to possess a cancer specificity, although some ground-breaking ideas that involve using the natural diversity of other host's TCRs have been proposed.