Team:Imperial College London/Research

this one uses dif sites in a smart way to cut out bits of dna we only want in the cell for a short period of time using endogenous recombinases that the cell (E.coli and B.subtilis have already)

This paper explains why NTDs are so in need of research and the problems they create in developing countries. Reading this made us want to raise awareness of NTDs and promote research into their diagnosis, treatment and environmental control. The authors also state that reducing the NTD burden would impact on seven of the eight Millennium Development Goals (MDGs) set by the UN. I found the section on Integrated Control particularly interesting, as this is an area in which our detection kit could be applied.

Diffusion of synthetic biology: a challenge to biosafety Systems and Synthetic Biology. Schmidt, 2008

This is a great read if you're interested in the regulation of synthetic biology. I also found it really inspiring as it looks towards the future of the field, but still keeps a sense of realism in terms of biosaftey measures and the accessibility of synthetic biology.

An unmodified heptadecapeptide pheromone induces competence for genetic transformation in Streptococcus pneumoniae. Havarstein, Coomaraswamy & Morrison, 1995

We were really concerned that the system might not be sensitive enough. However, we learnt about threshold levels of the AIP from reading this paper and it reassured us that only a very small concentration (10ng/ml) of CSP-1 is needed to produce a response. Phew!

Accumulation of a Recombinant Aspergillus oryzae Lipase Artificially Localized on the Bacillus subtilis Cell Surface., Kobayashi et al., 2000

cutL cDNA encoding a extracellular lipase, L1, from Aspergillus orzyae, was ligated to the cell wall binding domain (CWB) of the major autolysin LytC of B. subtilis. Expression and functionality of the recombinant protein CWB-Cut-L was tested using SDS-PAGE and zymography, showing that catalytic activity of L1 was maintained.

This paper was of fundamental importance for our detection module as it laid out nicely the possibility of anchoring peptides on the bacterial cell surface whilst maintaining the functionality. This proved to be precisely what we needed, allowing also for easy testing, as the major autolysin LytC used in this paper, is bind to the cell wall non-covalently and can thus be washed of the cell wall easily using high salt concentrations.

Human schistosomiasis, Gryseels et al., 2006

Schistosomiasis is a tropical disease caused by the water-borne schistosoma parasitehas infected over 200 milion people world wide. The disease is a cause of morbidity and can give rise to a number of complications in liver, intestines and urinary system. These are the result of complex immunological interactions with the parasite eggs in the human tissues. Furthermore diagnosis, treatment and prophylaxis are discussed.

This excellent review was most helpful in getting a broad overview of the parasitic life cycle, the disease schsitosomiasis as well as the conditions it can provoke in our body, without lacking detail on these parts. The article rounded up this summary with a great introduction into the treatment, diagnosis and approaches to the development of a vaccination, making it essential in for our wiki page on the parasite and schistosomiasis.

Mechanism of Interaction of Salmonella and Schitosoma Species, Melhem & LoVerde, 1984.

The interaction of these pathogens can often cause problems with treatment of salmonella infection. In the paper it is tested, by use of pilus positive and pilus negative strains of bacteria, if pili are used for this bacteria-parasite interaction, which is demonstrated conclusively. Furthermore this interaction is shown to be specific as mannose-like receptors and probably glycolipids of the parasite are targeted by the bacteria.

Discovering these findings was an important step for us, on the way to finding a feasible approach to parasite detection. It was the first example of specific bacteria-parasite interactions we came across and originally we hoped to exploit the bacterial receptor to detect schistosoma. However no suitable downstream mechanism was found to link receptor with output so ultimately we did not use this system at all but chose a much more elegant approach to parasite detection.

Surface Proteins of Gram-Positive Bacteria and Mechanisms of Their Targeting to the Cell Wall Envelope Navarre & Schneewind, 1999.

This review was a very comprehensive guide to the all different methods used by bacteria such as B. subtilis to secrete proteins and anchor them to the cell wall. It included homologous sequences from many different bacteria, as well as illustrating the systems and difference between these systems in simple manner without lacking detail.

This knowledge was indispensable in the design of our cell wall bound detection module, as it gave us an overview of the systems the could potentially be exploited, allowing for further research being much more directed towards specific parts of protein excretion and cell wall binding pathways.

Cercarial Elastase Is Encoded by a Functionally Conserved Gene Family across Multiple Species of Schistosomes Salter et. al., 2002.

The importance of cercarial elastase across several schistosome species that infect humans is examined. Elastase is found to be the single most important factor for successful skin penetration. Most importantly the paper determines the cleavage specificity of elastase to its substrate.

This paper was of crucial importance for two reasons: We had know about the elastase before but this paper first focused on this element of schistosoma and its role in the parasite life cycle. Additionally this paper provided invaluable information about the elastase cleavage specificity and hs helped in the design of our cleavable linker.