Bioengineering to combat the tuberculosis pandemic

Infectious diseases remain an ongoing cause of poor health and mortality in the poorest countries in the world. Tuberculosis kills more humans than any other infection and is principally a disease of poverty. Unfortunately recent studies examining new vaccine approaches or shorter antibiotic courses have not been successful, demonstrating that more research and understanding of the disease is required to combat the pandemic. Tuberculosis is also becoming progressively more resistant to antibiotics used to treat it. It is widely accepted that highly innovative approaches that draw on diverse specialists are required to achieve control of tuberculosis.

This project will combine expertise at the University of Southampton, which specifically focuses on cross-disciplinary research, with the African Health Research Institute in Durban, a state-of-the-art laboratory set up to be at the heart of the tuberculosis and HIV pandemics. It is centred on a new way of studying infection in the laboratory, which relies on an innovative cellular spraying technique that permits studies of infected human cells in three-dimensions and attached to lung supporting fibres. This system has been developed at Southampton and will be introduced laboratories in Durban, where we will harness the expertise in investigation of samples from patients and fluidics to further develop the model. We will prove that this system can be used to understand how infection occurs, to investigate new vaccine strategies and to identify novel antibiotic regimes.

There will be four programmes of work which will take place both in Southampton and Durban, with regular exchange of researchers between the centres, joint conferences and scheduled videoconferences. First, we will study cells isolated from lungs removed during surgery as part of their routine clinical care. We will compare cells from patients who either are controlling tuberculosis infection or who have developed disease to examine the factors leading to active disease. Secondly, we will separate cells which are controlling infection from cells where infection is progressing and systematically study biology to understand how human cells either control infection or permit progression. Thirdly, we will change the host immune cells using genetic engineering technology to unpick which components of the body's immune response is beneficial in controlling infection compared to that which causes damage. Finally, we will combine the human cell system with miniature fluid irrigation apparatus to permit modulation of antibiotic concentrations over time to identify l more effective treatment regimes.

This project will deliver a transformative approach to the tuberculosis pandemic, identifying new vaccine targets and antibiotic regimes, and initiate a highly complimentary collaboration which we will develop over the two years to deliver innovative cross-disciplinary research to address diseases affecting the poorest in the world.

Innovative cross-disciplinary platforms are required to address infectious diseases prevalent in resource limited settings. Tuberculosis (TB) kills more than any other infection and is becoming increasingly resistant to antibiotics. In Southampton, we have developed a three-dimensional bioelectrospray cell culture system to study the host-pathogen interaction and have published and unpublished data demonstrating that events more faithfully mimic events in vivo. At the Africa Health Research Institute in Durban, parallel research themes have developed expertise in the ex vivo analysis of clinical samples and microfluidics, centred within a unique laboratory infrastructure. This project will combine these complementary approaches to deliver a collaborative interdisciplinary network built on strengths of each institution and prove the potential of advanced cell culture modelling to address diseases affecting the world's poorest.

We will introduce the 3-D bioelectrospray system to the AHRI laboratories and utilise it to interrogate host immune response ex vivo from patients using primary lung cells. We will combine microspheres with a microfluidic sorter to systematically characterise granulomas containing TB infection from those with progression. We will utilise sequence data from granulomas removed at surgery for TB to transduce cells and characterise protective versus pathological host immune responses. Finally, we will combine microspheres with advanced microfluidic system to permit pharmacodynamic and physiological modelling of the peri-granuloma environment to develop more efficacious antibiotic combinations.

This work will demonstrate the transformative potential of the model to study infectious diseases in resource poor settings and can equally be applied to diverse infections characterised by a prolonged host-pathogen interaction. It will initiate a collaboratory network to develop these findings towards novel interventions to control the TB pandemic.

Tuberculosis (TB) is a disease of poverty and therefore is prevalent in all Official Development Assistance (ODA) countries. Furthermore, TB primarily affects young adults of working age, and so has a disproportionate effect of economic productivity. Addressing the TB pandemic will have widespread economic, societal and healthcare benefits in all ODA countries and therefore should be a very high priority for research. The recent disappointments in the TB field have led to the consensus that transformative interdisciplinary approaches are urgently needed. This proposal aims to develop a new approach to the TB pandemic that can equally be used to address diverse infectious diseases affecting resource-poor settings. We will build the skills and knowledge base by iterative technology exchange and by hosting African Health Research Institute researchers for training in Southampton, and concurrently develop a sustainable collaboration.

TB causes approximately 8 million new cases per year. We will develop a better model to improve the understanding of the host-pathogen interaction in TB and to identify new strategies to control the pandemic, including better understanding of host immunity and a revolutionary system for studying antibiotics in vitro. Furthermore, the bioelectrospraying of viable cells into 3-dimensional granulomas impregnated with components of the extracellular matrix will be relevant to all diseases where matrix remodelling is involved, and many of these are diseases prevalent in resource-poor settings. We will train highly skilled researchers, at both AHRI and the University of Southampton, who will become competent in an extensive range of cutting-edge research techniques, including bioelectrospray methodology, microfluidics and multi-parameter readouts. They will then train rotational postgraduate students at each laboratory in the system, to develop the impact locally. Furthermore, our model system can be widely used to replace animal experimentation, consistent with the principles of the 3Rs.

More widely, the impact of delivering a 3-D physiological cell cultures system integrated with microfluidics will be related both to the TB field and to the knowledge economy. The work will be of interest to pharmaceutical companies as it is directly translational and is addressing Cooksey's first gap in the translational pathway. The model will be relevant to a wide number of infections that require analysis of pathogens in the context of the host, other inflammatory diseases and conditions where advanced 3-dimenstional cell culture is required. As we will set up the system in the AHRI laboratories in Durban, along with the microfluidic expertise, ongoing development can be pursued within South Africa, bringing significant potential benefits in terms of competitiveness for a grant income and pharmaceutical collaboration.

Our studies are of direct translational impact and so we anticipate pharmaceutical engagement and the potential to attract research and develop investment. We have already had discussion with GSK about testing emerging drugs in this model system, as our data on pyrazinamide demonstrates that the system is a significant improvement on currently available model system. Tuberculosis can be considered the prototypic infectious disease to study in the 3-D bioelectrospray model, since a prolonged interaction between the pathogen and host occur, and so proving the efficacy of this approach for TB will not only identify novel approaches to TB, it will also prove the proof-of-concept for the efficacy of the model for diverse infectious diseases prevalent in overseas development countries, such as HIV, cysticercosis, salmonella and leishmaniasis.

Ultimately, our studies will identify candidate compounds to go forward to experimentation in follow-on studies in appropriate animal models and clinical trials to treat TB, and novel vaccination approaches that can control Mtb infection.