Rheumatoid arthritis (RA) is a chronic, autoimmune disease that affects ~1% of the population and an important cause of disability and premature mortality. The disease is driven by chronic inflammation of the joint synovial tissue in which there is accumulation of activated immune cells (macrophages, dendritic cells, T-cells, B-cells and plasma-cells). The therapeutic benefit of B-cell depletion with anti-CD20 mAb in RA demonstrated that autoreactive B-cells play a crucial pathogenic role. Likewise, blockade of inflammatory cytokines (TNFa, IL-6) results in significant clinical response. However, ~30-40% of patients remain refractory to current therapies. Thus, the development of better therapies in this area of unmet need remains of critical importance particularly in "resistant" patients where the identification of additional/alternative inflammatory pathways may lead to novel therapeutics. IL-21 is a potent pleiotropic cytokine involved in the activation/differentiation of many immune cell types including B and T cells but also stromal cells with the induction of metalloproteinases and inflammatory cytokines including TNFa. IL-21 is a member of the common cytokine receptor gamma chain-binding family and is mainly produced by activated T-cells including Th17 cells and TFh. TFh play a fundamental role in B cell activation and antibody production in secondary lymphoid organs and control humoral immune responses. IL-21 has been associated with RA based on genetic studies and increased expression in RA patients; however its pathogenic function in RA joints and its potential as a therapeutic target have not been fully addressed. Blockade of IL-21 receptor (IL-21R) considerably ameliorates disease progression in animal models of RA indicating that modulation of the IL-21/IL-21R pathway is a promising therapeutic approach. In support of this application we studied a large cohort of RA patients and demonstrated that i) the IL-21/IL-21R pathway is highly increased in a subset of RA patients presenting focal lesions called ectopic lymphoid structures (ELS) but not in patients with diffuse synovitis; ii) synovial IL-21 protein is expressed in strict association with a subset of TFh-like cells; iii) RA synovial fibroblasts, but not RA dermal fibroblasts, express high levels of IL-21R suggesting that IL-21 acts not only on infiltrating immune cells but also on resident synovial cells; iv) IL-21 and IL-21R expression is maintained for several weeks when RA synovial tissue is engrafted into immunodeficient (SCID) mice and support the production of human autoantibodies. Thus, we ultimately aim to develop effective IL-21 targeting strategies in RA through the following 4 steps: Step 1) Identification of the cellular sources and targets of IL-21 within the joints of RA patients. Step 2) Analysis of IL-21 function on immune and stromal cells isolated from the RA joints in vitro and in vivo in the RA/SCID model. Step 3) Testing IL21/IL21R blocking reagents for human use (in preclinical development with the industrial partner) in the human RA/SCID model. Step 4) Evaluating IL-21 contribution to disease outcome and response to existing traditional and biological therapies in patients with early arthritis and in those treated with anti-TNFa or anti-IL-6R Biologics. By addressing key aspects of IL-21 biology in RA this proposal will advance our knowledge of the role of IL-21 in chronic inflammation, B cell autoimmunity and ELS function with important implications for other autoimmune/chronic inflammatory diseases. Proof of concept studies of the effectiveness of human IL-21 blocking reagents on synovial inflammation and humoral autoimmunity in diseased tissue will advance the development of novel IL-21 therapeutics for the treatment of RA. Finally, the patient-based studies may enable better identification of key responders of IL-21 mediated arthritis and have a means of stratifying subjects in early clinical trials.

Doctoral Training Partnerships: a range of postgraduate training is funded by the Research Councils. For information on current funding routes, see the common terminology at https://www.ukri.org/apply-for-funding/how-we-fund-studentships/. Training grants may be to one organisation or to a consortia of research organisations. This portal will show the lead organisation only.

Doctoral Training Partnerships: a range of postgraduate training is funded by the Research Councils. For information on current funding routes, see the common terminology at https://www.ukri.org/apply-for-funding/how-we-fund-studentships/. Training grants may be to one organisation or to a consortia of research organisations. This portal will show the lead organisation only.

As the antibody sector has matured, it has seen SIGNIFICANT INCREASES IN UPSTREAM (USP) PRODUCTIVITES that have opened up the possibility for radical changes to the design and operation of cell culture suites. However, due to the inherently complex set of interactions that can affect cell culture performance, IT IS HARD TO PREDICT THE CONSEQUENCES ON THE IMPURITY PROFILES AND HENCE ROBUSTNESS OF DOWNSTREAM (DSP) OPERATIONS as titres increase. Quality by Design initiatives are driving the need for greater understanding of the impact of cell culture strategies on the downstream processing equipment duties so as to enable EFFECTIVE PROCESS INTEGRATION and hence CONTINUOUS IMPROVEMENTS. This project will explore STATE-OF-THE-ART HIGH THROUGHPUT CELL CULTURE and MULTIVARIATE DATA ANALYSIS techniques to characterise cell culture operations, not only in terms of growth and productivity BUT ALSO IMPURITY PROFILES AND QUALITY. The resulting cell culture statistical cause-and-effect correlations will be integrated into PROCESS ECONOMICS MODELS developed in the UCL Decisional Tools team so as to TO IDENTIFY THE MOST COST-EFFECTIVE INTEGRATED USP AND DSP MANUFACTURING STRATEGIES FOR THE FUTURE. The proposed programme will link MedImmune's leadership in antibody production and UCL's leadership in bioprocess decisional tools and scale-down techniques to tackle these intricate process-business decisions. Project stages: 1. MICROSCALE DATA GENERATION (Yr 1, 2). Increases in titres can be a result of different combinations of increases in cell densities or specific cell productivities, each with a different impact on impurity burdens on DSP. This depends on factors such as the cell line characteristics, bioreactor operating parameters, medium or feed type and the feeding strategy. These have a significant impact on cell growth, productivity, viability, impurity profiles and may also have an impact on product quality. Initially large datasets characterising cell culture strategies will be generated by a) leveraging historical data from MedImmune and b) high throughput experimentation using both the 'ambr microscale bioreactor system' (developed in a collaboration between The Automation Partnership and MedImmune) and microwell systems from current UCL EPSRC IMRC activities. 2. MULTIVARIATE ANALYSIS (Yr 2, 3). The next challenge will be exploring effective techniques to analyse such large datasets and reduce to predictive correlations. Advanced multivariate analysis techniques will be investigated to help predict the product and impurity profiles resulting from different cell culture strategies. Statistical (rather than mechanistic) cause-and-effect correlations will then be derived to link the impurity profile to key factors such as the cell density, specific cell productivity, culture duration, and titre. Key quality attributes that will be focused on are the levels of HCP (host cell proteins), HMW (aggregates), cell viability and product potency. 3. LINKAGE TO PROCESS ECONOMICS MODELS (Yr 3). The resulting cell culture predictive correlations will be linked to a whole bioprocess cost model developed at UCL in a TSB/EPSRC collaboration with MedImmune so as to predict the equipment sizes, COG and risks associated with different cell culture strategies. 5. SCENARIO ANALYSIS (Yr 3, 4). Several cell culture strategies will be plugged into the integrated cell culture and process economics model to enable rapid identification of the most promising and robust combinations of USP and DSP activities for more streamlined development in both existing and new facilities. The overall outputs of this research will be a systematic framework combining microscale experimentation with statistical correlations and cost modelling so as to enable selection of innovative cell culture strategies early in the development cycle that BALANCE THE NEEDS OF UPSTREAM AND DOWNSTREAM MANUFACTURABILITY, ROBUSTNESS TO PROCESS VARIABILITIES AND COST-EFFECTIVENESS.

Doctoral Training Partnerships: a range of postgraduate training is funded by the Research Councils. For information on current funding routes, see the common terminology at https://www.ukri.org/apply-for-funding/how-we-fund-studentships/. Training grants may be to one organisation or to a consortia of research organisations. This portal will show the lead organisation only.